Omnipolar versus bipolar mapping to guide ventricular tachycardia ablation

Abstract

Omnipolar technology (OT) was recently proposed to generate electroanatomical voltage maps with orientation-independent electrograms. We describe the first cohort of patients undergoing ventricular tachycardia (VT) ablation guided by OT. The purpose of this study was to compare omnipolar and bipolar high-density maps regarding voltage amplitude, late potentials (LP) annotation, and isochronal late activation maps (ILAM) distribution. A total of 24 patients (16 ischemic cardiomyopathy, 12 redo cases) underwent VT ablation under OT guidance. Twenty-seven sinus rhythm substrate maps and 10 VT activation maps were analyzed. Omnipolar and bipolar (HD Wave solution) voltages were compared. Areas of late potentials were correlated to the VT isthmuses areas and late electrograms misannotation was evaluated. Deceleration zones based on ILAM were analysed by 2 blinded operators and compared to the VT isthmuses. Omnipolar maps had higher points density (13.8 vs 8.0 points/cm2). Omnipolar points had 7.1% higher voltages than bipolar points within areas of dense scar and border zone. The number of misannotated points was significantly lower in omnipolar maps (6.8% vs 21.9%, p=0.01), showing comparable sensitivity (53% vs 59%) but higher specificity (79% vs 63%). The sensitivity and specificity of deceleration zones detection of the VT critical isthmus were respectively 75% and 65% for OT, and 35% and 55% for bipolar. At 8.4 months, 71% freedom from VT recurrence was achieved. OT is a valuable tool for guiding VT ablation, providing more accurate identification of late potentials and isochronal crowding due to slightly higher voltages.