Coronary artery spasm is a temporary, sudden narrowing of one of the coronary arteries (the arteries that supply blood to the heart). The spasm slows or stops blood flow through the artery and starves part of the heart of oxygen-rich blood.
The spasm often occurs in coronary arteries that have not become hardened due to plaque buildup (atherosclerosis). However, it also can occur in arteries with plaque buildup.
These spasms are due to a squeezing of muscles in the artery wall. They usually occur in just one area of the artery. The coronary artery may appear normal during testing, but it does not function normally.
About 2% of patients with angina (chest pain and pressure) have coronary artery spasm.
Medications that cause narrowing of the blood vessels (vasoconstriction)
Stimulant drugs such as amphetamines and cocaine
Cocaine use and cigarette smoking can cause severe spasms of the arteries, and can cause 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).
Spasm may be "silent" -- without symptoms -- or it may result in chest pain or angina. If the spasm lasts long enough, it may even cause a heart attack.
The main symptom is a type of chest pain called angina, which most often is felt under the chest bone (sternum) or left side of the chest, and is described as:
It is usually severe. The pain may spread to the neck, jaw, shoulder, or arm.
The pain of coronary artery spasm:
Often occurs at rest
May occur at the same time each day, usually between midnight and 8:00 AM
Lasts from 5 to 30 minutes
The person may lose consciousness.
Unlike angina that is caused by hardening of the coronary arteries, chest pain and shortness of breath due to coronary artery spasm are often not present when you walk or exercise.
Signs and tests
Tests to diagnose coronary artery spasm may include:
The goal of treatment is to control chest pain and prevent a heart attack. A medicine called nitroglycerin can relieve an episode of pain.
Your health care provider may prescribe other medications to prevent chest pain. You may need a type of medicine called a calcium channel blocker long-term. Your doctor may prescribe long-acting nitrates along with the calcium channel blocker.
Beta-blockers are another type of medication that may be used. However, beta-blockers may make the condition worse and may be harmful if used with cocaine.
Coronary artery spasm is a chronic condition. However, treatment usually helps control symptoms.
The disorder may be a sign that you have a high risk for heart attacks or potentially deadly irregular heart rhythms (arrhythmias). The outlook is generally good if you follow your doctor's treatment recommendations and avoid certain triggers.
Abnormal heart rhythms, which may cause cardiac arrest and sudden death
Calling your health care provider
Immediately call your local emergency number (such as 911) or go to the hospital emergency room if you have a history of angina and the crushing or squeezing chest pain is not relieved by nitroglycerin. The pain may be due to a heart attack. Rest and nitroglycerin do not completely relieve the pain of a heart attack.
A heart attack is a medical emergency. If you have symptoms of a heart attack, seek immediate medical help.
Take measures to reduce your risk of atherosclerosis. This includes not smoking, eating a low-fat diet, and increasing exercise.
If you have this condition, you should avoid coronary artery spasm triggers, including exposure to cold, cocaine use, cigarette smoking, and high-stress situations.
Cannon CP, Braunwald E. Unstable angina and non-ST elevation myocardial infarction. In: Bonow RO, Mann DL, Zipes DP, Libby P, Braunwald E, eds. Braunwald's Heart Disease: A Textbook of Cardiovascular Medicine. 9th ed. Philadelphia, PA: WB Saunders; 2011:chap 56.
Stern S, Bayes de Luna A. Coronary artery spasm: a 2009 update. Circulation. 2009 May 12;119(18):2531-4.
David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine; and Michael A. Chen, MD, PhD, Assistant Professor of Medicine, Division of Cardiology, Harborview Medical Center, University of Washington Medical School, Seattle, Washington. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M. Health Solutiosn, Ebix, Inc.