Myocardial infarction complicating dilated (congestive) cardiomyopathy in an industrial nitroglycerin worker. A case...

A 46-year-old black man employed in an explosives factory and in direct contact with industrial nitroglycerin complained of angina pectoris both at rest and with effort. Special investigations established the presence of dilated (congestive) cardiomyopathy (COCM), transmural anteroseptal and anterolateral myocardial infarction (MI), and total proximal occlusion of the left anterior descending branch of the left coronary artery. Apart from this total occlusion, the coronary arteries appeared free of disease on angiography. It is postulated that some of the episodes of angina pectoris at rest were related to industrial nitroglycerin withdrawal, and that the pathophysiological mechanism involved was coronary vasospasm leading to thrombus formation which culminated in MI, aggravating the congestive cardiac failure due to the COCM. It is less likely that this MI was caused by a coronary embolism originating from the mural thrombus in the left ventricle associated with COCM.