What is Prinzmetal Angina?
Vasospastic angina, also known as variant angina or Prinzmetal angina, is a medical condition where a person experiences chest pain while resting. This pain is accompanied by temporary changes in the heart’s electrical activity, specifically in the ST segment showing on an EKG, a test that measures your heart’s activity. The good news is that this condition typically responds quickly to a type of medication called nitrates. The discomfort experienced during an episode of this condition is usually caused by spasms, or sudden contractions, in the arteries that supply blood to the heart.
What Causes Prinzmetal Angina?
Printzmetal angina, a kind of chest pain, is caused by spasms in the coronary arteries, which are the major blood vessels that carry blood to the heart. When these spasms happen, the supply of blood to the heart muscle goes down, causing symptoms like chest pain.
Several factors can trigger these spasms. These include cold weather, exercise, or substances that cause blood vessels to narrow (known as vasoconstriction), like alpha-agonists. Alpha-agonists are drugs such as pseudoephedrine and oxymetazoline.
Recreational drugs like cocaine can also cause these spasms, especially when used together with smoking cigarettes.
Risk Factors and Frequency for Prinzmetal Angina
We still don’t know exactly how common Prinzmetal angina is. This is partly because it’s often mistaken for other conditions with similar symptoms and therefore might not be diagnosed correctly. Studies have found that people in Japan are more likely to develop this form of angina compared to people of Caucasian descent, in fact, they are three times more likely. It usually appears around the age of 50, and within the Japanese population, women are more often affected than men.
- We don’t yet know how many people are affected by Prinzmetal angina.
- Incorrect diagnosis could be a reason as it often gets confused with other conditions.
- Japanese people have triple the risk compared to Caucasian people of developing vasospastic angina.
- The average age when vasospastic angina typically shows up is around 50 years old.
- Within the Japanese population, vasospastic angina is more frequent among women.
Signs and Symptoms of Prinzmetal Angina
Vasospastic angina is a condition where patients experience a recurring pattern of chest pain, usually when at rest and frequently between midnight and early morning. These chest pain episodes tend to last for 5 to 15 minutes. An effective way to lessen the pain is to use short-acting nitrates.
Notably, when these patients undergo an electrocardiogram during a bout of chest discomfort, there are usually visible changes in the ischemic ST-segment. However, these changes revert to normal once their symptoms resolve. Unlike standard angina, physical exertion does not bring on the chest pain in this case, and rest does not ease it. Often, patients with this condition are younger and exhibit few or none of the classic risk factors associated with cardiovascular diseases.
These patients might also have other vasospastic disorders like Raynaud’s phenomenon or migraines. They may have experienced recent episodes of vasospastic angina, have had a history of such episodes, or have had symptom-free periods.
Testing for Prinzmetal Angina
To diagnose a condition known as vasospastic angina, doctors rely mostly on your medical history and heart activity recordings during a spontaneous episode of the chest pain. Vasospastic angina, also known as Prinzmetal angina, is a type of angina that happens when the arteries supplying the heart temporarily narrow.
The international team of coronary vasomotion disorders, COVADIS, has established a set of criteria to diagnose Prinzmetal angina. These criteria are:
- Relief from chest pain after taking nitrate medication during an episode.
- Changes in the electrocardiogram (a test that records the electrical signals in your heart) suggesting a lack of oxygen to the heart muscle during an episode. These changes can include an elevation or depression in the ‘ST-segment’ or new ‘U waves’, which are specific patterns in the heart’s electrical activity.
- Evidence of temporary narrowing of the coronary arteries during an angiography, a type of X-ray used to look at blood vessels.
If the usual electrocardiography doesn’t provide a clear diagnosis, your doctor might consider other tests. The first step would be to rule out a condition known as fixed obstructive coronary artery disease, which causes blockages in the coronary arteries.
If needed, your doctor might recommend a stress test, where the heart is made to work harder while being monitored. However, many patients with vasospastic angina will have normal results on stress tests. A small group of patients (10-30%) can show signs of exercise-induced spasms, which are not specific for vasospastic angina versus fixed coronary obstruction. These patients should undergo coronary catheterization to determine if any blockages exist in the coronary arteries. If a stress test is negative but there’s still suspicion of blockage, coronary catheterization should also be done.
During coronary catheterization, temporary narrowing of the coronary arteries can either be observed spontaneously or after drug administration. Drugs like Ergonovine, acetylcholine, and procedures like hyperventilation can help confirm the diagnosis of coronary vasospasm. However, these tests would only be warranted if the diagnosis of vasospastic angina is suspected but not confirmed. As of now, these drug tests are not routinely done.
Doctors can also use a portable electrocardiogram to capture changes in heart’s electrical activity during any sudden chest pain episodes. It’s important to remember that if you experience sudden chest pain, doctors’ priority will be to check for the possibility of any blockages in the coronary arteries.
Treatment Options for Prinzmetal Angina
Treatment for angina, a condition marked by severe chest pain due to reduced blood flow to the heart, mainly focuses on reducing the frequency of chest pain episodes and preventing serious heart-related complications. Certain lifestyle changes can help manage the condition, with quitting smoking being one of the most effective ways to reduce the frequency of angina episodes. It is also important to avoid certain medications or substances, like cocaine, marijuana, and ephedrine-based products, which can cause the blood vessels in the heart to tighten and spasm, triggering angina.
Medications also play a central role in managing angina. A group of drugs known as calcium antagonists or calcium channel blockers are often the first line of treatment. These drugs work by relaxing and opening up the blood vessels in the heart, which increases the flow of blood to the heart muscle. This can alleviate angina symptoms in about 90% of patients. In fact, one study found that the use of these medications significantly increased the likelihood of patients living without a heart attack.
Calcium antagonists, particularly the long-acting types like diltiazem, amlodipine, nifedipine, and verapamil, are usually recommended to be taken at night because angina episodes are often more frequent during the night and early morning hours. The dose of these drugs should be individualized for each patient, aiming for an adequate response with minimal side effects. In some cases, if a single calcium antagonist doesn’t effectively control symptoms, a second one might be added. Long-acting nitrates can also be effective in preventing angina episodes, but with regular use, the body might build up a tolerance to them.
Other medications might be beneficial for patients whose symptoms don’t improve with calcium antagonists. These include guanethidine, clonidine, and cilostazol. However, more research is needed on the effectiveness of these drugs in managing angina. Lastly, the medication fluvastatin has been found to be effective in preventing spasms in the coronary artery and may work by enhancing the effects of a molecule called nitric oxide or by acting directly on vascular smooth muscle, the muscle tissue in the walls of blood vessels.
Beta-blockers, especially those with nonselective adrenoceptor blocking effects, are generally avoided because these drugs can worsen the symptoms of angina.
What else can Prinzmetal Angina be?
Some conditions that exhibit similar symptoms and can potentially lead to a misleading diagnosis include:
- Acute pericarditis (inflammation of the lining around the heart)
- Angina pectoris (type of chest pain caused by reduced blood flow to the heart)
- Anxiety disorders
- Aortic dissection (serious condition in which the inner layer of the aorta tears)
- Cocaine toxicity
- Esophageal spasms (abnormal contractions of the muscles in the esophagus)
- Gastroesophageal reflux disease (stomach acid frequently flows back into the tube connecting your mouth and stomach)
- Myocardial infarction (heart attack)
- Panic disorder
- Unstable angina (condition in which your heart doesn’t get enough blood flow and oxygen)
Possible Complications When Diagnosed with Prinzmetal Angina
- Irregular heartbeat (Arrhythmia)
- Sudden death
- Heart attack (Myocardial infarction)