[Primary hypertrophic cardiomyopathies. Diagnosis and treatment].

Hypertrophic cardiomyopathy (HCM) is currently considered to be a condition characterised by abnormal diastolic function, sometimes associated with left ventricular outflow obstruction which appears to be a secondary phenomenon. It is important to avoid overlooking this diagnosis especially in young subjects, because of the risk of sudden death, but conversely, false positive diagnosis can result in a serious social and psychological handicap. Echocardiography has assumed a major role in the diagnosis and follow-up of HCM over the last decade. It allows analysis of the localisation, extension and severity of the septal hypertrophy and of the mechanism of systolic anterior motion of the mitral valve. Cardiac doppler completes the non-invasive assessment of this condition by demonstrating the presence or absence of outflow tract obstruction, evaluating diastolic dysfunction, and documenting mitral and occasionally aortic valve regurgitation. Only severely symptomatic patients who do not respond to high dose medical therapy and for whom surgery might be an option need cardiac catheterization. Strenuous physical activity and sport are not recommended in asymptomatic forms. It is vital to identify those patients at high risk of sudden death (family history of sudden death, 48 to 72 hour Holter monitoring). In the absence of silent arrhythmias, preventive therapy should be more general in patients under 30 years of age. Despite a better understanding of the disease, the indications of medical and surgical treatment remain controversial and poorly defined. Treatment is mainly medical with Propranolol as the drug of choice. The dosage has to be tailored for each individual patient.(ABSTRACT TRUNCATED AT 250 WORDS)