- Clinically significant cardiovascular disease including unstable angina pectoris, uncontrolled hypertension, and congestive heart failure related to primary cardiac disease, a condition requiring anti-arrhythmic therapy, history of sustained ventricular tachycardia, history of ventricular fibrillation or Torsade de Pointes, bradycardia (HR<50bpm) with or without a pacemaker, bifascicular block with a right bundle branch block and a left anterior block, ischemic or severe valvular heart disease, a myocardial infarction within 6 months or a left ventricular ejection fraction < 40% (by echocardiogram [ECHO] or multigated acquisition scan [MUGA]) within 3 months of study enrolment.