Qishenyiqi Dripping Pill for Coronary Microvascular Disease

Inclusion Criteria: * Repeated chest pain attacks with typical exertional angina pectoris or resting angina pectoris attacks; * Coronary normal or stenosis \< 20%; * Ischemic depression in ST segment during resting or exercise; * Blood flow reserve (CFR) of the anterior descending coronary artery \< 2.0; * Subjects or their guardians agreed to participate in this study. Exclusion Criteria: * Previous myocardial infarction or PCI or CABG treatment; * A history of heart failure; * Severe arrhythmia; * Refractory hypertension or hypertension accompanied by left ventricular wall thickness \> 12 mm; * Familial hypercholesterolemia; * Takayasu arteritis, Kawasaki disease or coronary artery malformation; * Pregnant or nursing, or having the intention to give birth within one year; * Hepatic or renal dysfunction; * Allergic to contrast agents or traditional Chinese medicines; * Patients who participated in clinical research of other drugs within 3 months before being selected.