Novel Mapping Technique for AF IntroductionIdentification of wavefront propagation pattern during AF remains challenging in ablation procedures. We sought to test a novel combination of a new mapping technology called Ripple Map and high-density mapping to distinguish focal and reentrant activation during atrial fibrillation (AF). Methods and ResultsSubjects were patients undergoing ablation for persistent AF. If AF remained after isolation of the pulmonary veins, the left atrium (LA) was mapped by a high-density mapping catheter for later analysis, after which ablation was continued using a conventional stepwise approach. After the procedure, electrograms from the high-density mapping catheter were analyzed using Ripple Map, which is a new feature in the CARTO (R) 3, and type of activation on 3 consecutive AF cycles was determined. High-density mapping was performed on 569 sites in 45 patients (13 3 sites per patient). AF wavefront propagation determined by Ripple Map was in good agreement with analysis of manual annotation of bipolar electrograms. Ripple Map's representation of wavefront activation pattern, which could include local as well as far-field activity, allowed us to identify focal activation in 64 (11%) sites and 1 (0.2%) reentrant activation site. Radiofrequency delivery in atrial regions with activation sites identified as focal by Ripple Map resulted in termination of AF more often than regions without focal activation (22% vs. 7%, P = 0.015). ConclusionThis study demonstrated that Ripple Map enabled quick identification of AF wavefront activation pattern, potentially being helpful for determining ablation targets in persistent AF.