bluuebunny/crossref_metadata_2025 huggingface dataset:
Patch Migration: A Serious Late Complication of Thoracotomy Lead Systems
Authors: SINGER IGOR , CALZADA NORBERTO , AUSTIN ERLE H
Published: July 2006

Thoracotomy patch leads used for implantable cardioverter defibrillators (ICDs) are generally safe and effective. We describe two patients in whom a late complication of patch lead migration occurred years after the original implants, causing a bronchopleural fistula in one and lingular lobe collapse in the other patient. We conclude that patch migration is a late but possible complication of extrapericardial ICD leads, and should be suspected in patients who present with hemoptysis, atypical pneumonia, or lung collapse after the initial ICD surgery.
Combined Use of a True‐Bipolar Sensing Implantable Cardioverter Defibrillator in a Patient Having a Prior Implantable Spinal Cord Stimulator for Intractable Pain
Authors: MONAHAN KEVIN , CASAVANT DAVID , RASMUSSEN CARL , HALLET NANETTE
Published: July 2006

Reported is a case involving a patient with a previously implanted spinal cord stimulator (SCS) who presented for an implantable. Cardioverter defibrillator (ICD). The SCS device was located in the left lower abdominal quadrant with a stimulation electrode array placed on the dorsal aspect of the spinal cord at the T‐11 thoracic level. Interaction testing demonstrated that the bipolar sensing transvenous ICD system (Medtronic 7221Cx PCD) did not detect the stimulator's output at burst rates ranging from 20–130 pulses/s, even with the ICD set to its maximum sensitivity of 0.15 mV and the stimulator programmed to the highest patient tolerated output combinations of 5 V, 0.45 ms in the bipolar configuration and 3 V, 0.45 ms in the unipolar (i.e., case‐electrode) configuration.
Internal Balloon Compression: A Method to Achieve Hemostasis when Removing an Inadvertently Placed Pacemaker Lead from the Subclavian Artery
Authors: OPHUIS A.J.M. OUDE , van DOORN D.J. , van OMMEN V.A. , den DULK K. , WELLENS H.J.J.
Published: July 2006

One of the possible complications of subclavian vein puncture is entry into the subclavian artery. If this is not recognized, a pacemaker lead may be placed arterially. Since this may lead to systemic emboli, the pacemaker lead must be removed. This case report describes a patient in whom an atrial lead was inadvertently placed in the ascending aorta, where it had good sensing values but poor atrial capture threshold values. This lead was subsequently removed and hemostasis was achieved with intraarterial balloon compression via the brachial artery.
Twiddler's Syndrome Variants in ICD Patients
Authors: BOYLE NOEL G. , ANSELME FREDERIC , MONAHAN KEVIN M. , BESWICK PHILIPPA , SCHUGER CLAUDIO D. , ZEBEDE JOSEPH , JOSEPHSON MARK E.
Published: July 2006

Three cases of twiddler's syndrome in patients with an abdominally implanted cardioverter defibrillator (ICD) and an endocardial lead system are reported. The condition was detected when an increase in pacing threshold or lead impedance was noted at routine follow‐up. Successful revision was possible in all patients: however, a recurrence in one patient necessitated removal of the device. Elderly female patients with some degree of obesity appear most susceptible. Minimizing pocket size and suturing of the device to the fascia should decrease the chance of developing this problem.
Treatment of Malignant Primary Vasodepressive Neurocardiogenic Syncope with a Rate Responsive Pacemaker Driven by Heart Contractility
Authors: DEHARO J.C. , PEYRE J.P. , RITTER* P.H. , CHALVIDAN T. , LE TALLEC L. , DJIANE P.
Published: July 2006

In a 41‐year‐old man suffering from frequent syncope, the tilt test reproducibly induced a primary Vasodepressive neurocardiogenic syncope. Pharmucotherapy either failed to prevent the syncope induced at the tilt test or was poorly tolerated. In the minutes preceding the syncope, a dramatic increase in heart contractility was sensed by a microaccelerometer located at the tip of a right ventricular pacing electrode. When the tilt test was repeated with the pacemaker programmed in the DDDR mode, high rate dual chamber pacing occurred during the tilt phase and prevented the syncope. Three months after implantation, the patient remains totally symptom free.
Novel Form of Atrial Tachycardia Originating at the Atrioventricular Annulus
Authors: NOGAMI AKIHIKO , SUGUTA MASAHIKO , TOMITA TOMOYUKI , NAITO SHIGETO , TANIGUCHI KOICHI , AONUMA KAZUTAKA , IESAKA YOSHITO
Published: July 2006

We report two patients with reentrant atrial tachycardia that originated at the AV annulus. Atrial tachycardia originated in the posterior portion of mitral annulus in one patient (case 1) and the posterolateral portion of tricuspid annulus in one patient (case 2). Tachycardia was successfully eliminated by RF catheter ablation in both patients, with the catheter placed underneath the mitral valve in case 1 and on the tricuspid annulus in case 2. Spiky potentials were recorded in the diastolic phase of the atrium during tachycardia at the sites of successful ablation. Spiky potentials were also recorded after atrial electrogram during sinus rhythm, and showed decremental properties during atrial pacing. An accelerated atrial rhythm was observed during RF application, and tachycardia could not be induced after ablation in either patient. Tachycardia in these patients seemed to be due to reentrant tachycardia originating in the accessory AV node (Mahaim fiber) without ventricular connection.
Pacemaker Therapy in Premature Children with High Degree AV Block
Authors: NOWAK BERND , KAMPMANN CHRISTOPH , SCHMID FRANZ‐XAVER , PRZIBILLE OLIVER , WIPPERMANN FRIEDRICH , HIMMRICH EWALD , MEYER JÜRGEN
Published: July 2006

