Beneficial effects of low dose amiodarone in patients with congestive cardiac failure: a placebo-controlled trial.
The effects of amiodarone in a low dosage (200 mg every 8 h for 2 weeks, then 200 mg/day) was assessed in a double-blind placebo-controlled trial in 34 patients with a history of severe congestive heart failure but no sustained ventricular arrhythmia. Left ventricular ejection fraction, treadmill exercise tolerance and 48 h electrocardiographic monitoring were assessed before and repeatedly after beginning amiodarone or placebo therapy over 6 months, and side effects were monitored. In patients receiving amiodarone, the ejection fraction increased significantly from 19 +/- 7 to 29 +/- 15% at 6 months (p less than 0.01 from baseline), but not significantly in 14 placebo-treated patients (18 +/- 5 to 22 +/- 9%). Exercise tolerance increased significantly in amiodarone-treated patients (median 433 s to 907 s, p less than 0.05), but not significantly in placebo-treated patients (757 to 918 s). Nonsustained ventricular tachycardia was present in 88% of amiodarone-treated patients before, but in only 21% of patients after 6 months of treatment (p = 0.06); it was seen in 43% of placebo-treated patients at baseline and in 50% after 6 months. Fifty percent of amiodarone-treated patients had side effects (principally nausea) and the drug was withdrawn in 28% of cases; no life-threatening effects were seen. Low dose amiodarone appears to have a multifaceted potential to produce benefits in arrhythmia control, exercise tolerance and ventricular function in patients with a history of severe congestive heart failure, but better control of side effects (principally nausea) appears essential. Effects on mortality could not be determined from this study; such assessment requires a larger cohort of patients.
Hamer
A W
AW
Department of Cardiology, Repatriation General Hospital, Heidelberg, Victoria, Australia.
Arkles
L B
LB
Johns
J A
JA
D000368:Aged; D000638:Amiodarone / Q000008:administration & dosage* / Q000009:adverse effects / Q000627:therapeutic use; D001145:Arrhythmias, Cardiac / Q000188:drug therapy; D002986:Clinical Trials as Topic; D005500:Follow-Up Studies; D006333:Heart Failure / Q000188:drug therapy* / Q000401:mortality / Q000503:physiopathology; D006801:Humans; D008875:Middle Aged; D005082:Physical Exertion; D012119:Respiration / Q000187:drug effects; D013318:Stroke Volume / Q000187:drug effects; D013961:Thyroid Gland / Q000187:drug effects
D000638:Amiodarone