What causes angina?

What causes angina?

The most common cause of angina is coronary artery disease. A less common cause of angina is spasm of the coronary arteries.

Coronary artery disease

Coronary arteries supply oxygenated blood to the heart muscle. Coronary artery disease develops as cholesterol is deposited in the artery wall, causing the formation of a hard, thick substance called cholesterol plaque. The accumulation of cholesterol plaque over time causes narrowing of the coronary arteries, a process called arteriosclerosis. Arteriosclerosis can be accelerated by smoking, high blood pressure, elevated cholesterol, and diabetes. When coronary arteries become narrowed by more than 50% to 70%, they can no longer meet the increased blood oxygen demand by the heart muscle during exercise or stress. Lack of oxygen to the heart muscle causes chest pain (angina).

Coronary artery spasm

The walls of the arteries are surrounded by muscle fibers. Rapid contraction of these muscle fibers causes a sudden narrowing (spasm) of the arteries. A spasm of the coronary arteries reduces blood to the heart muscle and causes angina. Angina as a result of a coronary artery spasm is called "variant" angina or Prinzmetal angina. Prinzmetal angina typically occurs at rest, usually in the early morning hours. Spasms can occur in normal coronary arteries as well as in those narrowed by arteriosclerosis.

Coronary artery spasm can also be caused by use/abuse of cocaine. The spasm of the artery wall caused by cocaine can be so significant that it can actually cause a heart attack.

« Index of "Angina"

« What is angina and what are the symptoms of angina?

» What are other causes of chest pain?