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Antitachycardia Pacing (antitachycardia + pacing)
Selected AbstractsPredictors of All-Cause Mortality for Patients with Chronic Chagas' Heart Disease Receiving Implantable Cardioverter Defibrillator TherapyJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 12 2007AUGUSTO CARDINALLI-NETO M.D., Ph.D. Background: Implantable Cardioverter Defibrillators (ICD) have sporadically been used in the treatment of either Sustained Ventricular Tachycardia (VT) or Ventricular Fibrillation (VF) in Chagas' disease patients. This study aimed at determining predictors of all-cause mortality for Chagas' disease patients receiving ICD therapy. Methods and Results: Ninety consecutive patients were entered the study. Mean left ventricular ejection fraction was 47 ± 13%. Twenty-five (28%) patients had no left ventricular systolic dysfunction. After device implantation, all patients were given amiodarone (mean daily dose = 331, 1 ± 153,3 mg), whereas a B-Blocking agent was given to 37 (40%) out of 90 patients. Results: A total of 4,274 arrhythmias were observed on stored electrogram in 64 (71%) out of 90 patients during the study period; SVT was observed in 45 out of 64 (70%) patients, and VF in 19 (30%) out of 64 patients. Twenty-six (29%) out of 90 patients had no arrhythmia. Fifty-eight (64%) out of 90 patients received appropriate shock, whereas Antitachycardia Pacing was delivered to 58 (64%) out of 90 patients. There were 31 (34%) deaths during the study period. Five patients were lost to follow up. Sudden cardiac death affected 2 (7%) out of 26 patients, whereas pump failure death was detected in the remaining 24 (93%) patients. Number of shocks per patient per 30 days was the only independent predictor of mortality. Conclusion: Number of shocks per patient per 30 days predicts outcome in Chagas' disease patients treated with ICD. [source] Implantable Cardioverter-Defibrillator Discharges Despite Successful Termination of Ventricular Tachycardia by Antitachycardia PacingPACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 6 2009REGINALD T. HO M.D. No abstract is available for this article. [source] Antitachycardia Pacing for Spontaneous Rapid Ventricular Tachycardia in Patients with Prophylactic Cardioverter-Defibrillator TherapyPACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 7 2006WOLFRAM GRIMM Aims: Antitachycardia pacing (ATP) has not routinely been used in patients who received implantable cardioverter defibrillators (ICDs) for primary prevention of sudden death. This study investigated the efficacy of empirical ATP to terminate rapid ventricular tachycardia (VT) in heart failure patients with prophylactic ICD therapy. Methods and Results: Ninety-three patients with a mean left ventricular ejection fraction of 22 ± 7% (range: 9,35%) due to nonischemic or ischemic cardiomyopathy received prophylactic ICDs with empiric ATP. At least 2 ATP sequences with 6-pulse burst pacing trains at 81% of VT cycle length (CL) were programmed in one or two VT zones for CL below 335 ± 23 ms and above 253 ± 18 ms. Ventricular flutter and fibrillation (VF) with CL below 253 ± 18 ms were treated in a separate VF zone with ICD shocks without preceding ATP attempts. During 38 ± 27 months follow-up, 339 spontaneous ventricular tachyarrhythmias occurred in 36 of 93 study patients (39%). A total of 232 VT episodes, mean CL 293 ± 22 ms, triggered ATP in 25 of 36 patients with ICD interventions (69%). ATP terminated 199 of 232 VT episodes (86%) with a mean CL of 294 ± 23 ms in 23 of 25 patients (88%) who received ATP therapy. ATP failed to terminate or accelerated 33 of 232 VT episodes (14%) with a mean CL of 287 ± 19 ms in 12 of 25 patients (48%) who received ATP therapy. Conclusions: Painfree termination of rapid VT with empirical ATP is common in heart failure patients with prophylactic ICD therapy. The occasional inability of empiric ATP to terminate rapid VT in almost 50% of patients who receive ATP for rapid VT warrants restrictive ICD programming with regard to the number of ATP attempts in order to avoid syncope before VT termination occurs. [source] Implantable Cardioverter-Defibrillator Shock: Appropriate or Inappropriate?ANNALS OF NONINVASIVE ELECTROCARDIOLOGY, Issue 2 2010F.R.C.P.C., Michael A. Nault M.D. A 76-year-old female with a single chamber implantable cardioverter-defibrillator implanted for secondary prevention was referred due to multiple discharges. The device was programmed for ventricular tachycardia (VT) detection at 400 ms, fast VT detection at 280 ms, and ventricular fibrillation detection at 320 ms. Antitachycardia pacing (ATP) during charge was enabled. Interrogation revealed a VT episode with a mean cycle length of 270 ms, which was successfully terminated with ATP during charge. Seconds later, the device delivered a shock. This case illustrates the importance of understanding programming algorithms as part of troubleshooting when facing a scenario of device discharge. Ann Noninvasive Electrocardiol 2010;15(2):181,183 [source] Transvenous Cardioverter-Defibrillator Implantation