The smallest pacemaker pulse generator and a steroid‐eluting bipolar epicardial lead were implanted in two premature children with symptomatic AV block. Stable capture threshold and high amplitude evoked response electrogram resulted in normal function of the pacemaker Autocapture algorithm, which adjusts output 0.3 V above the measured capture threshold. Autocapture hud previously been used only with endocardial leads. Longer‐term observation is required.
Atypical Form of the Fourth Criterion for Transient Entrainment
Authors: ASAMI KOHICHI , ASHIKAWA HIDENOBU , TERAI TOMOKO , ISHIHARA NAOKO , NAWATA HIROKO , HIRAO KENZO , MIYASAKA NOBUYUKI , KAWARA TOKUHIRO , HIEJIMA KAZUMASA , HARADA TOMOO , SUZUKI FUMIO
Published: July 2006

The typical fourth criterion for transient entrainment is defined when both a sudden shortening in conduction interval to and a distinct change in electrogram morphology at a bipolar recording site are demonstrated while performing overdrive pacing of a reentrant tachycardia from a single pacing site at two different constant rates. The purpose of this article was to test the hypothesis that if an intracardiac recording site showing both orthodromic and antidromic capture with entrainment pacing is located suitably distant from the circuit, sudden shortening in conduction interval to that site may occur without any significant change in the bipolar electrogram morphology (i.e., atypical form of the fourth criterion). Atrial overdrive pacing of orthodromic tachycardia was performed in 20 patients with either left anterior (12 patients) or left posterior (8 patients) accessory pathways. We investigated the effects of overdrive pacing from the proximal or distal coronary sinus, specifically effects on the electrogram interval and the electrogram morphology at the right atrial appendage. Overdrive pacing of orthodromic tachycardia from the proximal coronary sinus was performed in 10 of the 12 patients with left anterior accessory pathways; those 10 patients demonstrated the first entrainment criterion at the right atrial appendage site. Overdrive pacing of orthodromic tachycardia at still shorter cycle lengths demonstrated a sudden shortening in conduction interval to the right atrial appendage site. Despite shortening in conduction interval the morphology of the right atrial appendage electrogram was completely or almost identical to that during orthodromic tachycardia, indicating an atypical form of the fourth criterion. This criterion was not demonstrated in patients with left posterior accessory pathways. Thus, atypical fourth entrainment criterion was demonstrated during overdrive pacing of orthodromic tachycardia from the proximal coronary sinus only in patients with left anterior accessory path ways. Demonstration of atypical fourth criterion seems largely dependent on the location of the accessory pathway, the pacing, and the recording sites.
NASPE Expert Consensus Document: Use of IV (Conscious) Sedation/Analgesia by Nonanesthesia Personnel in Patients Undergoing Arrhythmia Specific Diagnostic, Therapeutic, and Surgical Procedures
Authors: BUBIEN ROSEMARY S. , FISHER JOHN D. , GENTZEL JOHN A. , MURPHY ELLEN K. , IRWIN MARLEEN E. , SHEA JULIE B. , DICK MACDONALD , CHING ELIZABETH , WILKOFF BRUCE L. , BENDITT DAVID G.
Published: July 2006

Use of IV (Conscious) Sedation/Analgesia by Nonanesthesia Personnel in Patients Undergoing Arrhythmia Specific Diagnostic, Therapeutic, and Surgical Procedures. This article is intended to inform practitioners, payers, and other interested parties of the opinion of the North American Society of Pacing and Electrophysiology (NASPE) concerning evolving areas of clinical practice or technologies or both, that are widely available or are new to the practice community. Expert, consensus documents are so designated because the evidence base and experience with the technology or clinical practice are not yet sufficiently well developed, or rigorously controlled trials are not yet available that would support a more definitive statement. This article has been endorsed by the American College of Cardiology, October 1997.
Insulation Lead Failure: Is it a Matter of Insulation Coating, Venous Approach, or Both?
Authors: ANTONELLI DANTE , ROSENFELD TIBERIO , FREEDBERG NAHUM A. , PALMA EUGEN , GROSS JAY N. , FURMAN SEYMOUR
Published: July 2006

Lead insulation material and implant route have a major impact on lead realiability and durability. We compare the incidence of lead insulation failure resulting from both the venous approach and insulation type. Two hundred ninty consecutive leads were followed for a mean period of 57 ± 30 months; leads with < 1 year follow‐up were excluded. There were 116 Silicone Rubber insulated leads and 174 with polyurethane (151 Pellethane 80A and 23 Pellethane 55D) insulation; 279 leads were bipolar and 11 unipolar; 274 leads were implanted in the ventricle and 66 in the atrium. The venous route was the subclavian vein for 170 leads (58%) and the cephalic vein for 120 leads (42%). Insulation failure was diagnosed when a single sign of oversensing, undersensing, failure to capture, early pulse battery depletion, and lead impedance < 250 Ω was present. Measurement of lead impedance was performed intraopera‐tively at implantation and during lead revision or pulse generator replacement. Lead failure caused by conductor coil fracture was not considered. There were 13 lead insulation failures, all among leads with polyurethane insulation (12 Pellethane 80A and 1 Pellethane 55D). Eleven failures (10%) occurred when the subclavian vein and 2 (3%) when the cephalic vein approach was used. The cumulative survival rate of polyurethane and silicone rubber insulated leads was 88.7% and 100%, respectively (P = 0.02); the cumulative survival rate of polyurethane insulated leads was 83.2% when the subclavian vein and 95.1% when the cephalic vein were used (P = 0.03). The mean time to polyurethane lead failure when the subclavian vein approach was used was 54 ± 17 months and when the cephalic route was 73 ± 4 months (P < 0.02). By multivariate analysis, the route of entry was found to be a significant variable related to polyurethane insulated lead failure (P < 0.05). At lead revision failure to capture was present in 7, over‐sensing in 4, and undersensing in 2 instances; impedance was < 250 Ω in all cases. Pellethane 80A insulated leads are prone to insulation failure, but more when the subclavian vein is used, rather than the cephalic vein.
Efficacy and Safety of Permanent Cardiac DDD Pacing with Contemporaneous Double Spinal Cord Stimulation
Authors: ROMANO MASSIMO , BRUSA STEFANIA , GRIECO ANTONIO , ZUCCO FURIO , SPINELLI ACHILLE , ALLARIA BIAGIO
Published: July 2006

