[Role of the atrioventricular septum and mitro-aortic separation in the pathogenesis of fixed subaortic stenosis].

PURPOSE: To analyze, by cross-sectional echocardiography, morphological features of the atrial atrioventricular and ventricular septum potentially involved in the genesis of fixed subaortic stenosis.

METHODS

Forty three children with fixed subaortic stenosis were compared with 86 normal children, matched by age, sex and body surface, and 43 children with congenital heart defects without fixed subaortic stenosis.

RESULTS

The groups did not differ in as age, sex or body surface. The atrioventricular septum was significantly smaller in children with subaortic stenosis than in normal children or patients with other congenital heart diseases. The ventricular septum was significantly more aligned with the atrial septum in cases than in normal children and in patients with other congenital heart diseases. The odds ratio for the development of fixed subaortic stenosis was statistically significant in the presence of a short atrioventricular septum and with alignment of the ventricular and atrial septum, when analyzed in isolation or when controlled by perimembranous ventricular septal defect.

CONCLUSION

It was concluded that in fixed subaortic stenosis the atrioventricular septum length is decreased and that this alteration may be a risk factor for its development.