Comparison of novel intrinsic versus conventional antitachycardia pacing for ventricular tachycardia among implantable cardioverter‐defibrillator recipients

Abstract Introduction Intrinsic antitachycardia pacing (iATP) is a novel automated antitachycardia pacing (ATP) that provides individual treatment to terminate ventricular tachycardia (VT). However, the clinical efficacy of iATP in comparison with conventional ATP is unknown. We aim to compare the termination rate of VT between iATP and conventional ATP in patients with implantable cardioverter‐defibrillators using a unique setting of different sequential orders of both ATP algorisms. Methods Patients with the iATP algorithm were assigned to iATP‐first and conventional ATP‐first groups sequentially. In the iATP‐first group, a maximum of seven iATP sequences were delivered, followed by conventional burst and ramp pacing. In contrast, in the conventional ATP‐first group, two bursts and ramp pacing were initially programmed, followed by iATP sequences. We compared the success rates of VT termination in the first and secondary programmed ATP zones between the two groups. Results Fifty‐eight and 56 patients were enrolled in the iATP‐first and conventional ATP‐first groups, and 67 and 44 VTs were analyzed in each group, respectively. At the first single ATP therapy, success rates were 64% and 70% in the iATP and conventional groups, respectively. At the end of the first iATP treatment zone, the success rate increased from 64% to 85%. Moreover, secondary iATP therapy following the failure of conventional ATPs increased the success rate from 80% to 93%. There was a significant benefit of alternative iATP for VT termination compared to secondary conventional ATP (100% vs. 33%, p = .028). Conclusions iATP may be beneficial as a secondary therapy after failure of conventional ATP to terminate VT.