Oral amiodarone in high-risk ventricular arrhythmias

Oral amiodarone was evaluated in 24 patients with complex forms of ventricular premature depolarizations (VPD) by means of ECG monitoring and measurement of systolic time intervals. The patients received 800 mg daily for 3 days, 600 mg daily for 7 days and 400 mg daily thereafter. Follow-up lasted from 6 to 17 months. Advanced forms of VPD were abolished and the VPD rate was reduced in 98% of patients. After 10 days repetitive VPD were absent in more than 80% and after 4 months more than 70% were completely free from arrhythmia. ECG changes revealed heart rate reduction and prolongation of PR, QRS and QTc intervals. Left ventricular performance was not influenced. After 6 months of treatment, 10 randomly selected patients received placebo instead of amiodarone in a single blind fashion until arrhythmia reappeared; the latter was again abolished by reinstituting amiodarone, The most frequent side effect were corneal microdeposits which were reversible and did not impair vision. It is concluded that amiodarone is effective and well tolerated in patients with high-risk VPD.