Early outcome of initiating amiodarone for atrial fibrillation in advanced heart failure.
BACKGROUND
Little information exists about the early outcomes of initiating amiodarone for atrial fibrillation in patients with advanced heart failure. This study assessed the initial rate of success and complications of amiodarone therapy initiated for patients with atrial fibrillation during hospitalization for heart failure.


METHODS
We reviewed medical records for 37 consecutive patients with left ventricular ejection fractions </=40% who underwent initiation of amiodarone for atrial fibrillation during hospitalization on a heart 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 was 3.1 (+/-1.1). Left ventricular ejection fraction was 24% +/- 7%. All patients had received oral amiodarone with an initial dose of 1.2 +/- 0.2 g/day. Bradyarrhythmia led to discontinuation of digoxin in 12 (32%) patients and to permanent pacemaker placement in 7 (19%) patients. Conversion to sinus rhythm occurred spontaneously in 2 patients and after electrical cardioversion 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%) patients, 4 with hypothyroidism.


CONCLUSIONS
Amiodarone with electrical cardioversion has a high initial success rate for treatment of atrial fibrillation in patients with heart failure with advanced systolic dysfunction. The major early side effect was bradyarrhythmia, frequently requiring discontinuation of digoxin or permanent pacemaker placement.
Cardiovascular Division, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri 63110, USA.
M S
MS
Weinfeld
M H
MH
Drazner
W G
WG
Stevenson
L W
LW
Stevenson
D000284:Administration, Oral; D000638:Amiodarone / Q000008:administration & dosage / Q000627:therapeutic use*; D000889:Anti-Arrhythmia Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D001281:Atrial Fibrillation / Q000150:complications / Q000188:drug therapy* / Q000503:physiopathology; D002304:Cardiac Pacing, Artificial; D002316:Cardiotonic Agents / Q000627:therapeutic use; D004077:Digoxin / Q000627:therapeutic use; D004347:Drug Interactions; D004554:Electric Countershock; D005260:Female; D006333:Heart Failure / Q000150:complications / Q000188:drug therapy* / Q000503:physiopathology; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013318:Stroke Volume / Q000187:drug effects; D016896:Treatment Outcome
D000889:Anti-Arrhythmia Agents; D002316:Cardiotonic Agents; D004077:Digoxin; D000638:Amiodarone