Valvular Heart Disease

Valvular Heart Disease

The recent widespread availability of RT3D echocardiography

obviates many of the practical limitations of

reconstructive 3D techniques and offers the potential

for greater clinical application for valvular heart disease

both in standard diagnostic evaluation and in

real-time guidance during surgical valve repair. This

technique is ideally suited for assessing valve function

given the nonplanar anatomy of the cardiac valves and

the associated anatomic and spatial alterations associated

with valvular heart disease.

Mitral Valve. The 3D echocardiography technique

has contributed significantly to our understanding of

mitral valve function and anatomy. The mitral valve is

particularly suited to 3D assessment because of the

complex interrelationships among the valve, chordae,

papillary muscles, and myocardial walls. This technique

can provide important insight into mitral valve

structure, demonstrating the saddle shape of the mitral

annulus, with high points located anteriorly and low

points oriented in a mediolateral direction (Figure 10,

video clip 8). This has helped clarify the appropriate

diagnostic imaging planes from which mitral valve

prolapse should be diagnosed, thereby avoiding falsepositive

interpretations.64,65

In addition, 3D echocardiography has provided important

mechanistic insights into functional and ischemic

mitral regurgitation resulting from derangements

of the normal spatial relationships of the mitral valve

leaflets to its chordal attachments, papillary muscles,

and the LV.13,66 Distortion of the normal spatial relationship

between the LV and mitral valve apparatus

results in papillary muscle displacement and tethering

of the mitral leaflets, leading to incomplete closure of

the leaflets and mitral regurgitation (video clip 9). The

3D echocardiography technique has identified

changes in annular shape occurring with functional

mitral regurgitation.67-69 These mechanistic and anatomic

insights based on 3D analysis have provided the

basis for the development of new approaches to

treating ischemic mitral regurgitation.70-74

Three-dimensional echocardiography has been used

to define and localize mitral leaflet lesions in mitral

valve prolapse, endocarditis, and congenital mitral

abnormalities.75-80 This application has been particularly

important in guiding surgical repair (video clips

10 and 11).81-83

The RT3D approach has also demonstrated efficacy

in quantifying mitral regurgitation by using 3D guidance

to directly measure the proximal flow convergence

region.84,85 It has provided insight into how

premitral orifice geometry affects the calculation of

mitral valve area in mitral stenosis.86 Calculation of

mitral valve area by 3D echocardiography has been

demonstrated to be accurate, reproducible, and less

variable than conventional 2D methods 

and thus has been recommended as the firstline

method.92 In addition, 3D echocardiography has

been used for guidance during percutaneous mitral

valvuloplasty.93,94

Aortic Valve. Three-dimensional echocardiography

has been applied for anatomic assessment of the aortic

valve and root morphology and to calculate the valve

area in aortic stenosis.95-99 The technique has been

used to delineate aortic flow patterns100,101 and has

demonstrated feasibility and accuracy in quantifying

aortic regurgitation.102,103 Other applications have included

the detection and localization of aortic valve

vegetations, assessment of congenital outflow obstruction

abnormalities, and demonstration of morphological

changes in the valve after balloon dilation.103-107

Tricuspid and Pulmonary Valves. Compared with

the aortic and mitral valves, the tricuspid and pulmonary

valves have been less widely studied with 3D

echocardiography. This technique has demonstrated

anatomic changes with rheumatic and degenerative

tricuspid valve disease.108-110 and has accurately reconstructed

congenital tricuspid valve abnormalities, such

as atrioventricular canal defects.111,112 For the pulmonary

valve, 3D assessment has been limited to descriptive

case reports defining anatomic abnormalities associated

with pulmonary valve stenosis and

endocarditis