What characterizes stable angina?

Stable angina is characterized primarily by episodes of chest pain or discomfort that are predictable in nature. It typically occurs during activities that increase the heart's demand for oxygen, such as exercise or stress, and it resolves with rest or the administration of nitroglycerin, which dilates blood vessels and improves blood flow to the heart.

The reason why responding well to rest and nitroglycerin is the defining feature is that patients often recognize their angina triggers and can manage their symptoms effectively by taking breaks or using medication. This predictability and responsiveness to rest distinguishes stable angina from other forms, such as unstable angina, which can occur unpredictably and at rest, or variant angina, which is related to spasms of the coronary arteries.

In essence, stable angina reflects a stable condition of coronary artery disease wherein the heart's oxygen demand temporarily exceeds its supply, typically during predictable stressors, and does not indicate an immediate critical heart condition as those patients are usually not experiencing severe symptoms or prolonged pain characteristic of more acute issues like myocardial infarction.