Echocardiography is the diagnostic gold standard for the evaluation of cardiac anatomy and myocardial function in most pediatric patients in the intensive care setting. Echocardiography is the imaging modality of choice because of its safety, portability, and ease of use. Furthermore, recent advances in technology have enabled the miniaturization of ultrasound machines, thus allowing for improved portability, battery operation, and digital storage capability.

In the intensive care unit (ICU), echocardiography can quickly and accurately identify valvular abnormalities (including valvular stenosis and regurgitation), evaluate intracardiac shunting, identify pericardial effusions, and evaluate cardiac function. The use of echocardiography has given cardiologists a noninvasive means to diagnose most congenital heart diseases; many infants and children are able to proceed directly to surgical cardiac repair without cardiac catheterization being performed.

In some patients, making an echocardiographic diagnosis may be more difficult because of poor acoustic windows (e.g., obesity, marked chest-wall abnormalities, surgical scar formation, pneumopericardium, pneumothoraces, or hyperaeration of the lungs). For the critically ill child in the ICU, routine echocardiographic examination may be difficult to perform because of the need for mechanical ventilation, the acuity and nature of the underlying diseases (renal failure requiring hemodialysis), and certain postoperative conditions (open chest after cardiac surgery).

In children who are difficult to image using standard echocardiographic techniques, transesophageal echocardiography (TEE) can be performed. TEE almost always allows excellent imaging of intracardiac structures. Transesophageal probes are relatively large (requiring that the child weigh at least 4 kg), and special considerations also must be made regarding the patient’s gastrointestinal status (esophageal stricture, active gastrointestinal bleeding, a perforated viscus, presence of a tracheoesophageal fistula) and respiratory status. At our institution, general anesthesia almost always is used for children requiring TEE.