Tissue mapping and treatment

Methods, systems, and devices are described for mapping and treating tissue during a medical procedure. In some cases, a device includes a mesh of wires with sensors coupled thereto. The device can be coupled to an expandable treatment element. The expandable treatment element can include multiple segments. The sensors can be used to map a tissue area and monitor the tissue during a medical procedure.

BACKGROUND

In many medical procedures, catheters are used to treat tissue.

DETAILED DESCRIPTION

During medical procedures using catheters, it can be difficult to identify tissue proximate to the catheter. Furthermore, in some cases, when the tissue is being treated it can be difficult to monitor the effects of the treatment on tissue proximate the tissue that is to be treated. A method and device described herein can be used as part of or in conjunction with a treatment device to map tissue at or near a target site and monitor the tissue at or near the target site during treatment. In same embodiments, the device can be used in conjunction with a treatment device used to treat cardiac arrhythmia. However, it will be understood that the methods and device described herein can be used with many types of treatment devices.

Cardiac Arrhythmia

Cardiac arrhythmia, a condition in which the heart's normal rhythm is disrupted, includes many different forms. For example, cardiac arrhythmia includes premature atrial contractions (PACs), atrial flutter, accessory pathway tachycardias, atrial fibrillation, atrioventricular (AV) nodal reentrant tachycardia (AVNRT), premature ventricular contractions (PVCs), ventricular tachycardia (VT), ventricular fibrillation, long QT syndrome, and bradyarrhythmias.

Certain types of cardiac arrhythmias, including atrial fibrillation (AF), may be treated by ablation (for example, radiofrequency (RF) ablation, cryoablation, ultrasound ablation, laser ablation, and the like), either endocardially or epicardially.

As mentioned above, one method of ablating tissue of the heart and pulmonary veins to control atrial fibrillation includes delivering radiofrequency (RF) energy to the tissue to be ablated. In particular, high frequency energy can be employed, for example, to cause ionic agitation and frictional heat in targeted tissue, causing permanent damage to the tissue. Once damaged, the tissue may no longer propagate or source electrical signals, and the fibrillation may be treated or reduced. The RF energy can be delivered by an RF catheter having an RF source at a distal treatment end that is positioned at a target site inside a patient during a treatment procedure.

Another method of ablating tissue of the heart and pulmonary veins to control atrial fibrillation is through cryotherapy, or the extreme cooling of body tissue. Cryotherapy may also cause permanent alteration to treated tissue, preventing the treated tissue from propagating or sourcing electrical signals, thereby reducing or eliminating atrial fibrillation. Cryotherapy may be delivered to appropriate target sites inside a patient's heart and circulatory system by a cryotherapy catheter. A cryotherapy catheter can include a treatment member at its distal end, such as an expandable balloon having a cooling chamber inside. A cryotherapy agent can be provided by a source external to the patient at the proximal end of the cryotherapy catheter and delivered distally through a lumen in an elongate member to the cooling chamber where it is released. Release of the cryotherapy agent into the chamber cools the chamber, the balloon's outer surface, and tissue that is in contact with the outer surface, to perform ablation. The cryotherapy agent may be exhausted proximally through an exhaust lumen in the elongate member to a reservoir external to the patient.

Furthermore, in the case of cryoballoon ablation, the distal hemisphere of the balloon contacts the pulmonary vein antrum in an occlusive manner. Tissue in contact with distal hemisphere of the cryoballoon will be ablated as liquid N2O evaporates in the distal balloon. As the tissues freezes, a shell of ice forms around the balloon and penetrates full thickness through the wall of the pulmonary vein antrum reaching extracardiac tissues. This can include non-targeted tissues such as the phrenic nerve, esophagus and vagus nerve. The same non-targeted tissues can also be damaged by other balloon directed therapies including but not limited to radiofrequency hot balloon, high frequency ultrasound balloon and laser balloon.

Phrenic Nerve Injury

One possible complication of an ablation procedure is damage to the phrenic nerves, which are involved in breathing and both receive and transmit nerve signals to the diaphragm. Phrenic nerve injury (PNI) can cause dyspnea, cough, hiccup, and/or sudden diaphragmatic elevation. The majority of patients with PNI recover over time, such as within days or months, but PNI may be persistent in a minority of patients.

The main function of the phrenic nerves is to control breathing by acting on the diaphragm. As such, it is possible to monitor phrenic nerve viability by stimulating the phrenic nerves electrically and detecting the corresponding physiologic response. Means for detecting physiologic response may include electromyography (the detection of electromyograms such as compound motor action potentials, or electrical potential generated by muscle cells when the cells are electrically or neurologically activated), mechanomyography (the detection of mechanomyograms, or mechanical signals observable from the surface of a muscle when the muscle is contracted), and kinemyography (the detection of electrical currents generated after deformation of a mechanosensor), auditory cardiotocography (detection of sound waves created by the diaphragmatic contraction). One can also directly observe the diaphragmatic movement fluoroscopically in a spontaneously breathing patient. Pacing of the nerve and palpation of the intensity of the diaphragmatic contraction can also be used to monitor the function of the nerve if the pacing source is positioned distal to the ablation source in the case of balloon cryoablation.

In some embodiments, to avoid phrenic nerve injury (PNI), the electrical activity of a pulmonary vein (or other target site) can be mapped prior to permanent ablation by either RF, high-frequency ultrasound (HIFU), laser, hot balloon, and/or cryotherapy, in order to pinpoint appropriate ablation target sites. Some apparent target sites may have non-targeted tissues such as the phrenic nerve or esophagus in close proximity and ablation at those sites may cause collateral damage such as injury to the phrenic nerve as the ablation penetrates deeper into the tissues. Treating other target sites may affect healthy tissue in undesirable ways (e.g., creating conduction blocks). Precisely mapping the electrical activity in a target treatment region can help focus the treatment and confirm its efficacy and safety.

Mapping Catheter

Various specialized mapping catheters may be employed to electrically map tissue, such as a circular catheter or a multi-electrode basket catheter. As a non-limiting example, in some embodiments, the Constellation catheter, available from Boston Scientific, can be used to electrically map tissue.

Such mapping catheters can be positioned at possible target sites inside a patient, and electrodes at those sites can provide signals to a processing system external to the patient that can process the signals and provide physicians with information to subsequently position a separate RF, HIFU, laser, hot balloon, or cryotherapy catheter and deliver with that separate catheter appropriately targeted ablation energy. In some cases, the mapping catheters can be used to pace and map the phrenic nerve as well.

With reference toFIG.1below, system10can include a mapping catheter14and an ablation catheter16. Each probe14/16can be separately introduced into target region12through a vein or artery (e.g., the femoral vein or artery) using a suitable percutaneous access technique. Alternatively, mapping catheter14and ablation catheter16can be assembled in an integrated structure for simultaneous introduction and deployment in target region12. However, it will be understood that in some embodiments, the system10can omit the ablation catheter16.

Mapping catheter14can include a catheter shaft18. The distal end of the catheter shaft18can include mapping device20, which can include a three-dimensional multiple electrode structure20. Mapping device20can take the form of a basket having a plurality of struts22(seeFIG.2), although other multiple electrode structures could be used. A plurality of mapping electrodes24(not explicitly shown onFIG.1, but shown onFIG.2) can be disposed along struts22. Each electrode24can be configured to sense intrinsic physiological activity in the anatomical region. In some embodiments, electrodes24can be configured to detect activation signals of the intrinsic physiological activity within the anatomical structure (e.g., the activation times of cardiac activity).

Electrodes24can be electrically coupled to a processing system32. A signal wire (not shown) can be electrically coupled to each electrode24on mapping device20. The wires can extend through shaft18and electrically couple each electrode24to an input of processing system32. Electrodes24can sense electrical activity in the anatomical region (e.g., myocardial tissue). The sensed activity (e.g., activation signals) can be processed by processing system32, which can assist the physician by generating an electrical activity map (e.g., a vector field map, an activation time map, etc.) to identify the site or sites within the heart appropriate for a diagnostic and/or treatment procedure. For example, processing system32can identify a near-field signal component (e.g., activation signals originating from cellular tissue adjacent to the mapping electrode24) or from an obstructive far-field signal component (e.g., activation signals originating from non-adjacent tissue). The near-field signal component can include activation signals originating from atrial myocardial tissue whereas the far-field signal component can include activation signals originating from ventricular myocardial tissue. The near-field activation signal component can be further analyzed to find the presence of a pathology and to determine a location suitable for ablation for treatment of the pathology (e.g., ablation therapy).

Processing system32can include dedicated circuitry (e.g., discrete logic elements and one or more microcontrollers; a memory or one or more memory units, application-specific integrated circuits (ASICs); and/or specially configured programmable devices, such as, for example, programmable logic devices (PLDs) or field programmable gate arrays (FPGAs) for receiving and/or processing the acquired activation signals. In at least some embodiments, processing system32includes a general-purpose microprocessor and/or a specialized microprocessor (e.g., a digital signal processor, or DSP, which can be optimized for processing activation signals) that executes instructions to receive, analyze and display information associated with the received activation signals. In such implementations, processing system32can include program instructions, which when executed, perform part of the signal processing. Program instructions can include, for example, firmware, microcode or application code that is executed by microprocessors or microcontrollers. The above-mentioned implementations are merely exemplary. A variety of processing systems32are contemplated.

In some embodiments, processing system32can be configured to measure the electrical activity in the myocardial tissue adjacent to electrodes24. For example, in some embodiments, processing system32can be configured to detect electrical activity associated with a dominant rotor or divergent activation pattern in the anatomical feature being mapped. Dominant rotors and/or divergent activation patterns can have a role in the initiation and maintenance of atrial fibrillation, and ablation of the rotor path, rotor core, and/or divergent foci can be effective in terminating the atrial fibrillation. In either situation, processing system32processes the sensed activation signals to generate a display of relevant characteristics, such as an isochronal map, activation time map, action potential duration (APD) map, a vector field map, a contour map, a reliability map, an electrogram, a cardiac action potential, and/or the like. The relevant characteristics can be used by the physician to identify a site suitable for ablation therapy.

Additionally, the electrodes24of the mapping catheter14can be used to pace and map the phrenic nerve. For example, one or more of the electrodes24can be activated. If the activated electrode24is within a threshold distance of the phrenic nerve it can activate it. In some cases, when paced, the phrenic nerve can cause the diaphragm to contract. Furthermore, as the proximity between the activated electrode and phrenic nerve increases, the strength of the contraction of the diaphragm can increase. Based on which electrodes24pace the phrenic nerve, all or portions of the phrenic nerve can be located. In some cases, to locate the phrenic nerve, the electrodes24can be activated (sequentially or otherwise) along a tine and/or in a circumference on the different tines. In certain embodiments when mapping in a circumference, once one circumference of electrodes is activated24a next circumference of electrodes can be activated (e.g., sequentially or otherwise). The next circumference can either be distal or proximal to the atrium with respect to the previous circumference (e.g., the activated circumference can move proximal-to-distal or vice versa).

In some embodiments, the portion of the phrenic nerve that is proximal (in some embodiments, the most proximal) to the atrium can be identified. In some cases, the determined location of the phrenic nerve (or portions thereof) can be displayed on a corresponding display. As will be described in greater detail below, in some embodiments, the placement of the mapping catheter14and mapping of the phrenic nerve can be based at least in part on an anatomical cycle, such as a respiration or cardiac cycle.

Treatment Catheter

Once the phrenic nerve has been mapped, a treatment device, can be used to treat the patient. In some cases, the treatment device can form part of the mapping catheter, can be placed in the patient while the mapping catheter is still present (e.g., can fit within the lumen of the mapping catheter or vice versa), and/or can be a device that requires removal of the mapping catheter before insertion. One embodiment of a treatment device is the Artic Front Advance Cardiac Cryoablation Catheter, which is commercially available from Medtronic, and can be used to ablate the tissue.

With reference toFIG.3below, the treatment device312can be a catheter with ablation, mapping, and/or audio sensing capabilities, and can have a longitudinal axis329. The treatment device312can additionally include pacing capabilities. As a non-limiting example, the treatment device312can generally include a handle316, an elongate body318having a distal portion320and a proximal portion322, one or more recording electrodes324for detecting electrophysiological signals, one or more treatment elements326for ablating or thermally treating tissue, and/or one or more audio sensors327for recording sounds generated from the thoracic region of the patient's body (for example, audio signals from the heart and/or diaphragm).

In some embodiments, the one or more recoding electrodes324and pacing electrodes328can be included on an electrophysiology catheter330. The electrophysiology catheter330can be can be used as a component of the treatment device312(as shown inFIG.3) or as an independent device. Likewise, the one or more audio sensors327can be included on a separate device.

