Coronary Vasospasm

Coronary vasospasm, also known as variant angina or Prinzmetal's angina, is a condition characterized by inappropriate constriction of the heart's arteries. Myron Prinzmetal first described the condition in 1959. Patients with this condition suffer from chest pain that is similar in every way to typical angina. It is described as crushing sub-sternal chest pain, which can radiate to the arm neck or jaw. It can happen at rest or with exertion. It can affect young and old, male or female.



At the root of this condition is a problem with the cells lining the walls of the coronary arteries. These endothelial cells do not respond correctly to natural chemicals secreted by the body to expand the arteries. In contrast, they actually contract or constrict. This can be seen while monitoring the electrocardiogram (ECG) of a patient with vasospasm. The ECG actually shows signs of ischemia or low blood flow to the heart.



If a patient with vasospasm were to present to an emergency room with these ECG changes, the treating physician might be able to differentiate this condition from a true blockage caused by a clot. The simple administration of nitroglycerin (nitro) under the tongue or by IV can often relax the artery and relieve the symptoms instantly. If a clot is present the symptoms don't often resolve completely. In an acute coronary syndrome, the rupture of a plaque inside an artery can cause spasm in addition to intermittent closure of the vessel. Nitro will also relieve this spasm and can improve symptoms, but it is often only temporary. To confirm the diagnosis of vasospasm, a coronary angiogram is necessary. The physician must show the arteries are free of obstruction, small in appearance and respond vigorously (dilate or enlarge) in response to nitroglycerin, or more elegantly constrict in response to acetylcholine.



Severe cases of vasospasm can result in a myocardial infarction, or heart attack. During stent insertion it is common to get some spasm at the distal (downstream) edge of the stent. This often resolves easily with nitro, but in cases that are severe a second stent may need to be inserted to prevent problems. The chronic management of vasospasm includes treatment with calcium channel blockers (diltazem, verapamil or norvasc). Long-acting oral nitrates are also used, as is short-acting sublingual nitro for quick relief. Statin therapy can help to "reprogram" the endothelial cells inside the arteries.



The long term prognosis is excellent with vasospasm and generally better than obstructive coronary artery disease. The risk of MI is generally low, and nitrates readily treat symptoms.