Adrenergic beta-Antagonists--therapeutic use Angina Pectoris--diagnosis Angina, Unstable--diagnosis Atenolol--therapeutic use Bisoprolol--therapeutic use Calcium Channel Blockers--therapeutic use Clinical Trials as Topic Electrocardiography Electrocardiography, Ambulatory Exercise Test Humans Multicenter Studies as Topic Myocardial Infarction--complications Myocardial Ischemia--diagnosis Myocardial Revascularization Nifedipine--therapeutic use Prognosis Sympatholytics--therapeutic use