Performance of a dual-chamber implantable defibrillator algorithm for discrimination of ventricular from supraventricular tachycardia (original) (raw)
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Pacing and Clinical Electrophysiology, 2001
Tachycardia detection and therapy algorithms in Implantable Cardioverter-Defibrillators (ICD) reduce, but do not eliminate inappropriate ICD shocks. Awareness of the pros and cons of a particular algorithm helps to predict its utility in specific situations. We report a case where PR logic™, an algorithm commonly used in currently implanted ICDs to differentiate supraventricular tachycardia (SVT) from ventricular tachycardia resulted in inappropriate detection and shock for an SVT, and discuss several solutions to the problem.
Prevention of inappropriate therapy in implantable cardioverter-defibrillators
Journal of the American College of Cardiology, 2004
The purpose of this randomized study was to investigate the performance of single-and dual-chamber tachyarrhythmia detection algorithms. BACKGROUND A proposed benefit of dual-chamber implantable cardioverter-defibrillators (ICDs) is improved specificity of tachyarrhythmia detection.
Pacing and Clinical Electrophysiology, 2003
MLETZKO, R., ET AL.: Safety and Efficacy of a Dual Chamber Implantable Cardioverter Defibrillator Capable of Slow Ventricular Tachycardia Discrimination: A Randomized Study. New developments in dual chamber implantable cardioverter defibrillators (ICD) have increased the specificity of therapy delivery. This study was performed to examine the performance of an algorithm, focusing on its ability to distinguish slow ventricular tachycardia (VT) from sinus rhythm or supraventricular tachyarrhythmias. The patient population included 77 men and 13 women, 63 ± 11 years old, treated with ICDs after episodes of spontaneous or inducible ventricular tachyarrhythmias. They were randomized to programming of the ICD to a lower limit of VT detection at 128 beats/min (group I, n = 44), versus 153 beats/min II (group II, n = 46). The primary endpoint of the study consisted of comparing the specificity and sensitivity of the algorithm between the two groups of patients. Over a 10.1 ± 3.5 months follow-up, 325 episodes were detected in the Tachy zone in group I, versus 106 in group II. The sensitivity and specificity of the algorithm in group I were 98.8% and 94.4%, respectively, versus 100% and 89% in group II (NS). A single episode of VT at a rate of 132 beats/min was diagnosed as SVT in group I. The sensitivity and specificity of the algorithm for tachycardias <153 beats/min were 97.4% and 94.5%, respectively. Overall VT therapy efficacy was 100% in both groups. The performance of this algorithm in the slow VT zone supports the programming of a long Tachy detection interval to document slow events, and allows to treat slow VT, if necessary, without significant risk of inappropriate interventions for sinus tachycardia.
Enhanced Detection Criteria in Implantable Defibrillators
Journal of Cardiovascular Electrophysiology, 1998
Enhanced Tachycardia Detection Algorithm introduction: Enhanced detection criteria in third-generation implantable defibrillators have been implemented to avoid inappropriate therapy of fast supraventricular arrhythmias. We prospectively analyzed the use of these criteria in patients with an implantable defibrillator with electrogram storing capability.Methods and Results: In 82 consecutive patients with a Guidant-CPI implantable defibrillator, sudden onset > 9% and stability < 40 msec were systematically programmed in zone 1 of therapy together with a sustained rate duration security mechanism. All detected tachycardia episodes were analyzed. The study population consisted of 59 patients who had at least one episode of tachycardia detected in zone 1 during follow-up. The tachycardia rate in zone 1 never exceeded 210 beats/min. Twenty patients had no episodes during follow-up, and three patients had episodes detected exclusively in zone 2 of therapy. Supraventricular arrhythmias were detected frequently in the ventricular tachycardia zone (193 of 690 tachycardia episodes in 23 of 59 patients). Use of sudden onset was very effective in detecting sinus tachycardias (65 of 67 episodes), and stability was very useful in detecting atrial fibrillation (31 of 32 episodes). However, sensitivity in detecting ventricular tachycardia was only 90% (451 of 497 episodes). Application of the sustained rate duration criterion allowed appropriate treatment of all ventricular tachycardia episodes, increasing sensitivity to 100%; however, specificity in appropriate non-treatment of supraventricular decreased from 96% to 83%. Subsequent analysis of different algorithms applied to our data showed that sudden onset > 9% and stability < 40 msec was the algorithm with the best specificity and sensitivity.Conclusion: Programming sudden onset and stability detection criteria with a sustained rate duration safety net for triggering tachycardia therapy results in appropriate device management in most patients with supraventricular and slow (< 210 beats/min) ventricular tachycardias.
