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Tuesday, March 29, 2011

Coronary artery **

A 32-year-old woman is brought to the hospital with chest pain after a party. She has had similar pain previously, primarily in the morning and rarely with exertion. The pain usually subsides spontaneously and occasionally is associated with diaphoresis but rarely with dyspnea. She almost lost consciousness at work during the most recent episode. The patient has occasionally inhaled cocaine. She is otherwise healthy and takes no medications. She has no family history of coronary artery disease.

On physical examination, blood pressure is 128/70 mm Hg and heart rate is 72/min. There is no jugular venous distention or carotid bruits. The lungs are clear, and cardiac examination shows a normal S1 and S2 and a faint mid-systolic click but no murmur. Electrocardiogram taken during the chest pain shows a 1-mV inferior ST elevation; a subsequent electrocardiogram taken after resolution of the pain is normal. Serum troponin concentration is elevated. Therapy with heparin, aspirin, metoprolol, and nitroglycerin is begun.

The next morning, coronary angiography shows a normal angiographic appearance of the arteries and normal left ventricular wall motion.

Which of the following is the most likely diagnosis?
A Coronary artery atherosclerosis
B Coronary artery dissection
C Coronary artery vasculitis
D Coronary artery vasospasm

Key Point
Coronary artery vasospasm is treated with nitrates in the short term and calcium channel blockers in the long term.

Answer and Critique (Correct Answer = D)

This patient has a presumptive diagnosis of myocardial infarction due to vasospasm of the coronary artery. Factors favoring this diagnosis are the normal angiographic appearance of the coronary arteries, use of cocaine, chest pain after a party (implying use of cocaine), and the episodic ST elevation with spontaneous resolution in the absence of fibrinolysis.

Coronary artery atherosclerotic disease is not likely, based upon the normal coronary artery catheterization. In addition to coronary artery vasospasm, other causes of myocardial ischemia or infarction in the absence of atherosclerotic coronary artery disease include coronary artery dissection, vasculitis (scleroderma and other connective tissue diseases), thromboembolism in the settings of endocarditis or paradoxical embolism, valvular disease, and hypertrophic cardiomyopathy. Spontaneous coronary artery dissection has been reported in pregnant women with or without hypertension but coronary artery dissection is unlikely in a nonpregnant woman Vasculitis seems unlikely in the absence of any additional signs or symptoms to support a diagnosis of collagen vascular disease. Endocarditis is unlikely in the absence of fever and a heart murmur, and hypertrophic cardiomyopathy is unlikely in the absence of a murmur and the normal electrocardiogram (following resolution of the chest pain).

The best treatment for coronary artery vasospasm is nitrates in the short term and calcium channel blockers over the long term. Angiotensin-converting enzyme inhibitors reduce mortality in patients with ST elevation myocardial infarction and in patients with a left ventricular ejection fraction <40% following an acute myocardial infarction. This patient meets neither of these criteria and is unlikely to benefit from this therapy. This patient should be strongly urged not to use cocaine.

1. Mirza MA. Angina like pain and normal coronary arteries. Uncovering cardiac syndromes that mimic CAD. Postgrad Med. 2005;117:41-6, 54. [PMID: 15948368]

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