Prognosis. Most children with KD recover fully after treatment. When cardiovascular complications occur, however, serious morbidity may result. Death occurs by coronary thrombosis or stenosis. Children with coronary abnormalities are followed with periodic ECG, echocardiography, myocardial perfusion testing at rest and during exercise, and/or cardiac magnetic resonance imaging based on their individual risk and the availability of various testing modalities at the individual center. Although echocardiography is very sensitive in visualizing coronary dilation, it does not detect stenoses of the coronary arteries. Cardiac catheterization of the coronary arteries remains the gold standard and may be performed in children who still have significant abnormalities after 1 year and in situations in which myocardial ischemia is suspected from the results of noninvasive testing.