Supravalvular aortic stenosis is a congenital obstructive narrowing of the

aorta The aorta ( ) is the main and largest artery in the human body, originating from the left ventricle of the heart and extending down to the abdomen, where it splits into two smaller arteries (the common iliac arteries). The aorta distributes ...

just above the

aortic valve The aortic valve is a valve in the heart of humans and most other animals, located between the left ventricle and the aorta. It is one of the four valves of the heart and one of the two semilunar valves, the other being the pulmonary valve. The ...

and is the least common type of

aortic stenosis Aortic stenosis (AS or AoS) is the narrowing of the exit of the left ventricle of the heart (where the aorta begins), such that problems result. It may occur at the aortic valve as well as above and below this level. It typically gets worse ove ...

. It is often associated with other cardiovascular anomalies and is one of the characteristic findings of

Williams syndrome Williams syndrome (WS) is a genetic disorder that affects many parts of the body. Facial features frequently include a broad forehead, underdeveloped chin, short nose, and full cheeks. Mild to moderate intellectual disability is observed in people ...

. The diagnosis can be made by

echocardiography An echocardiography, echocardiogram, cardiac echo or simply an echo, is an ultrasound of the heart. It is a type of medical imaging of the heart, using standard ultrasound or Doppler ultrasound. Echocardiography has become routinely used in t ...

MRI Magnetic resonance imaging (MRI) is a medical imaging technique used in radiology to form pictures of the anatomy and the physiological processes of the body. MRI scanners use strong magnetic fields, magnetic field gradients, and radio waves ...

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Genetics

Supravalvular aortic stenosis is associated with genetic damage at the

Elastin Elastin is a protein that in humans is encoded by the ''ELN'' gene. Elastin is a key component of the extracellular matrix in gnathostomes (jawed vertebrates). It is highly elastic and present in connective tissue allowing many tissues in the bod ...

gene locus on chromosome 7q11.23.Tassabehji, May, and Zsolt Urban. "Congenital Heart Disease." Congenital Heart Disease. Humana Press, 2006. 129-156. Fluorescent in situ hybridisation techniques have revealed that 96% of patients with

, where supravalvular aortic stenosis is characteristic, have a hemizygous deletion of the Elastin gene.Lowery, Mary C., et al. "Strong correlation of elastin deletions, detected by FISH, with Williams syndrome: evaluation of 235 patients." American journal of human genetics 57.1 (1995): 49. Further studies have shown that patients with less extensive deletions featuring the Elastin gene also tend to develop supravalvular aortic stenosis

Pathophysiology

Supravalvular aortic stenosis is due to diffuse or discrete narrowing of ascending aorta. The murmur associated with it is systolic murmur and is similar in character to valvular aortic stenosis murmur but commonly present at 1st Intercostal space (ICS) on the right. Individuals with this anomaly may have unequal carotid pulses, differential blood pressure in upper extremities and a palpable thrill in Suprasternal notch. Individuals with significant supravalvular AS chronically may develop left ventricular hypertrophy and also are at risk of developing coronary artery stenosis. With increased metabolic demands (e.g. exercise) such individuals may develop subendocardial or myocardial ischemia due to increased myocardial oxygen demand and seek medical help with symptoms of exercise induced angina.

Diagnosis

Treatment

References

Diseases of the aorta {{cardiovascular-stub