Potentially lethal ventricular arrhythmias. Minimizing the danger. Patients with potentially lethal ventricular arrhythmias are at an increased risk of sudden death. Antiarrhythmic drugs, with the exception of beta blockers and possibly amiodarone, have not been particularly effective in reducing mortality. Beta blockers have been used successfully to treat survivors of myocardial infarction, including patients with significant impairment of ventricular function. Evidence to date suggests that use of low-dose amiodarone may be appropriate for selected patients with chronic heart failure and potentially lethal ventricular arrhythmias. 