Efficacy of Enhanced External Counterpulsation on Ventricular Function

Inclusion Criteria: * More than 50% stenosis of left main trunk and 3 epicardial coronary arteries and their large branches showed by coronary angiography * Or history of myocardial infarction * Or history of prior revascularization * Signed informed consent to participate in the study Exclusion Criteria: * Clinically significant valvular heart disease * Aortic aneurysm * Congenital heart disease * Acute myocarditis * Arrhythmias significantly interfere with the triggering of the EECP device * History of cerebral hemorrhage * Hemorrhagic disease * Lower limb infection, phlebitis * Deep venous thrombosis * Malignant disease * International normalized ratio (INR) \> 2.5 * Uncontrolled hypertension, defined as systolic blood pressure \> 180mmHg or diastolic blood pressure \> 110mmHg * Pregnancy