The one or more treatment elements326can be coupled to or disposed on at least a portion of the distal portion320of the elongate body318. For example, the one or more treatment elements326can include an expandable element (such as a cryoballoon as shown inFIG.3, an expandable array of electrodes as shown inFIG.2, an expandable conductive mesh, and the like). Alternatively, the one or more treatment elements326can be borne directly on the distal portion320of the elongate body318(for example, the treatment device312can be a fixed-diameter catheter such as a focal catheter).

The elongate body318of the treatment device312can include one or more lumens333. If the treatment device312is a cryoablation catheter, for example, the elongate body318can include a main lumen, a fluid injection lumen in fluid communication with a coolant reservoir334, and a fluid return lumen in fluid communication with a coolant return reservoir336. In some embodiments, one or more other lumens can be disposed within the main lumen, can be disposed within the elongate body318along the longitudinal axis329parallel to the main lumen, and/or the main lumen can function as the fluid injection lumen or the fluid return lumen. If the treatment device312includes thermoelectric cooling elements or electrodes capable of transmitting RF (for example, the device shown inFIG.2), ultrasound, microwave, HIFU, laser, hot balloon, electroporation energy, or the like, the elongate body318can include a lumen within which one or more wires are disposed, the wires being in electrical communication with one or more energy generators338.

The console314can be in electrical and/or fluid communication with the treatment device312and can include one or more fluid (such as coolant or saline) reservoirs334, fluid return reservoirs336, energy generators338(for example, an RF or electroporation energy generator), and one or more computers340with displays342, and can further include various other displays, screens, user input controls, keyboards, buttons, valves, conduits, connectors, power sources, and computers for adjusting and monitoring system310parameters. The computer340can be in electrical communication with the one or more treatment elements326, the one or more recording electrodes324, and/or the one or more audio sensors327. Further, the computer340can include a processor344that includes one or more algorithms346executable to evaluate signals received from the one or more recording electrodes324and audio sensors327and to control, monitor, and/or suggest repositioning of the one or more treatment elements326.

The treatment device312can be used in association with an electrophysiology catheter330, with the treatment device312being used to ablate tissue and the electrophysiology catheter330being used to stimulate the phrenic nerve and, optionally, to record one or more electrophysiological signals from the heart. The electrophysiology catheter330can, for example, be slidably disposed within a lumen333of the device312such that the electrophysiology catheter330can be positioned within the patient's anatomy independently before advancing the treatment device312over the electrophysiology catheter330to a treatment location (as shown inFIG.3). Alternatively, the electrophysiology catheter330can be usable independent of the device312(as shown inFIG.3). The electrophysiology catheter330can be flexible (for example, capable of being deflectable into a hooped shape (as shown inFIG.3) and/or into a shape that includes one or more curves or bends. Further, the electrophysiology catheter330can include one or more pacing electrodes328that can be used to stimulate the phrenic nerve by transmitting energy in frequencies around approximately 100 Hz or more, for example, in a series of pacing pulses.

Device Placement

FIG.4Ais a diagram illustrative of an embodiment in which a mapping device402of an intravenous catheter is positioned within the right superior pulmonary vein (RSPV).FIGS.4A,4B,6, and9further illustrate the relative locations of various anatomical features, including the right atrium (RA), left atrium (LA), phrenic nerve, right hemidiaphragm, right inferior pulmonary vein (RIPV), left superior pulmonary vein (LSPV), left inferior pulmonary vein (LIPV), inferior vena cava (IVC), and mitral valve (MV), with respect to various medical devices.

In the illustrated embodiments ofFIGS.4A,4B,6, and9, the catheter has been moved intravenously to the heart and entered the left atrium via a transeptal puncture. In addition, in the illustrated embodiment ofFIG.4A, the mapping device402has been expanded to the circumference of the RSPV near the PV-LA junction.

The location of the mapping device402(and/or catheter) can be determined in a variety of ways, such as by performing fluoroscopy or a venogram, tracking the location of the mapping device402, using a 3D mapping system, occlusive venography, ultrasound (intracardiac echo or transesophageal echo), contact force sensors (e.g., the difference in impedance when in contact with tissue vs. not in contact can be compared), fiber optics, etc. In some embodiments, the determined location of the mapping device402can be traced onto a live fluoroscopy image.

Once the mapping device402is positioned in the desired location, the mapping device402can be expanded until contact is made on all sides of the PV (e.g., a circumference or perimeter of the mapping device402is in contact with the PV). A variety of techniques can be used to determine whether there is adequate juxtaposition to the wall of the pulmonary vein/antrum, such as, but not limited to, venography, an occlusive balloon venogram, a self-expanding nitinol array, contact force sensors, direct visualization in the case of an array mounted to or in direct contact with a balloon (fiber optics), or with intracardiac echo, etc.

Furthermore, as described above, once the mapping device402is placed within the RSPV, one or more of the electrodes of the mapping device402can be activated to pace and map (or determine the location of) the phrenic nerve. In some embodiments, multiple electrodes are activated to identify the location of (and map) the phrenic nerve. In certain embodiments, the electrodes are activated to identify the location of as much of the phrenic nerve as possible (e.g., the portions of the phrenic nerve that can be paced by the electrodes of the mapping device402). As discussed previously, activation of the electrodes closer to the phrenic nerve can result in a stronger, or more pronounced, diaphragmatic contraction (or other observable reaction). For example, in the illustrated embodiment, electrodes410a,410b,410ccan result in a stronger diaphragmatic contraction than the activation of electrodes410d,410e,410f. One may detect very proximal phrenic nerve stimulation and mapping of the phrenic nerve may extend into the PV antrum/atrium. The mapping array can be positioned in the PV antrum/atrium to complete the evaluation of the full extent of the phrenic nerve stimulation including the most proximal region of the phrenic nerve.

Using the results of the activation of the electrodes, the portions of the phrenic nerve near the mapping device402(and targeted tissue region) can be located and the phrenic nerve can be mapped. For example, a display can display the determined location of the phrenic nerve, the location of the electrodes that paced the phrenic nerve, and/or the (relative) strength of the contraction (or other observed reaction) when the particular electrode is activated compared to other electrodes. In this way, a map of the phrenic nerve can be achieved. The determined location and/or mapping of the phrenic nerve can be used to treat the targeted tissue region.

FIG.4Bis a diagram illustrative of an embodiment in which the mapping device402(and corresponding catheter) is replaced with a treatment device404having a treatment element405, such as an inflatable balloon. For example, following the mapping of the phrenic nerve, the mapping device402(and corresponding catheter) can be removed and replaced with the treatment device404.

In the illustrated embodiment, the treatment element405of the treatment device404is positioned and expanded within the RSPV at a similar location to the mapping device402. Similar to the mapping device402, in some embodiments, the treatment element405is expanded until contact is made on all sides of the PV (e.g., a circumference or perimeter of the treatment element405is in contact with the PV). Contact with the PV can be determined similar to the methods described above with respect to the mapping device402.

In some embodiments, the treatment element405can be positioned based at least in part on the determined location of the phrenic nerve (or its mapping), or portions thereof. For example, a display can display the phrenic nerve mapping while also displaying the location of the treatment element405.

In certain embodiments, the treatment element405can be positioned based at least in part on the determined location of an identified proximal portion of the phrenic nerve. In some embodiments, the identified proximal portion of the phrenic nerve is the portion of the phrenic nerve nearest to the PV-LA junction and/or the atrium.

Based at least in part on the proximity of the treatment element405to the determined location of the phrenic nerve (and/or the phrenic nerve mapping), a user can determine whether to proceed with treatment. For example, if the location of the treatment element405(and/or the portions thereof that are in contact with the PV) is distal to, or approximately equal to, the identified proximal portion of the phrenic nerve, the user can determine not to ablate because there can be a relatively high risk of PNI. If the treatment element405(and/or the portions thereof that are in contact with the PV) is proximal with respect to the identified proximal portion of the phrenic nerve, the user can determine whether there is a relatively intermediate or low risk of PNI (as a non-limiting example, <4 mm between the treatment element405and the phrenic nerve can indicate a relatively intermediate risk and >4 mm between the treatment element405and the phrenic nerve can indicate a relatively low risk, however, it will be understood that the level of risk can vary, for example, based on the treatment element405used, other factors, etc.).

In some embodiments, such as when there is a relatively intermediate risk, the treatment element405can be moved into the atrium, activated, and then pushed back into the PV. When activated, the circumference of the treatment element405can expand, which can reduce the distance in the vein to which the treatment element405can advance. For example, depending on the treatment device404used, the circumference of the treatment element405can expand from 26 mm to 28 mm. In this way, the physician can decrease the relative risk of PNI by increasing the distance between the phrenic nerve and the treatment element405during ablation as a larger diameter balloon will “wedge” at a more proximal location.

In the event the user determines to proceed with the treatment, the phrenic nerve can be monitored for potential injury during the treatment procedure. For example, the phrenic nerve can be paced (for example, by activating one or more electrodes of a catheter positioned in the superior vena cava (SVC) adjacent to the phrenic nerve and superior to the site of ablation in the pulmonary vein). If a reduction of the force of diaphragmatic contraction is detected (or other observable reaction changes) during ablation, the ablation procedure can be stopped. For example, the balloon can be forcibly deflated and a corresponding ice shell fractured with saline.

In the illustrated embodiment ofFIG.4B, a second catheter is shown that includes a pacing electrode412positioned near a portion of the phrenic nerve superior to the treatment element405in or near the SVC. The second catheter can be used to pace the phrenic nerve during operation of the treatment device404in order to detect phrenic nerve injury. For example, during treatment, the pacing electrode412can be activated to pace the phrenic nerve. If the diaphragmatic contractions weaken (or other observable reactions change) while the placement of the pacing electrode and its electrical output remain the same (or approximately the same), a potential phrenic nerve injury can be determined and the procedure stopped.

Complementary Devices

FIGS.5A-5Dare diagrams illustrating embodiments of a complementary mapping device502and treatment device504in different configurations and positions. In some embodiments, the complementary mapping device502and treatment device504can be implemented as part of a single catheter. In certain embodiments, the mapping device502and treatment device504can be implemented as separate, complementary catheters. For example, a mapping catheter can be sized to fit within the lumen of the treatment catheter or vice versa. In the illustrated embodiment, a mapping catheter is placed within a lumen503of a treatment catheter. In addition, in the illustrated embodiment, a lumen507of the mapping device502and a guidewire516are shown.

The mapping device502and treatment device504can be placed within an outer sheath506and can be independently operated. For example, the mapping device502can be independently, moved, collapsed, and/or expanded as desired. Similarly, the treatment device504can be independently moved, and its corresponding treatment element505can be independently collapsed, and/or expanded as desired. In the illustrated embodiments, a lever508is used to control the position and configuration of at least the mapping device502.

The mapping device502can be similar to the mapping device20described above with reference toFIG.2. For example, the mapping device502can include multiple independently activatable electrodes510that can be used to pace and/or map the phrenic nerve.

Portions of the mapping device502, such as portions of the tines512that are more proximate to the treatment element505and/or outer sheath, can be coupled to a runner514. In the illustrated embodiment, the runner514can move telescopically within the treatment catheter. However, it will be understood that the runner514can be implemented in a variety of ways. For example, the runner514can form an extension of the treatment device504, etc.

In the illustrated embodiment, the lever508controls the runner514, causing the runner514to advance or retract. As the runner514moves, the configuration of the mapping device502can change. For example, as the runner514advances away from the outer sheath506, the mapping device502can move from a collapsed configuration to an expanded configuration and from an expanded configuration to a treatment configuration. However, it will be understood that fewer or more configurations can be used as desired. For example, in some embodiments, the mapping device502can have two configurations: collapsed and expanded, or can have more than three configurations.

In some embodiments, the collapsed configuration can be used to advance the mapping device502through the patient and outer sheath506. In the expanded configuration, the mapping device502can be used to pace and/or map the phrenic nerve, and in the treatment configuration, the mapping device502can be used to provide space for the treatment element505, pace the phrenic nerve during tissue ablation and/or provide a buffer between the treatment element505and the phrenic nerve. One can also determine if the underlying tissues have been frozen by the loss of local electrograms upon freezing of the tissues.

The treatment element505can be similar to the treatment element326, described in greater detail above with reference toFIG.3. However, although illustrated as a cryoballoon catheter inFIGS.5A-5D, it will be understood that the treatment device504and treatment element505can be implemented using a variety of devices and technologies, including, but not limited to, RF, high-frequency ultrasound (HIFU), laser, and/or hot balloon.

