P wave and the development of atrial fibrillation.

Background: Terminal P-wave inversion in lead V₁ representing left atrial overload has been considered a precursor of atrial fibrillation (AF). Objective: The purpose of this study was to determine whether this P-wave morphologic characteristic can predict the development of AF. Methods: Digital analysis of 12-lead ECGs was performed to enroll patients with P terminal force ≥0.06 s × 2 mm in lead V₁ from among a database of 308,391 ECG recordings. The prognostic value of ECG characteristics for developing AF was determined. Results: A total of 78 patients (mean age 52 ± 19 years) with left atrial overload were chosen from among 102,065 patients in the database. During mean follow-up of 43 months, 15 (19%) patients developed AF (AF group) versus 63 (81%) patients who did not (non-AF group). No significant difference was noted between the AF and non-AF groups with regard to the area, duration, and amplitude of the P-wave terminal portion in lead V₁. In contrast, the area, duration, and amplitude of the P-wave initial portion in the same lead were significantly greater in the AF group than in the non-AF group (114.6 ± 73.0 μV × ms vs 73.1 ± 59.3 μV × ms, 42.2 ± 12.4 ms vs 35.7 ± 10.1 ms, and 94.0 ± 39.9 μV vs 68.8 ± 49.4 μV, respectively; P <.05 for each). Multivariate analysis confirmed that the area of the P-wave initial portion was independently associated with the development of AF (hazard ratio 4.02, 95% confidence interval 1.25–17.8; P = .018). Conclusion: P-wave initial portion in lead V₁ was an independent risk stratifier of AF development in patients with marked left atrial overload. [Copyright &y& Elsevier]