bluuebunny/crossref_metadata_2025 huggingface dataset:
Changes in Quality‐of‐Life After Pacemaker Implantation: Responsiveness of the Aquarel Questionnaire
Authors: STOFMEEL MONIQUE A. M. , POST MARCEL W. M. , KELDER JOHANNES C. , GROBBEE DIEDERICK E. , VAN HEMEL NORBERT M.
Published: July 2003

STOFMEEL, M.A.M., et al.: Changes in Quality‐of‐Life After Pacemaker Implantation: Responsiveness of the Aquarel Questionnaire. Before being introduced for widespread use, health status instruments should be evaluated for reliability, validity, and responsiveness to relevant clinical changes. In a previous study the validity and reliability of Aquarel, a disease‐specific quality‐of‐life (QOL) questionnaire for pacemaker patients, were tested and found satisfactory. The purpose of this study was to assess the sensitivity to change in health of Aquarel. A cohort of 51 patients was assessed at baseline and at 4–6 weeks after pacemaker implantation. We compared the sensitivity to change over time on the Aquarel scores to the scores on the SF‐36 using various techniques (t‐test value, effect size, standard error of measurement). Using the 1‐standard error of measurement (SEM) criterion for clinically relevant change, Aquarel seemed to provide better classification of patients compared to the SF‐36 alone. This study supports the value of Aquarel as a disease‐specific measure of QOL in pacemaker patients.
Excimer Laser‐Assisted Extraction of an Infected Bipolar Left Ventricular Pacing Lead Implanted 10 Years Ago
Authors: NÄGELE H. , SCHNEIDER J. CH. , KNOBELSDORFF G. V. , PETERSEN B. , RÖDIGER W.
Published: July 2003

NÄGELE, H., et al.: Excimer Laser‐Assisted Extraction of an Infected Bipolar Left Ventricular Pacing Lead Implanted 10 Years Ago. Routine intraoperative transesophageal echocardiography (TEE) revealed a previously undiscovered ventricular positioning of an infected ventricular lead left in place for 10 years. This case report describes successful removal of this lead from the left ventricle by means of excimer laser and discusses some important aspects to be considered.
Central Venous Access Resulting in Selective Failure of ICD Defibrillation Capacity
Authors: VARMA NIRAJ , CUNNINGHAM DAVID , FALK RODNEY
Published: July 2003

VARMA, N., et al.: Central Venous Access Resulting in Selective Failure of ICD Defibrillation Capacity. In a patient with a defibrillator system incorporating a lead with integrated bipolar sensing, physical contact between a guidewire (inserted for venous access) and the right ventricular defibrillation coil created sensing artefacts that triggered an inappropriate discharge. The presence of the guidewire in the heart during the discharge resulted in an electrical short with irreversible damage to the generator and rendered it incapable of delivering further high voltage therapy.
Clinical Value of Electrocardiographic Parameters in Genotyped Individuals with Familial Long QT Syndrome
Authors: MOENNIG GEROLD , SCHULZE‐BAHR ERIC , WEDEKIND HORST , BORGGREFE MARTIN , FUNKE HARALD , TOELLE MICHAEL , KIRCHHOF PAULUS , ECKARDT LARS , ASSMANN GERD , BREITHARDT GÜNTER , HAVERKAMP WILHELM
Published: July 2003

MOENNIG, G., et al.: Clinical Value of Electrocardiographic Parameters in Genotyped Individuals with Familial Long QT Syndrome. Rate corrected QT interval (QTc) and QT dispersion (QTd) have been suggested as markers of an increased propensity to arrhythmic events and efficacy of therapy in patients with long QT syndrome (LQTS). To evaluate whether QTc and QTd correlate to genetic status and clinical symptoms in LQTS patients and their relatives, ECGs of 116 genotyped individuals were analyzed. JTc and QTc were longest in symptomatic patients (n = 28). Both QTd and JTd were significantly higher in symptomatic patients than in asymptomatic (n = 29) or unaffected family members (n = 59). The product of QTd/JTd and QTc/JTc was significantly different among all three groups. Both dispersion and product put additional and independent power on identification of mutation carriers when adjusted for sex and age in a logistic regression analysis. Thus, symptomatic patients with LQTS show marked inhomogenity of repolarization in the surface ECG. QT dispersion and QT product might be helpful in finding LQTS mutation carriers and might serve as additional ECG tools to identify asymptomatic LQTS patients.
Implantation of a Dual Chamber Pacing and Sensing Single Pass Defibrillation Lead
Authors: GRADAUS RAINER , BLOCK MICHAEL , DORSZEWSKI ANJA , SCHRIEVER CHRISTOPH , HAMMEL DIETER , SCHELD HANS H. , BORGGREFE MARTIN , BREITHARDT GÜNTER , BÖCKER DIRK
Published: July 2003

GRADAUS, R., et al.: Implantation of a Dual Chamber Pacing and Sensing Single Pass Defibrillation Lead. Dual‐chamber ICDs are increasingly used to avoid inappropriate shocks due to supraventricular tachycardias. Additionally, many ICD patients will probably benefit from dual chamber pacing. The purpose of this pilot study was to evaluate the intraoperative performance and short‐term follow‐up of an innovative single pass right ventricular defibrillation lead capable of bipolar sensing and pacing in the right atrium and ventricle. Implantation of this single pass right ventricular defibrillation lead was successful in all 13 patients (age 63 ± 8 years; LVEF 0.44 ± 0.16; New York Heart Association [NYHA] 2.4 ± 0.4, previous open heart surgery in all patients). The operation time was 79 ± 29 minutes, the fluoroscopy time 4.7 ± 3.1 minutes. No perioperative complications occurred. The intraoperative atrial sensing was 1.7 ± 0.5 mV, the atrial pacing threshold product was 0.20 ± 0.14 V/ms (range 0.03–0.50 V/ms). The defibrillation threshold was 8.8 ± 2.7 J. At prehospital discharge and at 1‐month and 3‐month follow‐up, atrial sensing was 1.9 ± 0.9, 2.1 ± 0.5, and 2.7 ± 0.6 mV, respectively, (P = NS, P < 0.05, P < 0.05 to implant, respectively), the mean atrial threshold product 0.79, 1.65, and 1.29 V/ms, respectively. In two patients, an intermittent exit block occurred in different body postures. All spontaneous and induced ventricular arrhythmias were detected and terminated appropriately. Thus, in a highly selected patient group, atrial and ventricular sensing and pacing with a single lead is possible under consideration of an atrial pacing dysfunction in 17% of patients.
Safety and Efficiency of Pulse Charge Multiplication for Chronic Ventricular Output Programming
Authors: KINDERMANN MICHAEL , KUSCH OLIVER , FRÖHLIG GERD , MARKWIRTH TORSTEN , SCHWAAB BERNHARD , SCHWERDT HOLGER
Published: July 2003

