Changes in Electrocardiographic P Wave Parameters after Cryoballoon Ablation and Their Association with Atrial Fibrillation Recurrence.

Background: Changes in P wave parameters after circumferential pulmonary vein isolation (CPVI) have been previously identified. In this study, we aimed to determine the changes in P wave parameters surface electrocardiogram (ECG) after cryoballoon ablation (CBA) for atrial fibrillation (AF) and evaluate their relationship with AF recurrence.

Methods: Sixty-one patients (mean age 53 ± 11 years, 50.8% male) with paroxysmal AF who underwent CBA were enrolled. A surface ECG was obtained from all patients immediately before the procedure, and repeated 12 hours after the procedure. P wave amplitude (Pamp), P wave duration (Pwd), and P wave dispersion (Pdis) values in preprocedural and postprocedural ECGs were measured and compared. Recurrence rates of AF in 3, 6, and 9 months following ablation were recorded for all patients. Changes in P wave parameters were compared between patients with and without AF recurrence.

Results: Compared to preprocedural measurements, Pamp (from 0.58 ± 0.18 mV at baseline to 0.48 ± 0.17 mV, P < 0.001), Pwd (from 109.72 ± 18.43 ms at baseline to 91.36 ± 22.53 ms, P < 0.001), and Pdis (from 55.44 ± 20.45 ms at baseline to 45.30 ± 15.31 ms, P < 0.001) were significantly decreased after CBA. The difference in Pamp between pre- and postprocedural values (∆Pamp) was significantly higher in patients without AF recurrence compared to those with recurrence (0.10 ± 0.06 mV vs 0.04 ± 0.01 mV, P = 0.002). There was no difference in Pwd difference (∆Pwd) and Pdis difference (∆Pdis) between patients with and without AF recurrence (P > 0.05).

Conclusion: Pamp, Pwd, and Pdis parameters exhibited significant decrease after CBA compared to preprocedural measurements. Decreased Pamp was shown to be a predictor for good clinical outcomes following CBA.