Pulmonary vein antrum isolation and terminal part of the P wave.

BACKGROUND

Delayed interatrial conduction, manifested on the electrocardiogram as a P wave >or=110 ms (interatrial block, IAB), is highly prevalent and associated with atrial fibrillation (AF). It is correlated with P-terminal force (Ptf; product of the duration and amplitude of the negative terminal phase of the P wave in lead V1). Our purpose was to describe the modifications of the P-wave duration and Ptf after pulmonary vein antrum isolation (PVAI) in patients with paroxysmal AF.

METHODS

PVAI was performed in 45 patients with paroxysmal AF, either with the cryoballoon technique (n = 15) or radiofrequency ablation (n = 30). Electrocardiograms were recorded before PVAI, 3 and 6 months after ablation.

RESULTS

From the sample (median age 60 [53; 66] years; female 40%), median P-wave duration was 122 [114; 134] ms before PVAI and 116 [106; 124] ms at 3-month follow-up (P < 0.001). IAB was observed in 42 patients (93.3%) before ablation and in 31 patients (68.9%) at 3-month follow-up. Median Ptf was 0.047 [0.020; 0.068] before ablation and 0.013 [0.004; 0.025] at 3-month follow-up (P < 0.001). Twenty-six patients (57.8%) had a Ptf > 0.04 mV x ms before ablation and only one (2.2%) at 3-month follow-up. P-wave duration and Ptf were not significantly modified between 3- and 6-month follow-up.

CONCLUSION

The terminal part of the P wave is modified after PVAI, perhaps due to the loss of pulmonary vein antrum signals. P-wave duration and Ptf must be carefully interpreted after such a procedure. The prognostic value of these modifications should be evaluated.