Patent Description:
Currently, the standard pacing therapy for patients with AV conduction disease and requiring ventricular pacing, is to place a transvenous lead through the tricuspid valve and into the right ventricle (RV). This RV lead paces the ventricular myocardium which causes a cell by cell slow wave depolarization across the ventricles. This "cell by cell" depolarization of the ventricles utilizing a lead in the right ventricles causes the ventricles to contract in an unnatural way. With conventional RV pacing, the activation sequence of the ventricles is not the same as natural AV conducted contractions, with the right ventricle to depolarizing first and the left ventricle depolarizing slightly after. When patients are right ventricularly (RV) paced at a high percentage, there is an alarming progression of cardiac heart failure and pacing-induced cardiomyopathy. Pacing-induced cardiomyopathy (PICM) is most commonly thought of as a drop in left ventricular ejection fraction (LVEF) in the setting of chronic, high burden right ventricular (RV) pacing. It has been reported that about <NUM>% of patients develop PICM after <NUM> to <NUM> years of RV pacing. These negative effects are thought to be a direct result of the unnatural contraction dynamics and resultant ventricular dyssynchrony resulting from RV pacing.

His Bundle Pacing (HBP) has emerged as an alternative to traditional RV pacing. By directly pacing the His bundle, HBP engages electrical activation of both ventricles by means of the cardiac Purkinje fiber network through the natural cardiac conduction system. This type of cardiac pacing may avoid ventricular dyssynchrony and preserve cardiac ejection fraction. Recent studies have also demonstrated the potential of HBP in correcting an underlying left bundle branch block and reversing cardiomyopathy caused by traditional RV pacing. HBP holds promise as an attractive mode to achieve physiological pacing. Widespread adaptation of this technique is dependent on enhancements in technology.

The His bundle lies in most people within the membranous portion of the interventricular septum, with a proportion of the proximal bundle lying on the right atrial portion of the septum, superior to the tricuspid valve annulus. The His bundle is surrounded by fibrous connective tissue rather than myocardium, and then enters the muscular septum and divides to form the right and left bundles. It has been demonstrated that transvenous HBP could reduce QRS duration and normalize electrocardiographic appearances in patients with bundle branch block. There is currently widespread consensus regarding the benefits of HBP and enthusiasm that this therapy may improve patient outcomes.

The current procedural method of achieving HBP involves employing a lead with a fixed screw helix for fixation and one of two catheters to achieve lead position. The fixed helix pacing lead is advanced past the distal end of the catheter while manual catheter manipulation and unipolar mapping utilizing the exposed helix is preformed to locate the His bundle potential signal. Care must be taken when mapping inside the heart with the exposed fixed helix. This helix is fully exposed and can cause local intracardiac surface edema while surface mapping which can mask the His bundle potential. The process of mapping with the exposed helix can often create an acute bundle branch block which may or may not resolve with time. Another pitfall to avoid is the potential for tissue to become stuck in the exposed lead helix which prevents adequate mapping and fixation of the lead helix. The target region for HBP is relatively robust and the current catheters are rather flimsy, which avoids the potential for catheter perforation, although the risk of perforation is possible if the catheter is advanced unintentionally into the incorrect position.

The adoption of HBP has been hindered by the procedural difficulty of achieving good lead position without causing cardiac damage or perforation. The procedural success rates are much lower when compared to traditional RV pacing procedures due to the difficulty in mapping the His potential with the exposed helix and maintaining position while the pacing helix is fixated. The tools currently employed are currently simplistic and lacking the ability to adjust to varying anatomical differences or accurately maintain position within the beating heart during the implant procedure.

<CIT> discloses a multidirectional balloon tipped catheter system.

Embodiments of the disclosed invention provide a solution through a multidirectional balloon tipped catheter with sensing capability and will lead to increased procedural success and more widespread adoption of His Bundle Pacing (HBP) that has not been used prior and solves this problem.

These advantages and others are achieved, for example, by a multidirectional balloon tipped catheter system for conducting His bundle sensing and pacing. The catheter system includes a multidirectional catheter body having a proximal end and a distal end. The catheter body includes a plurality of curls and flexion points for multidirectional deflections. The catheter body further includes a plurality of lumens which include a pacing lead lumen including an exit port at the distal end and at least one balloon lumen including a balloon port near the distal end. The catheter system further includes an anchor balloon mounted to near the distal end of the catheter body, one or more mapping electrodes mounted to the distal end portion of the catheter body, and a pacing lead placed in the pacing lead lumen. The anchor balloon is in fluid communication with the balloon port and overhangs the distal end of the catheter body by a predetermined distance when the anchor balloon is inflated. The one or more mapping electrodes are configured to sense His bundle potential. The pacing lead is configured to protrude beyond the distal end of the catheter body when the pacing lead is in use.

