Characteristics of Effective Antitachycardia Pacing for Ventricular Tachycardia

Abstract

Background

Antitachycardia pacing (ATP) has a potential benefit for shock reduction of implantable cardioverter-defibrillator (ICD) recipients; however, its clinical utility and characteristics are unknown.

Objectives

This study aims to extract characteristics leading to a high ventricular tachycardia (VT) termination rate of ATP.

Methods

Patients who had a history of ≥1 ATP treatment episode from ICD or cardiac resynchronization therapy–defibrillator (CRTD) devices were included. All ATP treatments wherein intracardiac electrograms could be traced were reviewed. Two endpoints of VT termination were defined: type-I break (termination with 0-1 beat) and clinical endpoint of termination (≤5 beats). We assessed the characteristics associated with a high success rate of ATP using the logistic regression generalized estimating equation method.

Results

Of 756 recipients using high-power devices, 1,468 treatment episodes in 119 patients were analyzed. The VT rate of <188 beats/min (vs ≥188 beats/min), CRTD (vs ICD), and true septum right ventricular lead position were significantly associated with high success rate of type-I break termination (generalized estimating equation success rate: 78.7% vs 64.7%, P = 0.011; 80.1% vs 66.5%, P = 0.021; and 79.8% vs 60.5%, P = 0.023, respectively). True septum lead position and slow VT were also independently associated with successful termination with clinical endpoint. The termination rate was highest in the right ventricular true septum position across all positions at both endpoints. The pacing QRS interval was significantly shorter in the septum group than in the nonseptum group (166.2 ± 21.9 ms vs 198.7 ± 26.5 ms; P < 0.001).

Conclusions

True septum lead position, in addition to slow VT and CRTD, may be key to high ATP termination success.