Clinicopathologic study of the conduction systems in 10 patients with Kawasaki's disease (mucocutaneous lymph node syndrome).

Clinicopathologic study of the conduction systems was done on ten hearts obtained at autopsy from patients with Kawasaki's disease. The pathologic lesions were discovered in the atrioventricular (AV) conduction system in nine out of 10 cases and in five of eight cases in the sinoatrial (SA) conduction system. The lesions of the AV conduction system were classified according to duration of illness at death. Eearly acute state (0 to 9 days) was characterized by inflammation with cellinfiltration and edema without coronary stenosis. The most severe acute stage (21 to 31 days) was characterized by severe compression of conduction cells without the diffuse necrosis due to severe perivascular edema and cell infiltration. In the end stage (48 days to 7 months), old changes with perivascular fibrosis and fatty infiltration without considerable loss of the conduction cells were noted. Coagulation necrosis of the conduction cells was not evident despite the severe coronary stenosis. Lesions in the conduction system are therefore acute and inflammatory. Pathology and electrocardiogram showed a good correlation in seven of eight cases. PQ prolongation was a sensitive indicator of acute inflammation of the AV conduction system in the present study.