Coronary Artery Spasm

Overview

Coronary artery spasm is a sudden, temporary tightening (constriction) of the muscle within the wall of a coronary artery, one of the vessels that supply blood to the heart muscle. When the artery clamps down, it narrows and briefly reduces or cuts off blood flow to part of the heart, which can cause chest pain known as vasospastic or variant angina.

Unlike the more common type of angina caused by fixed cholesterol plaques narrowing the arteries, coronary artery spasm can occur in arteries that are otherwise relatively clear, and it often strikes at rest, including during the night or early morning. The spasm is usually short-lived, but it can be intense and, in some cases, lead to dangerous heart rhythm problems or a heart attack. Because the chest pain can closely resemble that of a heart attack, any new or severe chest pain should be treated as an emergency until a doctor evaluates it.

Symptoms

The main symptom is chest pain or discomfort that comes from the temporary reduction in blood flow.

• Chest pain or tightness, often described as squeezing or pressure, usually under the breastbone
• Pain that frequently occurs at rest, especially at night or in the early morning
• Pain that may spread to the arm, neck, jaw, or shoulder
• Episodes that often last from a few minutes up to around 15 minutes
• Shortness of breath, sweating, or nausea during an episode

In some cases the spasm can trigger an abnormal heart rhythm, causing fainting, or can lead to a heart attack. Because these symptoms overlap with a heart attack, they should never be ignored.

Causes

Coronary artery spasm happens when the muscle in an artery wall contracts excessively, but the exact reason is not always clear. Several triggers and contributing factors are recognized.

• Smoking and tobacco use: a major and well-established trigger.
• Stimulant drugs: cocaine and amphetamines can provoke severe spasm.
• Emotional stress and cold exposure: can bring on episodes.
• Certain medications: some drugs that constrict blood vessels.

The tendency to spasm may relate to how the artery lining and muscle respond to signals, and it can occur even when the arteries have little or no plaque buildup.

Risk Factors

Several factors raise the likelihood of coronary artery spasm.

• Smoking, which is the strongest modifiable risk factor
• Use of stimulant drugs such as cocaine or amphetamines
• High levels of emotional stress
• Exposure to cold
• Other conditions that affect blood vessel function
• Sometimes occurring without any obvious risk factors

Diagnosis

Diagnosing coronary artery spasm can be challenging because episodes are brief and may resolve before testing. A doctor combines history with tests of the heart and arteries.

• Electrocardiogram (ECG): may show characteristic changes during an episode of spasm.
• Coronary angiography: imaging of the heart arteries, sometimes with provocation testing to bring on a spasm under controlled conditions.
• Ambulatory ECG monitoring: a portable monitor worn over time to capture episodes.
• Blood tests: to check for heart muscle damage if a heart attack is suspected.

Distinguishing spasm from the more common plaque-related angina or a heart attack is important because the treatment differs.

Treatment

Treatment focuses on relaxing the arteries, relieving and preventing spasms, and removing triggers. Most people respond well to medication.

• Calcium channel blockers: the mainstay of treatment, these medicines relax the artery walls and help prevent spasm.
• Nitrates: such as nitroglycerin, which relax the arteries and can relieve an episode quickly and help prevent attacks.
• Stopping smoking and stimulants: essential, since these are major triggers.
• Managing triggers: reducing stress and avoiding cold exposure where possible.

With proper treatment, most people have far fewer episodes. Some medicines that can worsen spasm, such as certain beta-blockers used alone, may be avoided. Ongoing follow-up helps adjust treatment and reduce the small risk of serious complications.

Prevention and Self-Care

• Do not smoke or use tobacco, and avoid stimulant drugs entirely
• Take prescribed medicines such as calcium channel blockers consistently
• Manage stress with relaxation techniques and healthy habits
• Dress warmly and protect yourself from sudden cold
• Keep follow-up appointments and report worsening or more frequent episodes
• Know your emergency plan and how to use prescribed nitroglycerin

When to See a Doctor

See a clinician if you have repeated episodes of chest pain, especially at rest or at night, so the cause can be identified and treated. Because chest pain can signal a heart attack, treat it as an emergency:

Call emergency services right away if you have chest pain or pressure that lasts more than a few minutes, is severe, or comes with shortness of breath, sweating, nausea, fainting, or pain spreading to the arm, neck, or jaw. Do not wait to see whether it passes. If a spasm does not respond quickly to prescribed nitroglycerin, seek emergency care.

Related Topics

Frequently Asked Questions

References

1. Mayo Clinic. Coronary artery spasm and Prinzmetal angina.
2. American Heart Association (AHA). Angina and coronary artery spasm.
3. MedlinePlus, U.S. National Library of Medicine. Variant angina.
4. National Heart, Lung, and Blood Institute (NHLBI). Angina.