FIG.5Ais a diagram illustrating an embodiment of the complementary mapping device502and the treatment device504when the mapping device502is collapsed and the treatment element505is expanded. Although not illustrated, when the mapping device502and treatment device504are inserted into the patient, both can be in a collapsed position to enable movement through the patient and the outer sheath. Once the devices502,504are positioned, each one can be independently expanded/collapsed as desired.

FIG.5Bis a diagram illustrating an embodiment of the complementary mapping device502and treatment device504when the mapping device502and the treatment element505are expanded. In the illustrated embodiments, the control lever506is moved to alter the configuration of the mapping device502. As illustrated, when the control lever506is moved from a first position to a second position, the runner514advances and the mapping device502changes from a collapsed configuration to an expanded configuration. As described in greater detail above, in some embodiments, when in the expanded configuration, the mapping device502can be used to pace and/or map the phrenic nerve.

FIG.5Cis a diagram illustrating an embodiment of the complementary mapping device502and treatment device504when the mapping device502is moved to a third, or treatment, configuration. In the illustrated embodiments, when the control lever506is moved to a third position, the runner514advances further and the mapping device502changes to the third configuration. In the illustrated embodiment, in the third configuration, the mapping device502is in an umbrella shape, however, it will be understood that in the third configuration, the mapping device502can be put in any shape and/or can be collapsed and withdrawn from the tissue site as desired.

FIG.5Dis a diagram illustrating an embodiment of the complementary mapping device502and treatment device504when the mapping device502is in the treatment configuration and the treatment element505is moved in closer proximity to the mapping device502. The treatment element505can be moved more proximate to the mapping device502by using the control lever506, a separate control lever and/or by advancing the treatment catheter as desired. In some embodiments, by positioning the mapping device502in the treatment configuration and advancing the treatment element505, the mapping device502can be used to pace the phrenic nerve while the treatment element505ablates the target tissue. Furthermore, the mapping device502can be used as a buffer between the treatment element505and the phrenic nerve in order to reduce the likelihood of PNI. Flexible heaters can regionally warm the non-targeted tissues by resistive heating during balloon cryoablation to reduce the likelihood of PNI.

In the illustrated embodiments ofFIGS.5A-5D, the runner514and lever506are used to adjust the configuration of the mapping device502. However, it will be understood that the configuration of the mapping device can be adjusted in a variety of ways as desired. For example, a button or cord can be used to adjust the configuration and/or move the mapping device502and/or treatment device504.

FIG.6is a diagram illustrative of an embodiment in which the complementary mapping device502and treatment device504are positioned within the right superior pulmonary vein (RSPV). In the illustrated embodiment, the configuration of the complementary mapping device502and treatment device504are similar to the configuration shown inFIG.5D. For example,FIG.6can represent an embodiment in which the phrenic nerve has been mapped using the mapping device502and a healthcare provider is ready to treat the targeted tissue with the treatment device504. As described above, in such a configuration, the treatment element505can be used to treat the targeted tissue. In addition, the mapping device502can be used to pace the phrenic nerve during treatment (e.g., at a location superior to the location of treatment) and/or provide a buffer between the treatment element505and the phrenic nerve during treatment. Furthermore, the location and placement of the devices502,504can be determined similar to the manner in which the location of the mapping device402and treatment device404are determined.

Anatomical Cycle

In some embodiments, the determined placement and/or use of a medical device, such as the mapping device20/402/502and/or the treatment device312/404/504, can be based at least in part on an anatomical cycle, such as a respiration or cardiac cycle.

In some cases, during a procedure, anatomical cycles can cause portions of relevant tissue to move in a cyclical pattern with respect to the location of a medical device. For example, during the respiration cycle, the heart can move several centimeters depending on the tidal volume.

By taking into account movement due to the anatomical cycle in determining the location/use of a medical device, a user can increase the likelihood that two medical devices have been placed in the same location at different times, and reduce the likelihood of treating undesired tissue. For example, a user can increase the likelihood that the treatment element326/405/505has been placed in the same location that the mapping device20/402/502was when mapping the surrounding tissue (e.g., when mapping the phrenic nerve). In some cases, the amount of tissue movement due to an anatomical cycle can be reduced, such as by using jet ventilation in a non-paralyzed patient.

As a non-limiting example, at a particular portion of an exhalation cycle, such as at end exhalation, the location of the mapping device20/402/502can be determined. The location can be determined in a variety of ways, such as by performing fluoroscopy or a venogram, tracking the location of the mapping device20/402/502using a 3D mapping system, occlusive venography, ultrasound (intracardiac echo or transesophageal echo), contact force sensors (e.g., the difference in impedance when in contact with tissue vs. not in contact can be compared), fiber optics, etc. In some embodiments, the determined location of the mapping device20/402/502can be traced onto a live fluoroscopy image. The electrodes of the mapping device20/402/502can be paced and the location of the phrenic nerve determined. In addition, the location of some or all of the phrenic nerve, timed to end exhalation can be displayed on the live fluoroscopy image.

In some embodiments, once the mapping device20/402/502is moved or replaced with the treatment device312/404/504, the location of the treatment device312/404/504can be determined. In certain embodiments, the location of the treatment device312/404/504and/or treatment element326/405/505can be determined, timed to end exhalation. The determined location can then be compared to the determined location of the phrenic nerve and/or the mapping device20/402/502, and the user can determine whether to proceed with the procedure as described above.

Phrenic Nerve Injury Risk Determination Examples

FIG.7is a flow diagram illustrating an embodiment of a routine700for treating cardiac arrhythmia.

At block702, a venography is performed of one or more pulmonary veins of a patient. In some embodiments, the venography can be performed for the right-sided pulmonary veins and/or can be displayed in at least two orthogonal views. In certain embodiments, the venography can be timed to end exhalation. In some cases, the patient is spontaneously breathing (e.g., not paralyzed, not being assisted by the ventilator).

At block702, the veins are displayed on a screen, such as a live fluoroscopy screen. In certain embodiments, the veins can be displayed timed to end exhalation and/or in at least two orthogonal views.

At block704, a mapping device is placed in the pulmonary vein and/or pulmonary vein antrum and a fluoroscopy is performed to determine its location. In some embodiments, the fluoroscopy can be performed in the same view as those used in block702and/or can be timed to end exhalation.

At block706, the mapping device is displayed and/or traced onto the displayed veins. In certain embodiments, the mapping device can be displayed timed to end exhalation.

At block708, one or more electrodes of the mapping device are activated to determine the location of the phrenic nerve. As described in greater detail above, the activation of the electrodes can be used to determine the location of the phrenic nerve in the pulmonary vein and/or pulmonary vein antrum with respect to the mapping device. In some embodiments, the activation of the electrodes can be done at high output (e.g., 20 mA at 9 ms asynchronously).

At block710, a proximal portion of the phrenic nerve captured by the mapping device is identified and displayed. In some embodiments, the proximal portion of the phrenic nerve can be displayed in at least two orthogonal views and/or timed to end exhalation.

At block712, it is determined whether a proximal portion of the mapping device (proximal with respect to a central axis that is orthogonal to a longitudinal axis of the mapping device) is free of phrenic nerve stimulation. If not, the mapping device can be retracted until the proximal portion of the mapping device is free of phrenic nerve capture. In certain embodiments, the phrenic nerve is paced with high output. In some embodiments, if the mapping device is moved, blocks708and710can be repeated.

At block714, the position of the mapping device and the sites of phrenic nerve stimulation are displayed on a display. In some embodiments, the position of the mapping device and the sites of phrenic nerve stimulation can be displayed on a 3D mapping system.

At block716, the mapping device is replaced with a treatment device, such as a treatment device312/404/504, and at block718a treatment element of the treatment device is inflated to achieve occlusion. In some embodiments, the treatment element can be inflated after positioning the treatment element at one of the right-sided veins.

At block718, the vein is occluded, and at block720a venography is performed to confirm the occlusion. In certain embodiments, the venography can be performed through a distal port of the treatment device and/or can be timed to end exhalation.

At block722, the position of the treatment element of the treatment device is determined relative to the most proximal site of phrenic nerve stimulation. In some embodiments, the position can be determined timed to end exhalation.

At block724, the location of the treatment element is compared with an indication, such as a line or other graphic, of a most proximal portion of the phrenic nerve. If the treatment element overlaps the indication, the location is identified as high risk. If the treatment element is located within four millimeters of the indication, the location is identified as intermediate risk. If the treatment element is located greater than four millimeters of the indication, the location is identified as low risk. If the location is identified as high risk, the treatment element can be repositioned to an intermediate risk position or low risk position.

At block726, the phrenic nerve is paced while ablating. During the ablation, if a reduction of the force of diaphragmatic contraction is detected by palpation, the position of the catheter in the SVC can be verified. If the location was identified as low risk and the catheter pacing the phrenic nerve has moved, excursion of the right hemidiaphragm can be verified using fluoroscopy.

If a weakening of the diaphragm is detected fluoroscopically, the treatment element can be forcibly deflated and the ice shell fractured with saline administered through the distal port. If the diaphragm is moving normally on fluoroscopy, the treatment element can be repositioned in the SVC to regain phrenic nerve capture and the ablation continued.

If the case was identified as intermediate risk and the diaphragmatic contraction weakens by palpation, the treatment element can be deflated and the ice shell fractured. Fluoroscopy can be performed to assess the motion of the right hemidiaphragm.

At block728, the presence of pulmonary vein isolation (PVI) is assessed, and in certain cases, additional treatment provided. In some embodiments, PVI can be assessed by placing the mapping and/or treatment device at the pulmonary vein antrum and in the pulmonary vein, evaluating for the presence of local PV electrograms to determine the presence of entrance block, and pacing the pulmonary vein to determine the presence of exit block.

In response, if persistent PV conduction is detected, additional treatment can be provided. For example, in some cases, the earliest site of entrance conduction into the PV/PV antrum can be targeted with the treatment device. Additional sites can be treated based on additional assessments for PVI.

In addition, as part of the assessment, adenosine can be administered after PVI to determine the presence of dormant conduction. Following the administration of the adenosine, if PV conduction is detected, additional treatment can be provided. For example, the earliest site of entrance conduction into the PV can be targeted with the treatment device. In some cases, the presence of PVI can be repeatedly assessed until there is no evidence of dormant conduction.

It will be understood that the various steps described above can be performed in a variety of orders. Furthermore, some steps can be omitted. For example, in some embodiments, a 3D mapping system may not be used, etc. In certain embodiments, the anatomical cycle (e.g., end exhalation) can be ignored, such as, but not limited to, when a treatment device that includes mapping functionality is used. Furthermore, although described with respect to locating the phrenic nerve and the treatment of cardiac arrhythmia, it will be understood that routine700can be used to identify the location of non-targeted tissue near a tissue site in other locations of the body. For example, the mapping device can be placed at a tissue site other than the pulmonary vein, such as near the prostate, and electrodes activated to locate non-targeted tissue near the tissue site, such as nerves near the prostate or a proximal portion of non-targeted tissue near a tissue site. Once located, the mapping device can be replaced with a treatment device, and a treatment element of the treatment device inflated. The location of the treatment element can be compared with the determined location of the non-targeted tissue. Based on the comparison, it can be determined whether the location of the treatment element represents a relatively low risk, relatively intermediate risk, or relatively high risk. The treatment element can be moved or treatment can begin based on the determined risk level. During treatment, the non-targeted tissue can continue to be assessed, such as by stimulation. If an adverse reaction occurs, the treatment can be stopped.

FIG.8is a flow diagram illustrating an embodiment of a routine800for treating a tissue site. For example, routine800can be used to treat cardiac arrhythmia. Furthermore, it will be understood that any one or more of the blocks of routine700can be included with routine800.

At block802, a mapping device is placed at a tissue site and determine the location of the mapping device. In certain embodiments, the tissue site can be the pulmonary vein and/or pulmonary vein antrum. As described above, in some embodiments, a fluoroscopy is performed to determine the location. In some embodiments, its location can be determined timed to an anatomical cycle, such as end exhalation.

At block804, one or more electrodes of the mapping device are activated to determine the location of non-targeted tissue with respect to the mapping device. In some cases, the non-targeted tissue can be the phrenic nerve. However, it will be understood that when used in other areas of the body, the one or more electrodes can be used to determine the location of other non-targeted tissue near a tissue site.

At block806, a proximal portion of the non-targeted tissue captured by the mapping device is identified and displayed. In some embodiments, such as when treating cardiac arrhythmia, the proximal portion of the phrenic nerve can be identified. In certain cases, the determined location can be displayed in at least two orthogonal views and/or timed to a portion of the anatomical cycle, such as end exhalation.

At block808, the mapping device is replaced with (or moved for) a treatment device.

At block810, a treatment element of the treatment device is inflated for treatment. In certain embodiments, the treatment element is inflated to achieve occlusion of a vein.

