bluuebunny/crossref_metadata_2025 huggingface dataset:
Steroid‐Tipped Leads Versus Porous Platinum Permanent Pacemaker Leads: A Controlled Study
Authors: WISH MARC , SWARTZ JOHN , COHEN ANDREW , COHEN ROBERT , FLETCHER ROSS
Published: October 2007

WISH, M., ET AL.: Steroid‐Tipped Leads Versus Porous Platinum Permanent Pacemaker Leads: A Controlled Study. There is little data directly comparing steroid‐tipped permanent pacemaker leads to otherwise state‐of‐the‐art porous platinum leads. Eighteen patients receiving unipolar generators capable of low voltage outputs were randomized at the time of implant to receive either steroid‐tipped leads or porous platinum leads. All leads were unipolar, tined, passive fixation, and placed in the right ventricular apex or atrial appendage. This study is single center. At implant, threshold pulse width was determined at 3 voltages (2.5, 1.5, and 0.8 V). Follow‐up thresholds were determined at weeks 1, 2, 3, and 4, and at 3 and 6 months. There was no difference in implant thresholds or amplitudes for sensing. By 2 weeks postimplant, lower thresholds were noted for the steroid leads, and this discrepancy grew more significant with time. There was no significant postimplant rise in threshold for steroid‐tipped leads. At 6 months, the average threshold pulse width for ventricular steroid leads at 0.8 V was 0.3 ± 0.1 msec. In contrast, five patients with standard leads did not capture at maximum pulse width at 0.8 V (p < 0.0001). There was no significant difference in the amplitude of the chronic atrial electrogram. This study shows steroid‐tipped leads to offer a significant advantage in reducing thresholds early postimplant and chronically.
Sputter‐Deposited TiN Electrode Coatings for Superior Sensing and Pacing Performance
Authors: SCHALDACH MAX , HUBMANN MAX , WEIKL ANDREAS , HARDT ROLAND
Published: October 2007

SCHALDACH, M., ET AL.: Sputter‐Deposited TiN Electrode Coatings for Superior Sensing and Pacing Performance. The sensing and pacing performance of pacemaker electrodes is characterized by the electrochemical properties of the electrode/tissue interface affecting tissue reactions and the kinetics of the ionic exchange. The usually smooth metallic electrode surface results in a high pass filter characteristic. To better match the electrode's filter characteristic to the spectral content of the depolarization signal, various combinations of electrode shape, material and surface structure have been researched. The electrode with sputter‐deposited TiN coating presented in this report has been designed to meet the demand for low acute as well as chronic thresholds and superior sensing performance not only with respect to spontaneous activity but also regarding the detection of the evoked response. The clinical results obtained with this electrode prove the excellent pacing and sensing properties resulting from minimized polarization losses and optimized filtering of the signal to be detected, respectively. The acute and chronic clinical advantages over previous concepts are attributed mainly to the biocompatibility of the material used and the microcrystalline surface structure achieved by the coating process. The design concept of the new electrode is presented together with the clinical results obtained. While the advancements in microelectronics and battery technology have certainly formed the basis for the development of pulse generators featuring an ever increasing versatility of functions at the same or even smaller pacemaker dimensions, from a point of view of pacing system performance the development of improved electrode concepts as the one presented must be regarded as equally indispensable.
Appraisal of Pacing Lead Performance Using Transtelephonic Follow‐Up Data
Authors: KIM JOHN S. , SUGALSKI JOHN S.
Published: October 2007

KIM, J.S., ET AL.: Appraisal of Pacing Lead Performance Using Transtelephonic Follow‐Up Data. Reliable performance statistics for implantable pacing leads are not readily available because of difficulties involved in data collection. An alternate source of data exists in the form of commercial monitoring service data. The example considered here involves transtelephonic follow‐up data collected by CardioCare, a cardiac monitoring service. This presentation describes a procedure used to identify complications arising from pacing leads, and also presents a method for proper analysis of the data. Analyses comparing silicone leads and polyurethane leads were performed on leads manufactured by five major manufacturers in the United States. The results indicate that the performance of polyurethane unipolar leads is similar to that of the silicone unipolar leads. However, the polyurethane bipolar leads did not perform as well as the silicone bipolar leads.
Temporal Electrogram Analysis: Algorithm Development
Authors: PAUL V.E. , O'NUNAIN S. , MALIK M. , CAMM A.J.
Published: October 2007

PAUL, V.E., ET AL.: Temporal Electrogram Analysis: Algorithm Development. The automatic discrimination of physiological from pathological tachycardias by rate criteria alone lacks adequate specificity. Tachycardia detection algorithms based upon morphological analysis of the endocardial electrogram have been attributed high specificity although their specificity has not been proven. A previous study had shown temporal electrogram analysis TEA) to be an algorithm of high sensitivity in the detection of ventricular arrhythmias despite low computational demands. In this study, the specificity and potential for automatic implementation have been assessed. Manual adjustment of thresholds for individual patients gave a maximum potential sensitivity of 97% (26/27 arrhythmias correctly recognized as non‐sinus). The use of automatic setting of thresholds reduced sensitivity to 81%. The specificity of the algorithm, as assessed by exercise testing, was only 60%.
Atrial Antitachycardia Pacing in Patients with Supraventricular Tachycardia: Clinical Experience with the Intertach Pacemaker
Authors: MCCOMB JANET M. , JAMESON STUART , BEXTON RODNEY S.
Published: October 2007

