Abstract
Purpose: This study presents a new methodology of causality analysis for identification of the areas responsible for the atrial fibrillation (AF) maintenance, whose detection and ablation could terminate the arrhythmia.
Methods: We calculated the causality relations between all intracardiac recordings obtained by a multipolar spiral catheter in 4 paroxysmal AF patients during electrical pacing and induced AF. Causality results were incorporated into vector diagrams and maps indicating the location of the electrical sources and the dominant propagation directions for each region.
Results: During pacing, the source of the propagation patterns obtained via the causality analysis matched the location of the pacing electrode in all cases. During AF, propagation patterns presented temporal variability, but a dominant direction was found to account for significantly more waves than other possible directions (49±15% vs. 14±13% or less, p<0.01, Panel A). The sequentially measured causality relations covering the entire atria yielded a map of regional dominant propagation and localized the AF sources. In panel B, a sample case localizes the dominant source of the AF activation at a site between the left PVs in a patient in which AF terminated following ablation of the LIPV.
Conclusion: The causality method provides dominant propagation patterns during AF. Causality analysis allows the localization of fibrillation sources in the atria and can serve as guidance for ablation procedures in AF patients.
