Mitral regurgitation in Kawasaki disease

The clinical characteristics and prognosis of 16 cases of mitral regurgitation (MR) secondary to Kawasaki disease (KD) were studied, and its pathogenesis was discussed. The observation period ranged from 3 years and 17 months to 15 years. Six of the 16 patients died, and 10 are alive. MR has disappeared spontaneously in 2 of these survivors. Thirteen of the 16 patients were male and 3 were female, there being a predominance in male, which is a striking contrast to rheumatic mitral regurgitation which is predominant in females. The age at the time of diagnosis ranged from 3 months to 7 years. The appearance time of MR showed two different patterns, one with early onset within a few weeks to one month after affliction with KD and the other with MR developing months or years later during the course of the follow-up. The cardiothoracic ratio was greater in those who had a progressively downhill course, and whose sigma RV1-6 decreased with time course. This was considered to be due to the decrease of the remaining functioning myocardial mass. The outcome of the patients with a severe degree of coronary arterial stenosis and occlusion observed on the coronary angiogram was poor. The prognosis of the patients with severe left coronary arterial stenosis was especially poor. MR due to KD is regarded as a new clinical entity, and its pathogenesis is thought to be due to ischemia, papillary muscle dysfunction, coronary angitis, myocardial failure and valvulitis. Incidence of MR will increase when examined by Doppler echocardiography especially in the acute stage. Our experience as well as that of others indicates the presence of valvulitis, myocarditis or left ventricular dilatation leading to MR in the acute stage.