Abstract
We experienced intractable atrial or ventricular tachyarrhythmias in two cases of acute myocardial infarction resulted from left main coronary artetry occlusion and reperfusion therapy. Lidocaine, magnesium sulfate, or cardioversion failed to control ventricular tachycardia in the case 1. Disopyramide or cardioversion failed to control atrial flutter also in the case 2 on day 4 after the onset of myocardial infarction. In both cases, intravenous nifekalant followed by cardioversion disappeared arrhythmias. Nifekalant is a pure class III antiarrhythmic drug which prolongs the refractory period of the atrial and ventricular myocardium without negative inotropic action. Our cases showed the efficacy and safety of nifekalant in both atrial and ventricular tachyarrhythmias complicating acute myocardial infarction in left main coronary region with severe heart failure.
