BACKGROUNDCircumferential pulmonary vein isolation (CPVI), as the basal ablation strategy for treating atrial fibrillation (AF), not only isolates the connection between the left atrium (LA) and the pulmonary veins (PVs), but also induces extensive atrial endocardia damage. This could have an effect on the sinus pulse conduction in the LA and subsequently result in changes of P-wave characteristics of surface electrocardiogram (ECG).

METHODSFifty consecutive patients underwent CPVI for symptomatic drug-refractory paroxysmal AF. The 12-lead ECGs were recorded one day before CPVI and seven days after CPVI at sinus rhythm by a standard resting ECG device. Measured characteristics of the P-wave consisted of P-wave duration (PWD), P-wave amplitude (PWA), P-wave polarity (PWP), P-wave notch, P-wave dispersion and P-wave index.

RESULTSAfter CPVI, a prevalent decrease of PWD, PWA, and P-wave dispersion was observed; a transition of P-wave polarity was observed in the leads of III, aVL and aVF. The rate of P-wave notch decreased significantly in all leads, especially in the leads of II, III, aVF and V3. Patients with sinus rhythm had a shorter P-wave dispersion and P-wave index and had a lower rate of P-wave notch compared with the patients with recurrent atrial tachyarrhythmia.

CONCLUSIONObservations from using the surface ECG showed that CPVI has instant effects on the electrical conduction in the LA, and several changes of P-wave characteristics associated with development of AF are improved by CPVI.