Spinal cord stimulation (SCS) is currently used to treat peripheral vascular disease (PVD) and refractory angina pectoris not amenable to revascularization. In a case of contemporaneous SCS implant and permanent cardiac pacemaker (PPM), if multipolar electrodes are used it is possible to avoid any interference between the systems. We describe the case of a patient with a DDD pacemaker, in whom two bipolar SCSs were implanted at different times: one to control refractory angina pectoris and the other for PVD. No interference between the three systems has been observed.
Several Unsuccessful Internal and External Defibrillations During Active Can ICD Implantation in a Patient with Pneumothorax
Authors: SCHUCHERT ANDREAS , HOFFMANN MATTHIAS , STEFFGEN FRANK , MEINERTZ THOMAS
Published: July 2006

During implantable cardioverter defibrillator (ICD) implantation of an active can ICD several defihrillations with 20 J and 34 J as well as 360 J externally were ineffective. The implant criteria were finally met with a second defibrillation lead and reversed polarity. A left‐sided pneumothorax due to subclavian vein puncture was detected soon after ICD implantation. It is assumed that especially in the active can alignment the developing pneumothorax made defibrillation current flow more difficult. In case of several unsuccessful defibrillations during active can ICD implantation in which the subclavian vein was punctured, the possibility of a pneumothorax should be considered.
Implantation of Active Can Implantable Defibrillators in the right Pectoral Region
Authors: JENSEN STEEN M. , PIETERSEN ADRIAN , CHEN XU
Published: July 2006

Routinely the active can ICD is placed in the left side pectoral position, which theoretically gives optimal conditions for a low defibrillation threshold. Some patients, bowever, demand a right pectoral position, which possibly could result in a bigger defibrillation threshold. A right pectoral position was used in 3 of 85 active can ICDs implanted in our institution from 1994. the DFT was 12 J in two and 18 f in one patient. Thus, right pectoral implantation is feasible and offers an alternative approach in selected patients.
Tilt Table Testing of Young Adult Patients: Improved Speed and Sensitivity Using an Isoproterenol Bolus and a Continuous 60° Tilt
Authors: Van de WALLE JEAN‐PIERRE , PANAGIDES DEMETRAKIS , MESSIER MARC , IOVESCU DECEBAL , FOURCADE LAURENT , BORY MICHEL , TOUZE JEAN‐ETIENNE
Published: July 2006

The tilt table is a diagnostic device used to induce vagal syncope and determine etiology. Sensitivity enhancing techniques, such as the administration of isoproterenol, can be applied to children and young adults to compensate for the otherwise low sensitivity (20%‐30%) observed in that population. This study describes an improved test that offers a simplified approach while decreasing the amount of time involved by up to 50%, without compromising sensitivity. This 45‐minute procedure relies on sensitization with isoproterenol administered as a 2‐ to 8‐μg bolus instead of a continuous infusion. The isoproterenol is injected at the 30th minute of a 45‐minute 60° tilt test without returning the patient to the supine position. In this study, the isoproterenol bolus tilt test was found to be “positive” in 24 of 30 patients reporting unexplained syncope: 10 cases before the 30th minute (11.2 ± 8.4 min) and 14 cases after administration of 5.1 ± 1,9 μg of isoproterenol.
Subclavian Venogram as a Guide to Lead Implantation
Authors: SPENCER WILLIAM H. , ZHU DENNIS W.X. , KIRKPATRICK CINDY , KILLIP DONNA , DURAND JEAN‐BERNARD
Published: July 2006

Recent reports have raised doubts regarding the safety and efficacy of the blind subclavian venipuncture technique for intra‐cardiac lead implantation. To permit a more lateral entry, we used a simple subclavian venogram performed through the brachial vein of the ipsilateral arm of 22 consecutive unselected patients undergoing had implantation (19 permanent pacemakers and 3 intracardiac defibriUators). A total of 35 leads were implanted (31 left pectoral and 4 right pectoral). Lead insertion by venogram technique was used successfully in all patients. Two inconsequential arterial punctures occurred. There were no pneumotho‐races, infections, or other complications. Lateral placement should facilitate lead manipulation and minimize “subclavian crush.” The method of ipsilateral venogram guided lead insertion appears to be safe and reliable and deserves consideration in patients who require permanent lead placement via the subclavian vein approach.
“In‐Line” Bipolar, Steroid‐Eluting, High Impedance, Epimyocardial Pacing Lead
Authors: KARPAWICH PETER P. , STOKES KENNETH B. , PROCTOR KEITH , SCHALLHORN RICK , McVENES RICHARD
Published: July 2006