in a Patient with Tricuspid Mechanical ProsthesisJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 3 2007MAURO BIFFI M.D. Background. A 64-year-old woman was referred to our center because of poorly tolerated ventricular tachycardia (VT) at 210 bpm due to an old myocardial infarction. The patient had been operated on at age of 20 for mitral valve commissurolysis, at age of 49 for ductal carcinoma, at age of 56 for mitral valve replacement, and at age of 61 for tricuspid valve replacement. Left ventricular EF was 31%. The patient was in permanent atrial fibrillation (AF) since the age of 53. She had undergone three cardiac surgery procedures, ending with two prosthetic mechanical valves. The cardiac surgery team advised against an epicardial ICD implantation. Results. We achieved a fully transvenous implant, with a screw-in defibrillation coil in the low right atrium and a bipolar pacing/sensing lead in a posterolateral branch of the coronary sinus. Pacing/sensing parameters were reliable, and effective defibrillation occurred at 20 J by a stepdown protocol. During 16-month follow-up, three VT episodes at 210 bpm were terminated by antitachycardia pacing (ATP) therapy. Left ventricular pacing/sensing was stable at long term. Conclusion. Thanks to technologic improvements, transvenous ICD implantation is feasible and safe in patients with a tricuspid mechanical prosthesis. [source] Comparison of Induced and Spontaneous Atrial Tachyarrhythmias in Patients with a History of Spontaneous Atrial TachyarrhythmiasJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 8 2005CHRISTIAN G. WOLLMANN M.D. Introduction: This retrospective study investigated whether induced episodes could be used to predict the morphology of future spontaneous atrial episodes. Methods: Eighty-two patients (64 ± 12 years; 77% male; CAD in 60%; left ventricular ejection fraction 45 ± 16%) with a history of atrial tachycardia or atrial fibrillation (AT/AF) were implanted with a dual-chamber implantable cardioverter defibrillator (ICD) and followed for 6 months. A total of 224 episodes of induced and spontaneous AT/AF were classified into type I, II, and III according to the method of Israel et al. and then compared based on average cycle length (CL) and atrial amplitude. Episodes were also grouped as "pace-terminable" or "nonpace-terminable" based on the CL definition of Gillis et al. Results: The analysis of 121 induced episodes (from 80 patients) and 103 spontaneous episodes (from 43 patients) showed that within each arrhythmia type, there were no significant differences in CL or mean amplitude between induced and spontaneous episodes. Additional analysis of patients that had both induced and spontaneous episodes (n = 41) showed 78% had at least one spontaneous episode that matched the induced episode. Fifty-seven percent of spontaneous episodes were considered to be pace-terminable based on CL. Conclusions: Our data suggest that there is no significant difference between induced and spontaneous episodes of AT/AF of the same type. The majority of patients had at least one spontaneous episode of the same type as the induced episode, showing that induced atrial arrhythmias may be useful in predicting the morphology of future spontaneous episodes and in identifying patients potentially benefiting from atrial antitachycardia pacing. [source] Analysis of Implantable Cardioverter Defibrillator Therapy in the Antiarrhythmics Versus Implantable Defibrillators (AVID) TrialJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 9 2003RICHARD C. KLEIN M.D. Introduction: The implantable cardioverter defibrillator (ICD) is commonly used to treat patients with documented sustained ventricular tachycardia (VT) or ventricular fibrillation (VF). Arrhythmia recurrence rates in these patients are high, but which patients will receive a therapy and the forms of arrhythmia recurrence (VT or VF) are poorly understood. Methods and Results: The therapy delivered by the ICD was examined in 449 patients randomized to ICD therapy in the Antiarrhythmics Versus Implantable Defibrillators (AVID) Trial. Events triggering ICD shocks or antitachycardia pacing (ATP) were reviewed for arrhythmia diagnosis, clinical symptoms, activity at the onset of the arrhythmia, and appropriateness and results of therapy. Both shock and ATP therapies were frequent by 2 years, with 68% of patients receiving some therapy or having an arrhythmic death. An appropriate shock was delivered in 53% of patients, and ATP was delivered in 68% of patients who had ATP activated. The first arrhythmia treated in follow-up was diagnosed as VT (63%), VF (13%), supraventricular tachycardia (18%), unknown arrhythmia (3%), or due to ICD malfunction or inappropriate sensing (3%). Acceleration of an arrhythmia by the ICD occurred in 8% of patients who received any therapy. No physical activity consistently preceded arrhythmias, nor did any single clinical factor predict the symptoms of the arrhythmia. Conclusion: Delivery of ICD therapy in AVID patients was common, primarily due to VT. Inappropriate ICD therapy occurred