Impact of hybrid procedure on P wave duration for atrial fibrillation ablation

Hybrid procedure (HP) involves epicardial isolation of pulmonary vein and posterior wall of left atrium, and endocardial checking of lesions and touchups (if needed). We aimed at observing the effect of hybrid procedure on P wave duration (PWD), calculated automatically from surface ECG leads at start and end of HP, and also for relationship to atrial fibrillation (AF) recurrence at 9 months. Forty-one patients (32 male; mean age, 58.4 +/- 9.5 years) underwent HP, as first ever ablation. A new automated method was used for P wave segmentation and PWD estimation from recognizable P waves in ECG lead I or II before and after HP, based on fitting of each P wave by means of two Gaussian functions. Overall, PWD was significantly decreased after procedure (104.4 +/- 25.1 ms vs. 84.7 +/- 23.8 ms, p = 0.0151), especially in persistent AF patients (122.4 +/- 32.2 ms vs. 85.6 +/- 24.5 ms, p = 0.02). PWD preprocedure was significantly higher in persistent than in paroxysmal patients (122.4 +/- 32.2 ms vs. 92.5 +/- 17.9 ms, p = 0.0383). PWD was significantly decreased after procedure in prior electrical cardioverted patients (106.7 +/- 30.5 ms vs. 84.7 +/- 23.1 ms, p = 0.0353). After 9-month follow-up of 40 patients, HP-induced PWD decrease was significant for the 12 persistent patients without recurrence (122.4.1 +/- 35.3 ms vs. 85.6 +/- 22.0 ms, p = 0.0210). Preprocedure PWD was higher for persistent than paroxysmal patients. HP reduced PWD significantly. Nine-month follow-up suggests that HP is successful in restoring and maintaining sinus rhythm. To individualize AF therapy, AF type-based selection of patients may be possible before procedure. Automated analysis of PWD from surface ECG is possible.