Reduced left ventricular size and endocardial fibroelastosis as correlates of mortality in newborns and young infants with severe aortic valve stenosis.

30 patients with severe aortic valve stenosis presented in severe congestive heart failure within the first 2 months of life. In 25 of them, left ventricular volume and contractility were assessed; five of them had a left ventricle of normal size, in 11 left ventricular size was diminished, and in nine patients it was enlarged. Eleven of the infants had extensive endocardial fibroelastosis (EFE) evidenced angiographically by myocardial sinusoids in ten of them and established at autopsy in six. The presence of EFE correlated with the size of the left ventricle; eight of 11 with a small left ventricle, two of five with a normal-sized left ventricle, and one of nine with an enlarged left ventricle displayed EFE. The severe depression of left ventricular function associated with EFE was documented by left ventricular volume determinations on exclusion of the myocardial sinusoids. Of 30 patients, 12 (including eight of 26 who underwent surgery) did not survive. Mortality, severity, and early onset of symptoms were associated mainly with small size of the left ventricle and with the severe left ventricular dysfunction associated with EFE.