Bicuspid Aortic Valve Clinical Presentation

Updated: Jan 08, 2016
  • Author: Edward J Bayne, MD; Chief Editor: Steven R Neish, MD, SM  more...
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Presentation

History

Patients with bicuspid aortic valves may be completely asymptomatic. About 30% of individuals with a bicuspid aortic valve develop complications. [21, 25, 26] If symptoms are present, they relate to the development of aortic stenosis, [19] aortic insufficiency, or both. Occasionally, a congenitally bicuspid aortic valve may be the cause of critical aortic stenosis, with symptoms of severe congestive heart failure developing in early infancy. This critical form of stenosis is more frequently associated with a unicommissural valve. In patients in whom a bicuspid aortic valve is observed in association with other types of left heart obstruction (coarctation or interrupted aortic arch), the bicuspid valve generally functions well, and symptoms are usually caused by the associated disorder.

  • Inheritance: Although most cases of bicuspid aortic valve are sporadic, familial clusters have been identified, with incidence as high as 10-17% in first-degree relatives of probands. [27] Increasing evidence suggests an autosomal-dominant inheritance pattern with variable penetrance, encompassing the entire spectrum of left heart obstruction ( hypoplastic left heart syndrome, aortic stenosis, coarctation of the aorta) [28]
  • Associated syndromes
    • Coarctation or interrupted aortic arch (bicuspid aortic valve is present in >50% of patients with these lesions) [4]
    • Williams syndrome (bicuspid aortic valve associated with supravalvular aortic stenosis occurs in 11.6% of cases) [29]
    • Patent ductus arteriosus, also associated with hand anomalies [30]
    • Turner syndrome (bicuspid aortic valve occurs in 30% of patients) [31]
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Physical

Because the bicuspid aortic valve is frequently a clinically silent condition, general examination findings may be normal.

  • Typical features of Turner syndrome (eg, short stature in females with webbed neck and broad chest) or Williams syndrome (eg, elfin facies, mild retardation) may suggest the possibility of bicuspid aortic valve.
  • Cardiac examination findings include the following:
    • The precordium is usually normal to palpation, and no evidence of cardiomegaly is present.
    • The first heart sound is unaffected. The second heart sound splits normally with inspiration, with absent or minimal outflow gradient. With increasing aortic stenosis gradient, the splitting of the second sound is less apparent or may be absent. With severe stenosis, the second sound is split paradoxically (ie, with expiration). This splitting differs from normal splitting of the first heart sound (ie, with tricuspid and mitral valve closures) in that normal splitting is best appreciated at the lower left sternal border and is a softer lower-pitched sound than the click of a bicuspid aortic valve.
    • The most common abnormal sound heard with bicuspid aortic valve is a systolic ejection click. This sound is actually a less-distinct, medium-pitched, short sound heard well at the apex with the diaphragm of the stethoscope. It is heard in all phases of respiration just after the first heart sound, and its timing does not vary with maneuvers (eg, hand-grip, Valsalva, squatting). The ejection sound may also be heard in the aortic area (upper right sternal border), where it takes on a brighter and sharper quality. [32]
    • In contrast, the click of pulmonary valvular stenosis is intermittent (heard best during expiration) and located closer to the left sternal border. It is a bit less distinct than the aortic valve click. The click of mitral valve prolapse may also be heard at the apex but is softer, occurs later, and is less distinct than the bicuspid aortic valve click. The mitral prolapse click often varies in timing with changes in position or isometric handgrip and may be followed by the murmur of mitral regurgitation. Multiple showers of clicks are common, and the sound has been likened to crinkling cellophane.
    • Minimal or mild stenosis may produce a soft and fairly harsh ejection murmur at the upper right sternal border with possible radiation into the carotids. Increasing severity of stenosis produces a longer, louder, and harsher murmur with definite radiation into the carotids and possibly into the posterior shoulder. With more severe stenosis, a thrill may be felt in the suprasternal notch.
    • In the presence of a typical ejection click, the high-pitched sound of subtle aortic valve insufficiency may be heard at the third left intercostal space with the diaphragm of the stethoscope. Various maneuvers may be helpful in auscultation, including having the patient perform an isometric handgrip, having patients lean forward in a seated position (to bring the aortic area closer to the chest wall), and having patients hold their breath in expiration (also decreases the distance between the stethoscope and the left ventricle). [32]
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