MCCOMB, J.M., ET AL.: Atrial Antitachycardia Pacing in Patients with Supraventricular Tachycardia: Clinical Experience with the Intertach Pacemaker. During a 3‐year period, 22 patients with recurrent supraventricular tachycardia have been treated with antitachycardia pacemakers [Intermedics Intertach, 262–12, n = 17, and Intertach II, 262–16, n = 5). Eighty‐two percent were female, the mean age was 44 ± 14 years; 86% had atrioventricular node reentrant tachycardia. Symptoms had occurred over 11.8 ± 7.1 years, with 3.6 hospital admissions per patient, despite 4.7 ± 2.1 antiarrhythmic drugs. Following pacemaker implantation, during a follow‐up of 14.8 ± 11.5 months, only two patients have been readmitted to a hospital because of supraventricular tachycardia (mean 0.1 per patient). One patient is taking an antiarrhythmic agent, and four are taking beta adrenergic blocking agents. Thus, 23% are taking cardioactive drugs (it was anticipated that two patients would continue on drugs after pacemaker implantation). There have been no serious complications. Atrial antitachycardia is thus an effective therapy in carefully selected patients with recurrent supraventricular tachycardia, reducing hospital admissions for supraventricular tachycardia and reducing the need for antiarrhythmic drugs.
Clinical Experience with the Intertach 262‐12 Pulse Generator in Patients with Recurrent Supraventricular and Ventricular Tachycardia
Authors: FROMER MARTIN , GLOOR HANS , KUS TERESA , KAPPENBERGER LUKAS , SHENASA MOHAMMAD
Published: October 2007

FROMER, M., ET AL.: Clinical Experience with the Intertach 262‐12 Pulse Generator in Patients with Recurrent Supraventricular and Ventricular Tachycardia. An antitachycardia pulse generator, the Intermedics Intertach 262‐12 was implanted in 16 patients (14 patients with supraventricular tachycardia of various origins and two patients with recurrent ventricular tachycardia), who were not responsive to various antiarrhythmic drug regimens. The follow‐up was from 6–49 months (mean 30.9 ± 13.8). Five patients had a follow‐up of over 3 years. The device was used in all patients. One patient with ventricular tachycardia died from a nonarrhythmic cause. Loss of responsiveness to burst pacing was observed in 1/14 patients with supraventricular tachycardia and nontolerance of antitachycardia pacing in one patient. Overall clinical success of pacing was observed in 13/16 patients = 81%. The pacemaker proved to be a versatile system with reliable tachycardia detection and termination functions.
Supraventricular Tachycardia Control with Tachylog II: Long‐Term Follow‐Up
Authors: SULKE A.N. , BUCKNALL C.A. , SOWTON E.
Published: October 2007

SULKE, A.N., ET AL.: Supraventricular Tachycardia Control with Tachylog 11: Long‐Term Follow‐Up. Ten patients aged 16–63 years (mean 36.3) had the Siemens P56T “Tachylog II” pacemaker implanted for treatment of drug refractory supraventricular tachycardia. The pacemaker incorporates a noninvasive electrophysiological study (EPS) facility and a sophisticated Holter function combined with a unique “learning” self‐search antitachycardia algorithm. The Holter reveals that new tachycardias arise that are not previously detected at conventional EPS. The number of stimuli in the initiation sequences during noninvasive EPS proved highly variable, however, termination sequences remained constant in the long term. There was variability of timing of stimuli in the long term that was significantly greater for “new” tachycardias than for “original” arrhythmias. Long‐term follow‐up [at 1 month, 6 months, and 1 year] have shown that 90% of patients have good tachycardia control without the need for drugs. All patients confirm the acceptability of this pacemaker for control of their arrhythmias in the long term.
Differentiation of Sinus Rhythms from Supraventricular Tachydysrhythmias by Activation Sequence and Timing
Authors: WALSH CHRISTINE A. , SINGER LEWIS P. , MERCANDO ANTHONY D. , FURMAN SEYMOUR
Published: October 2007

WALSH, C.A., ET AL.: Differentiation of Sinus Rhythms from Supraventricular Tachydysrhythmias by Activation Sequence and Timing. Implantable device detection of tachydysrhythmias remains unreliable and inexact. False responses may occur because of misinterpretation of sinus tachycardia (ST) as a supraventricular tachydysrhythmia (SVTD). Timing of atrioventricular (AV) activation and ventricular dispersion identified and discriminated between ST and SVTDs in 11 dogs. Three bipolar epicardial electrodes recorded left atrial and left and right ventricular depolarizations simultaneously during normal sinus rhythm (NSRJ (mean of 5 beats in 11/11 dogs), ST produced by phlebotomy (50 beats in 10 episodes in 6/11) or isoproterenol infusion (105 beats in 21 episodes in 10/11), sinus bradycardia (SB) produced by vagal stimulation (140 beats in 29 episodes in 10/11), and during atrial flutter (AFL) (15 beats in 3 episodes in 3/11) and atrial fibrillation (AF) (152 beats in 31 episodes in 9/11) induced by programmed electrical stimulation. During lidocaine infusion, NSR (55 beats in 11 episodes in 10/11 dogs), SB (84 beats in 17 episodes in 7/11), AFL (10 beats in 2 episodes in 1/11], and AF (103 beats in 21 episodes in 7/11) were recorded. During isoproterenol infusion, SB (45 beats in 9 episodes in 5/11), AFL (15 beats in 3 episodes in 2/11), and AF (64 beats in 13 episodes in 5/11) were recorded in addition to ST. The interval between the left atrial and left ventricular intrinsic deflections (A‐V1) and between the left and right ventricular intrinsic deflections (V1‐V2) of each beat was measured. The mean value (msec) of A‐V1 and V1‐V2 in each episode was compared to NSR in the same dog. A difference of ≥ 16 ms was used for differentiation. In all cases except SB with first‐degree AV block, V1‐V2 in each episode was insignificant (0‐14msec), categorizing the rhythms as supraventricular. During NSR, ST and SB without AV block, Δ A‐V1 was small (0–15 msec). In contrast Δ A‐V1 was ≥ 16 ms in 6/8 episodes of AFL. The remaining two episodes could be differentiated by the greater number of atrial versus ventricular beats. AF could be detected by the variability of A‐V1. An algorithm using the relative number of atrial vs ventricular beats and A‐V1 and V1‐V2 timing can provide automated dysrhythmia detection, without effect from lidocaine or isoproterenol infusion.
Surgery of Tachyarrhythmia: Intracardiac Closed Heart Cryoablation
Authors: BREDIKIS JURGIS J. , BREDIKIS AUDRIUS J.
Published: October 2007

