Congenital Heart Disease

Congenital Heart Disease

Clinical investigations examining the role of 3D echocardiography

in patients with congenital heart disease

have emphasized the unique perspective provided by

3D imaging and the versatility of the technique in

patients with simple defects or complex conditions

and in the postoperative state.115,116 Three-dimensional

echocardiography, using both reconstruction

methods and RT3D, has been used to detect several

forms of congenital heart disease. The ability to record

and analyze the entire cardiac structure and the ability

to display complex spatial relationships are potential

advantages of 3D imaging over 2D echocardiography.

In addition, the decreased examination time afforded

by RT3D echocardiography may reduce the need for

sedation in some children.116

In patients with atrial septal defects, 3D echocardiography

can record the size and shape of the defect. It

also can show the precise location of the defect and

the extent of residual surrounding tissue. In patients

with secundum atrial septal defects (Figure 11, video

clip 13), the extent of the retroaortic rim often determines

the feasibility of repair with percutaneous closure

devices. Three-dimensional echocardiography

also has been used after atrial septal defect closure to

evaluate the success of the procedure and identify the

origin of residual shunting.117 In patients with ventricular

septal defects, the ability to interrogate the entire

septum is frequently cited as an advantage of the 3D

technique.118,119 A novel application of 3D imaging in

patients with ventricular septal defects involves using

offline reconstruction to measure the shape and size of

the color flow jet, which allows for accurate measurement

of the magnitude of shunting in patients with

isolated ventricular septal defects.119

Various 3D echocardiographic techniques have

been used to evaluate RV and LV size and function in

patients with congenital heart disease. The approach

to the LV is similar to that described previously and

permits quantification of dimension, volume, mass,

and ejection fraction.120 Owing to the ellipsoidal shape

of the LV, the advantages of 3D over 2D echocardiographic

techniques are limited, because simple geometric

assumptions can be used to calculate LV volumes;

however, the RV’s asymmetrical shape

invalidates the simple geometric assumptions used for

LV volume calculations. In this case, the ability to

record and analyze the entire chamber rather than

relying on simplifying assumptions has proven

superior.48 In patients with congenital heart diseases

that involve RV pathology, 3D echocardiography correlates

well with MRI for the measurement of RV

volume.48,121,122

Three-dimensional echocardiography has been

successfully applied to the detection and assessment

of several anatomic defects. For example,

the circumferential extent and severity of discrete

subaortic membranes have been successfully visualized

with 3D echocardiography.119,120 With the

apical view, a unique en face image of the membrane

can be recorded, which permits analysis of

the effective orifice area and the dynamic nature

of the defect. Congenital malformations of the

mitral valve also have been assessed with 3D

echocardiography.80 The complex nature of these

defects can make a thorough anatomic evaluation

difficult. In such cases, the perspective provided

by 3D echocardiography can provide a complete

preoperative assessment of the extent and severity

of the valvular abnormality.