Efficacy of i.v. amiodarone in converting rapid atrial fibrillation and flutter to sinus rhythm in intensive care patients

Abstract

Twenty-six consecutive patients (14 males, 12 females--mean age 66.6) were admitted to an intensive care unit (ICU) because of a rapid ventricular response to atrial fibrillation (RAF). Fourteen of them had been unsuccessfully treated by drugs (other than amiodarone) and/or DC shock before admission. A loading dose of i.v. amiodarone was administered (repeated boluses of 3 mg/kg in 3 min, or 30 min-infusions of 5 to 7.5 mg/kg), followed by continuous infusion, in order to reach a maximal total dosage of 1500 mg in 24 h. This treatment was considered efficacious if a reversion to stable sinus rhythm (SSR) occurred within 24 h and was maintained for more than 48 h. This was achieved in 21 out of 26 patients (80.8%). The mean time between the administration of therapy and the occurrence of SSR was 171 min. The total dose of amiodarone delivered to effect SSR was 6.9 +/- 2.3 mg/kg. No adverse reactions were encountered during the bolus injection but we recommend that continuous infusion be carried out through a central venous catheter to avoid phlebitis. The administration of 7 mg/kg of intravenous amiodarone delivered in 30 min proved a safe and successful first choice of management in atrial fibrillation with a rapid ventricular response.

A comparison of the electrophysiologic effects of intravenous and oral amiodarone in the same patient.

“…Clinically, the effects of intravenous amiodarone have been used successfully in the treatment of atrial fibrillation and atrial flutter in the postoperative and intensive-care setting.21 22 Our observations do not allow conclusions to be drawn on the applicability of intravenous amiodarone for the treatment of ventricular arrhythmias.…”

A randomized, controlled trial of RSD1235, a novel anti-arrhythmic agent, in the treatment of recent onset atrial fibrillation

“…For example, in recent onset AF, placebo-controlled studies of intravenous class IC agents (flecainide and propafenone) have had efficacy rates (corrected for placebo response rate) of 25% to 53% within 2 h of infusion (3). The efficacy of intravenous amiodarone is highly variable; however, it is considered less than that with the class IC agents (15)(16)(17)(18). Furthermore, responses that take 24 h to manifest, such as with amiodarone, are of limited usefulness for acute intravenous conversion of AF.…”

“…Electrical cardioversion is effective in restoring sinus rhythm but requires procedural sedation or anesthesia and is not successful in all cases. Currently available converting agents have highly variable efficacy and several safety limitations associated with their use (3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21). In addition, placebo-controlled trials that establish the efficacy and safety of these pharmacologic therapies for acute conversion are limited.…”

Intravenous amiodarone in intensive care

“…In uncontrolled trials [42,43,44,45] (Table 5) amiodarone cardioverted 61±89 % of various atrial tachyarrhythmias. When compared with other agents, amiodarone's performance is variable.…”