P Wave Amplitude and Duration may Predict Immediate Recurrence of Atrial Fibrillation After Internal Cardioversion

BACKGROUND: Although internal cardioversion (IC) for atrial fibrillation (AF) is effective at restoring sinus rhythm, immediate recurrence (IR) of AF after IC is a major and largely unpredictable clinical problem. The purpose of the study was to determine the role of P wave duration and amplitude in prediction of IR of AF after IC. Forty-five consecutive patients undergoing IC for chronic AF were evaluated. MATERIAL AND METHODS: After successful IC, 1-minute ECG recording was obtained in all patients. P wave duration and amplitude in Lead II and V1 were measured using computer. Forty patients (88%) had successful IC. Thirteen patients experienced IR of AF within 1 minute of restoring sinus rhythm. RESULTS AND CONCLUSION: As a result, the incidence of IR of AF after IC was higher in the patients with shorter P wave amplitude (for lead II P<0.01, for V1 P<0.01) and larger P wave duration (for lead II P<0.01, for V1 P<0.05).