Kawasaki disease: echocardiographic features in 91 cases presenting in the United Kingdom. Ninety-one patients with Kawasaki disease were examined by cross sectional echocardiography between 1980 and 1988. In the 75 patients evaluated during the acute phase of the illness (the first month), the first echocardiographic examination was carried out at a mean time of 16 days (range 5-30) and coronary arterial lesions were seen in 21 (28%). Two patients with medium sized aneurysms had myocardial infarctions, and one died. Coronary arterial lesions persisted in 17 (23%) patients, most often in younger children. The remaining 16 patients were examined from one month to four years after their acute illnesses, and this group did not have coronary arterial abnormalities. Seven patients with coronary artery lesions have reached school age and require regular echocardiographic examination and exercise electrocardiography. Selective coronary arteriography may be indicated in some patients to identify coronary artery stenosis, which the Japanese experience has shown may progress for several years after the acute illness. 