Recent advances in electrode surface designs have eliminated traditional threshold differences between endo‐ and epicardial pacing leads. Since the epicardial approach offers the potential of direct left ventricular pacing and the transvenous approach may not be feasible or warranted in all instances, more advanced leads are being designed to optimize epicardial pacing capabilities. This study was conducted to evaluate a bipolar epimyocardial lead. Six immature canines (age 3 months) were instrumented. The lead (Medtronic mode! 10389) is a single‐pass, “in‐line” bipolar electrode with low current drain and high impedance, with an intramyocardial steroid‐eluting cathode and nonsteroid epicardial anode. Twelve ventricular leads were implanted (two per animal) and the animals followed for 6 months with weekly analysis of pacing and sensing capabilities. Results at explant were compared with implant values and showed no significant differences between sensed R waves or in R wave slew rates in unipolar or bipolar modes. Explant lead impedances remained high in both modes: bipolar, 1658 ± 331; and unipolar, 1327 ± 308 Ω (P < 0.05). Chronic voltage (V) threshold at 0.5 ms showed no significant change from implant values during the study: unipolar, 0.3 ± 0.06 versus 1.0 ± 0.8; and bipolar, 0.4 ± 0.06 versus 1.6 ± 1.2. Histologic review showed negligible fibrous reaction at the electrode‐tissue interface. This study introduces a high impedance, low threshold, “in‐line” bipolar pacing lead design capable of stable chronic pacing with implant facilitated by a single suture technique.
Venous Dysfunction and the Change of Blood Viscosity During Head‐Up Tilt
Authors: YAMANOUCHI YOSHIO , JAALOUK SAFWAN , SHEHADEH ABBAS A. , FOUAD‐TARAZI FETNAT M.
Published: July 2006

The precise stimulus that induces vasovagal syncope is still unclear. We have previously demonstrated that the peripheral distribution of blood volume (venous pooling) is a strong predictor of tilt induced vasovagal reaction. We hypothesized that an increase in venous pooling during tilt accentuates the measured increase in blood viscosity. This hypothesis is based on the previously demonstrated increase in venous pressure and subsequent increase in transcapillary fluid transudation during tilt. The increased blood viscosity, in turn, increases vascular shear rate, which may alter the vasoconstrictive and other cardiovascular responses to decreased preload. We measured blood viscosity (supine and tilt) in 56 patients with a history of orthostatic intolerance (37 with venous pooling [VP] and 19 without venous pooling [non‐VP]). VP and non‐VP were separated into subgroups based on blood pressure and heart rate response to tilt. There was a positive correlation between blood viscosity and plasma aldosterone in the supine. In the group as a whole, neither supine blood viscosity nor its increase during tilt differed between VP and non‐VP. However, the tilt induced increase of blood viscosity was significant only in patients with tilt provoked tachycardia plus normal blood pressure response in VP group. We suggest that the increase of blood viscosity in this group led to the normal blood pressure response. The positive correlation between supine blood viscosity and supine plasma aldosterone indicates that the normal blood pressure response in this group possibly was via stimulation of the renin‐angiotensin‐aldosterone system.
Efficacy of Ventricular Rate Stabilization by Right Ventricular Pacing During Atrial Fibrillation
Authors: LAU CHU‐PAK , JIANG ZU‐YI , TANG MING‐OI
Published: July 2006

To assess the effect of right ventricular pacing on rate regularity during exercise and daily life activities, 16 patients with sinoatrial disease and chronic atrial fibrillation (AF) were studied. Incremental ventricular pacing was commenced at 40 beats/min until > 95% of ventricular pacing were achieved during supine, sitting, and standing. Thirteen patients also underwent randomized paired submaximal exercise tests in either a fixed rate mode (VVI) or a ventricular rate stabilization (VRS) mode in which the pacingrate was set manually at 10 beats/min above the average AF rate duringthe last minute of each exercise stage. The pacing interval for rate regularization was shortest during standing (692 ± 26 ms) compared with either supine or sitting (757 ± 30 and 705 ± 26 ms, respectively, P < 0.05). During exercise, VRS pacing significantly increased the maximum rate (119 ± 5.2 vs 106 ± 4.2 ms, P < 0.05), percent of ventricular pacing (85%± 5% vs 23%± 7%, P < 0.05), rate regularity index (5.8%± 1.6% vs 13.4%± 1.9%, P < 0.05), and maximum level of oxygen consumption (12.4 ± 0.5 vs 11.3 ± 0.5 ml/kg, P < 0.05) compared with VVI pacing. There was no change in oxygen pulse or difference in symptom scores in this acute study between the two pacing modes. It is concluded that right ventricular pacing may significantly improve rate regularity and cardiopulmonary performance in patients with chronic AF. This may be incorporated in a pacing device for rate regularization of AF using an algorithm that is rate adaptive to postural and exercise stresses.
Thoracoscopic Radiofrequency Ablation of the Myocardium
Authors: WATANABE GO , MISAKI TAKURO , NAKAJIMA KUNIKI , UEDA TETSUYUKI , YAMASHITA AKIO
Published: July 2006

Radiofrequency (RF) catheter ablation has been used for the treatment of ventricular tachycardia (VT), however, in some patients VT might result from subepicardiai macroreentry that could be successfully terminated by epicardial approach. This study examined the feasibility of thoracoscopic RF ablation of myocardium from epicardium using a custom made electrode. In five mongrel dogs, the thoracoscope was introduced through the 7th intercostal space. A 500‐kHz continuous wave RF energy was connected to a custom made multiple electrode probe. Under thoracoscopic guidance, the heart was exposed and the RF probe was introduced. RF ablation was performed on the nonvascular ventricular wall of the beating heart. The left ventricular free wall and right ventricular outflow tract were satisfactorily visualized and ablated. The total dose of RF energy ranged from 50 to 500 J. and the estimated volume of ablated lesions ranged from 41.0–799 mm3. There were significant correlations between the RF discharge output and the irradiated lesion volume (P < 0.01), and the depth of the lesions (P < 0.01). Grossly, after RF ablation the ventricular myocardium demonstrated a circular, well‐demarcated area of thermal injury. Volume and depth of the lesion depended upon the total dose of delivered RF energy. Thoracoscopic RF ablation appears to be a minimally invasive and useful method for creating irradiated myocardial lesions from epicardial surface. This method could he technically feasible for the treatment of Vts for which endocardial RF ablation is ineffective.
Cardiac Rehabilitation in Patients with Rate Responsive Pacemakers
Authors: GRECO ENRICO MARIA , GUARDINI SILVIA , CITELLI LUCA
Published: July 2006

