Two chambered left ventricle. Three new varieties.

A short review of two chambered left ventricle is given, and this rare condition is briefly compared and contrasted with the more common condition involving the right ventricle. Three cases are described, each of which presents a new variety of subdivision of the left ventricle; in two of these the condition was first shown by angiocardiography. The first case had left heart hypoplasia with dysplastic stenosis of the mitral and aortic valves and severe endocardial fibroelastosis of the main left ventricular cavity. The second case also showed dysplasia of the left sided valves with pronounced endocardial fibroelastosis, and in addition there was a congenital malformation of the left lung. The third case showed a bizarre ventricular subdivision without other congenital malformations. The role of the intertrabecular myocardial sinusoids in the pathogenesis of some types of two chambered ventricle is discussed and this is considered to have been of significance in the first two cases. The third case possibly represented an intramyocardial aneurysm of obscure aetiology.