---
title: Congenital supravalvular aortic stenosis
description: What congenital supravalvular aortic stenosis is, how it differs from narrowing of the aortic valve, why it happens, how it is found and treated and when urgent help is needed.
type: disease
aliases:
  - SVAS
  - Supravalvular aortic stenosis
  - Supravalvar aortic stenosis
  - SupraAS
sources:
  - tier: guideline
    org: minzdrav-rf
    title: Врожденный надклапанный стеноз аорты
    year: 2024
    url: https://cr.minzdrav.gov.ru/view-cr/702_2
  - tier: guideline
    org: esc
    title: 2020 ESC Guidelines for the management of adult congenital heart disease
    year: 2020
    doi: 10.1093/eurheartj/ehaa554
    url: https://doi.org/10.1093/eurheartj/ehaa554
  - tier: reference
    org: msd-manuals
    title: Aortic Stenosis
    year: 2025
    url: https://www.msdmanuals.com/professional/cardiovascular-disorders/valvular-disorders/aortic-stenosis
  - tier: reference
    org: msd-manuals
    title: Microdeletion and Microduplication Syndromes
    year: 2025
    url: https://www.msdmanuals.com/professional/pediatrics/chromosome-and-gene-abnormalities/microdeletion-and-microduplication-syndromes
sources_checked: 2026-10-14
review: null
---

Congenital supravalvular aortic stenosis (SVAS) is a defect in which the <Structure id="aorta">aorta</Structure> is narrowed above the <Structure id="aortic-valve">aortic valve</Structure>: at the level of the sinotubular junction and above it.<Cite n={1} /> The narrowing may be localised, or diffuse and stretched along the aorta.<Cite n={1} /> This is how the defect differs from [aortic stenosis](../aortic-stenosis/), in which the aortic valve itself is narrowed or does not open well.<Cite n={[1, 3]} /> In [subvalvular aortic stenosis](../subaortic-stenosis/), the obstruction lies below the valve.<Cite n={3} />

Supravalvular stenosis is uncommon.<Cite n={3} /> In most cases it is not just a local narrowing but part of a genetic disease of the artery wall: the branches of the aorta and the pulmonary arteries may be narrowed too.<Cite n={[1, 2]} />

The Russian Ministry of Health paediatric guideline this article draws on is written for children, and the European Society of Cardiology (ESC) guideline for adults with congenital heart disease; the text says which source says what.<Cite n={[1, 2]} />

<Diagram name="supravalvular-aortic-stenosis">
  <p slot="normal">
    Normally, during contraction (systole), blood flows freely from the left ventricle through the
    open aortic valve into the aorta.<Cite n={3} />
  </p>
  <p slot="disease">
    The diagram shows the most common form of the defect, the "hourglass": the aorta is pinched in
    just above the valve, and its lumen is narrowed.<Cite n={2} /> The aortic valve itself may be
    unchanged — the narrowing lies above it.<Cite n={[1, 2]} /> The coronary arteries leave the
    aorta below the narrowing, where the pressure is raised.<Cite n={[1, 2]} /> The ascending aorta
    beyond the narrowing is not widened.<Cite n={1} />
  </p>
</Diagram>

## Why it happens

<Patient>

In most cases the cause is a change (mutation) or loss (deletion) of the elastin gene on chromosome 7.<Cite n={[1, 2]} /> According to the Russian Ministry of Health paediatric guideline, the defect occurs in three variants:<Cite n={1} />

- as part of Williams syndrome (Williams–Beuren syndrome);
- a familial form: it runs in families, but there are no other features of Williams syndrome;
- isolated ("sporadic") cases.

**Williams syndrome** is a genetic syndrome in which a small piece of chromosome 7 is missing.<Cite n={4} /> It is marked by distinctive facial features, intellectual disability with well-preserved speech, and a sociable, outgoing personality with a tendency to anxiety and fears.<Cite n={4} /> According to the Russian Ministry of Health paediatric guideline, these children lag behind in physical development and may have bowel problems and increased sensitivity to sounds.<Cite n={1} /> In this syndrome supravalvular aortic stenosis is often combined with narrowing of the pulmonary trunk and the pulmonary arteries.<Cite n={1} />

According to the ESC, people with Williams syndrome or an elastin gene mutation have a 50% chance of passing the syndrome or the mutation on to a child, so relatives are examined too.<Cite n={2} /> Supravalvular stenosis is sometimes also found in homozygous [familial hypercholesterolaemia](../familial-hypercholesterolemia/).<Cite n={2} />

