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How does coronary heart disease lead to angina pectoris?

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The role of coronary artery disease in heart attack — cardiovascular disease This micrograph shows a cross section of a coronary artery narrowed by an atherosclerotic plaque (purplish matter inside the artery). Most heart attacks are caused by the rupture of an atherosclerotic plaque, which triggers the formation of a clot that abruptly blocks blood flow to part of the heart muscle.

Coronary heart disease leads to angina pectoris through the development of myocardial ischemia, which is a reduced blood supply to the heart muscle.1

This process occurs when coronary arteries become narrowed or blocked by fatty plaques, a condition known as atherosclerosis. This obstruction creates a disturbance in the equilibrium between the heart muscle's demand for oxygen and the actual supply it receives. When the heart's oxygen deprivation is insufficient to cause myocardial infarction (tissue death), the resulting ischemia manifests as the chest pain or discomfort characteristic of angina pectoris.21

Symptoms often emerge during periods of increased demand, such as physical exertion, because the restricted blood flow cannot adequately meet the heart's heightened metabolic needs. When the demand is reduced, the supply may become sufficient again, causing the discomfort to subside.1