Procainamide, oxprenolol and amiodarone as antidysrhythmic drugs in myocardial infarction.

Using Holrer recordings and based on the principie that most of the survivors of acute rnyocardiai infarction who are going o~ diu suddcniy after hospital discharge are those who present ventricular premarure beats (VPB), the authors have studicd the effecr of three different antidysrhythmic drugs — procainamide (PA), oxprenolol (OX) and amiodarones. (AMIOD) — in late phase of acute myocardial infarction. Ali the triais have been controiled Procainamide (47 patiencs studied), in comparison with placebo (P1.), revealed to be effective (a) in supressing and diminishing VPB/hour (p~O.0425), and (b) in maintaining patlents wirh no VPB (PA 89.6% — PL 64.7%). Oxprenolol (27 patients studied), in comparison with placebo, revealed to be effective (a) in maintaining patients with no VPB (p0.0525), and (b) in avoiding the increase of VPB/hour (p=O.0576). Finally amiodarone (37 patients studied), in comparison wirh piacebo, was effective (a) in maintaining patients with no VPB (AMIOD 50% — PL 39%), (b) in diminishing VPB/hour (AMIOD 29% — PL 9%), and (c) in avoiding the increase of VPB/hour (AMIOD 79% — PL 48%). The authors finish their paper emphasizing that no anridysrhythmic drug should be introduced in clinical practice before being submitted to controlled studies with Holter electrocardiography.