EVALUATION OF CORONARY FLOW VELOCITY DYNAMICS AND FLOW RESERVE IN PATIENTS WITH KAWASAKI-DISEASE BY MEANS OF A DOPPLER GUIDE-WIRE

Objectives. To assess the pathophysiologic effects of the coronary seq uelae of Kawasaki disease on coronary hemodynamic variables, we region ally evaluated the flow velocity dynamics and flow reserve in coronary vessels with lesions using an intracoronary Doppler how guide wire. B ackground. The pathophysiologic effects of the coronary sequelae of Ka wasaki disease on coronary hemodynamic variables have not been complet ely clarified, and we previously reported some discrepancies between c oronary angiographic findings and exercise stress tests in Kawasaki di sease. Methods. Doppler phasic coronary flow velocity was determined u sing an 0.018-in. (0.046-cm) intracoronary Doppler how guide wire at r est and during the adenosine triphosphate-induced hyperemic response i n 95 patients (75 male, 20 female, mean age 9.8 +/- 6.2 years) with Ka wasaki disease. Results. In 25 patients with coronary aneurysms in 29 vessels, the average peak velocity and diastolic to systolic velocity ratio were significantly (p < 0.05) decreased in the moderate-sized an d large-sized aneurysms. Significantly lower values in coronary how re serve (CFR) were noted in 3 of 10 vessels with moderate aneurysms and in 4 of 7 vessels with large aneurysms. A significant positive correla tion (y = 0.53x + 14.6, r(2) = 0.91) was observed between the percent diameter stenosis evaluated by angiography and that calculated from th e bow velocity measurement. However, the percent diameter stenosis cal culated from the flow velocity measurement was underestimated compared with that determined by angiography in the stenotic lesions of interm ediate severity. A reduced CFR was noted in five of seven vessels with intermediate stenosis ranging from 50% to 75%, and also in three vess els with mild stenosis ranging from 30% to 40%. A reduced CFR was also observed in six of the eight angiographically normal vessels associat ed with the area of reduced perfusion on exercise thallium-l;Ol myocar dial scintigraphy. Conclusions. Abnormalities in how dynamics and a re duction in flow reserve were revealed in coronary aneurysms of interme diate to large size and in stenotic lesions, even of mild to intermedi ate severity, in patients with Kawasaki disease. Abnormalities in the coronary microcirculation, as well as epicardial lesions, contribute t o the pathophysiologic responses in Kawasaki disease. (C) 1998 by the American College of Cardiology.