Aim: To evaluate the safety and the feasibility of sedation administered by cardiologists with rapid intravenous bolus of midazolam followed by flumazenil infusion during transthoracic biphasic electrical cardioversion (TEC) for atrial fibrillation (AF).
Methods: Two hundred and sixty-five consecutive patients (119 females, mean age 67.4 +/- 8.5 years) with either acute (24 patients) or persistent AF (mean arrhythmia duration 3.7 +/- 3.0 months) underwent TEC. Midazolam (0.05 mg/kg) was administered as rapid intravenous bolus by the cardiologist, whereas the anaesthesiologist was simply alerted. At the end of the procedure, intravenous flumazenil 0.25 mg was given, followed by 0.25 mg over 1 h. Patients received continuous electrocardiographic and pulse-oxymetric monitoring.
Results: Adequate sedation was obtained in 262 patients (98.9%), with a mean midazolam dose of 4.4 +/- 0.9 mg. After drug administration, the mean time to patient's sedation and reawakening were 3.1 +/- 1.9 and 6.1 +/- 2.7 min, respectively. The mean reduction in oxygen saturation was 5.4 +/- 3.7%. Sinus rhythm was restored in 254 patients (95.8%). All but 41 patients (15.5%) were completely amnesic. None reported pain. No adverse events were registered. No urgent call for the anaesthesiologist was made.
Conclusions: Conscious sedation with fast-administered midazolam followed by flumazenil for cardioversion of atrial fibrillation is safe, effective and well tolerated, easing the procedure and shortening its duration.