KINDERMANN, M., et al.: Safety and Efficiency of Pulse Charge Multiplication for Chronic Ventricular Output Programming. Fifty‐one patients with Intermedics pacemakers and different chronic (≥ 12 months) ventricular lead models were investigated. Ventricular charge thresholds (μC) were measured telemetrically at 1.0, 2.0, 2.5, and 3.5 V, respectively. Then pulse duration was increased until charge per pulse (μC) was twice the threshold value in patients not being pacemaker dependent (n = 39) and three times the threshold in pacemaker dependent patients (n = 12), thus giving a 2:1 or 3:1 safety factor in terms of charge (“safety charge”). At safety charge settings, the battery current was measured telemetrically for all four pulse amplitudes (PA) in VVI mode at 70 beats/min. For safety purposes, only pulse amplitudes were considered that fulfilled two conditions: (1) pulse duration threshold (PDT) ≤ 0.30 ms at PA and (2) PDT ≤ 1.00 ms at a pulse amplitude of (PA‐0.5 V). The combination of pulse amplitude and pulse duration that yielded the safety charge at the lowest battery current was defined as optimized ventricular output (Copt). It was found at 1.0 V in 27 patients and at 2.0 V in 24 patients. The safety pulse duration (SPD) that yielded a 2:1 safety charge in patients who were not pacemaker dependent was 0.32 ± 0.12 ms for both, 1.0 V (n = 23) and 2.0 V (n = 16), respectively. In pacemaker dependent patients, the SPD for the 3:1 safety charge was 0.61 ± 0.25 ms (at 1.0 V, n = 4) and 0.47 ± 0.11 ms (at 2.0 V, n = 8), respectively. The safety factor for conversion of PDT into SPD was 3.15 (range 3.00–3.38) for pacemaker dependent patients and 2.04 (range 2.00–2.43) for patients who were not pacemaker dependent, respectively. Charge thresholds measured at study entrance, after 24 hours, and again after 6 months showed a median variation of 14% and a maximum individual variation of 55%. On day 0 and 180, 24‐hour Holter recordings were obtained from all patients and revealed constant ventricular capture at output settings Copt. When the output was changed from a fixed setting (2.5 V at 0.50 ms) to Copt, the battery current decreased by 17.5% (P < 0.0001). In conclusion, pacing thresholds in patients with chronic ventricular leads are stable enough to permit programming battery‐saving low output settings, if pacemakers are followed on a regular basis. Titration of a 2:1 safety charge (a 3:1 safety charge in pacemaker dependent patients) by prolongation of pulse duration is safe, provided that pulse amplitude is chosen carefully. Using this approach, current consumption can significantly be reduced without jeopardizing patient's life.
Adenosine Induced Ventricular Arrhythmias in the Emergency Room
Authors: TAN HANNO L. , SPEKHORST HANS H.M. , PETERS RON J.G. , WILDE ARTHUR A.M.
Published: July 2003

TAN, H.L., et al.: Adenosine Induced Ventricular Arrhythmias in the Emergency Room. While adenosine effectively terminates most supraventricular tachycardias (SVT), rare case reports have demonstrated its proarrhythmic potential, including induction of ventricular tachycardia (VT). The aim of this study was to define the proarrhythmic effects of adenosine in a large, unselected population. During a 5‐year period, adenosine was used (average dose 9.7 mg) in the emergency room to manage 187 episodes of tachycardia in 127 patients. In two thirds of the cases, adenosine induced ventricular ectopy following successful termination of SVT, including premature ventricular complexes (PVC) and nonsustained VT. The adenosine induced PVCs and VT were transient and self‐terminating. More than half had a right bundle branch block morphology with a superior axis that suggested an origin in the inferior left ventricular septum. In conclusion, although adenosine is commonly used in clinical practice to treat SVTs, we found that it induced PVCs and VT in two thirds of the patients. The high incidence of ventricular arrhythmias following adenosine infusion was surprising but did not require further intervention. These arrhythmias appeared to frequently originate from the inferior left ventricular septum, suggesting that this area may be particularly susceptible to the proarrhythmic effects of adenosine.
A Cephalic Vein Cutdown and Venography Technique to Facilitate Pacemaker and Defibrillator Lead Implantation
Authors: TSE HUNG‐FAT , LAU CHU‐PAK , LEUNG SUM‐KIN
Published: July 2003

