Abstract
This report describes a 14-month-old boy receiving high-dose steroids for hypsarrhythmia and infantile spasms in whom the echocardiographic diagnosis of hypertrophic cardiomyopathy was made. Family studies were negative for hypertrophic cardiomyopathy, but positive for mitral valve prolapse. The steroid dosage was progressively decreased and finally discontinued; the echo was normal within 12 months. In infants receiving long-term steroid therapy, echocardiograms should be performed to monitor myocardial structure and function.