Inappropriate Detection of Supraventricular Arrhythmias by Implantable Dual Chamber Defibrillators: A Comparison of Four Different Algorithms

Abstract

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.

Inappropriate Implantable Cardioverter-Defibrillator Shocks in MADIT II

“…Dual-chamber ICD systems were used approximately as commonly in patients who experienced an inappropriate shock (38.6%) as in those who did not (44.4%, Table 3). Prior studies have often failed to show a benefit of dualchamber devices in preventing inappropriate detections of supraventricular arrhythmias (22,26,35,36). The Detect Supraventricular Tachycardia Study (DETECT SVT) recently showed a reduction in the percent of total SVT episodes that were inappropriately classified as VT in the dualchamber detection group (30.9%) than the single-chamber group (39.5%) (37).…”

A new method to investigate the response to the morphology discrimination algorithm in patients with ICD

“…However, the incidence of inadequate therapies or the withdrawal of adequate therapy delivery still remains a major problem [1][2][3][4]17], although sophisticated tachycardia discrimination algorithms have been implemented to the devices.…”

“…Supraventricular tachyarrhythmia are still the main cause for inappropriate therapy delivery in 8% to 22% of patients with implantable cardioverter defibrillators (ICD) [1,2], leading to patient discomfort or severe proarrhythmia [3,5]. Therefore, enhanced detection algorithms such as the sudden rate increase (''sudden onset''), the rate stability, or the morphology discrimination criterion have been implemented to modern ICDs [6 -8].…”

Algorithms for better arrhythmia discrimination in implantable cardioverter defibrillators

“…Systematic studies directly comparing the efficiency of the available algorithms are lacking [21,22]. Hintringer et al [23] tested four different dual-chamber algorithms by simulating various supraventricular tachycardias and VTs recorded during electrophysiologic studies. All devices revealed a very low specificity, ranging from 11% to 28% for all supraventricular arrhythmias.…”