[Antiarrhythmic effect of disopyramide in ventricular extrasystole and auricular fibrillation]

Disopyramide (B 712) was tested in 39 patients with chronic arrhythmias of different kind: 23 cases with atrial fibrillation, 16 cases with ventricular ectopic beats, two cases with supraventricular tachycardias. The effect of disopyramide was compared to a pretreatment with one or several antiarrhythmic drugs (quinidine, beta-blocking agents, verapamil, ajmalin-bitartrat, aprindine, propafenone, diphenylhydantoin) which had been discontinued either due to ineffectiveness or the occurrence of intolerable side effects. Therapeutical effectiveness was controlled by on-line arrhythmia computers in the CCU or Holter monitoring. 15 patients were treated longer than 4 weeks up to 16 months (mean 35+/-22,6 weeks). The following results were achieved: 1 atrial fibrillation, abolition or significant reduction of the rate of recurrence in 10 out of 23 patients; slight reduction or no effect in 13 patients; 2. ventricular ectopic beats: abolition or significant reduction in 6 out of 16 patients, slight reduction or no effect in the remaining 10 patients. Patients who were treated successfully received the same dosis as those without therapeutical success. In cases with atrial fibrillation, the success was dependent on the duration of this arrhythmia prior to treatment. In comparison to the pretreatment with one or several of the above-mentioned anti-arrhythmic drugs, disopyramide was as effective as the drug given before. The analysis of the Ecg revealed a slight but insignificant prolongation of the time intervals. In 22 patients reversible dosage-dependent side effects were observed which are due to the vagolytic action of the drug: dry mouth, blurred vision, urinary hesitancy, nausea, headache. These side effects occurred at daily dosages between 400 to 800 mg increasing markedly in patients on 800 mg a day. The drug had to be discontinued in 4 cases because of side effects. During long-term treatment no severe side effects were observed. Thus, disopyramide may serve as an alternative to quinidine, especially if the latter has to be stopped because of side effects.