Coronary Artery Spasm

A coronary artery spasm is a sudden, temporary tightening of the blood vessels that supply blood to your heart muscle. While these spasms may occur without any symptoms, they can also cause chest pain and increase the risk of serious heart complications.

Vasospastic angina, Prinzmetal’s angina, Variant angina, Coronary artery vasospasm

• Heart
• Coronary arteries

Table of contents

• What is a coronary artery spasm?
• Causes and risk factors
• Symptoms
• Diagnosis
• Treatment
• Prevention and lifestyle changes

What is a coronary artery spasm?

A coronary artery spasm is a tightening of the muscles within the walls of the coronary arteries (blood vessels that supply blood to your heart muscle). During a spasm, these arteries squeeze or contract suddenly, which temporarily decreases or blocks blood flow to your heart^[1].

In 1959, Dr. Myron Prinzmetal first described this condition as a different type of chest pain than the classic angina that had been known since 1772^[3]. The spasm causes the artery to narrow, which means less blood flows to the heart. This can lead to a range of problems from stable angina to acute coronary syndrome (a group of conditions caused by sudden, reduced blood flow to the heart)^[3].

Unlike typical angina caused by fatty deposits blocking arteries, coronary artery spasm is caused by a temporary contraction of the muscle layer in the blood vessel wall^[5]. The condition does not follow the traditional risk factors for coronary artery disease^[3].

Causes and risk factors

The exact cause of coronary artery spasms is not completely understood, but researchers believe multiple factors play a role. These include problems with the autonomic nervous system, inflammation, oxidative stress, dysfunction of the inner lining of blood vessels, overactive smooth muscle cells in the artery walls, genetic factors, and lifestyle choices^[3].

Certain conditions can increase your likelihood of experiencing a coronary artery spasm. If you have risk factors for heart disease, you also have risk factors for coronary artery spasms. The most common include high blood pressure, high cholesterol, smoking or using tobacco products, and recreational drug use^[1]. However, many people who experience coronary artery spasms do not have high blood pressure or high cholesterol. Smoking is a particularly strong risk factor^[1].

Several triggers can set off a coronary artery spasm in susceptible people. These include tobacco use, exposure to cold temperatures, extreme emotional stress, and use of stimulant drugs such as amphetamines or cocaine^[1][2]. Other known triggers include hyperventilation, alcohol consumption or withdrawal, certain medications (such as drugs used to treat migraines, decongestants containing pseudoephedrine, and some asthma medications), and even allergic reactions^[6].

The prevalence of coronary artery spasms is highest between the ages of 40 and 70, and tends to decrease after age 70. The condition occurs with different frequencies around the world, with the highest rates reported in Japanese populations compared to Western populations^[3].

Symptoms

You may not notice any symptoms of a coronary artery spasm at all. In fact, sometimes the spasm occurs without any detectable signs^[1]. When symptoms do occur, the main one is chest pain, which is called angina (chest pain or discomfort caused by reduced blood flow to the heart)^[2].

If you experience symptoms, you might feel chest pain that is typically light or moderate. This pain often occurs during rest, especially after midnight or in early morning hours, and is usually felt on the left side of your chest^[1]. The pain may feel like burning, fullness, pressure, or squeezing^[2]. A coronary artery spasm may wake you up at night^[1].

The pain can spread beyond your chest. You may also feel chest tightness or pain extending from your chest to your neck, arms, jaw, shoulder, or back^[1][2].

Coronary artery spasms vary in length. They typically last anywhere from five to 30 minutes^[1], though sometimes they may last only 30 to 60 seconds, or more commonly 5 to 10 minutes^[7]. You may have spasms as infrequently as a few times a year or as often as a few times a day^[1].

Coronary artery spasms are unpredictable but often happen at rest, usually overnight into early morning. This is different from typical angina, which tends to occur with physical activity^[2]. However, in some people, exercise may trigger coronary artery spasms^[7].

It is important to call emergency services if you are having sudden or unexplained chest pain. A sudden, extreme coronary artery spasm can lead to a heart attack^[2].

Diagnosis

To diagnose a coronary artery spasm, your healthcare provider will use several tests that check your heart health^[1].

An electrocardiogram (EKG) is a test that measures your heart’s electrical signals. The ECG recorded during chest pain episodes typically shows changes indicating reduced blood flow to the heart. During a coronary artery spasm, the ECG usually shows ST-segment elevation, which indicates severe reduction in blood flow to a portion of the heart muscle^[7].

An echocardiogram (also called an echo test) uses sound waves to take pictures of your heart^[1].

Coronary angiography is a procedure that uses a special dye and imaging scans to watch how blood flows through your heart arteries. In someone with coronary artery spasm, the coronary arteries can look clear and healthy on an angiogram, unlike in typical angina where the arteries show blockages^[1].

Your provider may also give you an ambulatory monitor (such as a Holter monitor) to wear at home. This device records your heart’s electrical activity as you do your daily activities. It provides a better view of your heartbeat throughout the day and night, which can be particularly important for diagnosing coronary artery spasms since they often occur during sleep^[1].

In most cases, a diagnosis can be made based on clinical symptoms and ECG findings from standard monitoring, ambulatory monitoring, or exercise testing. Occasionally, provocation tests may be needed to confirm the diagnosis. The most frequently used tests involve giving medications (acetylcholine or ergonovine) that can trigger a spasm in people who are susceptible to them^[7].

Treatment

The main goals of treatment are to prevent spasms from occurring and to relieve chest pain when spasms do happen^[1].

If you are having a spasm, a medicine called nitroglycerin can help. Nitroglycerin administered by any route (under the tongue, on the skin, or through a vein) works quickly to relax constricted arteries and stop episodes of chest pain within minutes^[1].

Calcium channel blockers are the first-line medication for preventing coronary artery spasms. These medicines relax the muscles in your arteries and help lower the risk of spasms^[2][7]. Common calcium channel blockers used include amlodipine, diltiazem, and long-acting nifedipine.

Nitrates are another important medication. Long-acting nitrate preparations help prevent coronary artery spasms from recurring^[2][7]. When symptoms are not well controlled by calcium channel blockers alone, long-acting nitrates can be added as second-line medications^[7].

In some countries, a medication called nicorandil is available and can be used as a second-line treatment when calcium channel blockers do not fully control symptoms^[7].

For coronary artery spasms that do not respond well to standard treatments, several other options have been proposed. These include medications that affect the nervous system, specialized nerve therapies, and in some cases, procedures to open narrowed arteries^[7].

In rare cases where coronary artery spasms cause dangerous heart rhythm problems or cardiac arrest, your doctor may recommend implanting a device. An implantable cardioverter defibrillator (ICD) may be needed if spasms cause fast, dangerous heart rhythms. A pacemaker may be considered if spasms cause very slow heart rhythms. The decision depends on the risk of recurrence and how well medications work to prevent spasms^[7].

Prevention and lifestyle changes

Making lifestyle changes is an important part of managing coronary artery spasms. The most important step you can take is to quit smoking if you smoke. Stopping tobacco use can significantly lower your chances of having coronary artery spasms^[1].

Your doctor may recommend following a heart-healthy diet and exercising under their guidance. You should avoid known triggers such as cold temperatures, extreme stress, and stimulant drugs^[2].

It is important to make and keep appointments with your doctor for routine checkups and follow-up tests to monitor your condition^[12].

Because fatty buildup in the arteries is common in patients with coronary artery spasms, medical and lifestyle interventions for preventing or treating this buildup should be implemented when appropriate^[10].