Chest pain is a common symptom of coronary artery disease. However, people without fixed, severe coronary blockages also can have chest pain due to a rare condition called coronary spasm. While the number of people with coronary spasm is very small, the disorder is often misdiagnosed or not diagnosed at all.

Cleveland Clinic cardiologist Frederick Heupler Jr., MD, has been treating patients with coronary spasm for more than four decades. Here he answers five top questions about the little-known condition.

1. How is coronary spasm different from coronary artery disease?

Both conditions cause angina. With fixed, severe coronary artery disease, this pain, tightness, burning or pressure in the chest is due to a major blockage in one or more arteries. You typically have pain during or after physical activity.

However, with coronary spasm (also called “variant angina” or “Prinzmetal angina”), angina usually occurs while you’re resting and can wake you from sleep. The pain also can occur with exertion and be severe. You may pass out.

Episodes usually last less than 15 minutes. They can occur a few times yearly, a few times daily or infrequently.

Most patients with coronary spasm have at least mild coronary artery disease. The chest pain also can be caused by:

• Inflamed cartilage in the chest
• Muscle spasm
• An issue with the esophagus or stomach
• Other unknown factors

2. Who is at risk for coronary spasm?

Most patients with coronary spasm are between ages 40 and 60. The condition has been linked to:

• Spasms in other arteries, causing conditions such as migraine or Raynaud’s syndrome
• Thyrotoxicosis (excessive thyroid hormone)
• Chronic allergic conditions such as Samter’s Triad (asthma, nasal polyps and aspirin allergy)
• Smoking
• Drinking large amounts of alcohol
• Menstrual cycles
• Some chemotherapy drugs
• Low magnesium

3. How is coronary spasm diagnosed?

To diagnose coronary spasm, you may need to wear a Holter monitor for up to 48 hours. The monitor records your heart’s electrical impulses, even during sleep. If you have chest pain in the middle of the night, for example, we may be able to see changes on the electrocardiogram (EKG) that indicate coronary spasm. However, not all patients show EKG changes during every episode.

To get a sure diagnosis, we can conduct an ergonovine stress test. Ergonovine is a drug that is injected intravenously. It can trigger coronary spasm, usually within minutes, at which point we inject another medication to stop it. Before, during and after the attack, we record your EKG. We also can see your coronary spasm on an angiogram.

We began performing ergonovine tests for coronary spasm in the Cardiac Labs at Cleveland Clinic in 1972, shortly after Dr. William Proudfit and Dr. Wayne Siegel introduced this test in the Coronary Care Unit.

4. How is coronary spasm treated?

Nitroglycerin usually relieves angina caused by coronary spasm. For some, long-acting nitroglycerin can even help prevent angina attacks.

However, most people with coronary spasm require calcium blockers – often in larger-than-normal doses. In some cases, a combination of different types of calcium blockers may be needed. Medications and dosing are individualized for each patient. Side effects of calcium blockers may include leg swelling and low pulse, but your doctor can help you manage them.

5. Can coronary spasm cause a heart attack?

Yes. But it’s unlikely if you’re taking calcium blockers.

Forty percent of patients with coronary spasm have syncope (passing out) with angina. In these people, a serious abnormal heart rhythm occurs with the spasm.

Call 911 and get to an emergency room immediately if:

• Your chest pain does not go away after taking two doses of nitroglycerin
• You are having other heart attack symptoms
• You feel like you’re going to pass out