Prinzmetal's Angina is a rare heart syndrome that is difficult to diagnose.

It consists of chest pain, pressure, or tightness (angina) caused by episodes of spasm (contraction of smooth muscle tissue) in the arteries that supply blood to the heart. This is in contrast to atherosclerosis which is caused by a buildup of fatty plaque and hardening of the arteries.

The episodes usually occur at rest, last between 5-30 minutes, and are prevalent during late night and early morning hours. It is difficult to "catch" a spasm in a clinical environment as it occurs - making diagnosis difficult. However, it is shown that spasm is documented in 2-10% of the population and thought to occur more frequently.

The following tests may be used to help diagnose the disease:

Electrocardiogram (ECG/EKG)

An ECG is a noninvasive test that records the electrical activity of the heart over a period of time using electrodes placed on the skin. This test typically consists of 12 leads (10 electrodes).

During an attack, there are specific changes to the electrical conduction of the heart. These changes often involve elevation, rather than depression, of the ST segment which is relieved with nitroglycerin. In rare cases, arrhythmias may occur secondary to other symptoms.

Due to their transient nature, spasms are difficult "catch" on an ECG - it must be set up on the patient immediately before/during an episode. A portable/wearable Holter monitor may be used as a less-comprehensive alternative for some patients.

Cardiac Enzymes

A cardiac enzyme test involves one or more noninvasive blood tests to measure the presence of or changes in specific cardiac enzymes.

A prolonged spasm may cause elevations in creatine kinase (CK), tropinin I (cTnI), and troponin T (cTnT). These changes, if detected, are indicative of damage to the heart muscle caused by a lack of oxygen-rich blood. However, a positive result does not rule out other causes of symptoms.

Chest X-ray

A chest X-ray is a noninvasive picture of the chest that shows the heart, lungs, airway, blood vessels, and lymph nodes.

The image(s) can also reveal the size and shape of the heart - helpful for ruling out structural abnormalities. This test is often used to exclude other causes of symptoms.


An echocardiogram is a noninvasive scan that uses a sonogram (ultrasound) to show the size and shape, capacity, location or extent of any tissue damage, and estimates of the general function of the heart. This test is often used to exclude other causes of symptoms.

Calcium Score

A calcium score is a noninvasive scan that uses a specialized X-ray to detects and measures calcium-containing plaque in the arteries of the heart.

If plaque is found, it can grow to restrict or block the flow of blood to the heart. This test is often used to exclude other causes of symptoms.

Coronary CT Angiogram (CTA)

A CTA is a noninvasive scan that uses computed tomography (CT) to assess the coronary arteries of the heart.

The patient receives an injection of contrast and then the heart is scanned to reveal blockages or occlusion of the coronary arteries. This test is often used to exclude other causes of symptoms.


An angiogram is an invasive medical test used to visualize the inside, or lumen, of blood vessels and organs of the body, with a particular interest in the arteries, veins, and heart chambers.

It is traditionally done using a system of guide wires and catheters along with a contrast agent (injected into the blood vessel) to be imaged using X-ray techniques such as fluoroscopy. In some cases, provocative testing involving drugs (ergonovine, methylergonovine or acetylcholine) or hyperventilation may be used to provoke a spasm during observation, though this can be dangerous.


A hyperventilation test is a provocative test that involves rapid breathing to trigger an episode of spasm in susceptible patients.

The test is often conducted along with an angiogram, echocardiogram, electrocardiogram (ECG/EKG) to observe visible changes to the arteries, wall motion, thickening, general muscle condition, or electrical conduction of the heart, respectively.

Stress Test

A stress test a noninvasive test used to measure the heart's ability to respond to external stress (exertion) in a controlled environment. The stress response is usually induced by exercise towards the patient's maximum or near-maximum heartrate on a treadmill.

If a patient experiences symptoms during this test, it may indicate traditional heart disease as opposed to spasm (which occurs at rest). This test is often used to exclude other causes of symptoms.

Nuclear Scan

A nuclear scan is a noninvasive imaging procedure in which a small amount of radioactive material is injected into a vein. A special camera (a gamma camera) and a computer take pictures to assess the function and size of the heart, as well as the flow of blood. This test can be combined with a stress test.

This test is often used to exclude other causes of symptoms.