Fixed subaortic stenosis(FSS) is important because of not only obstruction
but also aortic insufficiency. This study was performed to find out the characteristics
and combined anomalies of FSS. Echocardiographic and clinical data were reviewed in
31 children who were diagnosed as FSS between March 1985 and February 1991 (age:
2months-12yr7months, M:F = 2:1). Cardiac defects were associated in 26(84%) and the
majority of the cases were related to VSD(VSD only: 14 cases, VSD with other
anomalies: 7 cases). The type of VSD was perimembranous in 86%(18/21) and
subarterial in 14%(3/21). Aortic insufficiency(AO was present in 13 cases(42%) and the
degree of AI was usually mild. The mean pressure gradient between the left ventricle
and the aorta was 21mmHg by cardiac catheterization in 27. Operative resection was
done in 20; 11 during the correction of major defects, 4 for AI, 5 for significant pressure
gradient. The pathologic findings of 13 were mainly fibrosis and hypertrophied myocardium.
In conclusion, because of the possible association with other cardiac defects, especially
perimembranous VSD and its co~rt features, it is recommended to pay attention
to the coexistence of FSS during the evaluation of cardiac defects
