Valvular heart disease in Kawasaki syndrome: incidence and natural history

Kawasaki disease is an acute illness that causes inflammation of blood vessels, especially coronary arteries. Coronary aneurysms (balloon-like swelling due to vessel weakness) and constriction may occur, as can valvular heart disease. Loss of intact heart valves results in poorly controlled flow of blood through the heart, and leaks or surges of blood (detected as murmurs with a stethoscope) may occur when the heart is refilling for the next pumping cycle. Little information has been gathered about the nature of valvular disease in Kawasaki syndrome. The characteristics of 13 occurrences of valvular heart disease among 1,215 cases of Kawasaki disease were compared with those of 30 cases without valvular involvement. All but one case involved the mitral valve, which separates the atrium (the filling chamber) from the ventricle (the pumping chamber); the other case involved the valve separating the heart from the aorta, the main systemic artery. Although there were no differences between the two groups in terms of sex or age at onset of disease, 11 of the patients with valve disease were under 12 months; early age may be a risk factor to some extent. The duration of fever was significantly prolonged as well, and this is generally associated with more severe manifestations of the disease. Most patients had lesions of the coronary arteries as well. The murmurs resolved within two months in five patients, while they persisted for two years or more in another six patients. It is thought that valve disease that spontaneously resolves may indicate generalized inflammation of the heart, while prolonged valve disease may be due to dysfunction of the valves related to coronary artery lesions and constriction. Three patients died, one of congestive heart failure due to valvular disease. (Consumer Summary produced by Reliance Medical Information, Inc.)