Journal of Cardiovascular Electrophysiology, 1999
ICD with DDD Pacemaker. Introduction:X major drawback of therapy with an implantable defibrillator is the nonspecificity of detection. Theoretically, adding atrial sensing information to a decision algorithm could improve specificity of detection. Methods and Results: This open-label nonrandomized study compares tbe detection algorithm of tbe Ventak AV and the Ventak Mini implantable defihrillators. Tbe Ventak AV (n = 39) u.st'S dual cbamber detection as opposed to single chamber detection (with rate stability) in tbe Ventak Mini {n = 55). Programmed zone configurations, rate tbresbolds, and stability criteria were identical in all patients. In tbe Ventak AV group, 235 ventricular tachyarrhythmias were adequately detected and treated by tbe device. In tbe Mini group. 699 episodes of ventricular fibrillation/tacbycardia occurred. All but six of the latter episodes were correctly identified and treated: one patient witb incessant ventricular tacbycardia bad five episodes not terminated by the device, another episode occurred in a patient with a device/lead defect. In tbe Ventak AV group, 33 episodes of sinus tachycardia and 166 episodes of atrial fibrillation/fiutter activated the device; inappropriate therapy was applied to 41% of atrial fibrillation/flutter episodes. In the Ventak Mini group, 226 supraventricular tachyarrhythmias activated tbe device, eigbt of whicb were sinus tacbyeardia and 218 were atrial fibrillation or flutter; of the atrial fibrillation/ flutter episodes 24% were treated inappropriately (fewer vs Ventak AV, P < 0.001). Conclusion: The new detection algorithm incorporated in tbe Ventak AV did not inadvertently withhold therapy for ventricular tacbyarrbythmias, but at tbe same time tbe number of inappropriate tberapies for atrial fibrillation was not decreased in comparison to a single cbamber device.
Pacing and Clinical Electrophysiology, 1998
This study was designed to evaluate the ability to distinguish between supraventricular tachycardias (SVTs) and ventricular tachycardias (VTs) based on onset, stability, and width criteria in an implantable defibrillator. Inappropriate detection of atrial fibrillation and sinus tachycardia is a common problem in patients with implantable defibrillators. The onset, stability, and width criteria were studied in 17 patients who underwent implantation of a Medtronic 7218C implantable defibrillator by inducing sinus tachycardia and atrial fibrillation. Additional data on the width criteria was obtained by pacing at separate sites in both the left and right ventricle. Patients were studied at different times for up to 6 months to determine any changes in the criteria. The onset and stability criteria caused inappropriate detections in 36% and 12% of the episodes, respectively. The addition of the width criteria decreased the inappropriate detection using the onset and stability criteria to 5% and 2%, respectively. Pacing from the RV apex, RV outflow tract, and LV apex was appropriately detected as wide in 76%, 41%, and 94%, respectively. The width criteria changed over time in individual patients, but was stable by 6 months in all but one patient. No single criterion is satisfactory for distinguishing between SVT and VT in this patient population, but the combination of criteria seems to provide better discrimination. The width criteria can change dramatically over time and needs to be monitored carefully. Newer algorithms will need to be developed to allow better detection of supraventricular tachycardias.