The anchor balloon may be inflated with a fluid including air, saline, or contrast, and may be configured to be inflated in various sizes. The anchor balloon may be configured to expose the one or more mapping electrodes when the anchor balloon is deflated. The anchor balloon may overhang the distal end of the catheter body by two to three millimeters when the anchor balloon is inflated. The anchor balloon is a hydrophilic balloon.

The one or more mapping electrodes may include a first mapping electrode disposed at the distal end of the catheter body and a second mapping electrode disposed on the catheter body and spaced apart from the first mapping electrode. The first and second mapping electrodes may form a bipolar sensor. A diameter of the pacing lead lumen may be equal to or greater than <NUM>. A distance of a distal end of the anchor balloon from the distal end of the catheter body may be in a range of <NUM> to <NUM> when the anchor balloon is deflated. The pacing lead may include a screw helix. The catheter body may be configured to be insertable into a subclavian vein or other vascular access to approach His bundle. The plurality of lumens may further include one or more wiring lumens that house electrical wires connected to the one or more mapping electrodes.

These advantages and others are achieved, for example, by a method for conducting His bundle sensing and pacing with a multidirectional balloon tipped catheter system including a multidirectional catheter body. The method includes inserting the catheter system into a subclavian vein or vascular access, guiding the catheter system towards His bundle, sensing His bundle potential with one or more mapping electrodes disposed near the distal end of the catheter body, positioning a distal end of the catheter body at a location of the His bundle that is determined to be appropriate for pacing, anchoring the distal end of the catheter body at the appropriate location with inflated anchor balloon, and implanting a pacing lead into the appropriate location of the His bundle. The catheter system includes the anchor balloon mounted to the distal end portion of the catheter body, and the anchor balloon is inflated with a fluid supplied through at least one balloon lumen formed in the catheter body. The pacing lead is disposed in a pacing lead lumen formed in the catheter body and advances beyond the distal end of the catheter body while being implanted into the appropriate location of the His bundle.

The preferred embodiments described herein and illustrated by the drawings hereinafter be to illustrate and not to limit the invention, where like designations denote like elements.

The following detailed description is merely exemplary in nature and is not intended to limit the described embodiments or the application and uses of the described embodiments. As used herein, the word "exemplary" or "illustrative" means "serving as an example, instance, or illustration. " Any implementation described herein as "exemplary or "illustrative" is not necessarily to be construed as preferred or advantageous over other implementations. All of the implementations described below are exemplary implementations provided to enable persons skilled in the art to make or use the embodiments of the disclosure and are not intended to limit the scope of the disclosure, which is defined by the claims. It is also to be understood that the specific devices and processes illustrated in the attached drawings, and described in the following specification, are simply exemplary embodiments of the inventive concepts defined in the appended claims.

With reference to <FIG> shown are an embodiment of multidirectional balloon tipped catheter system <NUM> of the disclosed invention for sensing His bundle and positioning pacing lead. With reference to <FIG> shown are side views of the distal end portion of the multidirectional balloon tipped catheter system <NUM>. With reference to <FIG>, shown is a cross-sectional view of the section A-A' of the distal end portion of the multidirectional balloon tipped catheter system <NUM>.

The multidirectional balloon tipped catheter system <NUM> includes a multidirectional or deflectable flexible catheter body <NUM> that includes a proximal end <NUM> and a distal end <NUM>. The catheter body <NUM> is French sizes, and includes curls and flexion points to be multidirectional or deflectable. For example, the catheter body <NUM> may include a plurality of flexion points <NUM>, <NUM> to facilitate the multidirectional deflections or bending. The catheter body <NUM> has a length sufficient to reach a selected location in a patient's cardiac structures. The catheter body <NUM> is configured to be insertable into a subclavian vein or other vascular access to approach His bundle. The catheter body <NUM> includes a plurality of lumens. The plurality of lumens include at least a wire lumen <NUM> for cord <NUM> connected to a pacing lead <NUM>. The wire lumen <NUM> includes a wire access port (not shown) accessible to an operator at said catheter proximal <NUM> end and a wire exit port 111a at said flexible catheter distal end <NUM>, and a balloon lumen <NUM> for inflating and deflating at least one anchor balloon <NUM>. The balloon lumen <NUM> includes a balloon control port (not shown) for connecting to balloon control device accessible to an operator at the catheter proximal end <NUM> and a balloon port 114a near the multidirectional catheter distal end <NUM>. The plurality of lumens may further include other lumens such as lumens <NUM>, <NUM> for wires <NUM>, <NUM> connected to mapping electrodes <NUM>, <NUM>.

