When does angina pectoris typically occur?

Angina pectoris typically occurs when there is an imbalance between myocardial oxygen demand and oxygen supply. In situations where the heart requires more oxygen—often due to increased physical activity, stress, or other factors—and this demand surpasses what the coronary arteries can supply, the heart muscle becomes ischemic, leading to the characteristic chest pain associated with angina.

This demand-supply mismatch is primarily due to factors such as narrowed coronary arteries caused by atherosclerosis, increased heart rate, or heightened contractility. The correct understanding is crucial for recognizing the clinical presentation of angina and its management in pre-hospital settings.

The other conditions described, such as total occlusion of a coronary artery by plaque, excessive oxygen supply, or a sudden spasm of coronary arteries, do contribute to cardiac issues but do not specifically address the typical triggers or conditions directly associated with anginal pain itself. These situations can lead to other outcomes, such as a myocardial infarction or variant angina, but in the context of stable angina, the defining factor is the demand exceeding the supply of oxygen to the myocardial tissue.