[Myocardial infarct before the age of 36: 20 cases].

Twenty cases of myocardial infarction in 16 males and 4 females and less than 36 are reported. The number of heavy smokers was greater than in other age groups (86%), and an association between tobacco consumption and lipid abnormalities was found in 3/4 of cases. All the females were on contraceptive treatment, one recurring during pregnancy. The clinical features of the infarctions were an onset which was usually unexpected (n=14), ar attack which was sometimes precipitated by exercise (n=3), and the infrequency of residual angina. The exercise test (n=16) showed up an associated abnormality in only one case out of four, but the fact that the rate-pressure product was normal suggests that the coronary artery networks were in a satisfactory state of function. Ventriculography (n=14) was normal in 35% of cases. Coronary arteriography (n=18) showed significant lesions in 12 cases, one trunk being affected in 6, two trunks in 5, and 3 trunks in one; the lesion index was 1.6. In 6 cases there were few changes in the coronary arteries, and the probable mechanism of the infarct is discussed: besides the possibility of a recanalised thrombus, which appears to be the likely one in two of our patients, spasm played a possible role even though the ergonovine provocation test was negative. The mortality during the first month was zero; as a secondary event over a follow-up period of 38 months, there were two deaths and four recurrences, one of which occurred in a healthy coronary vascular tree.