Two-dimensional echocardiography is ideally suited for the evaluation
of congenital heart disease because of its ability to visualize
cross-sections of complex cardiac anatomic structures. Visualizing
heart walls, chambers, and valves, it is, in many ways, superior
to angiography for revealing complex spatial morphologic information.
This unit discusses the use of two-dimensional echocardiography
in the evaluation of congenital heart disease. It must be realized
that currently, conventional Doppler methods and Doppler color
flow imaging have added even more diagnostic power to cardiac
ultrasound for evaluation of congenital heart disease. For many
seemingly simple and some complex disorders, cardiac catheterization
is no longer necessary when data can be reliably obtained by echo
and Doppler methods. M-mode echocardiography has been almost totally
supplanted by these newer modalities.
The purpose of this unit is to provide a basic understanding
of congenital heart disease and how echocardiography is helpful
in establishing diagnoses. As such, its aim is principally toward
those with little background in this area. Not all disease entities
can be covered and only the more common disorders will be described.
Little discussion of patient management is possible.
All congenital heart disease is potentially complex. Such
a statement should not be frightening as it only reflects the
fact that the presence of one lesion increases the possibility
for another. Multiple lesions are possible. For example, transposition
of the great vessels may exist with or without ventricular septal
defects or with or without right ventricular outflow tract obstruction.
In addition, just like in adult acquired disease, congenital heart
disorders represent a spectrum. There can be mild, moderate, or
severe expressions of any disorder.
Views for Congenital Heart Disease
As with acquired heart disease, the standard apical, parasternal,
and subcostal views are used for the majority of recordings. In
addition, emphasis is placed on certain views that are particularly
rewarding. For example, the subcostal approaches (Fig. 1) identify
the interatrial septum and the relationships of the atrial and
ventricular septum to the atrioventricular valves. Suprasternal
views are good for examination of the great vessels and the aortic
arch. All views obviously must be utilized. In small children,
lack of attenuation from the rib cage permits routine imaging
with high frequency transducers such as 5MHz or higher.