Myocardial infarction with normal coronary arteries: The pathologic and clinical perspectives

Myocardial infarction with normal coronary arteries is a syndrome resulting from numerous conditions but the exact cause in a majority of the patients remains unknown. Cigarette smokers and cocaine users are more prone to dev elop this condition. The possible mechanisms causing myocardial infarction with normal coronary arteries are hypercoagulable states, coronary embolism , an imbalance between oxygen demand and supply, intense sympathetic stimul ation, non-atheroscierotic coronary diseases, coronary trauma, coronary vas ospasm, coronary thrombosis, and endothelial dysfunction. It primarily affe cts younger individuals, and the clinical presentation is similar to that o f myocardial infarction with coronary atherosclerosis. Thrombolytics, aspir in, nitrates, and beta blockers should be instituted as a standard therapy for acute myocardial infarction. Once normal coronary arteries are identifi ed on subsequent angiography, the calcium channel blockers could be added s ince coronary vasospasm appears to play a major role in the pathophysiology of this condition. The beta blockers should be avoided in cocaine-induced myocardial infarction because the coronary spasm may worsen. In myocardial infarction with normal coronary arteries, complications such as malignant a rrhythmia, heart failure, and hypotension are generally less common, and pr ognosis is usually good. Recurrent infarction, postinfarction angina, heart failure, and sudden cardiac death are rare. Stress electrocardiography and imaging studies are not useful prognostic tests and longterm survival main ly depends on the residual left ventricular function, which is usually good .