Coronary artery spasm: A sudden constriction of a coronary artery that deprives the heart muscle of blood and oxygen. This can cause a type of sudden chest pain referred to as variant angina or Prinzmetal angina. Coronary artery spasm can be triggered by emotional stress, medicines, street drugs (particularly cocaine), and exposure to extreme cold. Treatments include the use of beta-blocker medications and, classically, nitroglycerin to allow the coronary arteries to open.
