Left ventricular hypertrophy syndrome in infancy.

Cardiac hypertrophy in infancy has been the subject of considerable interest for many years. An increasing number of reports have appeared in the literature describing diverse cardiac lesions in infancy, which nevertheless have similar clinical manifestations. Rosenbaum et al. incorporated this group of diseases under the heading “Primary Myocardial Disease in Infancy and Childhood.” Since most of these lesions are not of primary myocardial origin and since they produce left ventricular hypertrophy as the predominant anatomic finding, we offer “Left Ventricular Hypertrophy Syndrome” as a more descriptive title. The Left Ventricular Hypertrophy Syndrome in infancy is characterized by; (1) cardiac enlargement-predominantly of the left ventricle; (2) absence of significant heart murmurs; (3) absence of central cyanosis; (4) electrocardiographic findings which are either normal or indicative of myocardial damage or of left ventricular hypertrophy; (5) at times, symptoms and signs of cardiac failure. The lesions associated with this syndrome are conveniently divided into those in which the predominant abnormality is endocardial, as in primary endocardial fibroelastosis; those in which the myocardium is primarily involved and a third group in which there is predominant alteration in function of the coronary arteries. A number of rather common congenital malformations producing left ventricular hypertrophy in the absence of cyanosis are seen in infancy. These are usually accompanied by significant murmurs and, by definition, are excluded from the syndrome under discussion. They include patent ductus arteriosus, ventricular septal defect, aortic or subaortic stenosis as well as coarctation of the aorta. In a characteristic instance of the left ventricular hypertrophy syndrome, the history is that of a previously healthy baby who has begun to eat poorly, and to show signs of restlessness and fatigue. Episodes of apparent pain may be noted. Restlessness increases and is often followed by respiratory distress. On examination, dyspnea, tachycardia, enlargement of the heart and, in some instances, gallop rhythm and poor heart sounds are noted. Hepatomegaly is often present due to associated cardiac failure. Cyanosis, if present, is usually transient or terminal. Heart murmurs are conspicuously absent or, if present, consist of soft, inconsequential, apical murmurs. Usually the lungs are clear but evidence of pulmonary infection or signs of atelectasis produced by cardiac enlargement may be present. Peripheral edema is uncommon except as a late manifestation. Radiologic examination reveals considerable cardiac enlargement, the silhouette often being globular in shape; occasionally the standard criteria for left ventricular enlargement are satisfied. The electrocardiogram may be diagnostic of left ventricular hypertrophy or reveal ST or T wave abnormalities indicative of myocardial anoxia or damage.