Abstract 17073: Avoiding Shocks by Programming a High Number of Antitachycardia Pacing Attempts for Fast Ventricular Tachycardia: A Prospective Study
Purpose: Antitachycardia pacing (ATP) is a painless therapy reducing defibrillation shocks in implantable cardioverter-defibrillator (ICD) recipients. One or 2 ATP attempts are usually programmed to terminate fast ventricular tachycardia (FVT) episodes and avoid shocks without delaying successful treatment in case of ATP failure. Programming more ATP attempts could probably reduce the occurrence of shocks.
Objective: We sought to analyze the long-term efficacy and safety of programming a high number of ATP attempts for FVT.
Methods: All patients receiving a first ICD in our center for coronary artery disease (CAD) and dilated cardiomyopathy in primary and secondary prevention indications between 2000 and 2009 were prospectively included in the study. ICDs were programmed to deliver 10 ATP attempts for FVT cycle lengths (CL) of 250 to 300 ms (200 to 240 bpm) before high energy shock delivery (5 bursts, then 5 ramps; 8 to 10 extrastimuli at 81 to 88% of the FVT CL; minimal pacing CL 180 ms).
Results: We prospectively included 770 patients (men 84%; CAD 75.5%; age 63.2 ± 11 years; secondary indication 54.3%; left ventricular ejection fraction 30.3±9%), followed for 40.6 ± 25.6 months. Among them, 137 patients (17.8%) had a total of 1839 episodes of FVT (mean frequency 209 ± 9.2 bpm). ATP terminated 1713 episodes of FVT (unadjusted efficacy, 93.1%; GEE adjusted 81.7%) and acceleration occurred in 5.8% of episodes. A large majority of episodes were successfully treated (98.3%) by 1 or 2 ATP sequences. Conversely, the patient-based analysis showed that 17 (12.4%), 8 (5.8%) and 5 patients (2.1%) had one episode or more treated by at least 3, 4 or 5 ATP attempts, respectively. These patients would have been shocked with a conventional ICD programming. The benefit of this strategy was reduced for 6 to 10 attempts and only 10 patients were shocks for ATP failure (20 episodes, 1.1%). Despite the high number of attempts programmed, FVT episodes were mainly asymptomatic and found during device interrogation: syncope and pre-syncope occurred in 0.2% and 0.4% of episodes, respectively.
Conclusions: Programming a high number of ATP attempts (at least 4 or 5 ATP sequences) in the FVT zone is both safe and useful. It could prevent painful shocks for FVT in a high proportion of ICD recipients.
- © 2011 by American Heart Association, Inc.