Once it is determined that the treatment element is inflated to a satisfactory level, such as occlusion of the vein, at block812the position of the treatment element is determined relative to the identified proximal portion of the non-targeted tissue, such as the phrenic nerve. In some embodiments, the position of the treatment element is determined timed to a portion of the anatomical cycle, such as end exhalation.

At block814, a risk level is determined based at least in part on determined position of the treatment element relative to the identified proximal portion of the non-targeted tissue.

At block816, the treatment is performed based at least in part on the determined risk level. As described in greater detail above with reference toFIG.7, in some embodiments, if the risk level is determined to be high, the treatment element can be moved.

At block818, the non-targeted tissue is monitored during treatment. For example, the non-targeted tissue can be monitored by electrical stimulation or other methods. If an adverse reaction is detected, the treatment element can be moved or the treatment stopped.

In embodiments in which the phrenic nerve is paced, during the ablation, if a reduction of the force of diaphragmatic contraction is detected by palpation, the position of the catheter in the SVC can be verified. If the location was identified as low risk and the catheter pacing the phrenic nerve has moved, the fluoroscopy can be repositioned. If a weakening of the diaphragm is detected fluoroscopically, the treatment element can be forcibly deflated and the ice shell fractured with saline administered through the distal port. If the diaphragm is moving normally on fluoroscopy, the treatment element can be repositioned in the SVC to regain phrenic nerve capture and the ablation continued. If the case was identified as intermediate risk and the diaphragmatic contraction weakens by palpation, the treatment element can be deflated and the ice shell fractured. Fluoroscopy can be performed to assess the motion of the right hemidiaphragm.

At block820, the targeted tissue site is assessed, and in certain cases, additional treatment provided. In some embodiment, once an initial treatment is completed, the tissue at the targeted tissue site can be examined to determine whether additional treatment is to be provided. For example, electrical signals near the targeted tissue site can be monitored.

With respect to embodiments in which cardiac arrhythmia is being treated, the presence of PVI can be assessed. In some embodiments, PVI can be assessed by placing the mapping and/or treatment device at the pulmonary vein antrum and in the pulmonary vein, evaluating for the presence of local PV electrograms to determine the presence of entrance block, and pacing the pulmonary vein to determine the presence of exit block. In response, if persistent PV conduction is detected, additional treatment can be provided. For example, in some cases, the earliest site of entrance conduction into the PV/PV antrum can be targeted with the treatment device. Additional sites can be treated based on additional assessments for PVI. In addition, as part of the assessment of PVI, adenosine can be administered after PVI to determine the presence of dormant conduction. Following the administration of the adenosine, if PV conduction is detected, additional treatment can be provided. For example, the earliest site of entrance conduction into the PV can be targeted with the treatment device. In some cases, the presence of PVI can be repeatedly assessed until there is no evidence of dormant conduction.

Fewer or more steps can be included as desired. For example, if the risk level is high, the treatment device can be moved. If the risk level is intermediate, the treatment device can be withdrawn from the tissue site, activated, and re-inserted into tissue site as described above. Furthermore, with respect to treating cardiac arrhythmia, during ablation, the phrenic nerve can be monitored and action taken, as described in greater detail above with reference toFIG.7. For example, in some cases, if weakening diaphragmatic contractions are detected, the treatment element can be deflated and an ice shell broken.

In addition, although specific embodiments are described with respect to identifying the location of the phrenic nerve during treatment of cardiac arrhythmia, it will be understood that routine800can be used to identify non-targeted tissue near targeted tissue sites during treatment of other areas of the body. For example, the greater and lesser cavernous nerves (non-targeted tissues) pass nearby the prostate gland and can be injured during prostate surgery causing erectile dysfunction. By identifying the location of the nerves prior to treatment, the likelihood of injury can be reduced.

Segmented Treatment Element

FIGS.9,10A and10Bare diagrams illustrating embodiments of treatment elements902,1002of treatment devices that include multiple segments, which can also be referred to as cells or compartments. Each segment can be formed by a separate inflatable device, such as a balloon, and/or encompass a distinct location and volume with respect to the other segments. Furthermore, each segment can include walls that separate it from the other segments.

In the illustrated embodiment ofFIG.9, the treatment element902includes two segments: a distal segment904and a proximal segment906. Further, in the illustrated embodiment ofFIG.9, the distal segment904is smaller than the proximal segment906. However, it will be understood that the segments can be the same size or the proximal segment906can be smaller than the distal segment904.

In the illustrated embodiment ofFIGS.10A and10B, the treatment element1002includes eight segments1004A,1004B,1004C,1004D,1004E,1004F,1004G,1004H that extend from a distal portion central lumen to a more proximal portion of the central lumen forming approximately equal partitions of the distal end of the treatment device corresponding to the treatment element, and which can also be referred to as wedge segments. It will be understood that the embodiments shown inFIGS.9,10A, and10Bcan be combined as desired and/or fewer or more segments can be used as desired. For example, the distal segment904and/or the proximal segment906can include multiple wedge segments and/or the treatment element902can include fewer or more segments, such as a central segment, etc. Similarly, the treatment element1002can include proximal and distal segments as desired and can include fewer or more wedge segments.

In certain embodiments, the cells can be independently controlled. For example, in some embodiments, each segment (or a subset of the total number of segments) can be independently and variably expanded and/or contracted. Furthermore, each segment (or a subset of the segments) can be independently heated or cooled.

In some cases, segments determined to be in close proximity to the phrenic nerve and/or esophagus can be converted to warming segments. For example, the distal segment904can be used for cryoablation during ablation of left sided PVs, and the proximal segment906can be a warming segment if the esophagus satisfies a distance threshold or temperature threshold, or is too close or became too cold during ablation of the left sided pulmonary veins.

Similarly, in cases where the distal segment904is determined to be too close to the phrenic nerve (for example, by pacing the phrenic nerve) or other tissue that is not to be treated, the proximal segment906can be used to cryo-ablate tissue and the distal segment904can be deflated and not used to cryoablate, inflated but not used to cryoablate, or inflated and used as a warming segment.

The segments can be made of a compliant material, such as polyurethane, polyester, composite material, laminate, or other material that allows for variable sizing to enable contact with the surrounding tissue, such as a pulmonary vein antrum, and to seal leaks between the surrounding tissue and the treatment element902,1002. The size of the segments can be adjusted by variably pressurizing during use, such as during cryoablation or warm high pressure mapping. As discussed in greater detail below, in certain cases, contact force sensors and flow sensors can be used to guide the appropriate size. If phrenic nerve location (or other tissue near a target site, but that is not to be treated) is a concern, high pressure warm mapping can be performed with to seal the tissue without risking injury to the nerve. In this way, the operator can test the occlusion of a vein, or other tissue, without risking injury to the surrounding tissue.

With respect to the treatment elements inFIGS.10A and10B, in some cases, if one or more of the segments1004A,1004B,1004C,1004D,1004E,1004F,1004G,1004H are determined to be too close to tissue that is not to be treated, the one or more segments1004A,1004B,1004C,1004D,1004E,1004F,1004G,1004H can be deflated, inflated without injecting high pressure refrigerant such as N2O to cryoablate, or used as warming segments either by applying a warming agent or leaving the segment empty of a solution.

Treatment Device with Sensors/Electrodes

FIGS.11and12are diagrams illustrating embodiments of treatment devices1102,1202that include one or more sensor/electrodes and can be used to pace and/or map the phrenic nerve and/or treat the targeted tissue region. Devices that can be used for mapping and treating a target location, such as treatment devices1102,1202,1302can also be referred to as an integrated device and/or an integrated treatment device. In some embodiments, when using the treatment devices1102,1202, the anatomical cycle can be ignored because the mapping and treatment devices described above are combined; provided however that the combined treatment devices are in direct contact with the targeted tissue during an anatomic cycle (non-limiting example: a combined treatment device positioned in PV antrum during an occlusive venogram. Furthermore, once the treatment device is inflated within the PV, the device can move with the tissue during the anatomical cycle. In some embodiments, the lumen of the treatment device1102,1202can be flush with the distal end of the treatment device1102,1202, thereby allowing the treatment device to be used without a guide wire.

As described in greater detail above with reference toFIGS.10A,10B, and10C, and as further illustrated inFIGS.11and12, in some embodiments, the treatment device can include two or more segments, such as a distal and proximal segment. In certain embodiments, mapping electrodes can be included on the surface of the treatment device, thereby allowing accurate real time assessment of the location of the phrenic nerve.

In the illustrated embodiment ofFIG.11, a distal portion of treatment device1102is shown including central lumen1112and a treatment element1103that includes a distal segment1104, a proximal segment1106, a plurality of electrodes/sensors1108. In the illustrated embodiment ofFIG.12, a distal portion of treatment device1202is shown including a central lumen1212and a treatment element1203that includes a distal segment1204, four proximal segments configured as wedge segments1206A,1206B,1206C,1206D (not shown), and a plurality of electrode/sensors1208. It will be understood that fewer or more compartments can be used as desired and that each of the segments can be independently controlled. Furthermore, each segment can be capable of cryoablation, cold mapping (low pressure), warm mapping (low pressure), warm fully inflated (high pressure), etc. It will be understood that warm mapping can include a solution at ambient temperature or a solution that is not cooled.

In some embodiments, the various segments of the treatment elements1103,1203can be enclosed by an outer casing1110,1210, which can be formed of a compliant material, such as polyurethane with a vacuum between it and each of the interior segments to ensure safety in the event of a rupture of any of the segments1104,1204,1106,1206A-1306D. In some cases, the electrodes/sensors1108,1208can be on the exterior of the outer casing1110,1210. In some embodiments, the sensors/electrodes1108,1208can be integrated into the outer casing1110,1210.

As further illustrated inFIGS.11and12, the treatment device1102,1202can include a series of sensing, pacing, mapping, ablation electrodes, contact force sensors, and/or flow sensors (collectively electrodes/sensor1108,1208) designed to characterize tissue, such as the pulmonary vein and surrounding tissues in the vein, including the phrenic nerve. For example, the electrodes/sensors1108,1208can be used to detect contact of the treatment element1103,1203to the antrum of the pulmonary vein or the pulmonary vein itself, locate, any flow of blood around the treatment device, obtain pulmonary venous electrograms, locate/map/pace the phrenic nerve, and/or determine the temperature of the tissue adjacent to the phrenic nerve, esophagus, and/or the remainder of the antrum/pulmonary vein itself. As such, in certain embodiments, the treatment device1102,1202can be utilized as a 3D mapping catheter able to collect 3D volume and activation times.

In some embodiments, the pacing electrodes can be used to stimulate surrounding tissue, such as a phrenic nerve. Based on the stimulation, the treatment device1102,1202can generate a map of the surrounding tissue.

The sensing electrodes can be used to detect electrical or other activity. For example, the sensing electrodes can identify electrical activity before and/or after the procedure. Before the procedure, the data from the sensing electrodes can be used to identify a location of tissue that is to be ablated. Following the procedure, the data from the sensing electrodes can be used to determine whether the procedure was successful.

The contact force sensors can be used to detect contact of the treatment element1103,1203to surrounding tissue and/or whether the tissue is properly occluded. The flow sensors can be used to detect any flow of blood or other substance around the treatment device and/or to determine whether the tissue is properly occluded.

Ablation electrodes can be used to isolate the pulmonary vein, in the event that the proximal segment of the treatment element1103,1203satisfies a distance threshold with respect to the phrenic nerve (for example, is too close to the phrenic nerve and/or cryoablation risks phrenic nerve injury). Additionally, the ablation electrode can be used for radiofrequency touchup to improve the ablation of certain tissue and/or increase likelihood of a successful procedure. In certain cases, the ablation electrodes can be configured in a ring. In some embodiments, the inclusion of ablation electrodes with the treatment device1102,1202can replace the use a separate radiofrequency catheter.

The temperature sensors can be used to monitor the temperature of tissue, before, after, or during ablation. Based on the temperature sensor data, the treatment element1103,1203can be moved and/or the procedure halted. In some embodiments, the temperature sensors can be positioned on the treatment element1103,1203adjacent to mapping electrodes and can demonstrate the temperature of the various regions of the treatment element1103,1203. The temperature of electrodes/sensors1108,1208near sites of phrenic nerve (or other tissue) stimulation can be used to assess the risk of injury and can help in the prevention of injury in intermediate risk cases. If the local temperature of electrodes/sensors1108,1208near the phrenic nerve (or other relevant tissue) satisfy a temperature threshold and/or are too cold, cryoablation can be stopped prior to injury of the nerve.

The treatment device1102,1202can include additional sensors/electrodes as desired. For example, the treatment device1102,1202can include optical elements to visualize the effects of ablation on the tissue, e.g., looking for gaps in the ablation lines or rings.

