Anti-tachycardia pacing was more efficacious at terminating slow compared with fast ventricular tachycardias (65% vs 46%, P=0.000039), while proximal delivery was more effective for fast VTs.
Does proximal delivery of ATP combined with an early termination detection algorithm improve termination of ventricular tachycardia in infarcted porcine computational models?
In a computational model of infarcted porcine hearts, ATP delivery proximal to the re-entrant circuit combined with an early termination detection algorithm improved the efficacy of terminating ventricular tachycardia.
Absolute Event Rate: 65% vs 46%
p-value: p=0.000039
AIMS: Anti-tachycardia pacing (ATP) is a reliable electrotherapy to painlessly terminate ventricular tachycardia (VT). However, ATP is often ineffective, particularly for fast VTs. The efficacy may be enhanced by optimized delivery closer to the re-entrant circuit driving the VT. This study aims to compare ATP efficacy for different delivery locations with respect to the re-entrant circuit, and further optimize ATP by minimizing failure through re-initiation. METHODS AND RESULTS: Seventy-three sustained VTs were induced in a cohort of seven infarcted porcine ventricular computational models, largely dominated by a single re-entrant pathway. The efficacy of burst ATP delivered from three locations proximal to the re-entrant circuit (septum) and three distal locations (lateral/posterior left ventricle) was compared. Re-initiation episodes were used to develop an algorithm utilizing correlations between successive sensed electrogram morphologies to automatically truncate ATP pulse delivery. Anti-tachycardia pacing was more efficacious at terminating slow compared with fast VTs (65 vs. 46%, P = 0.000039). A separate analysis of slow VTs showed that the efficacy was significantly higher when delivered from distal compared with proximal locations (distal 72%, proximal 59%), being reversed for fast VTs (distal 41%, proximal 51%). Application of our early termination detection algorithm (ETDA) accurately detected VT termination in 79% of re-initiated cases, improving the overall efficacy for proximal delivery with delivery inside the critical isthmus (CI) itself being overall most effective. CONCLUSION: Anti-tachycardia pacing delivery proximal to the re-entrant circuit is more effective at terminating fast VTs, but less so slow VTs, due to frequent re-initiation. Attenuating re-initiation, through ETDA, increases the efficacy of delivery within the CI for all VTs.
Qian et al. (Wed,) conducted a other in Ventricular tachycardia (n=7). Anti-tachycardia pacing (ATP) vs. Different delivery locations (proximal vs distal) was evaluated on ATP efficacy at terminating VTs (slow vs fast) (p=0.000039). Anti-tachycardia pacing was more efficacious at terminating slow compared with fast ventricular tachycardias (65% vs 46%, P=0.000039), while proximal delivery was more effective for fast VTs.