Quantitative assessment of regularity and synchronization of intracardiac recordings during human atrial fibrillation

This study proposes the morphology-based evaluation of the regularity (R) and the synchronization (S) of intra-atrial electrograms acquired during atrial fibrillation (AF). R is defined as the degree of repetitiveness over time of the shapes of the activation waves detected in single atrial recordings. S accounts for the simultaneous presence of morphologically similar activation waves in two atrial electrograms, and for the dispersion of the propagation delays between the two sites. Both R and S resulted unitary for normal sinus rhythm and decreased significantly moving from atrial flutter (R=0.93, S=0.88) to AF of increasing complexity class (type I AF: R=0.75, S=0.66; type II AF: R=0.32, S=0.21; type III AF: R=0.19, S=0.01). During paroxysmal AF, the proposed indexes allowed to locate atrial regions with high degree of organization and other areas with more complex patterns of electrical activation.