In certain cases, the treatment device1102,1202can include an ultrasound transducer that can be used to obtain geometry, determine if a leak is occurring (with color flow), determine the optimal size to inflate the treatment device1102,1202to obtain contact with the antrum of the pulmonary veins, etc. In some cases, the ultrasound transducer to construct 3D geometry for accurate navigation of the treatment device1102,1202without the use of fluoroscopy. Color flow can help determine the sizing of the treatment device1102,1202to ensure occlusion even in cases of left common ostium.

In addition, in some cases, an esophageal temperature probe can be positioned close to the treatment device1102,1202, and in some cases, as close as possible. The pairing of the esophageal probe, with the treatment device1102,1202can improve the ability to identify the location of the segments nearest the esophagus. The signals can be sent over to any physiologic recording system or 3D mapping system for viewing. In some cases, if the treatment device1102,1202is moved, rotated, or otherwise manipulated, the tissue can be remapped.

The electrodes/sensors1108,1208for each segment of the treatment elements1103,1203can be paired with a return electrode/sensor specific to the segment, such that pacing or sensing on that wedge segment can result in the completion of the circuit and enable the treatment device1102,1202to determine which segment is being evaluated on the console. For example, a return electrode can be paired with the distal segment1204, such that pacing any electrode on the distal segment1204causes the completion of a circuit that enables the treatment device1102,1202to recognize the distal segment1204. If the electrode being paced captures the phrenic nerve, a press of a touch screen can identify the segment or sub-segment. In some cases, the screen can turn the corresponding segment red, or otherwise highlight the segment that is being paced. Once selected, the corresponding segment can be configured for a warm mode, either low or high pressure, or a cryoablation mode.

In some embodiments, when in a mapping mode, all segments of the treatment element1103,1203can be inflated to map the tissue. The tissue can be characterized using the electrodes/sensors1108,1208. In some cases, the distal segment1104,1204can be used to keep a firm position in the vein while the phrenic nerve is being pacing using the electrodes/sensors1108,1208.

In some embodiments, the segments of the treatment element1103,1203that risk damaging tissue surrounding a target site, such as the phrenic nerve or esophagus, can be can be deflated and/or used as warming segments, whether at high pressure or low pressure. In addition, the temperature of the tissue adjacent to the target site can be monitored using the electrodes/sensors1108,1208during the procedure.

Based on the data collected during the mapping mode, the treatment device1102,1202can provide treatment (e.g., cryoablation, etc.) from any of the proximal1106,1206A-1306D, and/or distal segments1104,1204. If the phrenic nerve (or other tissue near a target site) is in jeopardy of being damaged and/or paralyzed by the distal segment1104,1204, the distal segment1104,1204can be converted to a warming balloon, inflated without cryoablating, and/or deflated. As such, the treatment device1102,1202can protect the phrenic nerve from cryoablation and also assess the function of the phrenic nerve by pacing the nerve using the electrodes/sensors1108,1208that are positioned on the treatment element1103,1203.

In some embodiments, as described in greater detail above, the distal segment1104,1204can remain cold mapping for cryoablation during ablation of left sided PVs, and the proximal segments1106,1206A-1306D can be used as warming segments if the esophagus satisfies a distance threshold or temperature threshold or becomes too cold during ablation of the left sided pulmonary veins.

As yet another example, the proximal segment(s)1106,1206A-1306D can be used to isolate the pulmonary vein. Pulmonary venograms can be assessed during the freeze to determine time to effect thereby reducing unnecessary additional cryoablation. In some embodiments, if it is determined that the mapped tissue is clear of any phrenic nerve activation and satisfies a threshold distance from the esophagus, all segments of the treatment element1103,1203can be used to ablate.

Furthermore, in some cases, the treatment device1102,1202can be used for a roof line or posterior wall isolation. The treatment device1102,1202can assess for bidirectional block across the pulmonary vein antrum (pulmonary vein isolation), block across the roof of the left atrium and posterior wall isolation, etc.

The treatment device1102,1202can be constructed such that the treatment element1103,1203can variably expanded to determine contact with the antrum, including cases of a left sided common ostium. Furthermore, as mentioned above, the segments of the treatment element1103,1203in close proximity to the phrenic nerve and/or esophagus can be converted to warming segments. In some embodiments in place of or in addition to the segments, the electrodes/sensors1108,1208of the treatment device1102,1202can be used to create warmth regions.

In some embodiments, the treatment device1102,1202can be controlled manually or robotically from a console without fluoroscopy. The treatment device1102,1202can collect 3D geometry and/or identify the location of the phrenic nerve and/or esophagus. The treatment device1102,1202can reconstruct the course of the phrenic nerve as a continuous variable. The various cells can be closed off (or not supplied with a solution), deflated, and/or converted to warming cells automatically to create a buffer to protect the nerve. The temperature of the tissue in contact with the phrenic nerve can be assessed and the catheter can convert more cells to warming cells if the temperature of the tissue near the esophagus gets too low or satisfies a temperature threshold. The temperature threshold can be based on a temperature at which tissue will be, or is likely to be, damaged. After the veins are isolated, the treatment device1102,1202can be used to achieve a roof line, if a roof dependent tachycardia is induced.

In some embodiments, the treatment device1102,1202can be used to assess for block across the roof by positioning the treatment element1103,1203across the line and pacing from each side (anterior and posterior to the line). The treatment device1102,1202can isolate the posterior wall of the left atrium and assess for electrical isolation. The energy modality used to achieve isolation can include, but is not limited to, cryoablation, laser, HIFU, radiofrequency, etc. An ultrasound catheter mounted to the treatment device1102,1202can recreate 3D geometry, assess for leaks and coupled with the array of sensors allow for non-fluoroscopic navigation of the treatment device1202,1202. 3D mapping and temperature assessment of the esophagus can enhance the safety of the procedure. Segments of the treatment device1102,1202adjacent to the esophagus can be turned to a warming mode to protect the esophagus.

A console can display the treatment device1102,1202, any portion thereof, such as treatment element1103,1203, or a virtual representation of thereof, and each segment of the treatment element1103,1203can be independently controlled for warm mapping (low pressure), warm mapping (high pressure), cold mapping (low pressure using N2O), and/or cryoablation.

By using the treatment device1102,1202, a healthcare provider can avoid changing catheters during surgery, i.e. from replacing the mapping device20with the treatment device312. The treatment device1102,1202can map in real time and also be used for ablation, thereby reducing, if not eliminating, error in accurate translation of phrenic nerve location to treatment device1102,1202location. Furthermore, the treatment device1102,1202can reduce the risk of inadvertent damage, reduce stress on the operator, and potentially enable the operator to be more aggressive with the ablation, due to the mapping. In cases where the distal segment1104,1204is made a warm high pressure balloon, the phrenic nerve can be paced from a stable, reliable position above the treatment level. Local tissue temperature next to the nerve can be assessed. As such, the phrenic nerve can be shielded, the temperature of its local environment assessed and its function tested with the treatment device1102,1202.

FIG.13is a diagram illustrative of an embodiment of a treatment device1302positioned within the right superior pulmonary vein (RSPV). The treatment device1302can be similar to the treatment devices1102,1202described previously with reference toFIGS.11and12, and can include one or more treatment elements1304and one or more sensors1306. The one or more sensors can also be referred to as a mapping portion1306. The mapping portion1306can be similar to the mapping devices20/402/502and/or the sensors1108,1208described previously, and the treatment element1304can be similar to any one or any combination of the treatment elements326/405/505/902/1002/1103/1203, described previously.

In the illustrated embodiment, the treatment device1302can be placed in a mapping mode and/or a treatment mode. In the mapping mode, various electrodes of the mapping portion1302can be activated to determine the location of the phrenic nerve. In the treatment mode, the treatment element1304(or segments thereof) can be activated in order to ablate the tissue. For example, the treatment element1304(or segments thereof) can be filled with a coolant for cryoablation. However, as described previously, the tissue can be ablated in a variety of ways. As described in greater detail above, with reference toFIGS.12and13, the segments of the treatment element1304can be individually and independently used as warming regions or as ablation regions.

FIG.13further illustrates a second catheter with a pacing electrode1308positioned near the phrenic nerve superior to the treatment device1302. In some embodiments, once the treatment element1304is activated, the electrodes of the mapping portion1302may not be usable. In such embodiments, the electrode1308can be used to detect phrenic nerve injury, similar to the electrode412described previously. If a potential phrenic nerve injury is determined, the procedure can be stopped and/or different portions of the treatment device can be activated as warming regions, as described previously.

Pulmonary Vein Assessment

After each pulmonary vein has been ablated, sensing and pacing electrodes on an independent mapping array such as the Constellation Basket, complementary mapping device502, a treatment device1102,1202,1302and a mapping overlay1501can be used to assess for the presence of entrance and exit block. Specifically, the presence of local electrograms (near-field signal) associated with the underlying atrial rhythm would indicate that the pulmonary vein antrum is not isolated if the integrated device is positioned opposed to the pulmonary vein antrum. The absence of signals or the presence of independent signals can indicate entrance block. Pacing of the vein from electrodes positioned distal to the ablation region can be used to assess for exit block.

Local capture of the vein can be evidenced by the generation of local PV potentials without capturing the atrium in a patient in normal rhythm can be used to determine exit block. In the case that a vein has persistent PV connection during sinus rhythm, atrial fibrillation, flutter, atrial tachycardia or other atrial rhythm, the location of the earliest local PV electrogram (near-field signal) can be mapped in both a circumferential and/or a longitudinal axis to determine the specific location of electrical entrance into the pulmonary vein antrum. Targeting this location with ablation can result in isolation of the vein and/or can reveal the presence of another site of earliest PV connection that must also be ablated to achieve isolation.

Adenosine

Adenosine, or other A1 (adenosine 1; AKA purine 1) receptor agonist, can be used post ablation in isolated veins to adjust the treatment device1102,1202upon an additional treatment, such as a freeze. For example, a given pulmonary vein is isolated as determined upon remapping post ablation with the treatment device1102,1202. IV adenosine can be given to the point of causing transient heart block, hypotension or sinus node suppression.

A transient acute PV reconnection (as evidenced by PV electrograms associated with sinus rhythm or other atrial rhythm) can be readily and specifically targeted prior to moving to the next pulmonary vein. These acute reconnections can involve an area that leaked during ablation. Directing the treatment device to target the site(s) of acute PV reconnection can result in elimination of dormant conduction, which has been demonstrated to improve the efficacy of the atrial fibrillation ablation.

Sensors Co-Located with Treatment Element

FIG.14is a flow diagram illustrating an embodiment of a routine1400for locating non-targeted tissue near a targeted tissue site and providing treatment to the tissue site based on the location of the non-targeted tissue. In some embodiments, routine1400can be used in conjunction with an integrated treatment device that includes sensors co-located with a treatment element. In certain embodiments, routine1400can be used in conjunction with a mapping overlay or mapping device, such as the mapping overlay described below with reference toFIGS.15A-15C and16A-16C, that is distinct from a treatment device but provides sensors or electrodes that are co-located with at least a portion of the treatment element of a treatment device.

At block1402, a treatment element of a treatment device is inflated at a targeted tissue site, which can also be referred to as a target site or treatment site. In some embodiments, the tissue site can be the pulmonary vein. In some embodiments, prior to inflation, the treatment element is placed in the pulmonary vein antrum and an occlusive balloon venogram is performed to determine its location.

At block1404, one or more electrodes of a mapping portion of the integrated treatment device or a mapping overlay (as described in greater detail inFIGS.15A-15C and16A-16C) coupled to a treatment device are activated to determine the location of a proximal portion of tissue near the target site, such as the phrenic nerve in the pulmonary vein.

At block1406, the proximal portion of the non-targeted tissue near the target site captured by the mapping portion or mapping overlay is identified and displayed. In some embodiments, it is determined whether a proximal portion of the mapping portion or mapping overlay is free of non-targeted tissue stimulation, such as phrenic nerve stimulation. If not, the device can be retracted until the mapping portion corresponding to the location of the treatment element is free of non-targeted tissue capture. In certain cases, such as when used to treat cardiac arrhythmia, this can reduce the likelihood that phrenic nerve function will be affected by the treatment element.

At block1408, a risk level is determined based at least in part on the position of the treatment element relative to the identified proximal portion of the tissue near the target site. In some embodiments, zones to be treated and zone of non-targeted tissue to be protected can be established.

At block1410, treatment is performed at the target site based at least in part on the determined risk level. As described in greater detail above with reference toFIG.7, in some embodiments, if the risk level is determined to be high, the treatment element can be moved and/or one or more segments or electrodes can be used to protect the non-targeted tissue. For example, one or more segments can be deflated or used as a warming balloon, etc.