BREDIKIS, J.J., ET AL.: Surgery of Tachyarrhythmia: Intracardiac Closed Heart Cryoablation. Closed heart surgery without the use of cardiopulmonary bypass (CPB) is one of the trends of surgical treatment of tachyarrhythmias. Having rich experience of epicardial cryoablation, the authors introduced the original technique of intracardiac cryoablation. They have demonstrated the feasibility of creation of complete AV block in patients with supraventricular tachycardias by AV node‐His‐bundle cryoablation, elimaintion of AV junctional (“nodal”) tachycardia by perinodal cryoablation, cryoablation of septal and paraseptal left posterior AV accessory pathways and ectopic foci in atrial septum, complete or partial cryoisolation or cryofragmentation of the atria in patients with atrial flutter and/or fibrillation, and cryoablation or arrhythmogenic zones in ventricles. Good results (arrhythmia‐free patients) were obtained in 82%‐100%. Cryoablation on the closed heart without the use of CPB has the following advantages: (a) the possibility of continuous monitoring of cardiac electrical activity during the operation; (b) ablation efficacy control; and (c) dimished trauma and little risk of surgical intervention.
The Results of Surgery for Tachyarrhythmias in Children
Authors: BOCKERIA L.A. , MIKHAILIN S.I.
Published: October 2007

BOCKERIA, L.A., ET AL.: The Results of Surgery for Tachyarrhythmias in Children. Tachycardia in children is generally considered harmful and frequently is transformed into so‐called arrhythmogenic cardiomyopathy. The goal of this report was the investigation of the result of surgical treatment and how it was dependent on the type of tachycardia, the presence of combined, or concomitant heart pathology. We have operated on 146 patients at an age of 8 months to 16 years (mean 9.6 ± 2.7 yrs) from 1982 until April 1, 1990. Surface mapping was performed in patients with WPW syndrome. All patients underwent electrophysiological study. The duration of the disease was 8.4 ± 1.9 years. 89% of patients suffered from syncopal episodes. The heart rate during tachycardia exceeded 200 beats/min in 95% of children. In 98% of patients palpitation lasted more than 3 hours. Seven types of tachycardia were seen in operated children. All patients were divided into three groups depending on the absence or presence of CHD or several types of arrhythmia. Sixty‐seven patients (45.8%) with so‐called noncomplicated tachycardias (without additional heart disease) were included in group I. Forty‐seven patients (32.20%) with tachycardia and CHD were in group II and 52 patients (21.9%) with multiple tachycardias that had life‐threatening prognosis were in group III. The total efficacy of surgical treatment in group I was 97%. The worst results were in group II patients. The total positive results in this group was 81%. In group 111 patients with life‐threatening arrhythmias, total efficacy was 93.8%.
Surgery for Atrial Tachycardia
Authors: GUIRAUDON GERARD M. , KLEIN GEORGE J. , YEE RAYMOND , LEITCH JAMES W. , KAUSHIK RAJ R. , McLELLAN DOUGLAS G.
Published: October 2007

GUIRAUDON, G.M., ET AL.: Surgery for Atrial Tachycardia. Atrial flutter is associated with a macro‐reentrant loop including an area of slow conduction cryoablation of which prevents atrial flutter to occur. Three patients underwent such intervention. Atrial fibrillation is associated with multiple reentrant circuits (leading circle of Allessie) that requires a critical surface area to perpetuate. We have designed an operation, the corridor operation, which isolate the sinus node and the AV node within a small segment of atrial tissue, to restore the chronotropic function of the sinus node. Nine patients underwent the corridor operation at our institution. There were eight men and one woman. Five had incessant atrial fibrillation and four paroxysmal. One patient had associated mitral valve stenosis and one cardiomyopathy. There were no perioperative complications. Six patients had normal sinus node function postoperatively including all the four patients with documented normal sinus node function preoperatively. Three patients required implantation of an AAI pacemaker. Two patients had recurrence of atrial fibrillation within the corridor. Our experience suggests that the corridor operation should be restricted to patients with documented good sinus node function and without structural heart disease. Our experience with five patients with paroxysmal sinus node tachycardia has been disappointing. Only one patient had long‐term success although better series have been published.
Fulguration for AV Nodal Tachycardia: Results in 42 Patients with a Mean Follow‐Up of 23 Months
Authors: HAISSAGUERRE M. , WARIN J.F. , D'IVERNOIS C. , MÉTAYER P.H. LE , MONTSERRAT P.
Published: October 2007

