- Patients with a history of cardiac disease are excluded; baseline electrocardiography and assessment of serum troponin (I) are included in the screening exams; subjects in whom these assays are abnormal (electrocardiogram [EKG] excluding first (1st) degree branch block, sinus bradycardia, sinus tachycardia or non-specific T wave changes, serum troponin >= grade 2) are ineligible