[Diagnosis of myocardial ischemia in Kawasaki disease: thallium-201 myocardial imagings at rest, with exercise and with dipyridamole administration].

Thallium-201 myocardial imaging was performed at rest in 131 children with coronary arterial lesions due to Kawasaki disease. The coronary arterial lesions were assessed by selective coronary angiography within a few days of the isotope study. Twenty-one children had occlusive lesions, and segmental stenotic lesions were seen in 16 children. Perfusion defects of the myocardial images were detected in nine of the former and in three of the latter. The locations of the perfusion defects coincided with the perfusion areas of the affected vessels on coronary angiography. Twelve patients with initial perfusion defects at rest had a follow-up study and the defects disappeared in five. These patients had re-establishment of coronary blood flow in the initially affected areas by either development of collateral vessels or recanalization. Myocardial imaging with exercise was performed in 27 patients including four with coronary arterial occlusion and two with segmental stenosis on coronary angiography. All with coronary artery lesions showed perfusion defects on the imaging with exercise, while the resting study showed the defects only in one patient, in whom more extensive perfusion defects were observed after exercise. Myocardial imaging following intravenous injection of dipyridamole was carried out in 43 patients. Perfusion defects after the injection were noted in 15 of 17 patients with coronary occlusion and in nine of 13 patients with segmental stenosis. In four patients with perfusion defects at rest, additional or more extensive defects were revealed by this drug in the areas of additional coronary arterial involvements. In 20 patients with perfusion defects only after dipyridamole injection, the perfusion defects coincided with the angiographic findings very well. A perfusion defect was documented following dipyridamole injection in one exceptional patient who had no stenotic lesions, but had three giant coronary aneurysms of the right coronary artery. Thus the dilated coronary lesions seemed to give a perfusion defect. In some of the patients whose perfusion defects disappeared at rest on a follow-up study, the defects were disclosed by exercise and/or dipyridamole administration. Thus, thallium-201 myocardial imagings combining resting and exercise or dipyridamole studies were valuable for the detection and assessment of coronary arterial lesions of Kawasaki disease.