Short- and long-term effects of propafenone in ventricular arrhythmias.

The effectiveness of short- (15 days) and long- (12 months) term propafenone treatment was assessed in 53 patients presenting with more than 30 premature ventricular complexes per hour as detected by 24-hour ambulatory Holter monitoring. Thirty-nine patients had no apparent concomitant heart disease while 14 had chronic coronary artery disease. The effects of propafenone were analysed by ambulatory Holter monitoring after 15 days and at 3, 6 and 12 months. The initial dose was 150 mg four times daily and was increased up to 300 mg four times daily when necessary. Favourable short-term effects were obtained in 39 patients (73.6%). After 12 months, 17 patients (32.1%) were still on propafenone treatment with good results. Treatment was discontinued on account of low compliance in 28.3%. This was because treatment was ineffective even at high doses in 15.2%, because of severe side effects in 13.2%, because of proarrhythmic effects in 5.6% and for other causes in 5.6%.