Non-Invasive Characterization of Atrial Activity Immediately Prior to Termination of Paroxysmal Atrial Fibrillation

Abstract

Atrial activity characterization with a high degree of detail can be reached by analyzing invasive recordings. Nevertheless, electrocardiographic signal processing tools can nowadays obtain equivalent information in some cases. The aim of this work is to study the electrocardiographic alterations produced during the last instants prior to spontaneous AF termination. Fifty patients in paroxysmal AF with an episode lasting more than two hours were selected. The last minute prior to spontaneous AF termination (group S) and the central minute (group N) from each episode were analyzed. Ventricular response, f waves morphology, and atrial activity spectral and organization were studied through the use of signal processing tools. RR intervals variability was a discriminative parameter (group S 630+/-200 ms vs. group N 740+/-100 ms; P=.034), although a low specificity was obtained (54.2%). Significative differences between both groups were not reported by the f waves morphological study. Group S presented a significative low dominant atrial frequency mean value than group N (group S 5.010+/-0.671 Hz vs. group N 6.514+/-0.804 Hz, P=4.55x10(-9)). Finally, group N showed a considerable low atrial activity organization degree than group S (group S 0.071+/-0.012 vs. group N 0.103+/-0.013, P=6.73x10(-12)). The analysis of the electrocardiographic interval prior to spontaneous AF termination has revealed an atrial activity organization process, which cannot be observed by visual inspection of f waves morphology, but can be successfully quantified through signal processing.