- A myocardial infarction within six (6) months prior to enrollment or having New York Hospital Association (NYHA) Class III or IV heart failure, uncontrolled angina, cardiomyopathy, severe uncontrolled ventricular arrhythmias, left bundle branch block, or electrocardiographic evidence of acute ischemic or active conduction system abnormalities (e.g., Long QT interval, Torsade de Pointes).