Chamberlin, William B.

The pulmonary vessels in 2 cases of cor triloculare with subaortic stenosis are compared. Each showed medial hypertrophy of the muscular arteries of the lungs. In 1 case concerning an 8 year old boy this class of vessels showed, in addition, severe intimal fibrosis. The arterioles were normal. It is emphasized that the changes in the pulmonary arteries are similar to those seen in the Eisenmenger complex, in coarctation of the aorta proximal to a patent ductus arteriosus and in the normal fetus. These conditions, though anatomically different from each other and from cor triloculare with subaortic stenosis, are functionally alike in that there is in each a common ventricular ejectile force for the pulmonary and the systemic circulations in the absence of stenosis in the major arterial pathways to the lungs. It is suggested that in cor triloculare biatriatum with subaortic stenosis, the structure of the pulmonary muscular arteries is, and that their function seems, similar to that of the fetus. The changes in the case of the malformation may be considered a carry-over from fetal life.