**6. Diagnosis**

dissection due to aortic root dilatation and therefore responsible for a much lower life expectancy in this subgroup of BAV disease [53, 54]. Due to the relative small body size, Turner Syndrome patients require an elective ascending aortic aneurysm replacement at a much smaller absolute size [54]. Moreover, it should be noted that the aortic size has to be properly indexed to the body surface area. Therefore, proper follow-up and evaluation of the cardiovascular lesions including imaging of the heart and the aorta for evidence of BAV disease or dilatation of the ascending aorta is mandatory. When imaging appears to be without any lesions and there are no additional risk factors for aortic dissection present, a repeated imaging should be conducted every 5 to 10 years or otherwise clinically indicat‐ ed. In contrast, when abnormal imaging is present, regular imaging at smaller intervals

**Figure 3.** Sagittal plane cardiac magnetic resonance imaging illustrating coarctation of the aorta. Typical post ductal

should be made with echocardiography or CMRI [67].

310 Calcific Aortic Valve Disease

**Table 1.** Known cardiovascular abnormalities related to BAV disease.

stenosis (arrow).

#### **6.1. Clinical examination**

AS or AR can present themselves with significant symptoms in patients with BAV disease during activity, stress or rest including angina, shortness of breath, syncope or dizziness. In many cases, clinical examination reveals an ejection sound during auscultation at the apex. When AS is present, an ejection click can be often heard at the S1. The S2 is often simultaneously with P2 when AS is present. A diastolic murmur can often be heard when an AR is present. Heart failure of unknown cause could also be present during clinical examination. The ejection sound in BAV patients is most likely associated with anterior movement of the dome shaped BAV, and in rare cases heart failure could also be present during clinical examination in case of rapid deterioration [55]. AS, mitral valve prolapsed, AR, and COA are several associated pathological findings which have to be considered with BAV when a murmer is present.

#### **6.2. Echocardiography**

The current golden standards for diagnosing, surveilling and monitoring BAV disease are echocardiography and cardiac magnetic resonance imaging (CMRI) [39].

Both transthoracic echocardiography (TTE) and transesophageal echocardiography (TEE) can be used in the diagnosis of BAV disease. TTE has a sensitivity of 78% to 87% and a specificity of 91% to 96% for the diagnosis of BAV disease whereas TEE has a sensitivity and specificity of 87% and 96%, respectively [56, 57, 58]. However, up to 25% of TTE have non-diagnostic findings for aortic valve morphology due to severe valvular calcification [57].

The features of BAV on a TTE include systolic doming, an eccentric closure line in the para‐ sternal long axis views, presence of a single commissural line in the diastolic phase with the occurrence of two cusps and the occurrence of two commisures in the parasternal short axis views [figure 4] [59, 60].

Moreover, both preoperative echocardiography and intraoperative TEE are essential for surgical preparation. When BAV disease is present, the degree of AS and AR should be determined with the help of Doppler analysis. After determining the severity of the AR, to ascertain the indication for surgery, especially TEE is needed to clarify the mechanisms that are responsible for AR. This is required to estimate the chance of successful repair and indispensible in surgical preparation. Moreover, any associated cardiovascular abnormalities or complications should be considered. Aortic diameters should therefore also be measured at several levels including valvular insertion, sinuses of Valsalva, sino-tubular junction and the ascending aorta. It should also be noted that in order to measure the severity of the AS by echocardiography- Doppler analysis, the aortic valve area and mean gradient should be applied rather than measuring only on peak systolic gradient, sequentially to prevent overes‐ timation of the severity of the AS [39]. Also, aortic valve area should always be indexed to body surface area in order to correct for different habitus and body sizes, especially in Turner Syndrome patients [39, 54].