This study investigated the suitability of our oxygen pulse reserve (OPR) method for tailoring parameters of rate responsive pacemakers and planning aerobic rehabilitation programs. We selected 11 patients, NYHA Classes I‐III (7 males and 4 females; mean age 60 years, range 18–83), with rate responsive pacemakers implanted for high degree AV block and chronotropic incompetence. Five pacemakers had activity sensors, 4 had temperature sensors, and 2 had dual sensors. All patients underwent a cardiopulmonary stress test (CPX). We determined anaerobic threshold time (ATT), VO2/AT, total exercise time (TET), VO2 Max, and VO2AT/VO2 Max. OPR (mL‐O2/beat) was calculated for each patient using the formula OPR = (VO2Max ‐ VO2 resting)/(HR Max ‐ HR resting). During CPX, this slope was used as the rate response tailoring guideline by comparing the mL‐O2/beat equation and the pacing rate. Rate response settings were modified until the optimal relationship between theoretical and paced rate was obtained. The work protocol yielded rate response settings capable of providing pacing rates within ± 10 beats of the theoretical values. Data relating to theoretical and measured rates have been analyzed statistically. Patients underwent an aerobic rehabilitation program that followed the American College of Sports Medicine guidelines. Pacing rate at the anaerobic threshold was considered the border for an aerobic workload. After 2–7 months, all patients showed an evident improvement in ATT (92%), VO2/AT(48%), TET(49%), VO‐,Max (23%), and VO2 AT/VO2 (21%). Particularly, two patients improved from Weber Class C to A, and three improved from C to B. At each CPX step, the mean values of pacing rate and theoretical rate almost overlap, and the relevant coefficients suggest an excellent correlation (P < 0.001). Our OPR method for tailoring rate response provides the basis for an effective rehabilitation program with functional advantages for patients.
Cerebral Embolism Due to a Retained Pacemaker Lead: A Case Report
Authors: BÖHM ÁDÁM , BÁNYAI FERENC , KOMÁROMY KATALIN , PINTÉR ARNOLD , PRÉDA ISTVÁN
Published: July 2006

There are only a few reported cases of a pacemaker lead migrating inadvertently into the left atrium or ventricle. An unusual complication of unremoved, unwanted pacemaker lead is presented. The free tip of the lead caused cerebral embolism after perforating the interatrial septum.
Short‐Term Atrioventricular Sequential Pacing Does Not Adversely Affect Collateral Blood Flow: A Study During Angioplasty
Authors: KYRIAKIDES ZENON S. , KOLETTIS THEOFILOS M. , SBAROUNI EFTIHIA , ANTONIADIS AIAS , GIAKOUMAKIS TSABIKOS , KREMASTINOS DIMITRIOS T.
Published: July 2006

Altered sequence of ventricular activation sequence results in marked derangements in mechanical events. In the present study, we investigated the comparative effects of atrial and AV sequential pacing on collateral blood flow during angioplasty. Twenty‐eight patients with stable angina and left anterior descending artery disease undergoing balloon angioplasty were studied. Collateral flow was determined during balloon inflation from the distal flow velocity of the ipsilateral artery (17 patients) or from the increase of the maximal diastolic blood flow velocity (Vc) of the contralateral artery (11 patients). Flow measurements were made using the Doppler flow guidewire. The relative resistance in the collateral vascular bed (RRj also was estimated in the latter group of patients. After the first balloon inflation, two similar consecutive balloon inflations were done under atrial and AV sequential pacing, at a rate of 15 beats/min higher than the sinus rate, in the absence ofvasoactive medication. One minute after the initiation of pacing, the second and third balloon inflations were begun and the pacing continued until the balloon inflations were completed. In the ipsilateral group, average peak velocity was 84.6 t 24.2 mm/s during atrial pacing and 82.7 ± 29.7 mm/s during AV sequential pacing (P = NS). In the contralateral group. Vc was l8%± 12% during atrial pacing and 17%± 14% during AV sequential pacing, and the RR was 4.5 ± 4.7 and 4.9 ± 6.4, respectively (both P = NS). The coronary wedge/mean blood pressure was similar during the two tested balloon inflations. Short‐term AV sequential pacing at rest does not adversely affect collateral blood flow and resistance in patients with left anterior descending artery disease.
Rhythm Management in Atrial Fibrillation—with a Primary Emphasis on Pharmacological Therapy: Part 2
Authors: COSTEAS CONSTANTINOS , KASSOTIS JOHN , BLITZER MARK , REIFFEL JAMES A.
Published: July 2006

Atrial fibrillation (AF) is the most common, sustained, symptomatic tachyarrhythmia that clinicians are called upon to manage. Management strategies include ventricular rate control coupled with anticoagulation, versus restoration and maintenance of sinus rhythm. Rate control may be achieved pharmacologically, with agents that impair AV nodal conduction directly and/or by increasing parasympathetic/sympathetic balance, or by modifying or ablating the AV nodal region anatomically. Rhythm control may be achieved by electrical or pharmacological conversion followed by maintenance of sinus rhythm by pharmacological (or occasionally ablative) therapies. This article will present current approaches to rate and rhythm control issues in AF. Part 1, published previously, dealt with rate control. Part 2, the current article, details approaches to the restoration of sinus rhythm by electrical and pharmacological means. The former may use transthoracic or catheter‐based energy delivery systems. The latter may use intravenous or oral drug approaches. Part 3, to be published in a subsequent edition of PACE will deal with the maintenance of sinus rhythm.
Oversensing in a Cardioverter Defibrillator System Caused by Interaction Between Two Endocardial Defibrillation Leads in the Right Ventricle
Authors: PFITZNER PETRA , TRAPPE HANS‐JOACHIM
Published: July 2006

