Electrocardiographic evidence of left ventricular hypertrophy in otherwise normal children. Clarification by echocardiography.

Eleven apparently normal children whose electrocardiograms demonstrated greatly increased precordial QRS voltages suggestive of left ventricular hypertrophy were studied by echocardiography to determine whether this finding represented an early manifestation of cardiac disease. Echocardiographic measurements of the thickness of the ventricular septum and of the left ventricular posterobasal wall were normal in all 11 subjects when compared with normal values for age. Also within normal limits were left ventricular, left atrial and aortic root internal diameters, left ventricular mass and the motion and structure of the anterior and posterior mitral valve leaflets. We conclude: (1) These children probably have normal hearts; (2) increased precordial QRS voltage in children and adolescents, in the absence of other abnormalities, is an unreliable indicator of left ventricular hypertrophy; and (3) echocardiography is a powerful diagnostic test in determining the significance of abnormal electrocardiograms suggestive of left venticular hypertrophy.