ABSTRACT
Objective: To observe the influence of circumferential pulmonary vein isolation (CPVI) on P-wave polarity and amplitude and to investigate whether the changes of P-wave are associated with patient outcomes after initial CPVI. Methods Fifty patients with paroxysmal atrial fibrillation (AF) underwent CPVI. For each patient, electrocardiograph (ECG) recordings were taken before and 7 days after ablation. The P-wave polarities and amplitudes were analyzed. Successful CPVI was defined as freedom of symptomatic and asymptomatic AF at the end of two consecutive follow-ups. Results: The amplitude of positive P-wave was significantly decreased in the leads of I, II, III, aVF, V5, and V6 after ablation (P<0.05). The amplitude of negative P-wave was significantly decreased in the leads of aVR and aVF after ablation (P<0.05). The total amplitude of P-wave was significantly decreased in the leads of I, II, aVR, V5 and V6 after ablation (P<0.05). The negative P-wave in the lead of III and the positive P-wave in the lead of aVL were increased after ablation. The amplitudes of negative, positive and total P-waves before and after ablation were not significantly different between successful CPVI (n=39) and failure CPVI (n=11) groups. Conclusion: CPVI can result in noticeable reduction of P-wave amplitude in several leads of ECG, indicating the reduction of left atrial electric capacity. The changes of P-wave polarity indicate a P-wave vector shift. The reduction degree of P-wave amplitude has no predictive value for the success or failure of CPVI.