A 53‐year‐old male patient underwent implantable Cardioverter defibrillator (ICD) implantation with a single lead (Endotak ®) transvenous system due to recurrent episodes of drug refractory ventricular tachycardia. After pulse generator replacement, inappropriate ICD shocks were observed due to muscle potential sensing. Intraoperatively, the old Endotak ® lead could not be extracted; therefore, it was transsected and capped. A new lead was inserted and tested without any problems. At the predischarge test, VF was induced and was followed by ICD shocks during sinus rhythm. In another surgical procedure, the old Endotak ® lead was explanted using a special instrument. The present report demonstrates that two endocardial Endotak ® leads should be avoided, because the leads may disturb each other and be followed by inappropriate ICD discharges.
Carcinoma of the Breast and Pacemaker Generators
Authors: ROTHENBERGER‐JANZEN KATRIN , FLUECKIGER ANDREAS , BIGLER RUDOLF
Published: July 2006

A 90‐yearold woman developed intraductol adenocarcinoma (TNM classification pT2, G2) of the left breast 18 years after initial pacemaker implantation deep to the left breast. There was no evidence of local or distant metastasis and she was treated with local excision and tamoxifen.
Catheter Entrapment in the Mitral Valve Apparatus Requiring Surgical Removal: An Unusual Complication of Radiofrequency Ablation
Authors: MANDAWAT MAHENDRA K. , TURITTO GIOIA , EL‐SHERIF NABIL
Published: July 2006

We describe a patient with Wolff‐Parkinson‐White syndrome in whom a steerable catheter became entrapped in the mitral valve apparatus, during radiofrequency ablation. Treatment consisted of surgical removal of the catheter. The occurrence of this previously unreported complication stresses the need for on‐going monitoring of risk and benefits of electrophysiological interventions.
An Optimized AV Delay Algorithm for Patients with Intermittent Atrioventricular Conduction
Authors: STIERLE ULRICH , KRÜGER DIETMAR , VINCENT ALPHONSE M. , MITUSCH ROLF , GIANNITSIS EVANGELOS , WIEGAND UWE , POTRATZ JÜRGEN
Published: July 2006

Detection and promotion of an intermittent atrioventricular (A V) conduction is the objective of an AV delay hysteresis algorithm in dual chamber pacemaker (DDDj pacing. The AV delay following an atrial event is automatically extended by a programmable interval (AV hysteresis interval) if the previous cycle showed spontaneous AV conduction, i.e., a ventricular event was detected within the previous AV delay. An automatic search mode scans for spontaneous ventricular events during the hysteresis interval: a single AV delay extension (equal to the programmed AV delay hysteresis) will occur after a successive, programmable number of AV cycles with ventricular pacing. If a spontaneous AV conduction is present, the AV delay will remain extended by the hysteresis interval. Our first results in 17 patients with intermittent AV block disclosed a satisfactorily working algorithm with effective reduction of ventricular stimuli. In relation to the underlying conduction disturbance and pacemaker settings, the majority of our patients showed a reduction of ventricular pacing events up to 90% without any adverse hemodynamic or electrophysiological changes. Based on clinical (promotion of a physiological activation and contraction sequence) and technical (reduction of power consumption) advantages, the AV hysteresis principle could be of incremental value for future dual chamber pacing in patients with intermittent complete heart block.
An Algorithm for Automatic Measurement of Stimulation Thresholds: Clinical Performance and Preliminary Results
Authors: DANILOVIC DEJAN , OHM OLE‐JØRGEN , STROEBEL JOHN , BREIVIK KJELL , HOFF PER IVAR , MARKOWITZ TOBY
Published: July 2006

We have developed an algorithmic method for automatic determination of stimulation thresholds in both cardiac chambers in patients with intact atrioventricular (AV) conduction. The algorithm utilizes ventricular sensing, may be used with any type of pacing leads, and may be downloaded via telemetry links into already implanted dual‐chamber Thera® pacemakers. Thresholds are determined with 0.5 V amplitude and 0.06 ms pulse‐width resolution in unipolar, bipolar, or both lead configurations, with a programmable sampling interval from 2 minutes to 48 hours. Measured values are stored in the pacemaker memory for later retrieval and do not influence permanent output settings. The algorithm was intended to gather information on continuous behavior of stimulation thresholds, which is important in the formation of strategies for programming pacemaker outputs. Clinical performance of the algorithm was evaluated in eight patients who received bipolar tined steroid‐eluting leads and were observed for a mean of 5.1 months. Patient safety was not compromised by the algorithm, except for the possibility of pacing during the physiologic refractory period. Methods for discrimination of incorrect data points were developed and incorrect values were discarded. Fine resolution threshold measurements collected during this study indicated that: (1) there were great differences in magnitude of threshold peaking in different patients; (2) the initial intensive threshold peaking was usually followed by another less intensive but longer‐lasting wave of threshold peaking; (3) the pattern of tissue reaction in the atrium appeared different from that in the ventricle; and (4) threshold peaking in the bipolar lead configuration was greater than in the unipolar configuration. The algorithm proved to be useful in studying ambulatory thresholds.
Systolic and Diastolic Function with Alternate and Combined Site Pacing in the Right Ventricle
Authors: BUCKINGHAM THOMAS A. , CANDINAS RETO , ATTENHOFER CHRISTINE , VAN HOEVEN HETTY , HUG ROSY , HESS OTTO , JENNI ROLF , AMANN F. WOLFGANG
Published: July 2006

