The disease occurs when cholesterol layers deposit on the inner wall of coronary arteries and narrow the lumens of the arteries . the process reduces blood supply to cardiac muscle and causes exertional chest pain known as angina 这种心脏病的成因是胆固醇层在冠状动脉内壁积聚,令动脉管腔收窄,以致心肌的血液供应减少,导致运动时出现心绞痛。