J Cardiovasc Ultrasound.  2015 Mar;23(1):1-7. 10.4250/jcu.2015.23.1.1.

Bicuspid Aortic Valve: Unresolved Issues and Role of Imaging Specialists

• Song JK

• KMID: 2135399
• DOI: http://doi.org/10.4250/jcu.2015.23.1.1

Abstract

Bicuspid aortic valve (BAV) is the most common congenital heart disease with marked heterogeneity in many aspects. Fusion patterns of the aortic cusp are quite variable with different type and severity of valvular dysfunction. Moreover, non-valvular cardiovascular abnormalities are associated with BAV. Among them, aortic aneurysm/dissection is the most serious clinical condition with variable patterns of segmental aortic dilatation. Potential association between BAV phenotype and valvulopathy or aortopathy has been suggested, but needs to be tested further. A lack of long-term outcome data at this moment is responsible for unresolved debate regarding appropriate management of patients with BAV, specifically to prevent development of aortic dissection. Long-term follow-up data of a well-characterized cohort or registry based on standardized classification of BAV phenotype and aortopathy are necessary for evidence-based medical practice. Advanced imaging techniques such as computed tomography or magnetic resonance imaging offer better opportunities for accurate phenotype classification and imaging specialists should play a central role to establish a collaborative multicenter cohort or registry.

Keyword

Bicuspid aortic valve; Phenotype; Aortopathy

MeSH Terms

Aortic Valve*
Bicuspid*
Cardiovascular Abnormalities
Classification
Cohort Studies
Dilatation
Heart Defects, Congenital
Humans
Magnetic Resonance Imaging
Phenotype
Population Characteristics
Specialization*

Figure

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  Fig. 1 Representative transthoracic (above) and transesophageal echocardiographic images (below) of the bicuspid aortic valve. Review of both systolic (left) and diastolic images is helpful for correct diagnosis.

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  Fig. 2 Diagrams showing the classic (A) and new (B) classification of bicuspid aortic valve phenotypes. The classic classification is basically based on demonstration of two fused aortic cusps, whereas new classification on the orientation of the fused bicuspid aortic valve (modified with permission from Buchner et al.7) and Kang et al.8)). AP: anterior-posterior, BAV-AP: bicuspid aortic valve with fusion of the right and left coronary cusps, BAV-RL: bicuspid aortic valve with fusion of the right or left coronary cusp and noncoronary cusp, L: left, LCA: left coronary artery, N: non-coronary, R: right, RCA: right coronary artery, LA: left atrium.

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  Fig. 3 Representative images showing additive benefit of transesophageal echocardiography for diagnosis of bicuspid aortic valve. Routine transthoracic echocardiography showed typical thickening and motion limitation of the mitral valve suggesting rheumatic involvement (A and B). However, transesophageal echocardiography with higher resolution confirmed bicuspid aortic valve-AP type (C and D). In the lower panel, short axis image of transthoracic echocardiography (E) failed to demonstrate bicuspid aortic valve-RL type, which was possible with transesophageal echocardiography (F, G, and H). AP: anterior-posterior, RL: fusion of the right and left coronary cusps.

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  Fig. 4 Multidetector computed tomographic images showing excellent demonstration of bicuspid aortic valve (BAV) phenotypes in selected patients with aortic valve calcification (modified with permission from Kang et al.8)). A: anterior cusp, AP: anterior-posterior, L: left cusp, LA: left atrium, LCA: left coronary artery, P: posterior cusp, R: right cusp, RA: right atrium, RCA: right coronary artery, RL: fusion of the right and left coronary cusps, RV: right ventricle.

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  Fig. 5 Development of localized aortic dissection in a patient with bicuspid aortic valve. This 35-year-old gentleman without previous history of heart disease visited emergency department due to prolonged chest pain. Computed tomography revealed both pleural effusion with markedly dilated ascending aorta with maximal diameter of 65 mm (A). Transesophageal echocardiography showed bicuspid aortic valve without significant valvular dysfunction and localized intimal flap in the ascending aorta (arrow, B).

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  Fig. 6 Development of aortic dissection after successful aortic valve replacement in a patient with bicuspid aortic valve. This gentleman underwent uneventful aortic valve replacement due to severe regurgitation in 2001. At that time, the maximal diameter of the ascending aorta was 48 mm. Five years later, sudden chest pain developed and computed tomography showed markedly dilated ascending aorta (up to 57 mm) with typical intimal flap involving both the ascending and descending aorta.

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  Fig. 7 Representative multidetector computed tomographic images of bicuspid aortopathy phenotypes using measurements of aortic dimensions in 10 different levels. Type 0 is a normal aorta; type 1 is characterized by dilated aortic root. If the aortic enlargement involves the tubular portion of the ascending aorta, it is classified as type 2, whereas in type 3, there is diffuse involvement of the entire ascending aorta and the transverse aortic arch. A indicates the aortic annulus; B, sinuses of Valsalva; C, sinotubular junction; D, tubular portion of the ascending aorta; E, proximal to the innominate artery (or common trunk in case of a bovine arch); F, distal to the innominate artery (or common trunk); G, proximal to the left subclavian artery; H, distal to the left subclavian artery; I, proximal descending aorta; and J, distal descending thoracic aorta at the level of the diaphragmatic hiatus (modified with permission from Kang et al.8)).

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