frequently. Use of ICD therapy as a surrogate endpoint for death in clinical trials should be avoided. (J Cardiovasc Electrophysiol, Vol. 14, pp. 940-948, September 2003) [source] Relationship between the Duration of the Basal QRS Complex and Electrical Therapies for Ventricular Tachycardias among ICD PatientsPACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 5 2010JAVIER JIMÉNEZ-CANDIL M.D., Ph.D. Background:,In implantable cardioverter-defibrillators (ICD) patients, the duration of the basal QRS complex (QRSd) is not associated with a greater risk of developing ventricular tachyarrhythmias. QRSd could be inversely related to the effectiveness of antitachycardia pacing (ATP) because it may be associated with longer conduction times of the paced-impulses and hence, with a greater propensity to require shocks to terminate ventricular tachycardias (VTs). Methods:,We followed 216 ICD patients (pacing site: right ventricular apex; QRSd , 100: 34%) for 21 ± 12 months. ICD programming was standardized. QRSd was determined on the electrocardiogram (50 mm/s) at device implantation. Results:,Five hundred and fifty-one VTs (cycle length: 329 ± 35 ms) occurred in 67 patients (36% had a QRSd , 100 ms). ATP terminated 86% of VTs and 11% needed shocks. Mean ATP efficiency per patient was 83%. QRSd was significantly correlated with the probability of successful ATP (C-coefficient: 0.66), the best cut-off point being 100 (sensitivity and specificity of 91% and 49%). Patients with QRSd , 100 had a higher ATP effectiveness (98% vs 75%; P = 0.003) and fewer VTs terminated by shocks (1% vs 23%; P = 0.003). By logistic regression, QRSd > 100 remained as an independent predictor of receiving shocks to terminate VTs (P = 0.01). According to Kaplan-Meier analysis, the occurrence of VTs was similar regardless of the QRSd (30% vs 38%; P = 0.2), but the incidence of shock due to VTs was higher in patients with a QRSd > 100 (19% vs 7%; P = 0.01). Conclusion:,Since QRSd is a negative and independent predictor of effective ATP, ICD patients with QRSd > 100 ms require shocks more frequently to terminate VTs. (PACE 2010; 596,604) [source] Initial Experience of Pacing with a Lumenless Lead System in Patients with Congenital Heart DiseasePACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 11 2009SANTABHANU CHAKRABARTI M.D. Background: Long-term pacing is frequently necessary in patients with congenital heart disease (CHD). Preservation of ventricular function and avoidance of venous occlusion is important in these patients. Site-selective pacing with a smaller diameter lead is achievable with the model 3830 lead (SelectSecure®, Medtronic Inc., Minneapolis, MN, USA), which was specifically designed to target these complications. We describe our initial experience with the Model 3830 lead in patients with CHD. Methods: Retrospective analysis of all patients undergoing site-selective implantation of a Model 3830 lead(s) from two congenital heart centers (Bristol, UK, and Dublin, Ireland) from October 2004 until February 2008. Results: We implanted 139 SelectSecure® leads (atrial n = 70; ventricular n = 69) in 90 patients (57 male) with CHD. Median age at implantation: 13.4 years (1.1,59.2 years), median weight: 43 kg. Sixty-nine patients (76%) were children (<18 years). Indications for lead implantation included atrioventricular block (n = 55), sinus node disease (n = 18), implantable cardiac defibrillator (n = 12), antitachycardia pacing (n = 4), and cardiac resynchronization (n = 1). Twenty-two patients underwent pre-existing lead extraction during the same procedure. All the attempted procedures resulted in successful pacing. One patient had a significantly raised threshold at implantation. There was no procedural mortality. There were two procedural complications. Three patients required lead repositioning for increasing thresholds early postprocedure (<6 weeks). Four leads (2.9%) had displaced on median follow-up of 21.8 months (0.5,42 months). Conclusions: The Model 3830 lead is safe and effective in patients with CHD. This is a technically challenging patient group yet procedural complication and lead displacement rates are acceptable. [source] Delayed Cardiac Perforation by Defibrillator Lead Placed in the Right Ventricular Outflow Tract Resulting in Massive Pericardial EffusionPACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 12 2008ERNEST W. LAU M.D. A 76-year-old man received a dual-chamber implantable cardioverter defibrillator (ICD), with the defibrillator lead positioned within the right ventricular outflow tract. The lead parameters at the time of implantation were satisfactory and the postprocedure chest X-ray showed the leads were in place. The patient was cardioverted from atrial fibrillation during defibrillation threshold testing and commenced on anticoagulation immediately. One month post implantation, he experienced multiple ventricular tachycardia episodes all successfully treated with antitachycardia pacing and shocks by his ICD, but he fell and hit his chest against a hard surface during one of these attacks. He developed a