We hypothesized that pacing at two ventricular sites simultaneously would activate the myocardium more rapidly and improve ventricular function. We studied the effect of pacing at the right ventricular outflow tract (RYOT) and the RV apex (EVA) on systolic and diastolic function. In 14 patients with a reduced systolic ejection fraction < 40% (mean EF 32%±4%)we measured RV pressures, left ventricular pressures, EF, cardiac output, peak dP/dt, peak negative dP/dt, and the time constant of relaxation, Tau, during intrinsic rhythm, atrial pacing and DVI pacing at the RVA, the RVOT, and both RV sites combined in random order. Repeated measures analysis of variance showed no significant differences in any of these parameters. The highest absolute values of dP/dt were observed during sinus rhythm and the lowest with RVA pacing. This parameter tended to improve progressively with pacing in the RVOT and at both sites. Peak negative dP/dt showed a similar nonsignificant trend. Conclusion: These data suggest that in patients with poor LV function, there may be subtle improvements in diastolic and systolic function with pacing in the RVOT and at combined sites in the RV compared to traditional RVA pacing.
Importance of Pacemaker Noise Reversion as a Potential Mechanism of Pacemaker‐ICD Interactions
Authors: GLIKSON MICHAEL , TRUSTY JANE M. , GRICE SUELLEN K. , HAYES DAVID L. , HAMMILL STEPHEN G. , STANTON MARSHALL S.
Published: July 2006

Numerous types of interactions between pacemakers and implantable cardioverter defibrillators (ICDs) have been described. Pacemaker outputs preventing appropriate detection of ventricular tachycardia or ventricular fibrillation by the ICD is one of the more serious. Asynchronous pacemaker activity during ventricular arrhythmias maybe caused by either nonsensing of the arrhythmia or by noise reversion, which is an algorithm that causes the pacemaker to switch to asynchronous pacing when repetitive sensing at a high rate occurs. We analyzed the mechanisms underlying asynchronous pacemaker activity in ventricular arrhythmias using pacemaker telemetry during the arrhythmia. Thirty‐nine induced arrhythmias from 26 different procedures in 19 patients with both pacemakers and ICDs were analyzed. Of the 39 arrhythmias, asynchronous pacemaker activity occurred in 16. The underlying mechanism was nonsensing in 4 episodes and noise reversion in 12 episodes. Clinically significant interference with detection arose on three occasions. Conditions favoring the occurrence of noise reversion include specific pacemaker models, arrhythmia cycle lengths in the range causing noise reversion of the individual pacemaker model, long noise sampling periods, and VVI pacing mode. Noise reversion can be diagnosed by telemetering the pacemaker marker channel during ventricular arrhvthmias as a part of routine pacemaker‐ICD interaction evaluation. It can be prevented or minimized by programming short ventricular refractory periods or using pacemakers with shoii retriggerable refractory periods.
Heart Rate Variability in Passive Tilt Test: Comparative Evaluation of Autoregressive and FFT Spectral Analyses
Authors: BADILINI FABIO , MAISON‐BLANCHE PIERRE , COUMEL PHILIPPE
Published: July 2006

The dynamic response of the autonomic nervous system during tilting is assessed by changes in the low (LF) and high frequency (HF) components of the RR series power spectral density (PSD). Although results of many studies are consistent, some doubts related to different methodologies remain. Specifically, the respective relevance of autoregressive (AR) and fast Fourier transform (FFT) methods is often questioned. Reat‐to‐beat RR series were recorded during 90° passive tilt in 18 healthy subfects (29 ± 5 years, eight females). FFT‐based (50% overlap, Manning window) and AR‐based (Levinson‐Durbin algorithm) PSDs were calculated on the same RR intervals. Powers in very low frequency (VLF: < 0.04 Hz), LF (0.04–0.15 Hz), and HF (0.15–0.40 Hz) bands were calculated either by spectrum integration (FFT and ARIN), by considering the highest AR component in each band (ARHP), or by summation of all AR components (ARAP). LF and HF raw powers (ms2) were normalized by total power (%P) and by total power after removal of the VLF component (nu). AR and FFT total powers were not different, regardless of body position. In supine condition, when compared to ARHP and ARAP. FFT underestimated VLF and overestimated LF, whereas in tilt position FFT overestimated HF and underestimated LF. However, supine/tilt trends were consistent in all methods showing a clear reduction of HF and a less marked increase of LF. Both normalization procedures provided a significant LF increase and further magnified the HF decrease. Results obtained with ARIN were remarkably close to those obtained with FFT. In conclusion, significant differences between AR and FFT spectral analyses do exist, particularly in supine position. Nevertheless, dynamic trends provided by the two approaches are consistent. Normalization is necessary to evidence the LF increase during tilt.
One‐to‐Two Atrioventricular Conduction Causing Nonreentrant Tachycardia: Successful Treatment with Radiofrequency Ablation
Authors: GLOTZ de LIMA GUSTAVO , ROY DENIS , TALAJIC MARIO , DUBUC MARC
Published: July 2006

The anatomical substrate for AV nodal reentrant tachycardia (AVNRT) is well known and is due to anterograde conduction through a siow conducting pathway and retrograde conduction using a fast conducting path way. In this report, we describe a patient with AVNRT who also presented with frequent episodes of paroxysmal nonreentrant tachycardia due to the occurrence of two conducted ventricular beats for each sinus depolarization. Palpitations and arrhythmias were abolished after radiofrequency ablation of the slow pathway.
Radiofrequency Catheter Ablation of Idiopathic Left Ventricular Tachycardia Originating in the Left Anterior Fascicle
Authors: DAMLE ROGER S. , LANDERS MARK , KELLY PATRICIA A. , REITER MICHAEL J. , MANN DAVID E.
Published: July 2006

