Supravalvular aortic stenosis

Supravalvular aortic stenosis (SVAS) is a rare congenital heart defect characterized by a narrowing (stenosis) of the ascending aorta just above the aortic valve. This narrowing obstructs blood flow from the left ventricle to the rest of the body, forcing the heart to work harder to pump blood. SVAS can occur as an isolated finding (familial or sporadic) or as part of Williams-Beuren syndrome (also known as Williams syndrome), a multisystem disorder caused by a microdeletion on chromosome 7q11.23 that includes the elastin (ELN) gene. Isolated familial SVAS is typically caused by point mutations or small deletions in the ELN gene, which encodes elastin, a critical structural protein in arterial walls. The condition primarily affects the cardiovascular system. The stenosis may be discrete (a localized hourglass-shaped narrowing), diffuse (a longer segment of hypoplasia), or membranous. Key symptoms depend on the severity of the obstruction and may include exertional dyspnea (shortness of breath with activity), chest pain, syncope (fainting), and heart murmur detected on physical examination. In severe cases, heart failure can develop. Patients with SVAS may also have stenosis of other arteries, including the pulmonary arteries, coronary arteries, renal arteries, and cerebral arteries, reflecting the systemic nature of the underlying elastin deficiency. Coronary artery involvement is particularly concerning as it can lead to myocardial ischemia and sudden cardiac death. Diagnosis is typically made through echocardiography, which can visualize the narrowing and assess its hemodynamic significance. Cardiac catheterization and CT or MRI angiography may be used for further evaluation. Treatment depends on the severity of the stenosis. Mild cases may be monitored with regular follow-up, while moderate to severe cases generally require surgical intervention. The most common surgical approaches include patch aortoplasty (widening the narrowed segment with a patch), the McGoon or Doty repair techniques, and the Brom three-sinus reconstruction. Outcomes after surgical repair are generally favorable, though long-term follow-up is essential as progressive stenosis at other vascular sites may occur. There is currently no medical therapy that can reverse or halt the progression of the stenosis itself.

Data sourced from FDA regulatory filings and ClinicalTrials.gov. Updated periodically.

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