TSE, H.–F., et al.: A Cephalic Vein Cutdown and Venography Technique to Facilitate Pacemaker and Defibrillator Lead Implantation. The aim of this study was to assess the feasibility of a cephalic vein cutdown and venography technique for implantation of a pacemaker or ICD and to determine the causes of failure of cephalic vein cutdown. In consecutive patients who underwent pacemaker or ICD implants, a modified cephalic vein guidewire technique was performed. This technique was attempted in 289 pacemaker implants and 26 ICD implants (155 men, 160 women; mean age 74 ± 10 years). The success rate for implantation of a single chamber and a dual chamber device by using this technique alone was 84% (54/64) and 74% (185/251), respectively (P = 0.10). In an additional 7% of patients with dual chamber implant, the cephalic vein can be used for passage of the ventricular lead. A cephalic venogram was required in 82 patients and facilitated the passage of the guidewire in 62 (79%) of them. No complication related to vascular access was observed with this technique. This technique failed in 54 (17%) of 315 patients due to (1) failure of cephalic vein isolation (48%), (2) venous stenosis (24%), or (3) venous torturosity or anomalies (28%). There were no significant differences in the patient's age, sex, type of device, and the fluoroscopic time for lead placement between patients with or without successful lead placement using this technique (all P > 0.05). In conclusion, a simple modification of the cephalic vein guidewire technique together with venography has facilitated the placement of leads during pacemaker and ICD implant. This technique is safe and applicable in the majority of patients and avoids the risk of subclavian puncture.
Spontaneous, Electrically, and Cesium Chloride Induced Arrhythmia and Afterdepolarizations in the Rapidly Paced Dog Heart
Authors: JONES DOUGLAS L. , PETRIE JEAN‐PAUL , LI HUAGUI G.
Published: July 2003

JONES, D.L., et al.: Spontaneous, Electrically, and Cesium Chloride Induced Arrhythmia and Afterdepolarizations in the Rapidly Paced Dog Heart. Despite frequent arrhythmia and sudden death in heart failure, attempts to study arrhythmia mechanisms in patients are difficult. The dog heart, paced for several weeks at a fast rate to induce heart failure is prone to arrhythmia. The aim of this study was to determine the activation patterns of spontaneous and electrically induced arrhythmia and the susceptibility of the failing dog heart to arrhythmia and early afterdepolarization (EAD) induced triggered activity elicited by exogenous administration of cesium chloride (CsCl). The hearts of 56 mongrel dogs were paced at 240 beats/min for 3–5 weeks (heart failure group). Twenty‐one similarly operated, but not paced dogs served as the control group. At baseline, all dogs were healthy as assessed electrophysiologically and hemodynamically. Spontaneous (bradycardia, tachycardia, and arrhythmic deaths) and electrically induced arrhythmia was frequent in dogs with heart failure. Also, the minimal dose of CsCl that produced ventricular tachycardia was significantly lower in the heart failure than the control dogs (1.02 ± 0.02 vs 1.21 ± 0.07 mMol/kg, P < 0.05). Epicardial mapping during spontaneous and electrically induced arrhythmia in the heart failure dogs showed initiation patterns with focal origin, often from multiple sites. This pattern was consistent with the patterns observed with CsCl induced ventricular tachycardia. In in vitro microelectrode studies, CsCl superfusion (2.5–5 mMol/L) induced triggered activity due to EADs within 30 minutes, in seven of the eight Purkinje fibers from four heart failure dogs. EADs were also found in ventricular myocytes of papillary muscle from two heart failure dogs. In contrast, 5 mMol/L CsCl induced EADs in only one of eight Purkinje fibers from the hearts of four control dogs and no papillary myocytes even with continuous superfusion for up to 60 minutes (P < 0.01). These results demonstrate that pacing induced heart failure in the dog has an increased tendency to develop ventricular tachycardia and triggered activity unmasked by CsCl.
Effect of the Atrial Blanking Time On the Detection of Atrial Fibrillation in Dual Chamber Pacing
Authors: NOWAK BERND , KRACKER STEFAN , RIPPIN GERD , HORSTICK GEORG , VINCENT ALPHONS , GEIL STEPHANIE , HIMMRICH EWALD , MEYER JÜRGEN
Published: July 2003

NOWAK, B., et al.: Effect of the Atrial Blanking Time On the Detection of Atrial Fibrillation in Dual Chamber Pacing. Patients with paroxysmal atrial fibrillation (PAF) and dual chamber pacemakers frequently have short postventricular atrial blanking times and sensitive atrial sensing thresholds used to provide reliable detection and mode switching during AF. However, short atrial blanking times increase the risk of atrial sensing of ventricular far‐field signals. We evaluated if the length of the atrial blanking time influences the detection of AF. The study included ten patients with a VDDR (n = 7) or DDDR system (n = 3), who presented with AF at 18 follow‐up visits. Bipolar atrial sensing was programmed to the most sensitive value. Atrial blanking times were programmed from 100 to 200 ms in 25‐ms steps in each patient. Using marker annotation, the following parameters were measured at ten consecutive ventricular beats: VAF = the interval between ventricular stimulus and first sensing of AF; AFS = the number of atrial‐sensed events between two ventricular events; and XAF = the interpolated number of atrial‐sensed events during atrial blanking time. The intervals between ventricular events and between atrial‐sensed event markers showed no significant differences for the five blanking times tested. There was no significant influence of the atrial blanking time onto the measured parameters (least square means ± standard error) with VAF between 281 ± 12 and 300 ± 12 ms (P = NS), AFs between 3.4 ± 0.2 and 3.6 ± 0.2 beats (P = NS) and XAF between 1.84 ± 0.12 and 2.03 ± 0.12 beats (P = NS). At ventricular rates < 100/min, the atrial sensing of AF in dual chamber pacemakers demonstrated no evidence for deterioration by an increase of the atrial blanking time from 100 to 200 ms. Thus, the risk of ventricular far‐field sensing may be reduced without compromising atrial sensing.
Bradycardia and Permanent Pacing After Bilateral Thoracoscopic T2‐Sympathectomy for Primary Hyperhidrosis
Authors: LAI CHAO‐LUN , CHEN WEN‐JONE , LIU YEN‐BIN , LEE YUAN‐TEH
Published: July 2003

