[Ventricular hypoplasia in congenital heart diseases]

Twenty-seven cases of autopsy showing hypoplasia of one of the ventricular cavities, prevalently the left, were selected from a series of 103 congenital cardiopathies (1979-1990). In 9 cases ventricular hypoplasia formed part of complex malformative syndromes with a well-known physiognomy: a further 18 cases showed a complete (9 cases) or incomplete (9 cases) hypoplastic heart syndrome. Subjects were prevalently female and the presence of other malformations indicating a genetic dysfunction was less evident than in other cardiopathies. The different pathogenetic hypotheses are discussed in the light of macro- and microscopic morphological factors, of which the most plausible is that involving an anomalous position or orientation of the musculo-membranous folds which give rise to the septation system of the various metamers of the cardiac tube.