Amiodarone appears to reduce sudden death in patients with left ventricular dysfunction resulting from an acute MI or a primary dilated cardiomyopathy, particularly if complex ventricular arrhythmias are present. Amiodarone's beneficial effect on mortality in these patients could be unrelated to its antiarrhythmic effects. Multiple factors could account for the improvement in mortality such as the drug's antiischemic effects, neuromodulating effects, its effect on left ventricular function and on heart rate. Moreover, patients with LV dysfunction who have survived an episode of sudden death would potentially benefit from amiodarone therapy. Future trials are needed to determine the precise subsets(s) of patients who would benefit from the drug and the most efficacious dosing regimen for the drug. Based on available data, amiodarone is the only antiarrhythmic agent which has not been shown to increase mortality in patients with chronic heart failure.