HAISAGUERRE, M., ET AL.: Fulguration for AV Nodal Tachycardia: Results in 42 Patients with a Mean Follow‐Up of 23 Months. This report describes a catheter ablation technique to treat atrioventricular nodal reentrant tachycardia while preserving anterograde conduction, and its application in 42 patients with drug‐refractory repetitive episodes of tachycardia. One of these patients had common and reverse forms of tachycardia. Using atrial activation in the His‐bundle lead as a reference, the optimal ablation site was selected by positioning an electrode catheter to obtain a synchronous or earlier atrial activation than the reference during tachycardia. At this site, His‐bundle deflection was completely absent, or was present at a low amplitude (< 0.1 mV). In the majority of patients, these criteria were found in the immediate vicinity of the site of proximal His‐bundle recording (adjacent to the reference catheter). Shocks of 160 or 240 joules (J) were delivered at this site (mean ± SD = 518 ± 392 J/session) with a resulting preferential abolition of impairment of fast retrograde conduction. Anterograde conduction, though modified, was preserved in all patients, except for four (10%) patients who remained in complete heart block. Thirty patients (70%) remained free of arrhythmia without medication or pacemaker for a mean follow‐up period of 23 ± 13 (2–63) months. Six other patients (15%) were controlled with a previously ineffective medication.
The Effect of Suppression of the Distortion Artifact during Transcutaneous Pacing on the Shape of the QRS Complex
Authors: PROCHACZEK FRYDERYK , GALECKA JERZY
Published: October 2007

PROCHACZEK, F., ET AL.: The Effect of Suppression of the Distortion Artifact during Transcutaneous Pacing on the Shape of the QRS Complex. The quality of the ECG recording during transcutaneous pacing was evaluated in six healthy volunteers. The transcutaneous pacing stimulator was an NP4D special unit to which was attached an electronic suppressor of artifact generated by the transcutaneous stimulating impulse. The relationship between this suppression of artifact distortion and the resulting QRS complex was analyzed. The results revealed that the suppression time (described as a 2‐mm oscillation from 100‐Hz frequency was required for ECG distortion elimination and that this is dependent on the threshold of ventricular pacing. The width of the resulting QRS complex diminishes as the suppression is extended over 110 ms. These results suggest the necessity of individual adjustment of the suppression time so that the efficacy of transcutaneous pacing is adequately assessed.
Transcutaneous Cardiac Pacing for Termination of Tachyarrhythmias
Authors: ALTAMURA GIULIANO , BIANCONI LEOPOLDO , TOSCANO SALVATORE , BIANCO FRANCESCO LO , JESI ANNA PATRIZIA , PISTOLESE MICHELE
Published: October 2007

ALTAMURA, G., ET AL.: Transcutaneous Cardiac Pacing for Termination of Tachyarrhythmias. Transcutaneous cardiac pacing (TCP) was used for interruption of tachyarrhythmias in 31 patients: 20 with ventricular tachycardia (VT); eight with atrioventricular reentrant tachycardia (AVRT) and three had atrioventricular nodal tachycardia (AVNT). The stimulators used (Pace Aid 50/52) allow pacing at programmable rates (50–160 ppm) and output (10–200 mA at 20‐msec pulse duration), when possible overdrive pacing was used. Short bursts of stimuli were delivered with increasing current intensity until interruption of the arrhythmia or to the maximum energy tolerated by the patient. VTs were interrupted in eight of the 20 patients: four of the six (67%) treated by overdrive pacing and four of the 14 (29%) were treated by underdrive pacing. Supraventricular tachycardias (SVT) were terminated in eight of the 11 patients: seven out of eight (88%) AVT, and one out of three AVNT (33%). We observed two cases of arrhythmia worsening: a VT acceleration and induction of ventricular fibrillation in a patient with AVNT. TCP was well tolerated by the majority of the patients. We conclude that TCP is an effective method for interruption of ventricular and supraventricular reentrant tachycardias, but the risk of arrhythmia worsening must be considered.
Transesophageal Atrial Pacing Complications in Patients Suspected of Tachy‐Brady Syndrome
Authors: RACZAK GRZEGORZ , SWIATECKA GRAZYNA , LUBINSKI ANDRZEJ , KUBICA JACEK
Published: October 2007

RACZAK, G., ET AL.: Transesophageal Atrial Pacing Complications in Patients Suspected of Tachy‐Brady Syndrome. The clinical effects of transesophageal atrial pacing (TAP) were assessed in 308 patients. Indications for TAP included evaluation for pacemaker implantation in patients suspected of sinus node dysfunction and determination of the suitable type of pacemaker. Most patients underwent program stimulation including rapid as well as burst stimulation. In one patient, following the study, cerebral arterial embolism occurred, most likely secondary to an induced arrhythmia. That was the only single case of permanent consequences following TAP. Additionally, one patient was accidentally stimulated in the ventricle using low voltage electric current that induced ventricular fibrillation. This was promptly reversed with defibrillation. Twenty‐six patients in whom an arrhythmia was previously induced, required medical therapy, two of whom required cardioversion, and 24 required drug therapy, subsequent to clinical intolerance of the arrhythmia. No lethal complications occurred.
Atrioventricular Wenckebach Point and Progression to Atrioventricular Block in Sinoatrial Disease.
Authors: HAYWOOD G. A. , WARD J. , WARD D. E. , CAMM A. J.
Published: October 2007

HAYWOOD, G.A., ET AL.: Atrioventricular Wenckebach Point and Progression to Atrioventricular Block in Sinoatrial Disease. The value of measurement of the atrioventricular (AV) Wenckebach point at rest as a predictor of progression to AV block was investigated prospectively. Twenty‐four patients with sinoatrial disease without evidence of conduction disturbance on 12‐lead ECG or 24‐hour ambulatory monitoring were paced with Medtronic Activitrax II, Medtronic Legend, or Telectronics Meta MV systems in AAI or AAIR modes. Patients were monitored for symptoms and evidence of AV block on 24‐hour tapes. The mean age of the patients was 67 years (range: 42–88). There were 11 males and 13 females. The mean follow‐up time was 10.7 ± 5 months. Four patients required revision of pacing system as a result of development of AV block during follow‐up. One other patient manifested intermittent second degree AV block and remains in AAI. The AV Wenckebach points measured at 1 month post implantation in the four patients who developed AV block requiring revision of system were 140, 125, 165, and 60 (mean 123 ± 4). The mean AV Wenckebach point at first assessment in the remaining 20 patients was 153 ± 24. The mean age of those requiring revision of system was 71 ± 7 compared with 67 ± 14 in those who did not. In this small series the frequency of development of significant AV block was 17%. This is markedly higher than in other recently reported series. The study demonstrates that an AV Wenckebach point above 120/min does not confer immunity from progression to AV block.
Improved Dual Chamber Pacing Mode in Paroxysmal Atrioventricular Conduction Disorders
Authors: GIRODO SYLVIE , RITTER PHILIPPE , PIOGER GUY , LAMAISON DOMINIQUE , MALHERBE ODILE
Published: October 2007

