 - Myocardial infarction within six 6 months prior to enrollment or having insufficient cardiac function defined as NYHA Grade 3 or 4, 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 