Spontaneous coronary artery dissection is an extremely rare cause of myocardial infarction. The prognosis and treatment of coronary artery dissection have not yet been defined. We report on a 42-year-old woman who was admitted to the emergency unit of a regional hospital with central chest pain and electrocardiographic signs of extensive acute anterior myocardial infarction (MI). She was treated with thrombolytics, yet her condition deteriorated rapidly, resulting in cardiogenic shock. An angiogram revealed dissection of the left main coronary artery that extended into the anterior descending (LAD) and circumflex arteries (LCX). At autopsy a recent anterolateral MI of the left ventricle was found. Dissection of the left coronary artery system was confirmed. Extension of the dissection may have been due to thrombolytic treatment.