Surgical Treatment of Idiopathic Hypertrophic Subaortic Stenosis in Children

Five children with idiopathic hypertrophic subaortic stenosis (IHSS) were operated upon during the past 7 years and all survived. Their ages ranged from 4 years and 5 months to 14 years (mean 8 years and 5 months). The operations performed were 1 right ventricular myectomy and 4 transaortic left ventricular myotomies. Whether surgery performed in childhood would change the natural history or not is still unknown, however, according to our results and many available reports, we have so far reached the following conclusions; 1. Transaortic left ventrlcular myotomy or myectomy is a safe and effective operation for localized muscular subaortic stenosis in children. 2. Because the disease is progressive, operation in childhood may be worth to be considered, when the resting or provocative pressure gradient is excessive. 3. For those who have a marked increase in left ventricular outflow pressure gradient by the provocation, operation would be considered even though the gradient at rest is less than 50 mmHg.