[Congestive cardiomyopathies in children. Natural history and studies]

Congestive cardiomyopathies represent a group of diseases having in common an intrinsic abnormality of the myocardial contraction, of which the cause often remains unknown. In children, there is a more marked incidence during the first year of life. At the Cardiology Institute of Quebec, 25 patients have been diagnosed with a congestive cardiomyopathy since January 1967. The mortality remains high at 48 per cent, and the morbidity at 28 per cent. Thus, the chance of total survival at 16 years was 33 percent. The evaluation and the treatment of the cardiac function as well as the search for a specific etiology must be carried out because the etiological treatment is sometimes possible. Biopsy of the skeletal muscle as the study of fatty acids metabolism have become very important since the identification of a carnitine deficiency. On the other hand, biopsy of the endomyocardium remains the only means to make a pathological diagnosis. Since the treatment of persisting myocarditis is feasible, the histological diagnosis is a pre-requisite in children. So, in four patients with congestive cardiomyopathy, biopsy of the endocardium has enabled to demonstrate a chronic inflammation of the myocardium in one patient. In three other cases, two had non specific lesions on histological examination an one had an extensive fibro-elastosis. As the symptomatic treatment is often deceiving, an in-depth investigation is mandatory in a child suffering from a congestive cardiomyopathy in order to identify an etiology. Such an approach will enable to apply a specific treatment, to achieve a better understanding and perhaps modify its natural history.