[Obstructive hypertrophic myocardiopathy and Osler's endocarditis].

Four cases of bacterial endocarditis (BE) complicating hypertrophic obstructive cardiomyopathy (HOCM) were observed between 1978 and 1980. The causal organism was a streptococcus in all cases and the portal of entry, dental. The mitral regurgitation (MR) observed in HOCM as an epiphenomenon of the obstruction became autonomous in 2 patients as shown by phonocardiography with methoxamine. In one case, the MR became severe and justified mitral valve replacement; at surgery, the chordal rupture suspected on echocardiography was confirmed. Antibiotic therapy was effective on the infectious process in all cases. However, 2 of the 4 patients died, one of thrombosis of the mitral prosthesis on the 15th postoperative day, and the other of a cerebrovascular accident. None of the patients had a detectable aortic or septal infectious lesion. Eight of 27 reported cases (30 p 100) of HOCM complicated by BE were operated; 10 (37 p. 100) died as a result of the endocarditis. These cases underline the incidence of BE in HOCM (5 p. 100) its gravity and the necessity for systematic antibiotic prophylaxis, especially before dental treatment.