GIRODO, S., ET AL.: Improved Dual Chamber Pacing Mode in Paroxysmal Atrioventricular Conduction Disorders.Dual chamber pacing may sometimes be directly indicated for carotid sinus hypersensitivity, vasovagal syndrome, and certain cases of sinoatrial block and intermittent atrioventricular (AV) block, although AV conduction is dominantly normal. At times of normal AV conduction, competition between ventricular pacing and spontaneous ventricular depolarization may occur, with its adverse hemodynamic effects on ventricular function and unnecessary drainage of pacemaker battery energy. A new mode of stimulation is described, called automatic DDD mode, which functions in ‘pseudo‐AAI’ mode during normal AV conduction and reverts to classical DDD function during episodes of AV blocks. Furthermore, during pseudo‐AAI function, the pacemaker measures certain physiological parameters that serve to automatically program certain parameters used in DDD mode. Preliminary clinical evaluation has shown that this new mode functions satisfactorily.
Diagnostic Value of Carotid Sinus Hypersensitivity
Authors: VOLKMANN H. , SCHNERCH B. , KUHNERT H.
Published: October 2007

VOLKMANN, H., ET AL.: Diagnostic Value of Carotid Sinus Hypersensitivity. In order to evaluate the diagnostic value of carotid sinus hypersensitivity (CSH) we have investigated 163 asymptomatic patients (88 male, 75 female, mean age 57.9 ± 22.7 years) and 210 symptomatic patients (108 males, 102 females, mean age 61.1 ± 28.1 years) with syncopes or dizziness. Thirty two of the 163 asymptomatic patients (20%) and 87 of the 210 symptomatic patients (41%) showed CSH (asystole ≥ 3 sec during carotid sinus pressure). Male patients had a higher number of CSH than female (28% vs 10% in the asymptomatic group, 48% vs 34% in the symptomatic group). Electrophysiological investigations were performed in all 210 symptomatic patients. Normal electrophysiological results had 94 of the 210 patients. Thirty seven of these 94 patients showed CSH (39%). Prolonged sinus node recovery time (SNRT) and/or prolonged sinoatrial conduction time (SACT) were evaluated in 38 patients. Seventeen of the 38 patients had CSH (45%]. Disorders of atrioventricular (AV) conduction were evaluated in 43 patients. Seventeen of the 43 patients showed CSH (40%). Thirty‐five patients had both AV conduction disorders and prolonged SNRT or SACT. Sixteen of these 35 patients showed CSH (46%). In conclusion, no significant difference was found between patients with and without pathological electrophysiological results. The CSH is without value for predicting sinus node dysfunction and AV conduction disorder.
Differences Between Atrial Single Chamber Pacing (AAI) and Ventricular Single Chamber Pacing (VVI) with Respect to Prognosis and Antiarrhythmic Effect in Patients with Sick Sinus Syndrome
Authors: STANGL K. , SEITZ K. , WIRTZFELD A. , ALT E. , BLÖMER H.
Published: October 2007

STANGL, K., ET AL.: Differences Between Atrial Single Chamber Pacing (AAI) and Ventricular Single Chamber Pacing (VVI) with Respect to Prognosis and Antiarrhythmic Effect in Patients with Sick Sinus Syndrome. Several studies suggest different effects of atrial (AAI) and ventricular single chamber pacing (VVI) for sick sinus syndrome with respect to the suppression of atrial tachycardias and to the prognosis. With this aspect in mind, we studied 222 patients with sick sinus syndrome, 110 of whom had been supplied with AAI systems, and 112 with VVI systems, in the period from January 1978to December 1986. The mean observation period was 53 ± 28 months. The cumulative 5‐year survival rate was not significantly different in the two groups. After subgroups with comparable underlying diseases had been differentiated, patients with coronary heart disease showed a significantly higher survival rate (p < 0.05) under AAI pacing, and the same was shown for patients with no underlying heart disease (p < 0.02). The incidence of chronic atrial fibrillation was 6% in the AAI group and 19% in the VVI group. Patients with preexisting atrial tachyarrhythmias showed the lowest incidence of chronic atrial fibrillation under AAI pacing. Under VVI pacing this incidence was a function of the basic rate of the pacemaker systems. In conclusion, the pacing mode seems to have a prognostic importance in spite of all methodological difficulties. A suppressive effect of AAI pacing on atrial dysrhythmias can also be assumed.
Symptoms, Cardiovascular Risk Profile and Spontaneous ECG in Paced Patients: A Five‐Year Follow‐Up Study
Authors: GRIMM WOLFRAM , LANGENFELD HEINER , MAISCH BERNHARD , KOCHSIEK KURT
Published: October 2007