massive pericardial effusion and computed tomography confirmed cardiac perforation by the defibrillator lead. Pericardiocentesis was performed and the defibrillator lead replaced with a different model positioned at the right ventricular apex. The patient made an uneventful recovery. The management and avoidance of delayed cardiac perforation by transvenous leads were discussed. [source] A Clinical Risk Score to Predict the Time to First Appropriate Device Therapy in Recipients of Implantable Cardioverter DefibrillatorsPACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 3 2007HAITHAM HREYBE M.D. Background:To develop a risk score to predict the occurrence of appropriate defibrillator [implantable cardioverter-defibrillator (ICD)] therapies. A simple clinical score predicting the risk of appropriate ICD therapy is lacking. Methods:A Cox regression model was developed from a database of ICD patients at a single tertiary center to predict the time to appropriate ICD therapy defined as shock or antitachycardia pacing. A risk score was derived from this model using half of the database and was validated using the other half. Results:A total of 399 patients were entered into the database between July 2001 and February 2004. There were no statistically significant differences between the derivation (n = 200) and validation (n = 199) groups in any of the demographic or clinical variables recorded. The risk score included three independent variables: indication for ICD implantation (P = 0.03), serum creatinine level (P = 0.015), and QRS width (P = 0.028). The observed risk scores were highly predictive of time to ICD therapy in the validation group (P = 0.02). Conclusion:We describe a new clinical risk score that predicts the time to appropriate device therapy in ICD recipients of a single tertiary center hospital. The performance of this risk score needs to be investigated prospectively in a larger patient population. [source] 25 Years of Insights into the Mechanisms of Supraventricular ArrhythmiasPACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 9 2003NASPE HISTORY SERIES The introduction of programmed electrical stimulation of the heart and intracardiac activation mapping 35 years ago made it possible to study the site of origin or pathway of a supraventricular tachycardia and to gain insight into the tachycardic mechanism. Information from these studies has been the basis for the development of new therapies, like arrhythmia surgery, antitachycardia pacing, and catheter ablation. The correlation of intracardiac findings with the 12-lead ECG during the tachycardia resulted in the recognition of characteristic ECG patterns for the different types of supraventricular tachycardias. Currently, gross localization of the site of origin of the arrhythmia is based on the 12-lead ECG during the arrhythmia with fine tuning using intracardiac activation mapping and pacing. These developments during the past 3 decades make accurate arrhythmia diagnosis possible and allow us to offer curative therapies to many of patients suffering from a supraventricular tachycardia. (PACE 2003; 26:1916,1922) [source] Alternans in QRS Amplitude During Ventricular TachycardiaPACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 2 2002PHILIPPE MAURY MAURY, P., et al.: Alternans in QRS Amplitude During Ventricular Tachycardia. Although the value of T wave alternans as an index of electrical instability has been extensively investigated, little is known about QRS alternans during VT. Intracardiac electrograms of 111 episodes of spontaneous monomorphic regular VT retrieved from implantable defibrillators in 25 patients were retrospectively selected. Three beat series, representing the total amplitudes and amplitudes from baseline to summit and from baseline to lower point of 16 or 32 successive QRS complexes before deliverance of electrical therapy were generated for each episode. Spectral analysis was then performed using the fast Fourrier transform. VT was considered as alternans if the magnitude of the spectral power at the 0.5-cycle/beat frequency was greater than the mean ± 3 SD of the noise in at least one of the three spectral curves. QRS alternans was present in 23 (20%) of 111 episodes and in 9 (36%) of 25 patients. Alternans was not related to the VT cycle length, QRS duration, QRS amplitude, signal amplification, nor to clinical variables. Alternans was more frequently detected in unipolar configuration and when a higher number of complexes was included in analysis. Failure of antitachycardia pacing was more frequent in case of alternans VT (50% vs 75% success in non-alternans VT, P = 0.05). Spontaneous termination before deliverance of therapy occurred in 16 nonalternans VT but never in alternans episodes (P = 0.02). Alternans in QRS amplitude is a relatively common finding during VT and could be associated with failure of antitachycardia pacing and lack of spontaneous termination. Lower efficacy of electrical therapies in case of QRS alternans must be confirmed in a way to improve the effectiveness of antitachycardia pacing. [source] | ||||||||||