LAI, C.‐L., et al.: Bradycardia and Permanent Pacing After Bilateral Thoracoscopic T2‐Sympathectomy for Primary Hyperhidrosis. A 23‐year‐old woman with craniofacial hyperhidrosis underwent bilateral thoracoscopic T2‐sympathectomy. Marked sinus bradycardia with a mean heart rate of 49 beats/min by Holter ECG monitoring occurred after the procedure and persisted for > 2 years. Normal sinus node function was found by an invasive electrophysiological study and unopposed vagotonia after sympathectomy was diagnosed. A permanent pacemaker was implanted. Although reduced heart rate is a common phenomenon after bilateral dorsal sympathectomy, intractable bradycardia with permanent pacing is rare. This patient demonstrates one of the potential cardiac complications of bilateral sympathectomy.
Central Clinical Research Issues in Electrophysiology: Report of the NASPE Committee
Authors: DOMANSKI MICHAEL J. , ZIPES DOUGLAS P. , BENDITT DAVID G. , CAMM A. JOHN , EXNER DEREK V. , EZEKOWITZ MICHAEL D. , GREENE H. LEON , LESH MICHAEL D. , MILLER JOHN M. , PRATT CRAIG M. , SAKSENA SANJEEV , SCHEINMAN MELVIN M. , SINGH BRAMAH N. , TRACY CYNTHIA M. , WALDO ALBERT L.
Published: July 2003

DOMANSKI, M.J., et al.: Central Clinical Research Issues in Electrophysiology: Report of the NASPE Committee. This article contains the results of an attempt by appointed members of the North American Society of Pacing and Electrophysiology to define the research frontier in electrophysiology and suggest areas of study as an aid in setting the research agenda.
Mechanisms of Antiarrhythmic Drug Action on Termination of Atrial Flutter
Authors: TAI CHING‐TAI , CHEN SHIH‐ANN
Published: July 2003

TAI, C.‐T., et al.: Mechanisms of Antiarrhythmic Drug Action on Termination of Atrial Flutter. Atrial flutter is an important arrhythmia in clinical practice. Although the reentrant circuit of human typical atrial flutter is well characterized, the action of antiarrhythmic drugs on this tachycardia is less understood. Based on the recent clinical trials, pure Class III drugs like ibutilide or dofetilide are more effective in acute termination of human atrial flutter than Class I drugs like procainamide or flecainide. The mechanisms of drug induced termination of atrial flutter include refractory block due to cycle length oscillation, fixed block due to a reduced safety factor for conduction, or a collision of opposing wavefronts due to loss of the lateral boundaries or return reexcitation. Because ventricular proarrhythmia is a major concern with ibutilide or dofetilide therapy, development of new drugs with more specific target profiles is a future direction for treatment of human atrial flutter.
Inappropriate Detection of Supraventricular Arrhythmias by Implantable Dual Chamber Defibrillators: A Comparison of Four Different Algorithms
Authors: HINTRINGER FLORIAN , SCHWARZACHER SEVERIN , EIBL GUENTHER , PACHINGER OTMAR
Published: July 2003

HINTRINGER, F., et al.: Inappropriate Detection of Supraventricular Arrhythmias by Implantable Dual Chamber Defibrillators: A Comparison of Four Different Algorithms. Inappropriate therapy of supraventricular tachyarrhythmias by an ICD is still a common problem. Dual chamber (DDD) ICDs provide additional atrial sensing and should result in higher specificity for detection of supraventricular tachyarrhythmias. However, a direct comparison of different dual chamber algorithms has not been reported. The detection algorithms of four different DDD ICDs were tested: Phylax AV, Defender IV, Ventak AV III DR, and Gem DR 7271. Based on arrhythmias recorded from patients undergoing invasive electrophysiological studies and in many cases of catheter ablation at our institution, a library consisting of 71 supraventricular and 15 ventricular tachyarrhythmias was created. The library consists of episodes of atrial fibrillation, atrial flutter with different AV conduction, typical and atypical AV nodal reentrant tachycardia, AV reentrant tachycardia, sinus tachycardia, and ventricular tachycardia with and without ventriculoatrial conduction. Atrial fibrillation was appropriately classified by all four algorithms. However, the specificity for detection of other supraventricular tachyarrhythmias achieved by the Biotronik (12%) and the Guidant (11%) devices was significantly lower compared to the specificity of the ELA (28%) and the Medtronic DDD ICD (20%). This is due to the fact that the Biotronik and the Guidant algorithm classified all supraventricular tachyarrhythmias resulting in a stable ventricular rate as ventricular tachycardia, whereas the ELA and Medtronic algorithms performed a more detailed analysis by assessment of PR association, atrial onset, or timing of the atrial event relative to the ventricular event, respectively. Atrial fibrillation, the most common supraventricular tachyarrhythmia in patients with ICD, was detected by all devices.
The World Survey of Cardiac Pacing and Implantable Cardioverter Defibrillators: Calendar Year 1997 ‐ Europe
Authors: ECTOR HUGO , RICKARDS ANTHONY F. , KAPPENBERGER LUKAS , LINDE CECILIA , VARDAS PANOS , OTO ALI , SANTINI MASSIMO , SUTTON RICHARD ,   THE WORKING GROUP ON CARDIAC PACING
Published: July 2003

ECTOR, H., et al.: The World Survey of Cardiac Pacing and Implantable Cardioverter Defibrillators: Calendar Year 1997 – Europe. The registry of the European Working Group on Cardiac Pacing (EWGCP) is based on the European Pacemaker Identification Card originally designed in July 1978. National registration centers collect the local data and send aggregated annual data to the EWGCP. For 1997, data were obtained from 2,887 hospitals in 20 European countries representing a population of 568 million. Across all participating countries, the median value for all implanted pacemakers was 378 per million population. For initial pacemaker implants, the median value was 290 per million population. Single chamber atrial pacing was important in Denmark, the Netherlands, Poland, Slovak Republic, Spain, and Sweden for the treatment of sick sinus syndrome. Dual chamber pacing accounted for < 50% of initial implants in only 5 of 14 countries for atrioventricular block, and in only 3 of 15 countries for sick sinus syndrome. In 7 of 15 countries, unipolar ventricular leads were used in ≥ 50% of cases. In 6 of 14 countries, there was > 15% use of unipolar atrial leads. Nine of 13 countries frequently used atrial active‐fixation leads. For the 1997 survey, ICD data were obtained from 16 countries. The total number of ICDs per million population was a median value of 14. Initial ICD implants per million population was 11. Only 3 of 16 countries implanted a total of 30 or more ICDs per million population. Pacing and ICD practices were dependent on the availability of medical and technical resources and influenced by economic constraints inherent in health care administration and insurance coverage patterns.
Hyperkalemia Diagnosed by Implantable Cardioverter Defibrillator T Wave Sensing
Authors: ARTHUR WAYNE , KAYE G.C.
Published: July 2003

