[Atypical pulmonary stenosis in certain polymalformative syndromes. Prevalence of associated hypertrophique myocardiopathy].

Certain pulmonary stenoses differ markedly from the usual types of isolated valvular stenosis in their clinical features (maximal murmur situated lower down), their radiological signs (absence of a prominent median arc), the electrocardiograph (atypical electrical axis), the haemodynamic findings (usually a poor gradient), and especially the angiocardiography (valvular dysplasia, lack of a post-stenotic dilatation). They are encountered especially in the multiple malformations, as shown by this series of 23 cases comprising the syndrome of Noonan (9), of Gorlin or 'leopard' (7), of Watson or 'café-au-lait spots' (3), or those defying classification, but always having a disorder of facial structure and mental deficiency, sometimes with deafness (4). The frequent finding of a gradually progressive hypertrophic cardiomyopathy is a feature of these syndromes, and usually accounts for the abnormal ECG findings. It leads to a discussion of the pathogenesis, and of the place of these syndromes in a wider context, alongside the phacomatoses and the hereditary forms of neuromuscular degeneration.