At block1412, the non-targeted tissue is monitored during treatment. For example, the non-targeted tissue can be monitored by electrical stimulation or other methods. If an adverse reaction is detected, the treatment element can be moved or the treatment stopped.

In embodiments in which the phrenic nerve is paced, during the ablation, if a reduction of the force of diaphragmatic contraction is detected by palpation, the position of the catheter in the SVC can be verified. If the location was identified as low risk and the catheter pacing the phrenic nerve has moved, the fluoroscopy can be repositioned. If a weakening of the diaphragm is detected fluoroscopically, the treatment element can be forcibly deflated and the ice shell fractured with saline administered through the distal port. If the diaphragm is moving normally on fluoroscopy, the treatment element can be repositioned in the SVC to regain phrenic nerve capture and the ablation continued. If the case was identified as intermediate risk and the diaphragmatic contraction weakens by palpation, the treatment element can be deflated and the ice shell fractured. Fluoroscopy can be performed to assess the motion of the right hemidiaphragm.

At block1414, the targeted tissue site is assessed, and in certain cases, additional treatment provided. In some embodiment, once an initial treatment is completed, the tissue at the targeted tissue site can be examined to determine whether additional treatment is to be provided. For example, electrical signals near the targeted tissue site can be monitored.

With respect to embodiments in which cardiac arrhythmia is being treated, the presence of PVI can be assessed. In some embodiments, PVI can be assessed using the mapping portion of the integrated treatment device, evaluating for the presence of local PV electrograms to determine the presence of entrance block, and pacing the pulmonary vein to determine the presence of exit block. In response, if persistent PV conduction is detected, additional treatment can be provided. For example, in some cases, the earliest site of entrance conduction into the PV/PV antrum can be targeted with the treatment device. Additional sites can be treated based on additional assessments for PVI. In addition, as part of the assessment, adenosine can be administered after PVI to determine the presence of dormant conduction. Following the administration of the adenosine, if PV conduction is detected, additional treatment can be provided. For example, the earliest site of entrance conduction into the PV can be targeted with the treatment device. In some cases, the presence of PVI can be repeatedly assessed until there is no evidence of dormant conduction.

Fewer or more steps can be included as desired. For example, if the risk level is high or intermediate, the treatment element can be moved, distal portions of the treatment element can be deflated and/or used as warming portions, and/or electrodes can be activated to create a warming region, etc. In addition, during treatment for cardiac arrhythmia, the phrenic nerve can be monitored, etc. Furthermore, it will be understood that any one or any combination of the steps described above with respect toFIGS.7and8can be used. For example, multiple images can be taken at different times and at different orthogonal views, etc.

In addition, although specific embodiments are described with respect to identifying the location of the phrenic nerve during treatment of cardiac arrhythmia, it will be understood that routine1400can be used to identify non-targeted tissue near targeted tissue sites during treatment of other areas of the body. For example, the greater and lesser cavernous nerves (non-targeted tissues) pass nearby the prostate gland and can be injured during prostate surgery causing erectile dysfunction. By identifying the location of the nerves prior to treatment, the likelihood of injury can be reduced.

Mapping Overlay

FIGS.15A-15Care diagrams illustrative of a mapping overlay1501, which can form part of a mapping device or mapping catheter. The mapping overlay1501can be used in association with a treatment device, such as the treatment devices312,404,504, form part (e.g., the mapping portion) of the integrated treatment devices1102,1202,1302, and/or be used in any one or any combination of the routines700,800, and/or1400.

In the illustrated embodiment, the mapping overlay1501includes a wire mesh1502extending beyond a catheter body1508, which can also be referred to as a lining or tube, and multiple sensors/electrodes1504(individually referred to as sensor/electrode1504). A distal end of the mesh1502can be coupled to a cap1506and a proximal portion of the mesh1502can be coupled to, or encircled by the body1508. In some embodiments, an interior diameter of the mesh1502can be sized to enable a treatment device, such as treatment devices312,404,504to pass therethrough. In certain embodiments, an exterior diameter of the mesh1502and body1508can be sized to pass within an inner diameter of a sheath1510.

The mesh1502can include a plurality of interwoven or braided wires1503(individually referred to as a wire1503). In certain embodiments, the mesh can form a tubular structure. In some embodiments, the wires1503can be wound helically and form a perimeter of a lumen. In certain cases, the mesh can include longitudinal wires running lengthwise with the lumen and woven wires that weave between the longitudinal wires. In some cases, the wires can be interlaced with each other like a braid. Any number of wires1503can be used for the mesh1502. In some cases, the mesh1502can be cylindrical with an interior lumen. However, it will be understood that the mesh1502can be formed in any shape. In some embodiments, the minimum number of wires1503is equal to at least the number of electrodes1504used with the mesh1502or twice the number of electrodes1504used with the mesh1502. For example, if 32 electrodes1504are attached to the mesh1502, the mesh can be made up of 32 wires1503or64wires1503. However, it will be understood that the mesh1502can include fewer or more wires1503as desired.

In some embodiments, the wires1503of the mesh1502can be made of steel, coated copper polyester, nitinol, composite material, platinum, platinum coating over nitinol core, tungsten (strength), or other biocompatible metal or conductor. In some embodiments, the wires can be multi-conductor wires or cables (non-limiting examples: coaxial cable with one more cores, multi-ribbon wire, etc.). Further, the wires1503can be coated in Teflon, polyester polyimide kapton, or other biocompatible electrical insulator, such as plastic, etc.

In some cases, the mesh1502can include a combination of different types of wires1503. For example, the mesh1502can include a one or more conductor wires, one or more structural wires, and/or one or more radiopaque wires. The different wires can be made of different material and can be braided together to provide the mesh1502with different characteristics. For example, the conductor wires (non-limiting examples: copper) can be used to provide an electrical signal to and/or from the sensors1505, the structural wires (non-limiting examples: steel, nitinol, tungsten) can be used to provide the mesh1502with rigidity and structure, and the radiopaque wires (non-limiting examples: tungsten, platinum, gold-plated) can be used to increase the visibility of the mesh1502when inserted into a patient. In certain cases, the sensors1504are coupled only to the conductor wires and are not coupled to the structural wires or the radiopaque wires. In certain cases, a conductor wire can also be used as a structural and/or radiopaque wire. In some cases, the majority of the wires of the mesh1502can be conductor wires. In certain embodiments, approximately one fourth of the wires can be structural wires. However, it will be understood that the mesh can include any combination of conductor wires, structural wires, and/or radiopaque wires.

The mesh1502can be constructed to expand/collapse passively or actively. To expand passively, the mesh1502can rely on a force applied to it from another object proximate thereto, such as a treatment element of a treatment device. For example, in some embodiments, as the treatment element enlarges, it can exert a deformation force on the wires1503. In response to the deformation force, the wires1503can deform and the mesh1502expand, as illustrated inFIG.15B.

Similarly, to collapse passively, the mesh1502can rely on a force applied to it from another object proximate thereto, such as the sheath1510. In some embodiments, once the deformation force from the treatment element is withdrawn due to a deflation and/or removal of the treatment element, the mesh1502can retain the shape created by the deformation force of the treatment element, or otherwise not return to its pre-deformed shape absent an additional force. In such embodiments, if the mesh is in an expanded state (as shown inFIG.15B) due to a previous deformation force applied thereto by a treatment element, the mesh1502can be passively collapsed using a force applied thereto by the sheath1510. For example, as the mapping overlay1501is withdrawn from the target site and pulled through the sheath1510, a deformation force on the mesh1502from the sheath1510can cause the mesh1502to deform back to a predetermined shape or a shape similar to the predetermined shape.

In some embodiments, the mesh1502can collapse passively based on the pliability characteristics of the wires1503. For example, the wires1503can be constructed to have sufficient spring such that once a deformation force, such as from a treatment element, is removed from the wires1503, the wires1503return to a predetermined shape or similar thereto. In some cases, the wires1503can return to a predetermined shape unless a deformation force that satisfies a wire pliability threshold is applied. If the deformation force satisfies the wire pliability threshold, the wires1503can maintain their new shape or not return to the predetermined shape.

To expand or collapse actively, the wires1503can be controlled by a user. For example, the user can manipulate a lever or knob to actively adjust the expansion and/or collapse of the wires. The lever or knob can enable the user to expand or collapse the mesh1502as desired. For example, moving a lever or slider button in one direction, such as a longitudinal axis of the mapping overlay can cause the mesh1502to expand and moving the lever or slier button in a different direction, such as an opposite direction, can cause the mesh1502to collapse.

In some embodiments, to form the mapping overlay or mapping catheter, an inner layer, such as a polymer or other flexible material, can be heat shrunk, or otherwise coupled or bonded, around a tube, such as a mandrel. One or more wires1503with or without electrodes can be pre-braided in a tubular structure and slid over the first layer on the mandrel to form a second layer. The mesh of wires1502can extend past a distal end and proximal end of the inner layer and the mandrel. A third layer can be laminated over the portion of the wires that that are on top of the mandrel. To provide structural or mechanical properties such as flexibility, pushability, and torqueability, other layers can be added to control said properties. After the layers are placed over the wires1503, the mandrel can be removed. Accordingly, a distal portion of the mapping catheter can include the mesh of wires without an inner layer or outer layer, the middle portion (or body1508) of the mapping catheter can include the mesh of wires sandwiched between the inner layer and outer layers of material, and a proximal portion of the mapping catheter can include the mesh1502. In some embodiments, 6-12″ of mesh can extend beyond the body1508of the mapping catheter at both the distal end and proximal end. However, it will be understood that the mapping overlay can be configured to have more or less mesh extend beyond the body1508. Furthermore, it will be understood that the mapping overlay can be constructed in a variety of ways. As another example, the body1508can extend along the entire length of the mesh1502. A distal end of the body1508and mesh1502can be dipped in acid to remove the inner and outer layers of the body1508from the mesh1502, etc.

In some embodiments, the mesh1502can provide a known spatial relationship between the electrodes1504. In addition, the mesh1502can provide the mapping overlay with flexibility and radial control, which can increase the likelihood of an accurate mapping of surrounding tissue.

With continued reference toFIGS.15A-15C, one or more sensors and/or electrodes1504, described in greater detail above, can be coupled to the mesh1502. A sensor/electrode1504can be coupled to a wire1503by using a biocompatible adhesive, bonding agent, welding, soldering, plated over exposed copper, or other coupling that is biocompatible and electrically conductive, etc. In some cases, to apply a sensor and/or electrode to a wire1502, a portion of the insulation of the wire can be removed. The exposed portion of the wire can be gold plated or have a stainless metal applied as the electrode1504. In certain cases, a portion of the wire1502can be cut and a resistive material can be applied to provide a heating electrode.

In some cases, a single sensor/electrode1504can be coupled to (only) one of the wires1503of the mesh1502. For example, a wire1503with a sensor/electrode1504can terminate at the cap1506. In such embodiments, the wire1503and electrode1504can act as a passive sensor or voltmeter. In certain cases, a sensor/electrode1504can be coupled to more than one wire1503. For example, the sensor/electrode1504can be affixed to a first wire carrying an electrical signal to or from a controller. The first wire can be electrically coupled to a second wire to carry the signal in the opposite direction as the first wire (non-limiting example: first wire carries electrical signal distally from controller and second wire carries electrical signal back to the controller, or vice versa). In some embodiments, more than one sensor/electrode1504can be coupled to a single wire1503. In embodiments, where more than one electrode1504is coupled to a wire, the wire can be a multi-conductor wire and/or the electrodes1504can be read using multiplexing. The wire(s)1503coupled to the relative sensor/electrode1504can provide the sensor/electrode1504with an electrical connection thereby enabling the control of the sensor/electrode1504and the ability to receive data from the sensor/electrode1004.

Additionally, in some embodiments, the wire(s)1503can keep the sensor/electrode1504in place. For example, the mesh1502can provide a 3D fixation for the sensor/electrode1504. As such, the location of the sensor/electrode1504relative to the treatment device can be known with greater accuracy and/or dependability.

When more than one sensor/electrode1504is used, the sensors/electrodes can be located in a variety of configurations. In some embodiments, the sensors/electrodes1504can be evenly (or unevenly) spaced from each other. In certain embodiments, the sensor/electrodes1504can be located on the mesh1502such that they are distal to or (approximately, such as ±5 cm) coaxial with the portion of a treatment element of a treatment device with the largest circumference or perimeter when the treatment element is expanded (e.g., the meridian of the treatment element). However, it will be understood that the sensor/electrodes1504can located anywhere on the mesh1502. For example, one or more sensor/electrodes1504can be located proximal to the meridian of the treatment element. Similarly, the sensor/electrodes1504can be located along an entire portion of a treatment element of a treatment device and/or distal or proximal to the treatment element of a treatment device.

