[Sudden death and myocardial infarction caused by thrombosis of normal coronary arteries: an anatomic study of 3 cases].

The anatomic lesions of two cases of sudden death (one man and one 24 years old woman) and of one case of rapidly fatal myocardial infarction (51 years old woman) are described. The coronary lesions were exclusively thrombotic with no associated atherosclerosis or pre-existing arterial wall change. The thrombi were occlusive from the outset or were constituted in successive mural stages, the last being occlusive and giving rise to the clinical symptoms (sudden death and/or myocardial infarction). Several points are discussed. The concept of normal coronary artery must be confirmed by anatomic examination: coronary angiography is not sufficient for the diagnosis of dangerous atherosclerotic plaques which are not particularly stenotic, eccentric, lipidic and fragile. Thrombogenic factors are better understood and some may play a role in these cases of "primary thrombosis", by they of plasma or platelet origin. The trigger role of spasm cannot be ignored as some of the spastic and thrombotic factors are similar. The preferential coronary site of these thromboses may be explained by constitutional changes (arterial hypolasia with narrow lumen) or acquired lesions (repeated arterial trauma due to shearing by the movements of the underlying left ventricle transmitted to the epicardial coronary arteries).