Variables correlated with early relapses after external electrical cardioversion of persistent atrial fibrillation.

BACKGROUND: The aim of this study was to identify the clinical and echocardiographic variables possibly correlated with the early relapses of atrial fibrillation (AF) after external electrical cardioversion (EC) in a large cohort of patients with persistent AF. METHODS: Two hundred patients (117 males, 83 females, mean age 67.9 +/- 8.7 years) with successful EC of persistent AF (> 72 hours) were included in the present study. In order to identify the predictors of early relapses (within 7 days) of AF, 16 clinical and echocardiographic variables were compared at univariate analysis. The variables with a p value < 0.10 at univariate analysis were subsequently analyzed at multivariate analysis. RESULTS: Seventy-five patients (37.5%) had relapses of AF within 7 days of EC. By univariate analysis only a younger age (65.9 +/- 8.9 vs 69.0 +/- 8.3 years, p = 0.01) was found to be significantly correlated with a higher incidence of early relapses of AF. At multivariate analysis no variable was found to be significantly correlated with early relapses of AF. CONCLUSIONS: In patients with persistent AF, recurrences of this arrhythmia within 7 days of EC occur frequently (37.5%). Multivariate analysis did not reveal any clinical or echocardiographic variable significantly correlated with the early recurrence of AF.

Effects of verapamil and metoprolol on recovery from atrial electrical remodeling after cardioversion of long-lasting atrial fibrillation.

The aim of this prospective, randomized study was to investigate the effect of pretreatment with two different intracellular calcium-lowering drugs (verapamil and metoprolol) on recovery from atrial effective refractory period (AERP) shortening after internal electrical cardioversion (EC) of persistent atrial fibrillation (AF) in patients on amiodarone. Twenty-one patients on amiodarone for at least 30 days were referred to our hospital for internal EC of a persistent AF refractory to external EC. They were randomized to receive only amiodarone (group AMI, n=7), or amiodarone and verapamil 240 mg/day (group VER, n=7), or amiodarone and metoprolol 100 mg/day (group MET, n=7). Left AERP was measured 10 min and 24 h after EC. AERP was also determined in 13 controls. The AERP after 10 min was significantly shorter in group AMI (201 (31) ms, P<0.02) and group MET (203 (34) ms, P<0.03) than in controls (249 (45) ms), but not in group VER (237 (51) ms, P=NS). The AERP after 24 h was still significantly shorter in group AMI (204 (38) ms, P<0.04) than in controls, but not in group MET (225 (52) ms, P=NS) or in group VER (290 (36) ms, P=NS). Pretreatment with amiodarone and verapamil prevents AERP shortening, while pretreatment with amiodarone and metoprolol only accelerated AERP recovery.