Fixed Subaortic Stenosis in Children

Choi, Eun Jin; Choi, Byung Ho; Hyun, Myung Chul; Lee, Sang Bum

Abstract

PURPOSE: This study attempted to describe the Doppler and two-dimensional echocardiographic features of fixed subaortic stenosis, the de novo occurrence and progression of this lesion and to review its etiology, treatment and course.
METHODS
We studied 17 patients of fixed subaortic stenosis who, between Jan. 1993 and Jan. 1996, ware diagnosed by echocardiographic examination at Kyungpook National University Hospital. The patients' charts, the Doppler and echocardiographic findings as well as the operative reports were retrospectively reviewed.
RESULTS
1) There were 17 patients (14 boys and 13 girls, male/female ratio 1:1) of fixed subaortic stenosis which comprised 1.1% of congenital heart disease (17/1609) and 15% of congenital left ventricular outflow tract (LVOT) obstruction (17/113). 2) Ages of first detection ranged from 3 days to 11 years (mean : 2.74 years), and most of them (14/17) were under 5 years, and 8 under 1. 3) All of them had other major cardiac diseases and subaortic stenosis was diagnosed incidentally during the evaluation (initial and follow-up) of major cardiac diseases. Mean duration between diagnosis of major cardiac diseases and that of subaortic stenosis (11 cases) was 2.83 years (4 months-10 9/12 years), and the other 6 cases were diagnosed coincidentally. 4) The types of fixed subaortic stenosis were membranous in 10 cases (58.8%) and fibromuscular in 7 cases (41.2%). 5) Mean left ventricular to aortic peak systolic pressure gradient (Doppler) at initial diagnosis (9 cases) was 26.6 mmHg and in 6 cases underwent surgical resection 29.17 mmHg but there were no gradient in 8 cases. 6) Aortic insufficiency was found in 4 cases (23.5 %). 7) There were some evidences of progression of the lesion in 4 patients inspite of relatively short follow-up period (mean : 2.08 years). 8) Resection of fixed subaortic stenosis (membranectomy) was performed in 6 cases.
CONCLUSIONS
Our data that most cases were coexisting with congenital heart diseases, and under 5 years of age suggest subaortic stenosis is a congenital lesion but also does not rule out it is an acquired lesion in the presence of some evidences of progression in our four patients.