Definition of Coronary artery spasm:

Coronary artery spasm is a temporary, sudden contraction in one location in the muscles in the wall of an artery in the heart. The spasm slows or stops blood flow through the artery and starves the heart of oxygen-rich blood.

Causes, incidence, and risk factors:

The spasm may occur in arteries that appear normal or it may take place in arteries that have turned hard due to plaque build up (atherosclerosis).

Coronary artery spasm is a cause of inadequate oxygen levels (ischemia) of the heart. It affects approximately 4 out of 100,000 people, and affects approximately 2% of patients with angina.

Spasm may be "silent" -- without symptoms -- or it may result in persons with stable angina or unstable angina. It is usually appears as variant angina, a type of chest pain that is thought to be due to endothelial dysfunction, a condition in which the coronary artery may appear normal, but does not function normally.

Prolonged spasm may even cause a heart attack.

Coronary artery spasm may occur without cause, or it may be triggered by:

• Alcohol withdrawal
• Emotional stress
• Exposure to cold
• Medications that cause narrowing of the blood vessels (vasoconstriction)

Cocaine use and cigarette smoking can cause severe spasm of the arteries while also causing the heart to work harder. In many people, coronary artery spasm may occur without any other heart risk factors( such as smoking, diabetes, high blood pressure, and high cholesterol).