[Antiarrhythmic drugs in chronic ventricular extrasystole (author's transl)]

Several class I antiarrhythmic drugs were used in an intraindividual comparative study in 15 patients with chronic stable ventricular extrasystole of various origins. In a randomised sequence lidocaine, ajmalin and, in a cross-over double blind study with placebo, the new antiarrhythmic Org 6001 were tested. Propafenon was given as a final preparation. Each substance was administered parentally in therapeutic doses. A significant placebo effect could be excluded, baseline control values before administration of individual substances correlated well. Comparing mean values obtained over one hour before and after administration of the substance it was shown that the effectiveness of drugs decreased as follows: ajmalin, propafenon, lidocaine, Org 6001. Whereas suppression of extrasystole was most marked after ajmalin, propafenon showed the longest period of activity. After Org 6001 divergent activity of arrhythmia could be observed; in some patients good antiarrhythmic effects could be demonstrated. For evaluation of effectiveness and validity of new antiarrhythmic substances intraindividual comparison with placebo and well established standard antiarrhythmic drugs is advisable.