Radiofrequency catheter ablation has been used to treat idiopathic left ventricular tachycardia with high success rates. The majority of reported cases have exhibited the typical findings of right bundle branch block morphology with left axis deviation and originate from within or near the left posterior fascicle. We report a case of idiopathic left ventricular tachycardia originating from within or near the left anterior fascicle, which was successfully ablated using a local Purkinje potential as a guide.
Pacemaker Lead Fracture Due to Twiddler's Syndrome
Authors: BÖHM ÁDÁM , KOMÁROMY KATALIN , PINTÉR ARNOLD , PRÉDA ISTVÁN
Published: July 2006

The authors report a case of pacemaker twiddler's syndrome that led to lead fracture and loss of consciousness. The role of chest X rays in the diagnosis of pacemaker twiddler's syndrome as well as the management of the syndrome is discussed.
Sotalol Associated Torsades de Pointes Tachycardia in a 15‐Month‐Old Child: Successful Therapy with Magnesium Aspartate
Authors: SASSE MICHAEL , PAUL THOMAS , BERGMANN PER , KALLFELZ HANS CARLO
Published: July 2006

Torsades de pointes (Tdp) is a form of ventricular tachycardia, and its occurrence in childhood is very rare. In adult patients treated with sotahl. Tdp has been reported to the occur with an incidence of 2%–4%. In children who are treated with sotalol. occurrence of Tdp has been reported in only a single case. A 15‐month‐old girl with Wolff‐Parkinson‐White syndrome developed recurrent syncopal attacks. She had been treated with sotalol 1.5 mg/kg daily since shortly after birth because of recurrent episodes of paroxysmal supraventricular tachycardia. ECG monitoring exhibited frequent Tdp tachycardia. Serum electrolyte levels were normal. Echocardiographic analysis excluded a structural heart defect and did not show any signs of myocardial infection. Sotalol treatment was stopped and an infusion with lidocaine was started. Despite this therapy the Tdp continued. Magnesium aspartate was then administered, which immediately stopped the Tdp. As no other reason was evident, Tdp in this child has to be judged as a proarrhythmia related to sotalol therapy.
Narrow Complex Tachycardia with VA Block: Diagnostic and Therapeutic Implications
Authors: HAMDAN MOHAMED H. , KALMAN JONATHAN M. , LESH MICHAEL D. , LEE RANDALL J. , SAXON LESLIE A. , DOROSTKAR PARVIN , SCHEINMAN MELVIN M.
Published: July 2006

To review our experience with cases of narrow complex tachycardia with VA block, highlighting the difficulties in the differential diagnosis, and the therapeutic implications. Prior reports of patients with narrow complex tachycardia with VA block consist of isolated case reports. The differential diagnosis of this disorder includes: automatic junctional tachycardia, AV nodal reentry with final upper common pathway block, concealed nodofascicular (ventricular) pathway, and intra‐Hissian reentry. Between June 1994 and January 1996, six patients with narrow complex tachycardia with episodes of ventriculoatrial block were referred for evaluation. All six patients underwent attempted radiofrequency ablation of the putative arrhythmic site. Three of six patients had evidence suggestive of a nodofascicular tract. Intermittent antegrade conduction over a left‐sided nodofascicular tract was present in two patients and the diagnosis of a concealed nodofascicular was made in the third patient after ruling out other tachycardia mechanisms. Two patients had automatic junctional tachycardia, and one patient had atroventricular nodal reentry with proximal common pathway block. Attempted ablation in the posterior and mid‐septum was unsuccessful in patients with nodofascicular tachycardia. In contrast, those with atrioventricular nodal reentry and automatic junctional tachycardia readily responded to ablation. The presence of a nodofascicular tachycardia should be suspected if: (1) intermittent antegrade preexcitation is recorded, (2) the tachycardia can be initiated with a single atrial premature producing two ventricular complexes, and (3) a single ventricular extrastimulus initiates SVT without a retrograde His deflection. The presence of a nodofascicular pathway is common in patients with narrow complex tachycardia and VA block. Unlike AV nodal reentry and automatic junctional tachycardia, the response to ablation is poor.
Different Trends of Changes in Heart Rate Variability in Patients with Anterior and Inferior Acute Myocardial Infarction
Authors: PITZALIS MARIA VITTORIA , MASTROPASQUA FILIPPO , MASSARI FRANCESCO , PASSANTINO ANDREA , LUZZI GIOVANNI , LIGURGO LUANA , COLOMBO ROBERTO , BIASCO MARIA GIUSEPPINA , RIZZON PAOLO
Published: July 2006

Modifications in heart rate variability (HRV) parameters occur after acute myocardial infarction. The aim of this study was to evaluate the trend of HRV change during the acute phase and the first month after myocardial infarction, and establish whether they were affected by the anterior or inferior location of the infarction. The time‐domain HRV measures of 59 patients with a first uncomplicated acute myocardial infarction were computed from 24‐hour ECG recordings made on days 1, 2, 10, and 28 after hospital admission. At day 1, the mean RR cycle length (NN), the standard deviation of the NN intervals (SDNN), and the root mean square successive difference of NN intervals (RMSSD) were lower in the patients with anterior myocardial infarction. Although the parameters were similar in all of the patients at day 28, their behavior over time was different (P = 0.01): the SDNN in the patients with inferior myocardial infarction had decreased to the values found in anterior myocardial infarction patients by day 2 but, at day 10, both NN and SDNN tended to recover in both groups; RMSSD had diminished in both groups by day 2, but at day 10, had increased in the patients with anterior, but not in those with inferior myocardial infarction. These findings suggest that (1) in the very early phase of myocardial infarction, HRV is different in the two locations, (2) during the first hours of myocardial infarction patients with inferior location showed a greater vagal activity than patients with anterior location that became lower at day 10, and (3) the recovery of HRV is an early phenomenon in both groups, being already evident by the second week after myocardial infarction.