[Late recurrences of atrial fibrillation in patients after direct-current cardioversion]

To analyze factors after successful direct-current cardioversion in patients with atrial fibrillation and to explore late recurrences of the arrhythmia.

Forty-three patients with atrial fibrillation without associated valvular heart disease, who underwent non-emergent cardioversion within the years 2002-2006, were included. We retrospectively analyzed clinical data from the medical records. Late reccurence of the arrhythmia was defined as arrhythmia in patients discharged with sinus rhythm.

Median follow-up of the patients was 33 (17, 48) months. We found 20 late recurrences of atrial fibrillation in the total group of 43 patients after successful direct-current cardioversion (46.5%). In a 6-month period after direct-current cardioversion the recurrence of arrhythmia was found in two patients, in a one-year period in 6 patients and in a period longer than one year in 12 patients. Median time to recurrence was 15 (6, 33) months. Females relapsed more frequently than males (p < 0.02), what could be explained by higher age, incidence of hypertension and thyreopathy in females. Patients with a history of thyropathy had more frequent occurrence of arrhythmia, despite normal values of TSH, as compared to patients without a history of thyropathy (p < 0.04). Patients with recurrence of the atrial fibrillation had higher systolic pressure (130 vs 120 mm Hg, p < 0.05) and pulse arterial pressure (50 vs 40 mm Hg, p < 0.01) after cardioversion. No significant difference between the two groups in age, left atrium diameter, left ventricle ejection fraction and cardiovascular, or non-cardiovascular risk factors was found.

Despite successful direct-current cardioversion, the risk of late recurrence of the atrial fibrillation in a following period is at least 46.5%. Females, patients with a history of thyropathy and those with higher systolic and pulse arterial pressures are at higher risk of late recurrences.