Improved discrimination of VT from SVT in dual-chamber ICDs by combined analysis of dual-chamber intervals and ventricular electrogram morphology

The PR Logic dual-chamber defection algorithm discriminates VT/VF from SVT using hierarchical rules based on the pattern and timing of AA, VV, AV, and VA intervals. It cannot always discriminate rapidly-conducted atrial fibrillation(AF) from double tachycardia. Coexisting AF and VT/VF, or SVT with 1:1 antegrade conduction from VT with 1:1 retrograde conduction. This study evaluated a new tachyarrhythmia detection algorithm that supplements analysis of dual-chamber intervals with analysis of ventricular electrogram morphology based on the Wavelet Dynamic Discrimination Algorithm. Combined analysis of dual-chamber intervals and ventricular electrogram morphology reduced inappropriate detection of SVTs by 79% compared to dual chamber intervals alone without compromising sensitivity for detection of VT/VF.