In some embodiments, the sensors/electrodes1504can be arranged into one or more groups1505A,1505B,1505C of sensors/electrodes1504. For example, multiple sensors/electrodes1504can be located at approximately the same distance from the cap1506such that a group (e.g., groups1505A,1505B,1505C) of sensors/electrodes1504form a ring. In such an embodiment, when the treatment element of a treatment device is enlarged (as shown inFIGS.15B,15C), the group1505A,1505B,1505C of sensors/electrodes1504can form a ring around a particular portion of the treatment element, such as a particular circumference or perimeter around the treatment element. In the illustrated embodiment ofFIG.15, the sensor/electrodes1504are arranged into three groups1505A,1505B,1505C. The sensor/electrodes1504within a group1505A,1505B,1505C can be the same type of sensor/electrode1504and/or a combination of different sensor/electrodes1504.

Furthermore, in some embodiments, one group of sensor/electrodes1504can be offset with respect to a proximate group of sensor/electrodes1504. For example, in the illustrated embodiment ofFIG.15, the group1505A of sensor/electrodes1504is offset with respect to the group1505B of sensor/electrodes1504such that if all of the sensor/electrodes1504of groups1505A,1505B were on the same axis, the sensor/electrodes1504from group1505B would be in between the sensor/electrodes1504of group1505A. In certain embodiments, the groups of sensor/electrodes1504are not offset, such that if all of the sensor/electrodes1504were on the same axis, a sensor/electrode1504from group1505B would be co-located with a sensor/electrode1504of group1505A.

The cap1506can be coupled with a distal portion of the mesh1502. In some embodiments, a distal portion of the wires1503can be coupled to the cap1506. For example, an end of each wire1503can be may be adhered or bonded to the cap1506using a biocompatible adhesive, bonding agent, welding, soldering, crimping, etc. As yet another example, a portion of the wire1503, such as an end or middle portion, can be wound around the cap1506or inserted through a hole in the cap1506. In some embodiments, the cap1506can provide electrical connections between wires1503to enable a completed circuit to be formed for each sensor/electrode1504. In some cases, the cap can include an inner lumen large enough to fit a guidewire. For example, the inner lumen can be between 0.032″-0.035″ in diameter. It will be understood that lumen's diameter can be other widths as well.

In certain embodiments, the cap1506can include an inner portion and an outer portion. The inner portion can be used to couple the cap1506to the mesh1502and to the treatment device. The outer portion can cover the inner portion to protect the interconnections from the environment and can have an atraumatic shape to avoid damaging the tissue when inserted into a patient. In some embodiments, the cap1506can include a central lumen1512. The central lumen1512can be sized for a guidewire or portion of a treatment device. In some embodiments, the central lumen1512can include a sphincter that can be broken when the treatment device is inserted.

In addition, the cap1506can be coupled with a distal end of the treatment device. For example, the cap1506can include a protrusion or indentation that can be used to engage with the treatment device to prevent unwanted relative movement between the mapping overlay and the treatment device when the treatment device is in use. In some cases, an interior portion of the cap1506can include threads that can engage with a distal end of the treatment device. The cap1506and the treatment device can be disengaged by twisting and/or pulling the two apart.

The body1508can be made of one or more layers of polymer or other flexible material. In some embodiments, the body1508can be coupled with a proximal portion or middle portion of the mesh1502. For example, as described above, the body1508can include one or more inner layers of polymer and one or more outer layers of polymer and a portion of the mesh1502can be located between the inner/outer layer(s).

In certain embodiments, a proximal portion or middle portion of the mesh1502can be located within the body1508and/or sandwiched between layers of the body1508. In some cases, the mesh1502can extend at least along the length of the body1508within the sheath1510. In some embodiments, the mesh1502can extend beyond a distal end of the body1508, as illustrated inFIG.15A. Furthermore, the mesh1502can extend beyond a proximal end of the body1508(not shown).

The outer portion of the body1508can be coated in Teflon, hydrogel, or other lubricious material, to reduce the amount of friction between the body1508and an outer sheath1510. In certain embodiments, the body1508can also include a junction box for receiving the electrical signals from the sensors. The junction box can be located at a proximal end of the body1508that is not inserted into a patient during a procedure.

When the mesh1502expands either passively or actively, its length can decrease. In some embodiments, as the length decreases, the body1508can be pulled towards the cap1506.

FIGS.15B and15Care diagrams illustrating the mesh1502of the mapping overlay1501in an expanded state, which can be caused by the enlargement of a treatment element of a treatment device. As described above, in the expanded state, the sensor groups1505A,1505B,1505C can form a ring around different portions of the treatment element of the treatment device.FIGS.15B and15Cfurther illustrate the helical nature of the windings of the wires1503and the coupling between a sensor1504and a wire1503.

FIGS.16A-16Care diagrams illustrating embodiments of the mapping overlay1501and a treatment device1602in different configurations and positions. The treatment device1602can be similar to the treatment devices312,404,504described previously and can include a treatment element1604to treat a target site.

In some embodiments, the mapping overlay1501and treatment device1602can be implemented as part of a single catheter. In certain embodiments, the mapping overlay1501and the treatment device1602can be implemented as separate devices, such as two distinct catheters and/or a sheath and a catheter. For example, the mapping overlay1501can be sized such that the treatment device1602fits within an inner lumen of the mapping overlay1501.

In the illustrated embodiment ofFIG.16A, the sheath1510is shown with the cap1506of the mapping overlay1501protruding from a distal portion thereof. The illustrated configuration ofFIG.16Acan represent a scenario in which the sheath1510has been placed at a target site or proximate to a target site and the mapping overlay1501and/or the treatment device1602have been guided to the target site by the guidewire1606through the sheath1510. For example, in a cardiac ablation procedure, the sheath1510can be inserted near the groin and follow the femoral vein and inferior vena cava to the heart and the mapping overlay1501and treatment device1602can be inserted inside the sheath1501and follow the sheath1501to the heart. A non-limiting example of a sheath is the FlexCath® Steerable Sheath available from Medtronic. Destino Twist® deflectable steerable guiding sheath from Oscor; Agilis NXT steerable introducer sheath from St. Jude; etc.

In the illustrated embodiment ofFIG.16B, the mapping overlay1501and the treatment device1602are visible protruding from the sheath1510. The configuration illustrated inFIG.16Bcan represent a scenario in which a user is preparing to treat the target site. In the illustrated embodiment, the treatment device1602including the treatment element1604is visible within the mesh1502of the mapping overlay1501. As described in greater detail above, the treatment element1604can be used to treat the target site using RF, HIFU, laser, hot balloon, and/or cryotherapy. In some embodiments, the mapping overlay1501can be sized such that it generally extends across the entire length of the treatment element1604.

In the illustrated embodiment ofFIG.16C, the treatment element1604of the treatment device1602is shown in an expanded state. The configuration illustrated inFIG.16Ccan represent a scenario in which a user has filled the treatment element with a gas in preparation for treating the target site. In such a configuration, the mapping overlay1501can be used to map the target site and/or to monitor the effect of treatment on the target side, as described in greater detail above. As a non-limiting example, the sensor/electrodes1504can be used to pace tissue at the target site, such as a phrenic nerve, monitor a temperature at the target site, etc.

As illustrated in theFIG.16C, when the treatment element1604is enlarged, the mesh1502in the area of the treatment element can expand as well. The expansion of the mesh1502where the treatment element1604portion can induce a force on the remaining portion of the mesh1502which can pull the body1508further out from the sheath1510. Accordingly, in some embodiments, the interior of the sheath1510and the exterior of the body1508can be constructed to have a low friction coefficient such that the body1508can slide with relative ease when treatment element1604is expanded.

Furthermore, as described in greater detail above, the wires1503of the mesh1502can be constructed to achieve a particular level of pliability such that when the treatment element1604is deflated, the mesh1502can retain its expanded shape. In such an embodiment, the mesh1502can retain the expanded shape until pulled inside the sheath1510. The force exerted on the mesh1502by the sheath1510can flatten the mesh1502back to a predetermined shape or similar to a predetermined shape. It will be understood, however, that the mesh1502can be constructed so that when the treatment element is reduced in size and/or removed, the mesh1502can return to its predetermined shape or similar thereto

In some embodiments, the mapping overlay1501and treatment device1602can be placed within an outer sheath and can be independently operated. For example, the mapping overlay1501can be independently moved. Similarly, the treatment device1602and treatment element1604can be independently moved, collapsed, and/or expanded as desired.

Although described above as being distinct from the treatment device1602, it will be understood that in some embodiments, the mapping overlay1502can be permanently affixed to or form part of the treatment device1602. For example, the mapping overlay1502can form part of an integrated treatment device, similar to integrated treatment devices1102,1202,1302, described in greater detail above. In such embodiments, the treatment device can include the treatment element1604, the mesh1502and/or the sensors1504. In addition, the mapping overlay can be used in any one or any combination of the routines700,800, and/or1400described above.

Furthermore, it will be understood that the various embodiments described herein can be combined in any fashion. For example, a mapping overlay can be used in conjunction with any one or any combination of the treatment device embodiments.

