What is a primary cause of angina pectoris?

Angina pectoris is primarily caused by coronary artery disease (CAD). In CAD, the coronary arteries become narrowed or blocked due to atherosclerosis, which is the buildup of plaque made of fat, cholesterol, and other substances. This narrowing reduces blood flow to the heart muscle, particularly during times of increased demand for oxygen, such as physical exertion or emotional stress. When the heart does not receive enough oxygen-rich blood, it results in the chest pain or discomfort known as angina.

While other factors like arrhythmias, myocardial infarction, and hypertension can influence heart health, they are not the direct primary cause of angina. Arrhythmias may complicate underlying conditions but are typically results of issues with heart rhythm rather than a primary cause of angina. A myocardial infarction, or heart attack, occurs when there is a complete blockage of blood flow, leading to tissue death, while hypertension can contribute to the development of CAD but does not directly cause angina by itself.