Optimization of a Novel Activation-Repolarization Metric to Identify Targets for Catheter Ablation

Identification of targets for catheter ablation of arrhythmias remains a significant challenge. Traditional mapping techniques often neglect the tissue repolarization, hampering the detection of pro-arrhythmic regions. We have recently developed a novel mapping procedure, termed the Reentry Vulnerability Index (RVI), which incorporates both activation (AT) and repolarization (RT) times to identify ablation targets. Despite showing promise in a series of experiments, the RVI requires further development to enable its incorporation into a clinical protocol. The goal of this study was to use computer simulations to optimize the RVI procedure for its future usage within the clinic. A 2D sheet model was employed to investigate the behavior of the RVI algorithm under mapping catheter recordings resembling clinical conditions. Conduction block following premature stimulation was induced and mapped in a cardiac tissue model including repolarization heterogeneity. RVI maps were computed based on the difference between RTs and ATs between successive pairs of electrodes within a given search radius. Within 2D sheet models we show that RVI maps computed on irregular sparse recording sites were in good agreement with high resolution maps. We concude that the RVI algorithm performed well under clinically-relevant mapping conditions and may be used to guide ablation.