Long-short sequence may predict immediate recurrence of atrial fibrillation after external cardioversion

We thought, that analysis of surface electrocardiograms recorded immediately after electrical external cardioversion (EC) might enlighten the mechanisms responsible for immediate recurrence of atrial fibrillation (AF) and especially to test whether atrial ectopic beats (PAC) with long-short (LS) sequence are related to the recurrence of arrhythmia after cardioversion in patients with chronic AF.

One hundred and thirty-seven patients (mean age 57+/-7 years) undergoing EC for chronic AF entered the study. Evaluation of the patients included clinical history, physical examination, ECG, routine laboratory tests, and transthoracic echocardiography. The cardioversion was performed with monophasic waveform shock and immediately after successful EC, 1 min of recording of the ECG lead II was analysed. One hundred and twenty patients (87%) of 137 patients enrolled in the study had had successful EC and 33 (27%) of them experienced immediate recurrence of AF within 1 min (Group I) and 87 patients had no arrhythmia recurrence (Group II). In group I in 24 patients (73%) recurrence of AF was initiated by PAC with LS sequence. In only 12 of 87 (13%) patients who did not experience immediate recurrence of AF (Group II) PACs were recorded.

Atrial ectopic beats (PACs) with LS sequence, being responsible for AF relapse in about 70% of patients, might predict early re-initiation of arrhythmia after EC. Electrocardiograms, recorded immediately after EC, are a potentially feasible approach in establishing the patterns of AF relapse that may be useful in the management of AF recurrence.