Various example embodiments of the disclosure can be described in view of the following clauses:Clause 1. A method for ablating tissue, the method comprising:activating one or more electrodes of a mapping device to stimulate non-targeted tissue proximate a target tissue site;determining a location of at least a proximal portion of the non-targeted tissue based at least in part on said activating;determining a risk level associated with treatment of the target tissue site based at least in part on the determined location of the proximal portion of the non-targeted tissue; andtreating tissue at the target tissue site using a treatment device based at least in part on the determined risk level.Clause 2. The method of clause 1, wherein the non-targeted tissue comprises a phrenic nerve, the target tissue site comprises a pulmonary vein, the treating comprises ablating the tissue, and the treatment device comprises an ablation device.Clause 3. The method of any of clauses 1 and 2, wherein the proximal portion of the phrenic nerve comprises the portion of the phrenic nerve that is closest to a junction of a pulmonary vein and left atrium.Clause 4. The method of any of clauses 1-3, wherein the electrodes are located on an exterior portion of the treatment device.Clause 5. The method of any of clauses 1-4, wherein the mapping device forms at least a portion of a mapping catheter and the treatment device forms at least a portion of an ablation catheter that is distinct from the mapping catheter.Clause 6. The method of any of clauses 5, wherein at least a portion of the ablation catheter is positioned within a lumen of the mapping catheter.Clause 7. The method of any of clauses 1-6, wherein the mapping device comprises a mesh of braided wires and the one or more electrodes comprises a plurality of electrodes coupled to the braided wires.1. The method of any of clauses 1-7, wherein the mapping device further comprises a body, the body comprising:one or more inner layers, andone or more outer layers,wherein at least a portion of the braided wires is located between the one or more inner layers and the one or more outer layers, and the braided wires extends past a distal end of the body.Clause 8. The method of any of clauses 1-8, wherein the mapping device further comprises a cap coupled to a distal end of the mesh of braided wires.Clause 9. The method of any of clauses 1-9, wherein the treatment device comprises a cryoablation balloon and the electrodes are located on the exterior of the cryoablation balloon.Clause 10. The method of any of clauses 1-10, wherein said activating comprises sequentially activating the one or more electrodes along a perimeter of the mapping device.Clause 11. The method of any of clauses 1-11, wherein said activating comprises sequentially activating the one or more electrodes along a wire of the mapping device.Clause 12. The method of clause 5, wherein at least a portion of the mapping catheter is positioned within a lumen of the ablation catheter.Clause 13. The method of any of clauses 1-13, further comprisingdetermining a location of the mapping device timed to a particular portion of an anatomical cycle; anddetermining a location of the ablation device timed to the particular portion of the anatomical cycle, wherein the risk level is further determined based at least in part on the determined location of the mapping device and the ablation device timed to the particular portion of the anatomical cycle.Clause 14. A method for ablating tissue, the method comprising:providing a mapping device at a first tissue location proximate an atrium of a heart of a patient;sequentially activating one or more electrodes of the mapping device to pace a phrenic nerve;determining a location of a most proximal portion of the phrenic nerve to the atrium based at least in part on said activating and on monitoring a diaphragmatic contraction of the patient;providing a treatment device at the first tissue location based at least in part on the determined location of the most proximate portion of the phrenic nerve; andablating tissue at the first tissue location based at least in part on a determination that an active region of the treatment device satisfies a distance threshold with respect to the most proximal portion of the phrenic nerve.Clause 15. A mapping catheter comprising:a mapping device, comprising:a plurality of wires, anda plurality of electrodes, at least one electrode located on each tine; anda control device, wherein the control device is configured to alter a configuration of the mapping device between a collapsed configuration, an expanded configuration, and a treatment configuration.Clause 16. The mapping catheter of clause 16, wherein the control device is coupled to a runner that advances or retracts based at least in part on movement of the control device, and wherein at least a portion of each tine is coupled to the runner.Clause 17. A treatment device, comprising:a treatment element; anda mapping portion including a plurality of sensors located on an exterior portion of the treatment element.Clause 18. The device of clause 18, wherein the treatment element comprises a proximal balloon and a distal balloon that is smaller than the proximal balloon.Clause 19. The device of any of clauses 18 and 19, wherein the plurality of sensors are located on an exterior portion of the proximal balloon and the distal balloon.Clause 20. The device of clause 19, wherein the treatment element further comprises a third balloon that encapsulates the proximal balloon and the distal balloon.Clause 21. The device of any of clauses 19-21, wherein the proximal balloon and the distal balloon are independently inflatable/deflatable.Clause 22. The device of any of clauses 19-22, wherein the proximal balloon and the distal balloon are independently fillable with a cooling agent or a warming agent.Clause 23. The device of any of clauses 1-23, wherein the proximal balloon comprises a plurality of segments.Clause 24. The device of clause 24, wherein each of the plurality of segments are independently fillable with a cooling agent or a warming agent.Clause 25. The device of any of clauses 18-25, wherein the plurality of sensors comprise at least one of a pacing/sensing electrode, a radiofrequency electrode, a flow sensor, a temperature sensor, an optical sensor, or a force sensor.Clause 26. The device of any of clauses 18-26, wherein the plurality of sensors comprise a plurality of electrodes configured to provide an electrical pulse to determine a location of a phrenic nerve and different portions of the treatment element are activated based at least in part on the determined location of the phrenic nerve.Clause 27. A method for placing catheters, the method comprising:providing a first medical device at a first tissue location of a patient timed to a particular portion of an anatomical cycle of the patient;performing a first medical diagnostic and/or procedure with the first medical device;moving the first medical device to a second location;providing a second medical device at the first tissue location timed to the particular portion of the anatomical cycle; andperforming a second medical diagnostic and/or procedure with the second medical device.Clause 28. The method of clause 28, wherein moving the first medical device comprises removing the first medical device from a patient.Clause 29. The method of any of clauses 28 and 29, further comprising imaging the first medical device at the first tissue location timed to the particular portion of the anatomical cycle.Clause 30. A method for ablating tissue, the method comprising:providing a mapping device at a first tissue location within a heart of a patient;determining a location of the mapping device at the first tissue location timed to a particular portion of a respiration cycle of the patient;determining a location of a phrenic nerve of the patient using the mapping catheter;moving the mapping device to a second location;providing a treatment balloon at the first tissue location;determining a location of the treatment balloon at the first tissue location timed to the particular portion of the respiration cycle of the patient; andablating tissue at the first tissue location based at least in part on a determination that an active region of the treatment balloon satisfies a distance threshold with respect to the phrenic nerve when timed to the particular portion of the respiration cycle of the patient.Clause 31. The method of clause 31, further comprising displaying the location of the phrenic nerve on an image of the first tissue location timed to the particular portion of the respiration cycle of the patient, wherein the determination that the cryoablation balloon is proximal to the phrenic nerve with respect to the catheter is based at least in part on a comparison of the determined location of the phrenic nerve with respect to the determined location of the cryoablation balloon.Clause 32. A mapping overlay for a treatment device, the mapping overlay comprising:a mesh of wires; anda plurality of sensors coupled to the mesh of wires, wherein the mesh of wires forms a lumen for a treatment device.Clause 33. The mapping overlay of clause 33, wherein the plurality of sensors comprise at least one of a temperature sensor or a pacing electrode.Clause 34. The mapping overlay of any of clauses 33 and 34, wherein the plurality of sensors are grouped into two or more rings of sensors.Clause 35. The mapping overlay of clause 35, wherein, sensors of at least one ring of the two or more rings of sensors are equidistant from a distal end of the mesh of wires.Clause 36. The mapping overlay of any of clauses 33-36, wherein each of the wires is coated with an electrical insulator.Clause 37. The mapping overlay of any of clauses 33-37, wherein the wires are braided.Clause 38. The mapping overlay of any of clauses 33-38, wherein the wires are wound helically.Clause 39. The mapping overlay of any of clauses 33-39, further comprising a cap coupled to a distal end of the mesh of wires.Clause 40. The mapping overlay of any of clauses 33-40, wherein the cap comprises an inner cap and an outer cap and the distal end of the mesh of wires is coupled to the inner cap.Clause 41. The mapping overlay of any of clauses 33-41, wherein the cap comprises a lumen for a guidewire.Clause 42. The mapping overlay of any of clauses 33-42, further comprising a body comprising one or more inner layers and one or more outer, wherein at least a portion of the mesh of wires is located between the one or more inner layers and the one or more outer layers.Clause 43. The mapping overlay of any of clauses 33-43, wherein the one or more inner layers and the one or more outer layers comprise a polymer.Clause 44. The mapping overlay of any of clauses 33-44, wherein the mesh of wires passively expands in response to a force applied thereto by an expanding treatment element of a treatment device.Clause 45. The mapping overlay of any of clauses 33-45, wherein when the force applied to the mesh of wires by the expanding treatment element dissipates, the mesh of wires retains a deformed shape.Clause 46. The mapping overlay of any of clauses 33-42 and 45-46, further comprising a body coupled to a proximal portion of the mesh of wires.Clause 47. The mapping overlay of clause 43, 44, or 47, wherein as the mesh of wires expands in response to the force applied thereto by the expanding treatment element, the body is pulled towards the cap.Clause 48. The mapping overlay of any of clause 43, 44, 47 and 48, wherein the mesh of wires extends across a length of the body and extends beyond a distal end of the body.Clause 49. The mapping overlay of clause 43, 44, and 47-49, wherein the mesh of wires extends beyond a proximal end of the body.Clause 50. The mapping overlay of any of clauses 33-50, wherein the mesh of wires comprises a plurality of conductor wires and a plurality of structural wires that are made from a different material than the plurality of conductor wires, and wherein the plurality of sensors are coupled to the plurality of conductor wires.Clause 51. The mapping overlay of any of clauses 33-51, wherein the mesh of wires forms a tubular structure.Clause 52. A treatment device, comprising:a mesh of wires forming a perimeter of a lumen;a plurality of sensors coupled to the mesh of wires, andan expandable treatment element located within the lumen.Clause 53. The treatment device of clause 53, wherein the expandable treatment element comprises multiple segments.Clause 54. The treatment device of clause 54, wherein the multiple segments comprise a distal segment and a proximal segment.Clause 55. The treatment device of any of clauses 53-55, wherein the plurality of sensors comprise at least one of a temperature sensor or a pacing electrode.Clause 56. The treatment device of any of clauses 53-56, wherein the plurality of sensors are grouped into two or more rings of sensors.Clause 57. The treatment device of clause 57, wherein, sensors of at least one ring of the two or more rings of sensors are equidistant from a distal end of the mesh of wires.Clause 58. The treatment device of any of clauses 53-58, wherein each of the wires is coated with an electrical insulator.Clause 59. The treatment device of any of clauses 53-59, wherein the wires are braided.Clause 60. The treatment device of any of clauses 53-60, wherein the wires are wound helically.Clause 61. The treatment device of any of clauses 53-61, further comprising a cap coupled to a distal end of the mesh of wires.Clause 62. The treatment device of clause 63, wherein the cap comprises an inner cap and an outer cap and the distal end of the mesh of wires is coupled to the inner cap.Clause 63. The treatment device of any of clauses 62 and 63, wherein the cap comprises a lumen for a guidewire.Clause 64. The treatment device of any of clauses 53-64, further comprising a body coupled a proximal portion of the mesh of wires.Clause 65. The treatment device of any of clauses 53-65, further comprising a body comprising one or more inner layers and one or more outer, wherein at least a portion of the mesh of wires is located between the one or more inner layers and the one or more outer layers.Clause 66. The treatment device of any of clauses 53-66, wherein the one or more inner layers and the one or more outer layers comprise a polymer.Clause 67. The treatment device of any of clauses 53-67, wherein the mesh of wires passively expands in response to a force applied thereto by an expanding treatment element of a treatment device.Clause 68. The treatment device of clause 68, wherein when the force applied to the mesh of wires by the expanding treatment element dissipates, the mesh of wires retains a deformed shape.Clause 69. The treatment device of any of clauses 53-65, 68, and 69, further comprising a body coupled to a proximal portion of the mesh of wires.Clause 70. The treatment device of clause 66, 67, and 70, wherein as the mesh of wires expands in response to the force applied thereto by the expanding treatment element, the body is pulled towards the cap.Clause 71. The treatment device of any of clause 66, 67, 70 and 71, wherein the mesh of wires extends across a length of the body and extends beyond a distal end of the body.Clause 72. The treatment device of clause 66, 67, and 70-72, wherein the mesh of wires extends beyond a proximal end of the body.Clause 73. The treatment device of clause 73, wherein the mesh of wires comprises a plurality of conductor wires and a plurality of structural wires that are made from a different material than the plurality of conductor wires, and wherein the plurality of sensors are coupled to the plurality of conductor wires.Clause 74. A mapping overlay of a mapping catheter, the mapping overlay comprising:a mesh of wires located forming a lumen for a treatment device, the mesh of wires comprising:a plurality of conductor wires, anda plurality of structural wires formed of a different material than the plurality of conductor wires, wherein the plurality of conductor wires and the plurality of structural wires are braided to form the mesh of wires;a plurality of sensors coupled to the plurality of conductor wires;a cap coupled to a distal end of the mesh of wires; anda body coupled to the mesh of wires, the body comprising:one or more inner layers, andone or more outer layers,wherein at least a portion of the mesh of wires is located between the one or more inner layers and the one or more outer layers, and the mesh of wires extends past a distal end of the body.Clause 75. The mapping overlay of clause 75, wherein the plurality of sensors comprise at least one of a temperature sensor or a pacing electrode.Clause 76. The mapping overlay of any of clauses 75 and 76, wherein the plurality of sensors are grouped into two or more rings of sensors.Clause 77. The mapping overlay of clause 77, wherein, sensors of at least one ring of the two or more rings of sensors are equidistant from a distal end of the mesh of wires.Clause 78. The mapping overlay of any of clauses 75-78, wherein each of the plurality of conductor wires is coated with an electrical insulator.Clause 79. The mapping overlay of any of clauses 75-79, wherein the wires are wound helically.Clause 80. The mapping overlay of any of clauses 75-80, wherein the cap comprises an inner cap and an outer cap and the distal end of the mesh of wires is coupled to the inner cap.Clause 81. The mapping overlay of any of clauses 75-81, wherein the cap comprises a lumen for a guidewire.Clause 82. The mapping overlay of any of clauses 75-82, wherein the one or more inner layers and the one or more outer layers comprise a heat shrunk polymer.Clause 83. The mapping overlay of any of clauses 75-83, wherein the mesh of wires passively expands in response to a force applied thereto by an expanding treatment element of a treatment device.Clause 84. The mapping overlay of any of clauses 75-84, wherein when the force applied to the mesh of wires by the expanding treatment element dissipates, the mesh of wires retains a deformed shape.Clause 85. The mapping overlay of clause 75-85, wherein as the mesh of wires expands in response to the force applied thereto by the expanding treatment element, the body is pulled towards the cap.Clause 86. The mapping overlay of any of clauses 75-86, wherein the mesh of wires forms a tubular structure.

Additional Embodiments

While the examples above have been described with respect to the treatment of atrial fibrillation, it will be understood that the devices, systems, and methods described herein can be used in a variety of applications where it is desirable to place two medical devices in the same location at different times and the location moves based on an anatomical cycle. For example, a first medical device can be placed at a particular location and its location can be determined with reference to a particular portion of an anatomical cycle, such as end exhalation. The first medical device can be removed and/or moved and a second medical device can be placed in approximately the same location as the first medical device. The location of the second medical device can be determined with respect to the same portion of the anatomical cycle. In this way, a provider can better determine whether the two medical devices are placed at the same location at different times.

Furthermore, reference is made throughout to various catheters that can be used to map and/or treat tissue. It will be understood that the catheters and sheaths described herein can be made of any one or a combination of polymers, including, but not limited to, silicone rubber, nitinol, nylon, polyurethane, polyethylene terephthalate (PET), latex, and thermoplastic elastomers as desired. In addition, the treatment elements and/or balloons described here can be made of polyurethane or other flexible and biocompatible material.