</Patient>

<Student>

The elastin gene is located at 7q11.23.<Cite n={[1, 2]} /> In Williams–Beuren syndrome it is deleted or disrupted together with many neighbouring genes; in the familial autosomal dominant form it is affected by a translocation (a rearrangement of a segment) or a loss-of-function point mutation.<Cite n={1} /> According to the ESC, this leads to obstructive arteriopathy of varying severity, most pronounced at the sinotubular junction.<Cite n={2} />

Forms: membranous — a fibrous diaphragm just distal to the coronary ostia; hourglass — according to the ESC the most common, an external hourglass deformity of the aorta with a corresponding narrowing of the lumen; diffuse — narrowing of the whole ascending aorta.<Cite n={2} /> In the hourglass form the thickened intima forms an internal fold or ridge, which may even cover the ostium of the left coronary artery; more often, however, the coronary ostia are dilated because of the raised pressure below the stenosis.<Cite n={1} /> The diffuse form is less common and may extend to the aortic arch and the origins of the brachiocephalic arteries.<Cite n={1} />

Aortic valve abnormalities, hypoplasia of the entire aorta, and stenoses of major branches of the aorta and of the pulmonary arteries may be present.<Cite n={2} /> According to the Russian Ministry of Health paediatric guideline, progressive renal artery stenosis can lead to renovascular [hypertension](../hypertension/), and cerebral artery stenosis to neurological complications.<Cite n={1} />

</Student>

<HeartModel highlight={['aorta', 'left-ventricle', 'left-main-coronary-artery', 'right-coronary-artery']} />

The 3D model shows a normal heart. It highlights the aorta, which in this defect is narrowed just above the valve; the <Structure id="left-ventricle">left ventricle</Structure>, which has to pump blood out through the narrowing; and the <Structure id="left-main-coronary-artery">left</Structure> and <Structure id="right-coronary-artery">right coronary arteries</Structure>, which in this defect leave the aorta below the narrowing.<Cite n={1} />

## Symptoms

<Patient>

According to the ESC, in most patients the defect shows itself in childhood, with signs of obstruction to the outflow of blood from the heart or of too little blood reaching the heart muscle (ischaemia).<Cite n={2} /> The Russian Ministry of Health paediatric guideline advises the doctor to ask the parents whether the child has:<Cite n={1} />

- delayed physical development;
- unusual tiredness;
- shortness of breath, especially during physical activity;
- attacks of palpitations;
- fainting;
- chest pain like angina.

In children the narrowing of the aorta may get worse over time.<Cite n={1} /> In adults, according to the ESC, it rarely gets worse, but the risk of heart complications remains.<Cite n={2} /> Sudden death is rare; according to the ESC, it is more common in Williams syndrome, with diffuse peripheral stenoses of the pulmonary arteries and with involvement of the coronary arteries, particularly in connection with anaesthesia.<Cite n={2} />

</Patient>

<Student>

Auscultation reveals a loud systolic ejection murmur, with no systolic ejection click over the aortic valve.<Cite n={[1, 2]} /> When the stenosis extends to the aortic arch and the subclavian artery, blood pressure in the right arm may be higher than in the left, and the pulse in the left arm may be weak.<Cite n={1} />

According to the Russian Ministry of Health paediatric guideline, patients with SVAS are considered at risk of sudden death because of increasing coronary artery obstruction or progressive stenosis of the outflow tracts of both ventricles.<Cite n={1} /> In Williams–Beuren syndrome, stenoses of the pulmonary trunk and the peripheral pulmonary arteries lead to right ventricular overload and hypertrophy.<Cite n={1} /> According to the Russian Ministry of Health paediatric guideline, over time the supravalvular aortic obstruction progresses, while the pulmonary stenoses regress somewhat.<Cite n={1} />

</Student>

## How it is diagnosed

<Patient>

The main test is a heart ultrasound ([echocardiography](../../diagnostic/echocardiography/)): it shows where and how much the aorta is narrowed, how the left ventricle works and any other heart defects.<Cite n={[1, 2]} /> An [ECG](../../diagnostic/ecg/) may show thickening (hypertrophy) of the left ventricular wall and sometimes signs of ischaemia.<Cite n={1} /> A chest X-ray shows no particular signs except one: in this defect the ascending aorta is not widened.<Cite n={1} />

Because other arteries may be narrowed too, the Russian Ministry of Health paediatric guideline recommends for all children with SVAS an ultrasound of the arteries of the arms and of the arteries to the head, and of the abdominal aorta and its branches.<Cite n={1} /> CT or MRI gives more detail on the aorta, the coronary arteries and the branches of the aorta.<Cite n={[1, 2]} />

A consultation with a geneticist is also needed.<Cite n={[1, 2]} /> To confirm or rule out Williams syndrome, a genetic test with a DNA microarray is done; in the form without the syndrome, the ESC considers testing of the elastin gene useful.<Cite n={[1, 2]} />