The multidirectional balloon tipped catheter system <NUM> includes compliant or non-compliant anchor balloon <NUM> that is mounted on the multidirectional catheter body <NUM> near the distal end <NUM> of the catheter body <NUM>. <FIG> and <FIG> show deflated anchor balloon <NUM>, and <FIG> and <FIG> show inflated anchor balloon <NUM> at the distal end <NUM> portion of catheter body <NUM>. The anchor balloon <NUM> is connected to the balloon port 114a of the catheter body <NUM>, and is in fluid communication through the balloon lumen <NUM>. Fluid, which is injected or removed at the balloon control port at the proximal end <NUM>, inflates or deflates the anchor balloon <NUM> through the balloon lumen <NUM>.

The anchor balloon <NUM> may be inflated with air, saline, contrast and other solutions, and may be inflated to various sizes. The anchor balloon <NUM> is placed at a selected distance from the distal end <NUM> of the catheter body <NUM>. For example, when the anchor balloon <NUM> is deflated, the distance L1 of a distal end of the anchor balloon <NUM> from a distal end <NUM> of the catheter body <NUM> may be in the range <NUM> (<NUM> inches) to <NUM> (<NUM> inches). When the anchor balloon <NUM> is inflated, the anchor balloon <NUM> may overhang the distal end <NUM> of the catheter body <NUM> by a distance L2 which may be two to three millimeters.

The multidirectional balloon tipped catheter system <NUM> includes at least one mapping electrode <NUM> near the distal end <NUM> of the catheter body <NUM>. The mapping electrode <NUM> allows atraumatic mapping of the His bundle potential. The mapping electrode <NUM> works as a unipolar sensor for detecting and mapping the His bundle potential. In another embodiment, the catheter system <NUM> may include second mapping electrode <NUM> that is placed a few millimeters behind the first mapping electrode <NUM> (toward proximal end <NUM>). In this configuration, mapping electrodes <NUM>, <NUM> together work as a bipolar sensor for atraumatic mapping of the His bundle potential, making bipolar sensing possible. The anchor balloon <NUM> is configured such that the mapping electrode <NUM> is exposed at the distal end <NUM> of the catheter body <NUM> when the anchor balloon <NUM> is deflated so that mapping the His bundle potential may be performed by using the electrode <NUM> and/or electrodes <NUM>, <NUM> to find an appropriate location of the heart tissue <NUM> for His bundle pacing.

The catheter body <NUM> may include wiring lumens <NUM>, <NUM> that house electrical wires <NUM>, <NUM> connected to the mapping electrodes <NUM>, <NUM>. The wires <NUM>, <NUM> at the proximal end <NUM> of the catheter body <NUM> may be coupled to an external device that may send signals to or receive signals from the mapping electrodes <NUM>, <NUM>.

The multidirectional balloon tipped catheter system <NUM> includes pacing lead <NUM> that is connected to cord <NUM> disposed in the lumen <NUM>. The catheter body <NUM> includes pacing lead lumen <NUM> that includes a cord access port (not shown) accessible to an operating device at the proximal end <NUM> and exit port 111a at the distal end <NUM> of the catheter body <NUM>. The pacing lead lumen <NUM> may be positioned at a center of the cross-section of the catheter <NUM> as shown in <FIG>. The diameter of the pacing lead lumen <NUM> may be equal to or greater than <NUM> (<NUM> inches). The pacing lead <NUM> may be placed inside the pacing lead lumen <NUM> while mapping His bundle potential and positioning the catheter system <NUM> against heart tissue <NUM>. The pacing lead <NUM> may advance out of the pacing lead lumen <NUM> beyond the distal end <NUM> of the catheter body <NUM> to be placed or implanted on the heart tissue <NUM>. The pacing lead <NUM> may have a form of screw helix. <FIG> and <FIG> show the pacing lead <NUM> advancing out of the distal end <NUM> of the catheter body <NUM>.

The anchor balloon <NUM> may be used in an atraumatic fashion over cardiac structures. The anchor balloon <NUM> may glide over the cardiac structures, while sensing is performed by using the mapping electrodes <NUM>, <NUM> to obtain the best site for lead implantation. Once an appropriate location of the heart tissue <NUM> is determined for His bundle pacing, the catheter system <NUM> is used as a conduit for implantation of the pacing lead <NUM>. The anchor balloon <NUM> may be inflated to anchor the distal end <NUM> of the catheter body <NUM> at the appropriate location of the heart tissue <NUM>. When the distal end <NUM> of the catheter body <NUM> with the inflated anchor balloon <NUM> is positioned and stabilized at the location, the pacing lead <NUM> may be advanced to be implanted in the heart tissue <NUM>. Once the pacing lead <NUM> is in place, the catheter body <NUM> may be removed using multiple methods which may include slitting and splitting the catheter body, or may be removed by methods that are general practices for lead implantation.

