Efficacy and safety of different antitachycardia pacing sites in the termination of ventricular tachycardia in patients with biventricular implantable cardioverter-defibrillator.

ABSTRACT

AIMS: We sought to evaluate the efficacy and safety of different antitachycardia pacing (ATP) sites in heart failure (HF) patients with a biventricular implantable cardioverter-defibrillator (ICD). METHODS AND RESULTS: Between January 2003 and December 2008, 89 consecutive patients with biventricular (BiV) ICDs (Medtronic Inc., St Paul, Minnesota, USA) were enrolled. In these patients, stored electrograms of the true spontaneous ventricular tachycardia (VT) episodes with at least one ATP therapy were analysed. Out of the 89 patients, 46 experienced 259 VT episodes. When we considered all VT forms, both left ventricular (LV)-ATP (91%) and BiV-ATP (89%) were significantly better than right ventricular (RV)-ATP (72%) in terminating VTs (P = 0.03 and 0.04, respectively). In the fastVT zone, there was a trend for higher efficacy of BiV-ATP compared with RV-ATP and LV-ATP (75 vs. 60 vs. 60%, P = 0.10). Fast VT acceleration occurred to a similar extent in all ATP groups (20% in RV-ATP vs. 20% in LV-ATP vs. 20% in BiV-ATP, P = NS). In the slow VT zone, RV-ATP was significantly less effective than LV-ATP (74 vs. 100%, P = 0.001) and BiV-ATP (74 vs. 100%, P = 0.014). Incidence of acceleration was lower with LV-ATP and BiV-ATP than RV-ATP (0 vs. 0 vs. 9%, P = 0.03) in the slow VT zone. CONCLUSIONS: In HF patients treated with BiV ICD, overall ATP efficacy is higher when delivered from LV or BiV than from RV. Biventricular-ATP and LV-ATP are also safer than RV-ATP in the slow VT zone.