Myocardial ischemia in Kawasaki disease; evaluation by dipyridamole stress thallium-201 (Tl-201) myocardial imaging and exercise stress test.

The detection of myocardial ischemia is essential for evaluation of patients with Kawasaki disease, especially who have had coronary artery lesions. To evaluate the clinical efficacy of Tl-201 single photon emission computed tomography (SPECT) after dipyridamole infusion (maximum dose 0.70 mg/kg) for detecting myocardial ischemia, 44 patients with Kawasaki disease aged 7.7 +/- 4.8 years at the study and 10 age matched controls were observed. In the Kawasaki disease group, significant coronary artery stenosis was observed in 14, coronary aneurysm without stenosis in 18, the regression of the coronary aneurysms in 2 and without coronary lesions in 10 patients. In 22 of 44 patients, treadmill exercise stress test was also performed at the same period. Myocardial ischemic changes were observed in 11 patients, all combined with significant coronary artery stenosis. The sensitivity of SPECT for detection of overall coronary stenosis was 79%, contrary that of treadmill exercise test was only 33% (p < 0.001). Furthermore, among the patients having significant coronary stenosis, the severity score was significantly elevated in patients who had electrocardiographic abnormal Q wave compared to those without abnormal Q wave (51.0 +/- 38.8 versus 20.0 +/- 12.1, p < 0.05). These data suggest that the pharmacological stress scintigraphy using dipyridamole injection provides not only the accurate detection but quantitative evaluation of myocardial ischemia in these patients. This noninvasive technique may become one of the most useful index for detection and follow-up of myocardial ischemia in Kawasaki disease.