Antiarrhythmic effects of stirocainide in acute myocardial infarction.
Ventricular arrhythmias, especially ventricular fibrillation, are assumed to be a main cause of sudden death during the first 24 h of acute myocardial infarction. Effective prophylaxis and acute suppression of these life-threatening rhythm disturbances are a major therapeutic problem. The present study was undertaken to investigate the efficacy of the new antiarrhythmic compound stirocainide (2-(1-benzylidene)cycloheptenimino-oxyethyl-diisopropylamine -2-butenedionate, Th 494) in suppressing "2nd phase arrhythmias" arising from large anteroseptal myocardial infarctions using a standardized experimental canine preparation. Our results demonstrate that "2nd phase arrhythmias"--i.e. frequent ventricular ectopics, tachycardias, salvos, and R-on-T phenomena--are reduced by 80-90% (sometimes even completely abolished) by stirocainide (dose: 4 mg/kg within 3 min, followed by 300 micrograms/kg X min over a 20-min period). The administration of the drug at the dose used does not produce severe cardiodepression, but intraventricular conduction time is significantly prolonged. Thus, Th 494 is a highly effective antiarrhythmic agent in acute myocardial infarction, and further experimental and clinical investigations on its antiarrhythmic and antifibrillatory properties may lead to beneficial therapeutic results.
D000818:Animals; D000889:Anti-Arrhythmia Agents / Q000627:therapeutic use*; D004285:Dogs; D004983:Ethanolamines / Q000627:therapeutic use*; D006339:Heart Rate / Q000187:drug effects; D009200:Myocardial Contraction / Q000187:drug effects; D009203:Myocardial Infarction / Q000188:drug therapy* / Q000503:physiopathology; D009206:Myocardium / Q000378:metabolism; D010101:Oxygen Consumption / Q000187:drug effects
D000889:Anti-Arrhythmia Agents; D004983:Ethanolamines; C026705:stirocainide