GRIMM, W., ET AL.: Symptoms, Cardiovascular Risk Profile and Spontaneous ECG in Paced Patients: A Five‐Year Follow‐Up Study. Only few data are available about the course of symptoms, cardiac diseases, and spontaneous rhythm in pacemaker patients. Therefore, we followed the course of 308 paced patients (age 72 ± 11 years) with a mean implantation time of 63 ± 45 months. Results: The symptom triad of syncope, dizziness, and dyspnea improved remarkably in 93% of patients. Thirty‐nine percent suffered from coronary heart disease. The risk factors of hypertension (47%), nicotine (37%), and diabetes mellitus (25%) were found significantly more often than in a normal population with the same age and sex profile. In VVI paced patients with sick sinus syndrome (SSS, n = 67) atrial fibrillation (AF) occurred significantly more often (42%) than in patients with AV block (n = 80, 23%, p < 0.05). Only one out of 41 DDD paced patients showed AF at follow‐up. VVI stimulation seems to favor AF due to retrograde conduction in SSS. Only 3% of patients with SSS developed second‐ or third‐degree AV block. Therefore, atrial pacing is preferable in most patients with SSS.
Heart Rate Variability and Sudden Infant Death Syndrome
Authors: PERTICONE FRANCESCO , CERAVOLO ROBERTO , MAIO RAFFAELE , COSCO CARMELA , MATTIOLI PIER LUIGI
Published: October 2007

PERTICONE, F., ET AL.: Heart Rate Variability and Sudden Infant Death Syndrome. The sudden infant death syndrome (SIDS) is the most common cause of death in infancy. The pathophysiological mechanism leading to SIDS is still obscure. In the QT hypothesis, the mechanism must be an arrhythmogenic sympathetic imbalance: the infants die suddenly of cardiac arrhythmia. Recently, it has been suggested that analysis of heart rate variability (HRV), expressed as standard deviation or variance analysis, can provide adequate information on sympathovagal interaction. We studied 150 newborns enrolled in a previous prospective electrocardiographic study to evaluate the predictive value of QT interval for SIDS. We analyzed the ECGs recorded with infants alert on the fourth day of life and after 2 months. For each ECG, the HRV was calculated using the first standard deviation of of RR intervals (ms) measured for 1 minute. The average RR interval was 441 ± 71 ms at the fourth day and 420 ± 39 ms at the second month. The QTc and HRV mean values were 396 ± 23 and 23 ± 12 ms at the fourth day, 412 ± 19 and 15 ± 7 msec at the second month. Therefore, the SD values of heart rate were correlated with QTcin order to assess a possible relationship between the two variables. The correlation coefficient and regression equation were: ‐0.639 and y = 423.67 ‐ 2.18*× (P < 0.002) at the fourth day, ‐0.146 and y = 418.09 ‐ 0.37*× (NS) at the second month. In conclusion, our data seems to confirm a delayed maturation or impaired fuctioning of the autonomic nervous system in the first weeks of life, reflecting a direct correlation with QT prolongation.
Distinctive Response of Arrhythmogenic Right Ventricular Disease to High Dose Isoproterenol
Authors: HAISSAGUERRE M. , MÉTAYER P. LE , D'IVERNOIS C. , MONTSERRAT P. , WARIN J.F. , BARAT J.L.
Published: October 2007

HAISSAGUERRE, M., ET AL.: Distinctive Response of Arrhythmogenic Right Ventricular Disease to High Dose Isoproterenol.Arrhythmogenic right ventricular disease is a potential cause of ventricular arrhythmias. Diagnosis is important due to the risk of sudden death, particularly as first symptom. Diagnosis is based on the angiographic demonstration of abnormal right ventricular morphology and function, while the sensitivity of noninvasive tests is relatively low. Following a particular observation studied in 1984, we prospectively assessed the diagnostic value of high dose isoproterenol infusion in 44 patients with an angiographically determined arrhythmogenic right ventricle. A continuous infusion of isoproterenol (8–30 µg/min) was administered during a 3‐minute period, regardless of the obtained heart rate. In a control group of 50 patients without structural heart disease, isoproterenol induced a monomorphic ventricular tachycardia salvo in only one patient (2%). In patients with an arrhythmogenic right ventricle, isoproterenol induced one or more ventricular tachycardia runs in 39/44 cases (88%): one triplet in three patients, several runs in 23 patients and a sustained ventricular tachycardia in 13 patients. Arrhythmia was polymorphous in 85% of cases, but left bundle branch block morphelogy was the predominant pattern. In conclusion, high dose isoproterenol is a highly sensitive test for the diagnosis of arrhythmogenic right ventricular disease.
Predictors of Ventricular Tachvcardia Inducibility in Programmed Electrical Stimulation and the Effectiveness of Serial Drug Testing: Polish Multicenter Study
Authors: WNUK‐WOJNAR ANNA‐MARIA , GIEC LESZEK , DRZEWIECKI JANUSZ , TRUSZ‐GLUZA MARIA , DABROWSKI ANDRZEJ , PASYK STANISŁAW
Published: October 2007

WNUK‐WOJNAR, A.M., ET AL.: Predictors of Ventricular Tachycardia Inducibility in Programmed Electrical Stimulation and Effectiveness of Serial Drug Testing: Polish Multicenter Study. In 100 patients with IHD and complex ventricular arrhythmias, programmed electrical stimulation was performed using up to three extrastimuli at sinus rhythm, and paced 100, 120, and 140 beats/min delivered from the RV apex, outflow tract or the LV with ventricular mapping to evaluate late potentials (LP) in 41 patients. Sustained monomorphic VT (SMVT) was provoked in 91% of 42 patients with a history of VT/VF, p < 0.001, all five patients had SMVT in 24‐hour ECG, p < 0.005, and 91% of 21 patients with LV dyskinesis, p < 0.01. After depolarizations were found in 62% of 21 patients with a history of VT, in 58% of 31 patients with inducible VT, p < 0.01 and in five of six patients with LV dyskinesis. In patients with inducible VT, LP had a higher amplitude (105 ± 35 vs 60 ± 47 µV) and were more delayed (202 ± 96 vs 133 ± 75 msec) than in noninducible patients. In 17 patients, serial drug testing was performed after oral administration using mexilitene, disopyramide, chinidine, propafenone, sotalol, and amiodarone. If one drug was tested, the therapy efficacy was 25% if two drugs‐60%, and if three drugs‐75%. In eight patients, VT was inducible in all tests, but in only one of these patients chronic antiarrhythmic therapy was not effective. We conclude that the most important predictors of VT inducibility are a history of VT or 24‐hour ECG, and LV dyskinesis. Serial drug testing is efficient only when many drugs are tested, but even if VT is inducible, it does not exclude the possibility of a good clinical outcome in chronic therapy.
Reentrant Junctional Tachycardias
Authors: AKHTAR MASOOD
Published: October 2007