ARTHUR, W., et al.: Hyperkalemia Diagnosed by Implantable Cardioverter Defibrillator T Wave Sensing. A patient with congestive heart failure and an ICD had undergone atrioventricular nodal ablation and optimization of heart failure medical therapy. Intracardiac T wave sensing by the ICD drew attention to the new development of asymptomatic hyperkalemia. Surface ECG features of hyperkalemia were not readily identified due to pacemaker dependence.
Spontaneous Reattachment of a Dislodged Atrial Lead
Authors: YIN WEI‐HSIAN , JEN HSU‐LUNG , YOUNG MASON‐SHING
Published: July 2003

YIN, W.‐H., et al.: Spontaneous Reattachment of a Dislodged Atrial Lead. Acute lead dislodgment is a complication that should be managed immediately. Spontaneous reattachment of a dislodged atrial pacing lead has never been reported before. This case report describes a lucky patient whose atrial lead spontaneously gained a new functioning position after dislodgment from its initial implantation site.
Myocardial Injury During Radiofrequency Catheter Ablation: Comparison of Focal and Linear Lesions
Authors: CARLSSON JOERG , ERDOGAN ALI , GUETTLER NORBERT , SCHULTE BRITTA , LAY DAGMAR , NEUZNER JOERG , HAMM CHRISTIAN W. , PITSCHNER HEINZ F.
Published: July 2003

CARLSSON, J., et al.: Myocardial Injury During Radiofrequency Catheter Ablation: Comparison of Focal and Linear Lesions. The aim of study was to investigate the extent of myocardial injury incurred by creation of continuous RF current induced linear ablation lesions (LL; ablation of atrial fibrillation, right atrial procedure) in comparison to focal RF lesions (FL; AV node reentry tachycardia, WPW tachycardia). In 23 patients with LL (age 51.3 ± 11.2 years, 18 men, 5 women) and in 16 patients with FL (age 53.9 ± 5.1 years, 8 men and 8 women), levels of creatine kinase (CK), myoglobin (MG), CKMB mass (CKMB M), CKMB activity (CKMB A), and cardiac troponin T (cTnT) were determined before and 2, 4, 8, 24, and 48 hours after ablation. CKMB A was normal in 87% in LL and 100% in FL (< 6% of CK) with median maximum CK values of 214 (45–1583) U/L in LL and 36 (29–212) U/L in FL. Peak values of all parameters were significantly higher in LL than in FL. The sensitivity of cTnT was 50% in FL and 100% in LL. In FL MG, total CK, and CKMB M were abnormal in only 12.5% of cases while in LL MG and CKMB M were pathological in 100% and total CK was abnormal in 91.3% of patients. The amount of energy and number of RF applications correlated with cTnT, MG, and CKMB M (P = 0.01). In conclusion, (1) long linear RF current lesions for ablation of atrial fibrillation are associated with significantly greater myocardial injury than focal ablations. (2) In focal lesions only cTnT provided a sensitivity of 50% in the detection of myocardial injury while in linear lesions cTnT, CKMBM, and CKMB M seemed suitable for detection of RF current induced myocardial damage with 100% sensitivity. All biochemical parameters do not differentiate patients with coronary ischemia up to 48 hours after an ablation. (3) Further investigations are necessary to determine if RF current linear lesions lead to impaired atrial contractility in cases of extensive tissue damage.
Successful Pediatric Stenting of a Nonthrombotic Coronary Occlusion as a Complication of Radiofrequency Catheter Ablation
Authors: STROBEL GUNNAR G. , TREHAN SANJEEV , COMPTON STEVEN , JUDD VICTORIA E. , DAY RONALD W. , ETHERIDGE SUSAN P.
Published: July 2003

STROBEL, G.G., et al.: Successful Pediatric Stenting of a Nonthrombotic Coronary Occlusion as a Complication of Radiofrequency Catheter Ablation. This is a case of a right coronary artery occlusion complicating a RF catheter ablation of a posteroseptal accessory connection in an 8‐year‐old boy. After multiple balloon angioplasty attempts in the occluded vessel, only transient patency was achieved. The occlusion was successfully treated with placement of an intracoronary stent.
Pneumomediastinum and Subcutaneous Emphysema from Pacemaker Placement
Authors: ESPIRITU JOSEPH D. , KELLER CESAR A.
Published: July 2003

ESPIRITU, J.D., et al.: Pneumomediastinum and Subcutaneous Emphysema From Pacemaker Placement. Percutaneous insertion of permanent pacemaker leads through the subclavian vein is an alternative to the cephalic vein approach. A rare occurrence and successful conservative management of extensive pneumomediastinum and subcutaneous emphysema without concomitant pneumothorax resulting from permanent transvenous pacemaker insertion in an 80‐year‐old man with syncope and arrhythmia is reported.
Intraoperative Study of Polarization and Evoked Response Signals in Different Endocardial Electrode Designs
Authors: LAU CHING , NISHIMURA SANDRA C. , YEE RAYMOND , LEFEUVRE CATHERINE , PHILIPPON FRANCOIS , CAMERON DOUGLAS A.
Published: July 2003

