[Therapy of ventricular arrhythmias with propafenone]

In 16 patients with angiographically-documented coronary artery disease and repetitive ventricular responses the effects of oral propafenon 300 mg t.i.d. on the continuous 24-hour ECG were analyzed in a study carried out according to a double-blind, randomized, crossover, placebo-controlled protocol. Comparisons were made for the number of couplets (Lown IVa) and ventricular tachycardias (Lown IVb) as well as the overall incidence of ventricular premature beats during the two last days of a five-day placebo phase and on the second and third day of treatment with propafenon. In 15 further patients with electrocardiographically-documented sustained ventricular tachycardias, the effect of intravenous propafenon (1.5 mg/kg in three minutes) was also investigated. Repeat electrophysiologic studies were performed in eight of the 15 patients after two to 13 days of continuous treatment with oral propafenon 300 mg t.i.d. The stimulation protocol incorporated delivery of a maximum of four extra stimuli during sinus rhythm and during apical right ventricular stimulation at each of four basic intervals (600, 500, 400 and 330 ms) as well as burst stimulation with intervals between 300 and 250 ms. Stimulation was terminated after induction of sustained ventricular tachycardia. In patients in whom ventricular tachycardia could be induced prior to medication with one or two stimuli, after propafenon no more than two extra stimuli were applied. As compared with placebo, propafenon led to a more than 90% reduction in couplets in 56% of the patients and in 64% of the patients there was a complete suppression of ventricular tachycardia.(ABSTRACT TRUNCATED AT 250 WORDS)