Left Bundle Branch Area Antitachycardia Pacing Improves Success Rate Compared to Right Ventricular Antitachycardia Pacing.

BACKGROUND

Antitachycardia pacing (ATP) therapy applies a sequence of pacing pulses to terminate ventricular tachycardia (VT). Clinically, left bundle branch area (LBBA) pacing has emerged as a novel way to induce synchronous ventricular activation.

OBJECTIVES

The main aim of this study was to compare the efficacy and safety of ATP delivered to an LBBA lead and a conventional right ventricular (RV) lead.

METHODS

Using a preclinical animal model (n = 7), pacing leads were implanted in the RV apex and LBBA and connected to implantable cardioverter-defibrillators. The left anterior descending artery was occluded for 2 hours to cause an ischemia-reperfusion injury. Four days following ischemia-reperfusion injury, VT episodes were induced using programmed pacing, and burst ATP therapy was delivered to the RV/LBBA leads for each VT episode. Activation sequences from an implanted basket catheter were determined for the pretherapy VT and ATP beats.

RESULTS

VT was induced 80 times, with a mean VT cycle length of 180.0 ± 30.0 milliseconds. ATP delivered to the LBBA terminated VT more often than RV ATP (70.2% vs 47.3%; P = 0.040). There was no significant difference in VT acceleration or ventricular fibrillation induction. The number of ATP pulses required for the activation sequences to correlate with the captured ATP pattern rather than the pretherapy VT pattern was lower for LBBA compared to RV ATP (4.1 vs 5.1 pulses; P = 0.047).

CONCLUSIONS

Improved performance of LBBA compared to RV ATP provides an incentive for future clinical studies in patients who are at risk of sudden cardiac death.