Maximal voluntary work and cardiorespiratory fitness in patients who have had Kawasaki syndrome.

To assess the natural history of Kawasaki syndrome and its effect on maximal voluntary work and cardiorespiratory fitness, we performed cycle ergometry testing in 47 patients who had had the syndrome. Forty-one patients performed maximal effort as judged by achievement of 95% predicted heart rate response. Oxygen consumption, carbon dioxide production, and minute ventilation were performed in 23 patients. There was no difference in maximal voluntary work (total work, mean power) or maximal oxygen consumption between case subjects and control subjects. There were no differences between patients with and those without aneurysms. Serial exercise studies were performed in 10 patients; of these, two with initially normal exercise study findings had decreased maximal voluntary work and oxygen consumption with ischemic changes, and both were at high risk for the development of stenotic or occlusive coronary arteries. The other eight patients had normal cardiorespiratory reserve and no ischemic changes with serial studies. These results suggest that patients have normal cardiorespiratory fitness after Kawasaki syndrome. With the development of ischemic heart disease, they may have decreased cardiorespiratory reserve. Serial evaluation of cardiorespiratory fitness may demonstrate ischemic heart disease.

Clinical spectrum of Kawasaki disease in infants younger than 6 months of age.

We report an unselected series of eight patients younger than 6 months of age with Kawasaki disease evaluated between January 1982 and May 1984. The incidence of coronary artery aneurysms (six patients) and the mortality (two patients) were unusually high in this small series. Because of the confusing clinical presentation in three patients, diagnosis was delayed until pathologic or echocardiographic evidence of coronary vasculitis or aneurysm was discovered. The currently accepted clinical criteria for Kawasaki disease may not always identify patients with the pathologic findings of the syndrome who are younger than 6 months of age. The diagnosis of Kawasaki disease and echocardiographic evaluation of the coronary arteries should be considered in young infants with prolonged fever of unknown origin.