Vasospastic Angina

Variant angina, also called vasospastic angina or Prinzmetal angina, is angina pectoris caused by a cramping (spasm) of a coronary artery. The muscle layer in the artery wall contracts too strongly, so the vessel narrows sharply or closes for a moment. Unlike stable angina, which is triggered by physical activity, variant angina attacks usually occur at rest. Between attacks, the coronary arteries may look normal or only slightly narrowed on angiography.

What Happens During an Attack

During a spasm, blood flow to part of the heart muscle drops sharply. An ECG recorded at that moment may show ST-segment changes that resemble a heart attack and then return to normal once the spasm eases. Attacks usually last from a few minutes to about 15 minutes and are quickly relieved by short-acting nitrates. Attacks often come at roughly the same time of day, especially from midnight to early morning, while the ability to exercise during the day often remains good.

Common Triggers

Smoking is the main risk factor. Other triggers include cold air, emotional stress, fast and deep breathing (hyperventilation), excessive alcohol, cocaine or amphetamines, triptan or ergot migraine medicines, some decongestants, and some chemotherapy drugs. Low magnesium levels have also been linked to a tendency toward spasm.

Who Is More Often Affected

Vasospastic angina is reported more often in East Asian populations, such as in Japan and Korea, than in European populations. People with this condition tend to be younger than people with stable angina and are often smokers. Spasm can occur together with a disorder of the small blood vessels of the heart, covered on the Microvascular Angina page.

Outlook with Treatment

By quitting smoking, avoiding triggers, and taking spasm-preventing medicines regularly, most people with this condition can control their attacks, and the long-term outlook is generally good, especially when there is no major plaque narrowing. Spasm-preventing medicines are usually taken long term. Stopping them suddenly can trigger more severe attacks, so any change in your medicines should first be discussed with your doctor. Regular follow-up visits help assess whether treatment needs adjusting.

Because attacks often happen at home at night, your description of the symptoms is the first clue: when the pain starts, how long it lasts, what triggers it, and whether it eases quickly with nitrates. The diagnosis becomes strong when an ECG recorded during pain shows temporary ST-segment changes that return to normal after the attack. To capture such an attack, your doctor may ask for long-term ECG recording with a Holter monitor.

Coronary angiography or CT coronary angiography is done to look for plaque narrowing. If the arteries are not severely blocked, a provocation test with acetylcholine or ergonovine during catheterization can confirm spasm in a controlled way. This test is done under close monitoring, and any spasm that appears is relieved right away with nitrates given directly into the coronary artery.

According to the COVADIS criteria, a definite diagnosis is made when angina that eases with nitrates is accompanied by temporary ischemic ECG changes during an attack or by spasm proven on a provocation test.

Chest pain at rest that you are having for the first time needs prompt checking in the emergency room, because at home it cannot be told apart from a heart attack. If similar attacks recur and ease within a few minutes, make an appointment with a cardiologist to find the cause. Note the time, duration, and trigger of each attack, because these notes help with the diagnosis. If the pain does not ease a few minutes after using nitrates, lasts longer than your usual attacks, or comes with fainting and a pounding heartbeat, go to the emergency room right away.

• Recurring chest pain at rest, especially from midnight to early morning.
• Chest pain after using migraine medicines, decongestants, or stimulants.
• Attacks that keep occurring even though you are already taking spasm-preventing medicines.
• A plan to quit smoking that needs support.