Endomyocardial anomalies of the left heart.

J ]jaIformations of the endomyocardiurn of the left heart are far less common than those affecting the valves or septa; yet they are encountered often enough to constitute a challenge to the physician in diagnosis and proper management. They are more often found in infants than in children or adults. Murmurs are absent or inconspicuous. The condition is apt to be recognized when an infant suddenly and expectedly goes into cardiac failure or when a roentgenogram of the chest obtained, perhaps for an unrelated reason, gives indications of it. Endocardial fibroelastosis is the most common of these malformations. The thickened, restrictive endocardium lines either a contracted (Fig 1) or, more often, a dilated left ventricle. In the former, the signs and symptoms are those of pulmonary venous obstruction, pulmonary hypertension, and right-sided cardiac failure. In the latter, the manifestations are those of left ventricular failure. In either form, the thickening of the endocardium may extend onto the aortic or mitral valve (Fig 1). Endocardial fibroelastosis has been found in postmortem examination of the fetus. In liveborn infants, the effects of the contracted type may be manifest in the first hours or days of life. In the dilated form, symptoms more often present only after a few weeks or months. Such an occurrence is illustrated in Figure 2, which compares the chest roentgenogram on the first day of life of a prematurely born baby with that taken 21/2 months later on admission, almost moribund, in shock and cardiac failure. Death occurred a few minutes after admission, before emergency measures to treat the cardiac failure had time for effect. The electrocardiogram in the dilated form shows