[Course and prognosis of primary hypertrophic cardiomyopathies].

33 patients with hypertrophic cardiomyopathy were followed for a mean duration of 48 months. 29 of them were reviewed; 6 had died, including 4 with a familial form belonging to two different families. No cases of sudden death were observed. The mortality rate was 4 p. cent at 1 year, 11 p. cent at two years and 21 p. cent at 5 years. The clinical course was marked by a functional deterioration in one-third of cases and, on echocardiography, by an increase in the diastolic diameter of the left ventricle and in the thickness of the septum, independent of the clinical course. Subjects from "high risk" families have a very poor prognosis (4 deaths out of 7 patients at an average age of 25). These families present major conductive disturbances on the electrocardiogram and a very marked parietal hypertrophy on the echocardiogram. No other prognosis factor independent of the familial aspect was revealed.