What Is Angina and How Does It Differ from a Heart Attack?

Angina pectoris — commonly called angina — is chest pain or discomfort caused by reduced blood flow to the heart muscle (myocardial ischemia). It is a symptom of underlying coronary artery disease, not a disease itself, and represents the heart's signal that it is not receiving enough oxygen to meet its current demand. Understanding what angina is, the different types, and critically how it differs from a heart attack is essential knowledge for anyone at cardiovascular risk — and for anyone who might witness a cardiac emergency.

WHAT CAUSES ANGINA?

In a healthy heart with open coronary arteries, blood flow increases proportionally when oxygen demand rises — during exercise, emotional stress, or other exertion. In a heart with coronary artery disease, atherosclerotic plaques narrow the coronary arteries. Resting blood flow may be adequate, but when demand increases, the narrowed arteries cannot deliver sufficient blood. This mismatch between supply and demand causes myocardial ischemia — oxygen deprivation of heart muscle cells — which produces the sensation of angina.

The experience of angina reflects the heart's distress signal — mediated through cardiac nerve fibers that transmit pain signals to the chest, jaw, arms, back, and other areas sharing nerve pathways.