AKHTAR, M.: Reentrant Junctional Tachycardias. Most of the tachycardia arising in the atrioventricular (AV) junction are reentrant in nature. The two most common variety are AV nodal reentry and AV reentry utilizing an accessory pathway of the Kent bundle type. Typically these tachycardias have narrow QRS complex and are regular but an associated right or left bundle branch block could result in a wide QRS complex. Other mechanisms for wide QRS in AV junctional tachycardia include: (a) antidromic reentry; (b) preexcited tachycardia using two accessory pathways; (c) AV nodal reentry with incidental accessory pathway participation; and (d) atriofascicular (nodoventricular) Mahaim participation. A variety of surface ECG and intracardiac electrophysiological methods are used to delineate the precise mechanisms which is essential for successful nonpharmacological therapy in these patients.
Electrophysiological Basis of Ventricular Late Potentials
Authors: EL‐SHERIF NABIL , GOUGH WILLIAM B. , RESTIVO MARK , CRAELIUS WILLIAM , HENKIN RAPHAEL , CAREF EDWARD B.
Published: October 2007

EL‐SHERIF, N., ET AL.: Electrophysiological Basis of Ventricular Late Potentials. The presence of late potentials on the body surface recording was correlated with ventricular activation maps of reentrant circuits in the postinfarction canine model of reentrant excitation. Late potentials were found to correlate with delayed myocardial activation. However, during a reentrant rhythm complete diastolic activity on the body surface could not be detected if the mass of electrically active cells was too small and/or if very slow conduction in part of the reentrant circuit generated low amplitude extracellular potentials. Myocardial zones responsible for late potentials during a basic rhythm (e.g., sinus rhythm) may not necessarily be part of the critical zone of slow conduction during reentrant activation. Dynamic changes in late potentials are not amenable to temporal signal averaging techniques but could be detected by a high resolution beat‐to‐beat recording. A thorough understanding of the electrophysiological limitations of late potentials in the signal‐averaged ECG could result in better utilization of the technique in clinical practice as well as in the development of new approaches for the detection of the arrhythmogenic substrate.
Application of Beat‐to‐Beat Techniques
Authors: FLOWERS NANCY C. , HORAN LEO G. , YANG WEIQUN
Published: October 2007

FLOWERS, N.C., ET AL.: Application of Beat‐to‐Beat Techniques.The focus of this report is to describe a system for recording surface His‐Purkinje and ventricular late potentials on a beat‐by‐beat basis outside of a shielded environment. An AC magnetic field monitoring device was designed for improved site selection, orientation, and quality control of the acquisition. His‐Purkinje signals are detected utilizing spatial averaging and specific channel selection algorithms applied to discriminate random noise from signal. Beat‐by‐beat vectormagnitude complexes were generated from pairs of X, Y, and Z leads. Both infinite impulse response (IIR) filters, modified for beat‐by‐beat approaches, and finite impulse response (FIR) filters were utilized. Using the IIR filter, beat‐by‐beat recordings from test subjects were compared to the signal averaged electrocardiogram (SAECG). Measurement parameters from normal test subjects fell within the previously specified normal range for the SAECG. The IIR filter applied to beat‐by‐beat recordings exhibited sharp frequency response and a precisely defined cutoff frequency allowing maximal attenuation of the low frequency components in the ST segment. While filter ringing was eliminated, discontinuity and distortion of the filtered waveform resulted. The FIR filter with linear phase response retained the integrity and morphology of the complex but because of its flat frequency response, the ST segment was not as well attenuated and it was more difficult to isolate late potentials. A high order FIR filter should be used if the desire is to match the frequency response of the four‐pole IIR filter, since the frequency response of the FIR filter is primarily determined by the order of the filter. With the FIR filter the waveform will be widened on both sides in time and therefore a trade‐off results between the order of the filter and the cutoff frequency. A low order and a high cutoff frequency were necessary to attenuate the low frequency components of the ST segment without significantly widening the QRS. To record high resolution ECGs without noticeable 60‐Hz noise, the magnetic field of 60 Hz should be smaller than 6.6 × 10‐8 Tesla. This study indicates that real‐time analysis of both His‐Purkinje potentials and late potentials in an unshielded environment is possible. (PACE, Vol. 13, December, Part II 1990)
Do European GSM Mobile Cellular Phones Pose a Potential Risk to Pacemaker Patients?
Authors: BARBARO VINCENZO , BARTOLINI PIETRO , DONATO ANDREA , MILITELLO CARMELO , ALTAMURA GIULIANO , AMMIRATI FABRIZIO , SANTINI MASSIMO
Published: October 2007

