What is the first step in evaluating for cardiac complications in a child with symptoms consistent with Kawasaki disease?

The first step in evaluating for cardiac complications in a child with symptoms consistent with Kawasaki disease is performing a transthoracic echocardiogram. This imaging study is critical because Kawasaki disease can lead to serious cardiovascular complications such as coronary artery aneurysms. The echocardiogram allows clinicians to assess the structure and function of the heart and the blood vessels surrounding it, providing essential information about any potential complications that may arise from the disease.

Evaluating the heart early with echocardiography is vital, as it aids in immediate management decisions and helps establish a baseline for future assessments. Early detection of vascular involvement can significantly influence the choice of treatment, such as the initiation of intravenous immunoglobulin (IVIG) therapy, which is aimed at reducing inflammation and preventing coronary artery damage.

Other options, such as a chest X-ray, can provide valuable information about pulmonary issues but are not specific for cardiac evaluation related to Kawasaki disease. Administering aspirin is part of the treatment protocol but does not assess cardiac status. A complete blood count can help identify overall inflammatory markers but lacks specificity for evaluating heart complications associated with Kawasaki disease. Thus, a transthoracic echocardiogram is the most appropriate first step to directly evaluate potential cardiac complications.