Clinical experience of encainide (MJ 9067): a new anti-arrhythmic drug.

Encainide is a new anti-arrhythmic drug, which is highly effective against ventricular extrasystoles, both single and coupled, in the dose range of 80--140 mg i.v. Ventricular extrasystoles were abolished in 31 out of 33 cases treated. The drug is also relatively effective against supraventricular extrasystoles, but has little effect on atrial fibrillation. Both subjects with clinically normal hearts and those with ischaemic heart disease have been successfully treated. The drug prolongs the QRS and QT duration. Its effectiveness appears to be of the same order of magnitude and the range of indications similar to those of aprindine and lorcainide. Further study of the drug seems to be warranted.