Early outcome of initiating amiodarone for atrial fibrillation in advancedheart failure

Background: Little information exists about the early outcomes of initiatin g amiodarone for atrial fibrillation in patients with advanced heart failur e. This study assessed the initial rate of success and complications of ami odarone therapy initiated for patients with atrial fibrillation during hosp italization for heart failure. Methods: We reviewed medical records for 37 consecutive patients with left ventricular ejection fractions less than or equal to 40% who underwent init iation of amiodarone for atrial fibrillation during hospitalization on a he art failure service. Results: Atrial fibrillation was present in 35 (95%) and atrial flutter in 2 (5%), with mean duration of 30 months. New York Heart Association class w as 3.1 (+/-1.1). Left ventricular ejection fraction was 24% +/- 7%. All pat ients had received oral amiodarone with an initial dose of 1.2 +/- 0.2 g/da y. Bradyarrhythmia led to discontinuation of digoxin in 12 (32%) patients a nd to permanent pacemaker placement in 7 (19%) patients. Conversion to sinu s rhythm occurred spontaneously in 2 patients and after electrical cardiove rsion in 26 patients, for an initial success of 76%. After a median follow- up of 9.5 months, 21 of 37 (57%) patients remained in sinus or atrial-paced rhythm. Amiodarone complications occurred after discharge in 5 (14%) patie nts, 4 with hypothyroidism, Conclusions: Amiodarone with electrical cardioversion has a high initial su ccess rate for treatment of atrial fibrillation in patients with heart fail ure with advanced systolic dysfunction, The major early side effect was bra dyarrhythmia, frequently requiring discontinuation of digoxin or permanent pacemaker placement.