LAU, C., et al.: Intraoperative Study of Polarization and Evoked Response Signals in Different Endocardial Electrode Designs. Some new generation pacemakers use an algorithm based on evoked response (ER) detection to verify beat‐to‐beat capture and to enable automatic adjustment of output. This is a prospective acute study of polarization signal (PS) and ER in nine currently available electrodes. Intraoperative testing of ventricular bipolar electrodes used the Autocapture (AC) algorithm. The intrinsic R wave, PS, ER, acceptance of AC function, and stimulation thresholds (STs) were obtained. Ventricular electrodes were categorized as follows: titanium nitride (TiN)‐coated passive and active fixation, high impedance (HI), passive fixation (VP), iridium oxide‐coated titanium (IROX) (VI), and platinum helix (PH) active fixation. Acute testing was performed in 217 patients with an average age of 74.26 years, 59.6% were men with primary pacing indication‐SSS (46.3%). There were no significant differences found with respect to R wave and threshold between the various electrodes. PH active‐fixation electrodes had significantly higher ER and PS than other groups including the TiN‐coated active‐fixation electrodes. TiNcoated electrodes (active and passive fixation) had significantly lower PS than other electrodes. As a result, TiN electrodes had a significantly higher functional rate of AC (91.7%), whereas PH had the lowest rate (0%). In conclusion, (1) polarization characteristics are significantly different for commercially available ventricular electrodes, (2) certain physical features at the tissue to electrode interface like TiN coating appears to be more important in determining PS than electrode tip size and fixation method, and (3) the current algorithm for AC requires electrodes that provide low polarization for satisfactory performance.
The Prognostic Significance of Atrial Arrhythmias Recorded Early After Cardioversion for Atrial Fibrillation
Authors: MAOUNIS THEMISTOCLIS , KYROZI ELENA , KATSAROS KONSTANTINOS , BILIANOU ELENI , VASSILIKOS VASSILIOS P. , MANOLIS ANTHONY S. , COKKINOS DENNIS
Published: July 2003

MAOUNIS, T., et al.: The Prognostic Significance of Atrial Arrhythmias Recorded Early After Cardioversion for Atrial Fibrillation. In a substantial number of patients, AF recurs after successful electrical cardioversion. The purpose of this study was to investigate if the atrial arrhythmias recorded immediately after cardioversion are associated with the risk of recurrence of the arrhythmia and to compare the prognostic significance of this parameter with that of other established risk factors. In a series of 71 patients, the risk factors for recurrence of AF during the first year after successful electrical cardioversion were analyzed. A new parameter that was investigated was the frequency of atrial premature beats and the presence of runs of supraventricular tachycardia in the Holter recording started immediately after the cardioversion. Age, left atrial size, left ventricular systolic function, duration of the arrhythmia before cardioversion, underlying cardiac disease, or medication taken were not found to be predictive of recurrence of the arrhythmia. However, the natural logarithm of the number of atrial premature complexes per hour of the Holter recording in the 37 patients in whom AF recurred was higher compared to that of the 34 patients who maintained sinus rhythm (P < 0.0005). The same was true if only the first 6 hours of the recording were analyzed (P < 0.0005). There was a trend for more frequent arrhythmia recurrence if runs of supraventricular tachycardia were present. The finding of > 10 atrial premature complexes per hour in the recording had a relative risk of 2.57 (1.51–4.37), a positive predictive accuracy of 76.5%, and a negative predictive accuracy of 70.3% for subsequent arrhythmia recurrence. We can conclude that frequent (> 10/hour) atrial premature complexes in the Holter recording after electrical cardioversion for AF is a significant risk factor for recurrence of the arrhythmia.
Spontaneous Regression Over a 16‐Year Period of Tachyarrhythmias to Sick Sinus Syndrome and Complete Atrioventricular Block in a Young Patient with Ebstein's Anomaly
Authors: NODA MAKOTO , YAMAGUCHI HIROAKI , FUJII HIROYUKI , KAKUTA TSUNEKAZU , SARASHINA MAKO , SAKURADA HARUMIZU , KISHI YUKIO , ISOBE MITSUAKI , NUMANO FUJIO
Published: July 2003

NODA, M., et al.: Spontaneous Regression Over a 16‐Year Period of Tachyarrhythmias to Sick Sinus Syndrome and Complete Atrioventricular Block in a Young Patient with Ebstein's Anomaly. A 25‐year‐old man with Ebstein's anomaly showed spontaneous regression of tachyarrhythmias to sick sinus syndrome and complete atrioventricular block over a 16‐year period. This is the first clinical report supporting the hypothesis that abnormal cell death might contribute to the disturbance of the heart conduction system in Ebstein's anomaly.
Triple‐Site Ventricular Pacing in a Biventricular Pacing System
Authors: VAN GELDER BERRY M. , BRACKE FRANK A. , PILMEYER ART , MEIJER ALBERT
Published: July 2003

VAN GELDER, B.M., et al.: Triple‐Site Ventricular Pacing in a Biventricular Pacing System. This case report describes a patient with heart failure in whom a biventricular pacing system was successfully implanted. During control of the pacing system, three morphologies of the paced QRS complex could be elucidated. Right ventricular stimulation, biventricular stimulation, and biventricular pacing with additional stimulation from the anodal electrode of the right ventricular lead determined the morphologies.
Acute Loss of Capture Due to Flecainide Acetate
Authors: ANTONELLI DANTE , FREEDBERG NAHUM A. , ROSENFELD TIBERIO
Published: July 2003

ANTONELLI, D., et al.: Acute Loss of Capture Due to Flecainide Acetate. Antiarrhythmic drugs increase pacing threshold, but this is rarely of clinical significance. Administration of flecainide acetate in a 75‐year‐old woman with an implanted AAIR pacemaker because of sick sinus syndrome caused an abrupt rise of pacing threshold and failure of pacing. Pacing threshold returned to the normal value a few days after flecainide treatment was stopped.
Magnetocardiographic Intra‐QRS Fragmentation Analysis in the Identification of Patients with Sustained Ventricular Tachycardia after Myocardial Infarction
Authors: KORHONEN PETRI , MONTONEN JUHA , ENDT PETER , MÄKIJÄRVI MARKKU , TRAHMS LUTZ , KATILA TOIVO , TOIVONEN LAURI
Published: July 2003