#### **6.3. Cardiac magnetic resolution imaging**

CMRI as a noninvasive diagnostic tool appears to have a high diagnostic sensitivity and specificity. CMRI showed a sensitivity of 100% and a specificity of 95% with steady state freeprecession (SSFP) cine [61]. It seems that CMRI is more reliable than the standard TTE in diagnosing BAV [Figure 5]. When TTE is found to be non-diagnostic for aortic valve mor‐ phology, particularly in patients with severe AS, CMRI can be conducted as a complementary test [62].

When the diagnostic results of AR with the use of echocardiography is indefinite or at borderline, CMRI can be used to quantify the AR more accurately [39]. In addition, the valve can be visualized with any correlated lesion of the ascending aorta. This could be used for proper evaluation of the entire aortic and to prepare complex surgical interventions for both the aorta valve and the surrounding cardiovascular structures including the ascending aorta and the aortic root. Of importance, all patients with evidence of BAV should have the aortic root and ascending aorta inspected for indication of aortic dilatation with echocardiography or MRI [67].

> **Figure 5.** Panel (A, B) Cardiac magnetic resonance imaging in the axial plane illustrating a normal tricuspid valve in the diastolic (A) and systolic phase (B). (Panel C, D) Bicuspid aortic valve with fusion of the right coronary cusp and the non coronary cusp in the diastolic (C) and systolic (D) phase. (Panel E) Sagittal plane illustrating a dilatation of the ascend‐

Bicuspid Aortic Valve

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http://dx.doi.org/10.5772/55325

Up to 50% of the adults who present with AS show evidence of BAV disease [71]. BAV degeneration is due to both fibrosis and calcification and is age related [16, 72, 73]. Addition‐ ally, the incidence of BAV related AS that is observed in patients with the age of under 60 years,

Patients with BAV generally require AVR 5 years earlier compared with the patients who have an AS of the tricuspid valve [75]. Three-quarters of the patient with BAV who underwent AVR showed to have an isolated AS [7]. Both fibrosis and cusp calcifications occur in an accelerated pattern in BAV compared with tricuspid aortic valve [Figure 4, E &F] [76]. Moreover, several valve related factors seem to accelerate the calcification in BAV including larger sized cusp, presence of raphé and the overall BAV anatomy. It seems that sclerosis of the aortic valve starts in the second decade whereas calcification tends to develop around the fourth decade onwards with a 18 mmHg per decade increase of the average aortic valve gradient [75, 12]. Both R-N BAVs and asymmetrical sized cusps seem to contribute to the acceleration of the stenosis due to the progressive calcification and fibrosis with 27 mm Hg per decade [9, 45, 12]. It has to be noted that smoking and a poor lipid panel are both modifiable independent risk factors that could have a great impact on BAV degeneration [77]. In children, BAV with stenosis can

60 to 75 years, and more than 75 years are 59%, 40% and 32%, respectively [74].

ing aorta (Arrow).

**7.1. Aortic stenosis**

**7. Complications associated with BAV**

**Figure 4.** (A) Transthoracic echocardiography short axis view illustrating a normal tricuspid aortic valve. (B) Trans‐ thoracic echocardiography short axis view illustrating a bicuspid aortic valve with fusion of the left and right coronary cusps. (C) Transthoracic echocardiography long axis view illustrating a dilated ascending aorta (Arrow). (D) Transthora‐ cic echocardiography short axis view illustrating a bicuspid aortic valve with fusion of the right and non coronary coro‐ nary cusps. (E) Transthoracic echocardiography short axis view illustrating a severe calcified bicuspid aortic valve with fusion of the right and non coronary coronary cusps. (F) Transthoracic echocardiography long axis view illustrating a severe calcified bicuspid aortic valve.

**Figure 5.** Panel (A, B) Cardiac magnetic resonance imaging in the axial plane illustrating a normal tricuspid valve in the diastolic (A) and systolic phase (B). (Panel C, D) Bicuspid aortic valve with fusion of the right coronary cusp and the non coronary cusp in the diastolic (C) and systolic (D) phase. (Panel E) Sagittal plane illustrating a dilatation of the ascend‐ ing aorta (Arrow).
