Left ventricular outflow obstruction occurs in 3% to 5% of cardiac anomalies encountered in the pediatric age group. The obstructing lesion may be supravalvular, valvular, subvalvular, or a combination of more than one lesion.1,2
The indication for surgical intervention in these patients is not yet fully defined. Some controversy exists as to the risk of conservative management as compared to the risk of surgery in patients with moderate obstruction. Most of these children have few symptoms and lead normal lives through childhood and adolescence. With more severe obstructions, it is estimated that the incidence of sudden death may be as high as 7%. Thus, we are confronted with predicting which patient will die suddenly from his aortic stenosis. Also, it may be difficult to decide at what age operations to relieve the valvular stenosis should be performed. It is obvious that the older child is a better surgical risk