Efficacy of biventricular sensing and treatment of ventricular arrhythmias.

While much is known concerning the hemodynamic effects of biventricular (BV) pacing, little has been reported concerning the efficacy of BV sensing and pacing in the detection and treatment of ventricular tachyarrhythmias. Two hundred nineteen heart failure (HF) patients with VT or VF and a QRS > or = 120 ms during sinus rhythm received an ICD capable of BV pacing and sensing. Detection times of induced VF and success rates for terminating induced VT were measured. The ICD system used a left ventricular epicardial lead implanted via thoracotomy (52 patients) or a specially designed percutaneous, over-the-wire lead inserted in the coronary venous system. VF detection times and VT termination rates by antitachycardia pacing (ATP) were compared with those measured in a population of recipients of ICD using a RV lead alone. Median induced VF detection times were comparable (2.0-s BV vs 1.8-s RV). Termination of induced VT on the first attempt was comparable with BV pacing (87.4%) versus RV pacing (89.6%). The time to detect induced VF was not different with ICDs using BV sensing versus conventional ICDs using RV sensing alone. Similarly, the rates of successful termination of induced VT by ATP with BV or RV pacing were comparable.