With reference now to <FIG>, shown is an exemplary embodiment of a mechanical deflection device <NUM> that can be employed at the proximal end <NUM> portion of the catheter body <NUM> to control deflections of the distal end portion of the catheter system <NUM>. Mechanical deflection mechanism may enable distal end of catheter body <NUM> to be deflected or angulated to various angles with respect to a longitudinal axis (from the proximal end <NUM> to the distal end <NUM>) of the catheter system <NUM>. Mechanical deflection device <NUM> may include a pull wire anchor <NUM> affixed to the catheter body <NUM> and pull wire actuator <NUM> connected to pull wire anchor <NUM> with pull wire (not shown). Rotation of pull wire actuator <NUM>, as shown, may exert force on pull wire anchor <NUM> that deflects or angulates distal end of the catheter body <NUM>. Pull wire actuator <NUM> may be rotated by handle connected thereto (not shown). The deflection device <NUM> together with the flexion points and curls formed in the catheter body <NUM> enables the catheter body <NUM> to easily navigate over heart structures. <CIT> by the same inventor discloses an improved handle that can be used for the catheter system <NUM> of the disclosed invention to provide deflections.

With reference to <FIG>, shown is a workflow diagram for a method <NUM> for conducting His bundle sensing and pacing with a multidirectional balloon tipped catheter system <NUM> including a multidirectional catheter body <NUM>. The catheter system <NUM> is inserted into a subclavian vein or vascular access, block <NUM>. The catheter system <NUM> is guided towards His bundle, block <NUM>. The catheter system <NUM> senses His bundle potential with one or more mapping electrodes <NUM>, <NUM> disposed at a distal end portion of the catheter body, block <NUM>. The distal end of the catheter body <NUM> is positioned at a location of the His bundle <NUM> that is determined to be appropriate for pacing, block <NUM>. The distal end of the catheter body <NUM> is anchored at the appropriate location with inflated anchor balloon <NUM>, block <NUM>. A pacing lead <NUM> is implanted into the appropriate location of the His bundle, block <NUM>. After the pacing lead <NUM> is implanted, the catheter body <NUM> with deflated anchor balloon <NUM> may be removed while leaving the pacing lead <NUM> in place.

The anchor balloon <NUM> is atraumatic and allows for use of a more robust catheter designs. The increased rigidity of the catheter body facilitates increased positional precision and an improved procedural success rate. In an embodiment, the anchor balloon <NUM> may be a hydrophilic balloon with a surface having hydrophilic nature. The catheter system <NUM> of the disclosed invention provides advantages over the conventional devices. Unlike the conventional devices, the pacing lead <NUM> of the catheter system <NUM> of the disclosed invention is not exposed while the catheter system <NUM> maps the His bundle potential to find an appropriate location of heart tissues for His bundle pacing, preventing any issues that can be caused by exposed screw helix in the conventional devices. The catheter system <NUM> of the disclosed invention utilizes atraumatic anchor balloon that allows maneuvering of the catheter system <NUM> over cardiac structures without causing any injuries or damages to heart tissues and also allows to use more rigid multidirectional catheter body, which increases the ability to adjust to varying anatomical differences and to accurately maintain position within the beating heart during the implant procedure.

Claim 1:
A multidirectional balloon tipped catheter system (<NUM>) for conducting His bundle sensing and pacing, comprising:
a multidirectional catheter body (<NUM>) having a proximal end (<NUM>) and a distal end (<NUM>) and including a plurality of curls and flexion points (<NUM>,<NUM>) for multidirectional deflections, wherein the catheter body (<NUM>) includes a plurality of lumens (<NUM>, <NUM>) comprising:
a pacing lead lumen (<NUM>) including an exit port (111a) at the distal end; and
at least one balloon lumen (<NUM>) including a balloon port (114a) near the distal end;
an anchor balloon (<NUM>) mounted to near the distal end (<NUM>) of the catheter body (<NUM>), wherein the anchor balloon (<NUM>) is in fluid communication with the balloon port (114a) and wherein the anchor balloon overhangs the distal end (<NUM>) of the catheter body by a predetermined distance when the anchor balloon is inflated;
one or more mapping electrodes (<NUM>,<NUM>) mounted to a distal end (<NUM>) portion of the catheter body, wherein the one or more mapping electrodes (<NUM>,<NUM>) are configured to sense His bundle potential,
wherein the anchor balloon (<NUM>) is configured to expose the one or more mapping electrodes (<NUM>,<NUM>) mounted to the distal end (<NUM>) portion when the anchor balloon is deflated; and
a pacing lead (<NUM>) placed in the pacing lead lumen (<NUM>), wherein the pacing lead (<NUM>) is configured to protrude beyond the distal end (<NUM>) of the catheter body (<NUM>) when the pacing lead (<NUM>) is in use.