BARBARO, V., et al.: Do European GSM Mobile Cellular Phones Pose a Potential Risk to Pacemaker Patients? A series of in vivo trials were carried out in order to verify whether the electromagnetic field radiated by GSM (Groupe Systemes Mobiles) mobile cellular phones might affect implanted pacemakers. Two European GSM phones of 2‐watt power were tested and trials conducted on 101 pacemaker implanted outpatients attending day hospital for routine check‐up, who volunteered for trials. Forty‐three pacemaker models from 11 manufacturers were tested in all. When the sensing threshold of the pacemakers was set at a minimum and the antenna of the phone was in direct contact with the patient's chest, interference was detected for 26 implanted pacemakers. Specifically, pulse inhibition in 10 of 101 cases, ventricular triggering in 9 of 46 DDD‐VDD pacemakers, and asynchronous pacing in 4 of 52 devices. Pulse inhibition was also observed combined with asynchronous pacing in 1 of 52 cases and with ventricular triggering in 2 of 46 cases. Minimum effect duration was ca. 3 seconds but in 6 cases effects continued as long as the interfering GSM signal was on. No permanent malfunctioning or changes in the programmed parameters were detected. Whenever interference was detected, trials were repeated to determine the maximum sensing threshold at which interference persisted (with the antenna in contact with the skin over the pacemaker). Then maximum distance between antenna and pacemaker at which interference occurred was determined at pacemaker maximum and minimum sensing threshold. Under our experimental conditions electromagnetic interference effects were detected at a maximum distance of 10 cm with the pacemaker programmed at its minimum sensing threshold. When the phone antenna was in direct contact with patient's skin over the implant, electromagnetic interference effects occurred at maximum ventricular and atrial sensing thresholds of 4 mV and 2.5 mV, respectively.
Echocardiographic Imaging of Coronary Sinus Diverticula and Middle Cardiac Veins in Patients with Preexcitation Syndrome: Impact on Radiofrequency Catheter Ablation of Posteroseptal Accessory Pathways
Authors: OMRAN HEYDER , PFEIFFER DIETRICH , TEBBENJOHANNS JÜRGEN , SCHUMACHER BURGHARD , MANZ MATTHIAS , LAUCK GERHARD , HAGENDORFF ANDREAS , JUNG WERNER , FEHSKE WOLFGANG , LÜDERITZ BERNDT
Published: October 2007

OMRAN, H., et al.: Echocardiographic Imaging of Coronary Sinus Diverticula and Middle Cardiac Veins in Patients with Preexcitation Syndrome: Impact on Radiofrequency Catheter Ablation of Posteroseptal Accessory Pathways. To determine the value of echocardiography for identifying coronary sinus (CS) diverticula and middle cardiac veins (MCVs) in patients with posteroseptal accessory pathways (PAPs), transthoracic (TTE) and transesophageal echocardiography (TEE) were performed in 18 consecutive patients with PAP and in 15 control subjects with left lateral accessory pathway before CS angiography. The size, shape, and location of CS diverticula and MCV were described and compared to angiography. TEE and angiography were concordant for the identification of diverticula (n = 5) and agreed for depicting MCV in 22 of the 27 cases. TTE revealed 4 of 5 diverticula and identified 4 of 27 MCV (P < 0.001). Fourteen MCV but no diverticula were found in the control subjects. There was no significant difference between transesophageal and angiographic measurements for the width (23.5 ± 4.9 vs 26.8 ± 6.6 mm) and height (13.5 ± 3.8 vs 15.7 ± 3.4 mm) of the diverticula, and the width (3.5 ± 0.7 vs 3.7 ± 0.6 mm) of MCV. TEE underestimated the length of the MCV (12.0 ± 1.8 vs 27.2 ± 6.0, P < 0.001). Delivery of radiofrequency energy within the neck of a diverticulum or within an MCV was successful in 5 of 5, and 6 of 13 cases in patients with PAPs, respectively. In conclusion, echocardiography was as reliable as angiography for detecting and describing CS diverticula and MCV in patients with preexcitation syndrome. Echocardiography is recommended prior to electrophysiological study because it may simplify radiofrequency catheter ablation.
Catheter Ablation of Idiopathic Left Ventricular Tachycardia
Authors: ZARDINI MARCO , THAKUR RANJAN K. , KLEIN GEORGE J. , YEE RAYMOND
Published: October 2007

ZARDINI, M., etal.: Catheter Ablation of Idiopathic Left Ventricular Tachycardia. Idiopathic left ventricular tachycardia (ILVT) characterized by right bundle branch block, left axis morphology, response to verapamil and inducibility from the atrium in patients without structural heart disease may represent a distinct clinical entity. We report our experience with catheter ablation of this uncommon arrhythmia using radiofrequency energy (RF) and/or direct current (DC) shocks. Six men and 2 women, aged 16–50 years (mean ± SD, 32 ± 13), had recurrent VT for 16 ± 16 years with a mean frequency of 4 ± 3 episodes/ year. Three patients had syncope during VT. None had identifiable structural heart disease. Catheter ablation was guided by earliest endocardial activation, presence of a high frequency presystolic potential and/or pacemapping of the left ventricle. The left ventricle was accessed via a retrograde aortic approach in 6 patients, a transeptal approach in 1 patient, and a combined approach in the remaining patient. All patients had inducible right bundle branch block morphology, left axis VT with a mean cycle length (CL) of 361 ± 61 ms. A presystolic potential preceding ventricular activation and the His potential during VT was identified in 4 patients. All ablation sites were identified in a relatively uniform location, in the inferoapical left ventricle. Noninducibility of VT was obtained with RF in 3 patients and with DC in 5 patients. In 1 patient, DC delivery after unsuccessful RF prevented further inducibility. Similarly, RF was successful in 1 patient in whom an initial DC attempt was ineffective. Mean total procedure time was 282 ± 51 minutes and mean total fluoroscopy time was 40 ± 15 minutes. There were no complications. One patient treated with DC shock had recurrence of VT during treadmill test the day after ablation and refused repeat ablation. During a mean follow‐up of 17 ± 13 months, no VT recurrences or other cardiovascular events occurred. In conclusion, catheter ablation in the inferoapical left ventricle is an effective treatment for this type of ILVT. RF energy can be safely complemented by low energy DC shocks when the former is ineffective.