Coronary Artery Spasm
62Coronary Artery Spasm
In coronary artery spasm, a spontaneous, sustained contraction of one or more coronary arteries causes ischemia and dysfunction of the heart muscle. This disorder also causes Prinzmetal's angina and even myocardial infarction in patients with unoccluded coronary arteries.
The direct cause of coronary artery spasm is unknown, but possible contributing factors include the following:
• Intimal hemorrhage into the medial layer of the blood vessel
• Hyperventilation
• Elevated catecholamine levels
• Fatty buildup in lumen
The major symptom of coronary artery spasm is angina. But unlike classic angina, this pain commonly occurs spontaneously and may not be related to physical exertion or emotional stress; it is also more severe, usually lasts longer, and may be cyclic, frequently recurring every day at the same time. Such ischemic episodes may cause dysrhythmia, altered heart rate, lower blood pressure, and, occasionally, fainting caused by diminished cardiac output. Spasm in the left coronary artery may result in mitral valve prolapse, producing a loud systolic murmur and, possibly, pulmonary edema, with dyspnea, crackles, and hemoptysis.
After diagnosis by coronary angiography and EKGs, the patient may receive calcium channel blockers (verapamil, nifedipine, or diltiazem) to reduce coronary artery spasm and to decrease vascular resistance, and nitrates (nitroglycerin or isosorbide dinitrate) to relieve chest pain.
When caring for a patient with coronary artery spasm, explain all, necessary procedures and teach him how to take his medications safely. For calcium antagonist therapy, monitor blood pressure, pulse.rate, and EKG patterns to detect dysrhythmias. For nifedipine and verapamil therapy monitor digoxin levels and check for signs of digitalis toxicity. Because nifedipine may cause peripheral and periorbital edema, watch for fluid retention.
Because coronary artery spasm is sometimes associated with atherosclerotic disease, advise the patient to stop smoking, avoid overeating, use alcohol sparingly, and maintain a balance between exercise and rest.
(From Diseases and Disorders Handbook)