</Patient>

<Student>

According to the ESC, the Doppler gradient may over- or underestimate the actual pressure drop across the obstruction; transoesophageal echocardiography allows good visualisation of the coronary ostia.<Cite n={2} /> According to the Russian Ministry of Health paediatric guideline, CT coronary angiography is superior to other imaging methods in assessing coronary artery anatomy.<Cite n={1} /> Patients with a history of fainting undergo [Holter monitoring](../../diagnostic/holter-monitoring/).<Cite n={1} />

According to the ESC, cardiac catheterisation is needed when non-invasive assessment remains uncertain.<Cite n={2} /> The Russian Ministry of Health paediatric guideline warns that in patients with a high gradient between the LV and the aorta, catheterisation and angiocardiography are risky, and CT can give enough information.<Cite n={1} />

</Student>

## How it is treated

<Patient>

There are no medicines that remove the narrowing.<Cite n={1} /> The main treatment is surgery.<Cite n={2} /> Doctors decide when it is needed based on the pressure drop across the narrowing, the symptoms, and how well the left ventricle works and how thick its wall is.<Cite n={[1, 2]} /> According to the Russian Ministry of Health paediatric guideline, if there are reasons for surgery, it is not put off, because the defect gets worse over time.<Cite n={1} />

During the operation the narrowed part of the aorta is widened with a patch.<Cite n={1} /> There are several techniques; which one is chosen depends on the form and length of the narrowing and on the surgeon's experience.<Cite n={1} /> The surgeon always examines the openings of the coronary arteries and, if they are narrowed, corrects this too.<Cite n={1} /> Narrowed branches of the aortic arch and the renal arteries are sometimes widened first from inside the vessel, through a catheter.<Cite n={1} /> The diffuse form is harder to treat: an attempt to remove the narrowing may only move it further along the aorta.<Cite n={1} />

Follow-up is needed for life — both before and after surgery.<Cite n={[1, 2]} /> After surgery the aorta may narrow again, an aneurysm may form, and coronary artery disease may get worse.<Cite n={[1, 2]} /> Children with SVAS — whether or not they have had surgery — are followed up by a paediatric cardiologist with regular heart ultrasound.<Cite n={1} /> According to the ESC, adults are followed up in specialised centres for adults with congenital heart disease.<Cite n={2} /> For children with moderate or severe SVAS, the Russian Ministry of Health paediatric guideline advises against overdoing physical exercise.<Cite n={1} /> Children with Williams syndrome are also followed up by other specialists: an endocrinologist, a urologist-andrologist, an ophthalmologist, a neurologist and an orthopaedic surgeon.<Cite n={1} />

</Patient>

<Student>

According to the Russian Ministry of Health paediatric guideline, the techniques used for patch enlargement of the ascending aorta are the McGoon, Doty, Brom and Myers operations; the Doty operation enlarges the aorta with a "pantaloon" (inverted-Y) patch.<Cite n={1} /> For a child with SVAS, severe hypoplasia of the aortic arch and a significant pressure gradient between the LV and the aorta, and also after a previous intervention on the ascending aorta, an extra-anatomic bypass between the LV and the descending aorta is recommended: it unloads the LV, and correction is revisited at an older age.<Cite n={1} />

According to the ESC, the operative mortality rate for a fibrous diaphragm and the hourglass deformity is under 5%.<Cite n={2} /> Since the coronary arteries are under high pressure, the ESC states that surgery might be considered earlier than in valvular aortic stenosis, particularly when no valve substitute is required.<Cite n={2} /> Aortic regurgitation may be present after surgery, but it is usually not progressive.<Cite n={2} /> Among the consequences of repair, the Russian Ministry of Health paediatric guideline also lists a residual gradient, residual peripheral artery stenoses and progression of myocardial ischaemia due to generalised arteriopathy.<Cite n={1} />

</Student>

## When to call an ambulance

The Russian Ministry of Health paediatric guideline names the conditions that require emergency hospital admission: deterioration due to worsening [heart failure](../heart-failure/) or heart rhythm problems, an acute shortage of blood to the heart muscle (acute coronary insufficiency), [infective endocarditis](../infective-endocarditis/), and signs of too little blood reaching other organs.<Cite n={1} /> Call your local emergency number (112 in the EU, 911 in the US and Canada, 999 in the UK) if a child or adult with supravalvular aortic stenosis has chest pain, faints, has an attack of strong palpitations or has rapidly worsening shortness of breath.<Cite n={[1, 2]} /> As with any heart condition, call an ambulance for fainting, chest pain or severe shortness of breath: this is the site's general safety rule, repeated at the bottom of every page.

<Quiz />