KORHONEN, P., et al.: Magnetocardiographic Intra‐QRS Fragmentation Analysis in the Identification of Patients with Sustained Ventricular Tachycardia after Myocardial Infarction. The aim of this study was to investigate if magnetocardiographic (MCG) analysis of cardiac micropotentials within the QRS complex can identity patients prone to ventricular arrhythmias, and to compare it to MCG time‐domain, late‐field analysis. The study population consisted of 136 patients with remote MI, 53 with and 83 without a history of VT. After averaging and high pass filtering of multichannel MCG signals, time‐domain parameters describing the end‐QRS activity and fragmentation index M and score S describing the whole QRS complex were computed. Fragmentation and time‐domain parameters differed between the VT and control groups: fragmentation index M was 12 ± 3 versus 9 ± 2 (P < 0.001), fragmentation score S was 83 ± 42 versus 56 ± 21 (P < 0.001), and filtered QRS duration was 144 ± 32 versus 114 ± 19 ms (P < 0.001) in VT and control groups, respectively. A combination of fragmentation parameters yielded 87% sensitivity and 61% specificity in VT identification. Corresponding figures for a time‐domain parameter combination were 81% and 72%. Sensitivity of time‐domain analysis was 88% and specificity was 75% in a subgroup with anterior MI. In multivariate analysis, fragmentation and time‐domain analyses discriminated VT patients from controls independently of the extent of coronary artery disease or left ventricular dysfunction. MCG in postinfarction patients reveals pathology associated with propensity to ventricular arrhythmias inside and not only at the end of the QRS complex. MCG seems most accurate in the anterior infarct location.
A Randomized Comparison of the Straight Linear Approach with Electrogram Mapping Focal Approach in Selective Slow Pathway Ablation
Authors: HAYASHI MEISO , KOBAYASHI YOSHINORI , MIYAUCHI YASUSHI , INO TAKESHI , ATARASHI HIROTSUGU , TAKANO TERUO
Published: July 2003

HAYASHI, M., et al.: A Randomized Comparison of the Straight Linear Approach with Electrogram Mapping Focal Approach in Selective Slow Pathway Ablation. The aim of this study was to evaluate the efficacy and safety of the anatomic linear approach in selective AVN slow pathway ablation, in comparison to the widely used electrogram mapping focal approach. It remains undetermined whether or not anatomic linear ablation has a greater potential for eliminating slow pathway conduction than does focal ablation. Fifty consecutive patients (21 men, 29 women, age 56 ± 14 years) with common type AVNRT were randomly assigned to the linear approach (25 patients) or local electrogram mapping approach (25 patients). A linear lesion was created between the tricuspid annulus, at the midlevel of the coronary sinus (CS) ostium, and the anterior aspect of the CS infundibulum. In 22 (88%) patients in the linear group, the AVNRT was successfully eliminated by 1.5 ± 0.8 linear RF applications without any complications. All 25 patients in the focal group satisfied the endpoint criteria after 3.8 ± 2.4 focal RF deliveries. The success rate did not significantly differ between the two groups. Out of the 22 patients with a successful outcome in the linear group, 17 (77%) attained complete abolition of the slow pathway conduction, whereas this was observed in only eight (32%) patients in the focal group (P < 0.005). The session time was significantly shorter in the linear group. Recurrence of the tachycardia was not documented in any patient during a mean follow‐up of 18 ± 8 months except one with residual slow pathway conduction in the focal ablation group. In conclusion, the anatomic linear approach can be performed safely and possesses a greater potential for slow pathway interruption compared to the electrogram mapping focal approach.
Recognition and Correction of Subcuticular Malposition of Pacemaker Pulse Generators
Authors: FURMAN SEYMOUR , CURTIS ANNE B. , CONTI JAMIE BETH
Published: July 2003

FURMAN, S., et al.: Recognition and Correction of Subcuticular Malposition of Pacemaker Pulse Generators. Implantation of a cardiac pacemaker should be in the tissue plane deep to the subcutaneous tissue (i.e., between the fatty layer and the pectoralis fascia of the chest wall). Five patients with pacemaker implants between the cutis and the subcutaneous fat presented months later with chronic, unremitting, and often excruciating pain. The pulse generator in each case seemed excessively superficial and displaced, appeared too large for its known size, and was seemingly fixed to the overlying skin with exquisite sensitivity to light touch by a garment or palpation. Each had multiple consultations and treatments for pain, all without effect other than the temporary relief of local anesthesia. In three patients with obvious large subcutaneous fatty layers, the pulse generator was markedly superficial. Wound cultures were sterile in each case. Correction consisted of operative repositioning of the pulse generator into the readily developed subcutaneous tissue plane. In each patient, total and permanent relief of pain was achieved. Subcuticular positioning of permanent pacemaker pulse generators causes chronic pain that is readily relieved by operative repositioning of the pulse generator in the proper tissue plane.
Far‐Field R Wave Oversensing in a Dual Chamber Arrhythmia Management Device: Predisposing Factors and Practical Implications
Authors: WERETKA SLAWOMIR , BECKER RUEDIGER , HILBEL THOMAS , KARLE CHRISTOPH , OSSWALD BRIGITTE R. , KUEBLER WOLFGANG , SCHOELS WOLFGANG
Published: July 2003

