Related Experiment Videos
Abnormalities of the left ventricular outflow tract associated with discrete subaortic stenosis in children: an
G Sigfússon1, T A Tacy, M D Vanauker
1Cardiac Dynamics Laboratory, Division of Cardiology, Children's Hospital of Pittsburgh, Pennsylvania 15213, USA.
Insights
A steep aortoseptal angle, identified by echocardiography, is linked to subaortic stenosis in children. This finding may indicate a risk factor for developing this condition.
Area of Science:
- Pediatric Cardiology
- Echocardiography
- Congenital Heart Defects
Background:
- Subaortic stenosis is an acquired, progressive heart lesion with an unknown cause.
- The study investigates the initial morphologic abnormalities in the left ventricular outflow tract.
- A four-stage etiologic process for subaortic stenosis development is proposed.
Purpose of the Study:
- To examine echocardiographic abnormalities of the left ventricular outflow tract in children with subaortic stenosis.
- To identify specific anatomical features associated with subaortic stenosis.
- To explore potential risk factors for subaortic stenosis development.
Main Methods:
- Echocardiographic studies of 33 patients with isolated subaortic stenosis and 12 with ventricular septal defect and subaortic stenosis were analyzed.
- A size- and lesion-matched control group was used for comparison.
- Measurements included aortoseptal angle, aortic annulus diameter, and mitral-aortic separation by two independent observers.
Main Results:
- Patients with subaortic stenosis (isolated or with VSD) exhibited a significantly steeper aortoseptal angle compared to controls (p < 0.001).
- No correlation was found between aortoseptal angle and patient age or body surface area.
- A trend towards smaller indexed aortic annulus diameter was observed but did not reach statistical significance (p = 0.08).
Conclusions:
- Subaortic stenosis in children is associated with a steepened aortoseptal angle, confirmed by two-dimensional echocardiography.
- This association is present in patients with and without a ventricular septal defect.
- A steep aortoseptal angle may serve as a risk factor for the development of subaortic stenosis.
Objectives:
The purpose of this study was to examine the echocardiographic abnormalities of the left ventricular outflow tract associated with subaortic stenosis in children.
Background:
Considerable evidence suggests that subaortic stenosis is an acquired and progressive lesion, but the etiology remains unknown. We have proposed a four-stage etiologic process for the development of subaortic stenosis. This report addresses the first stage by defining the morphologic abnormalities of the left ventricular outflow tract present in patients who develop subaortic stenosis.
Methods:
Two study groups were evaluated-33 patients with isolated subaortic stenosis and 12 patients with perimembranous ventricular septal defect and subaortic stenosis-and were compared with a size- and lesion-matched control group. Subjects ranged in age from 0.05 to 23 years, and body surface area ranged from 0.17 to 2.3 m2. Two independent observers measured aortoseptal angle, aortic annulus diameter and mitral-aortic separation from previously recorded echocardiographic studies.
Results:
The aortoseptal angle was steeper in patients with isolated subaortic stenosis than in control subjects (p < 0.001). This pattern was also true for patients with ventricular septal defect and subaortic stenosis compared with control subjects (p < 0.001). Neither age nor body surface area was correlated with aortoseptal angle. A trend toward smaller aortic annulus diameter indexed to patient size was seen between patients and control subjects but failed to achieve statistical significance (p = 0.08). There was an excellent interrater correlation in aortoseptal angle and aortic annulus measurement. The mitral-aortic separation measurement was unreliable. Our results, specifically relating steep aortoseptal angle to subaortic stenosis, confirm the results of other investigators.
Conclusions:
This study demonstrates that subaortic stenosis is associated with a steepened aortoseptal angle, as defined by two-dimensional echocardiography, and this association holds in patients with and without a ventricular septal defect. A steepened aortoseptal angle may be a risk factor for the development of subaortic stenosis.