The coronary arteries supply a constant flow of oxygen-rich blood to the heart. Sometimes, for unknown reasons, a coronary artery goes into spasm. This “vasospasm” (VAS’o-SPAZ’m) can reduce or even stop blood flow to a part of the heart. The spasm briefly narrows the coronary artery, and the heart muscle does not get enough blood. Coronary artery spasm usually happens in a coronary artery that has been blocked or has plaque buildup (atherosclerosis), but it may also happen in a normal coronary artery.
Coronary artery spasm causes a rare type of angina pectoris called variant angina pectoris (or Prinzmetal angina). Angina pectoris is a squeezing, suffocating, or burning feeling in the chest. Unlike typical angina, variant angina usually happens during rest. Some patients have the attacks between midnight and 8 o’clock in the morning. The attacks often happen at the same time each day, and they may be very painful.
Calcium channel blocker medicines may be given to patients with coronary artery spasm to ease the symptoms of the variant angina. Patients with variant angina have a greater risk of heart attack, an irregular heartbeat (arrhythmia), and sudden death.
Texas Heart Institute www.texasheartinstitute.com/HIC/Topics/Cond/CoronaryArterySpasm.cfm
American Heart Association www.americanheart.org/presenter.jhtml?identifier=4520
Medline Plus www.nlm.nih.gov/medlineplus/ency/article/000159.htm