WERETKA, S., et al.: Far‐Field R Wave Oversensing in a Dual Chamber Arrhythmia Management Device: Predisposing Factors and Practical Implications. Initial experience with the Medtronic Jewel 7250, the ICD designed to detect and treat ventricular and supraventricular tachyarrhythmias, is very promising. Its effectiveness, however, depends on sensing performance, which has not yet been systematically examined. The aim of the study was to determine the incidence of, predisposing factors for, and practical implications of far‐field R wave oversensing (FFRWOS) in this dual chamber ICD. During a total follow‐up of 797 months in 48 patients who had the Jewel 7250, follow‐up strip charts, 12‐channel Holter recordings and, in particular cases, Holter recordings with intracardiac markers were analyzed for the presence of FFRWOS. FFRWOS was documented in ten (21.3%) patients. Compared to other lead locations, the right atrial appendage lead position was most frequently associated with FFRWOS (7/27 vs 3/21, P < 0.05). Patients with FFRWOS had significantly more treated and nontreated atrial episodes, many of which were judged to have been detected inappropriately. In one case, inappropriate atrial antitachycardia pacing due to R wave oversensing triggered sustained ventricular tachycardia, terminated eventually with a high energy shock. In dual chamber ICDs, FFRWOS may represent a frequent phenomenon possibly leading to serious consequences. For atrial leads, a lateral atrial wall position seems to be preferable. In most cases, FFRWOS can be eliminated by optimization of atrial sensing parameters. Given the possibility of ventricular proarrhythmia with atrial pacing therapy, the capability of ventricular backup defibrillation in respective devices is at least reassuring.
Cycle Length‐Associated Modulation of the Regional Dispersion of Ventricular Repolarization in a Canine Model of Long QT Syndrome
Authors: CHINUSHI MASAOMI , CAREF EDWARD B. , RESTIVO MARK , NOLL GIANDOMENICO , AIZAWA YOSHIFUSA , EL‐SHERIF NABIL
Published: July 2003

CHINUSHI, M., et al.: Cycle Length‐Associated Modulation of the Regional Dispersion of Ventricular Repolarization in a Canine Model of Long QT Syndrome. Previous tridimensional activation mapping showed that the development of functional conduction block at the onset of torsades de pointes was regionally heterogeneous; conduction block was frequently observed in the LV and the interventricular septum (IVS) but not in the RV, in the canine anthopleurin‐A (AP‐A) model of long QT syndrome (LQTS). This may be related to the distribution of myocytes with M celllike electrophysiological characteristics. To better understand the regional difference of arrhythmogenicity in LQTS, the authors investigated cycle length related modulation of ventricular repolarization among three different layers: the endocardium (End), mid‐myocardium (Mid), and epicardium (Epi) of the LV and RV and at two different areas: the Epi and septum (Sep) in the IVS. The LQT3 model was produced by AP‐A in dogs. Using constant pacing and single premature stimulation (S1S2), the ventricular repolarization pattern was analyzed from 256 unipo2 lar electrograms. Activation‐recovery intervals (ARIs) were used to estimate local repolarization. In seven experiments, AP‐A increased regional ARI dispersion to 88.1 ± 36.0 ms in the LV, to 72.9 ± 35.7 ms in the IVS, and to 23.0 ± 8.7 ms in the RV at the pacing cycle length (CL) of 1,000 ms. Development of the large ARI dispersion was due to greater ARI prolongation at the Mid site in the LV and at Sep site in the IVS. As the S1S2 interval was shortened, regional ARI dispersion decreased gradually, and finally, ARI dispersion showed a reversal gradient of repolarization between the Mid and Epi sites in the LV and between the Sep and Epi sites in the IVS. Two factors contributed to create the reversal gradient of repolarization: (1) a difference in restitution kinetics at the Mid site in the LV and at the Sep site in the IVS, characterized by a larger Δ ARI and slower time constant (τ), and (2) a difference in diastolic intervals at each site resulting in different input to restitution at the same CL. However, the RV showed small alteration in the transmural dispersion of repolarization in the S1S2 protocol. S2 created heterogeneous functional conduction block in the LV and IVS but not in the RV. In the LQT3 model, the arrhythmogenicity of torsades de pointes is primarily due to dispersion of repolarization in the LV and IVS because of prominent distribution of M cells. The RV seems to participate passively in reentrant excitation during torsades de pointes.
A Randomized, Double‐Blind, Placebo‐Controlled Evaluation of the Efficacy and Safety of Intravenously Administered Dofetilide in Patients with Wolff‐Parkinson‐White Syndrome
Authors: KRAHN ANDREW D. , KLEIN GEORGE J. , YEE RAYMOND
Published: July 2003

KRAHN, A.D., et al.: A Randomized, Double‐Blind, Placebo‐Controlled Evaluation of the Efficacy and Safety of Intravenously Administered Dofetilide in Patients with Wolff‐Parkinson‐White Syndrome. Pharmacological conversion of arrhythmias in Wolff‐Parkinson‐White (WPW) syndrome is often frequently undertaken. Current antiarrhythmic drugs used for conversion can be associated with significant side effects and variable efficacy. Fifteen male patients (mean age 34, range 18–63 years) with WPW syndrome and atrial fibrillation or AVRT induced in the electrophysiology laboratory were enrolled in a prospective, randomized, placebo‐controlled crossover study. Patients were randomized to one of two doses of intravenous dofetilide or placebo. Patients who failed to respond to this initial infusion received a second higher dose infusion of dofetilide. With the initial infusion, six of ten dofetilide patients converted to sinus rhythm compared to one of five placebo patients. After a second infusion of dofetilide for placebo patients and higher dose dofetilide for low dose dofetilide patients, the overall conversion rate was 71% with dofetilide compared with 20% for placebo (P = 0.046). Atrial fibrillation converted to sinus rhythm in 82% of patients who received dofetilide. Intravenous dofetilide was safe and effective at converting induced atrial fibrillation in patients with WPW syndrome.
Biventricular Pacing Using Two Pacemakers and the Triggered VVT Mode
Authors: O'COCHLAIN BRENDAN , DELURGIO DAVID , LEON ANGEL
Published: July 2003

O'COCHLAIN, B., et al.: Biventricular Pacing Using Two Pacemakers and the Triggered VVT Mode. Pacemaker dependent patients exhibit interventricular conduction delay due to right ventricular lead placement. The addition of a transvenous coronary sinus lead for biventricular pacing has been shown to be effective. Venous stenosis and thrombosis postpacemaker implantation can occur in up to 35% of patients. This report describes a patient with a preexisting left‐sided dual chamber pacemaker and chronic left subclavian vein occlusion that was upgraded to a biventricular system by placing a coronary sinus lead and single chamber ventricular triggered pacemaker on the opposite side.