The coronary arteries are the blood vessels that supply blood and oxygen to the heart. A coronary artery spasm is temporary narrowing of the artery.
Symptoms occur during the spasm because the blood flow to the heart is temporarily blocked.
The cause of spasm is unknown. The decrease or loss of blood flow to the heart during a spasm causes the patient to experience angina. The symptoms of angina may vary from person to person. The symptoms may even vary with each episode. Symptoms can include a tightness, pressure, aching, or burning behind the breastbone.