Journal of Arrhythmia (Jun 2014)
Rhythm and rate control effects of intravenous amiodarone for atrial fibrillation complicated by acutely decompensated heart failure
Abstract
Background: Atrial fibrillation (AF) often occurs in the acute phase of heart failure (AHF), and is usually associated with a rapid ventricular response. No drug with proven efficacy in the treatment of AF in the setting of AHF has been approved in Japan. We prospectively investigated the efficacy and safety of intravenous amiodarone injection in patients with AHF using a unified protocol. Methods: The study included 20 consecutive patients (15 males; mean age, 67±8 years) admitted for AHF accompanied by AF with rapid ventricular response (mean, 137±15 beats/min). Eleven patients had recent-onset/transient/paroxysmal AF, and the other 9 had persistent/long-standing persistent AF. Amiodarone injection was administered for 24 h under continuous ECG monitoring according to a protocol used for ventricular tachyarrhythmias in Japan. Results: In 10 of the 11 patients with recent-onset/transient/paroxysmal AF, AF was converted to sinus rhythm at a mean of 5.8 h after initiation of intravenous amiodarone. In these patients, the heart rate during AF was reduced from 132±15 to 101±20 beats/min (P<0.01). Five patients experienced a recurrence of AF during amiodarone administration, with a heart rate of 95±18 beats/min during AF, which was again converted to sinus rhythm in the course of amiodarone administration. AF was not converted to sinus rhythm in the remaining recent-onset/transient/paroxysmal AF patient and the 9 patients with persistent/long-standing persistent AF, but a significant reduction in heart rate was noted from 6 h after amiodarone initiation and was maintained during the administration period (141±15 beats/min at baseline and 101±20 at 24 h after administration, P<0.01). No severe adverse events were noted during the intravenous administration of amiodarone. Conclusions: Intravenous amiodarone seems to be useful and tolerable in the treatment of AF with rapid ventricular response in Japanese patients with AHF while showing rhythm and rate control effects.
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