Time Variability of P-wave Features from the Preoperative Electrocardiogram Predicts Recurrence After Catheter Cryoablation of Atrial Fibrillation

Abstract

[EN] Pulmonary vein isolation is nowadays the cornerstone for the treatment of paroxysmal atrial fibrillation (AF). However, its success rate is not as high as clinically desirable, and repeated procedures are often required. In this context, the development of noninvasive, pre-ablation predictors of the procedure failure is essential to enable tailored approaches. For that purpose several P-wave features have been analyzed from short electrocardiogram (ECG) recordings, but their time variability has not been studied yet. Hence, this work explores the ability of time variability of two common P-wave parameters, such as duration and amplitude, to anticipate cryoablation failure. Before ablation, a standard 12-lead ECG was recorded continuously for 5 minutes from 45 paroxysmal AF patients. All P-waves in lead II were delineated with an automatic algorithm. Duration and amplitude of all waves were computed, and then mean, standard deviation (std), and coefficient of variation (CV) were obtained for both parameters and correlated with ablation outcome after a follow-up of 9 months. The CV for both P-waves features reported the best separation between the patients who maintained sinus rhythm and those who relapsed to AF. Moreover, improvements about 10% in diagnostic ability were obtained by the CV with regards to the mean, reaching values about 70%. These results suggest that time variability of the P-wave can provide new insights about atrial conduction heterogeneity, which could be helpful in improving the selection strategy of optimal candidates for cryoablation.