Evaluation of echogenicity of the heart in Kawasaki disease

Macrophages and cytotoxic T cells infiltrate the destructed mitral tissue in Kawasaki disease

Kawasaki disease (KD) is an acute febrile systemic vasculitic syndrome especially affecting medium-sized arteries, including the coronary artery. Inflammation may involve all organs, and valvulitis is one of the cardiovascular complications that occurs in the acute phase of KD. However, details regarding the mechanism are unclear. An infant developed KD and severe mitral regurgitation with deformity and prolapse of the mitral tissue and underwent mitral valvotomy 1 year later. Histopathological study was conducted, and infiltrating cells consisted of mainly macrophages and cytotoxic T cells were found in resected mitral valve tissue. In addition, inflammation remained a long time after KD had developed.

Quantitative evaluation of myocardial fibrosis by cardiac integrated backscatter analysis in Kawasaki disease

Background

Kawasaki disease is an acute, systemic vasculitis that affects the coronary arteries. However, the relationship between myocardial fibrosis and Kawasaki disease has been completely unknown until now. We aimed to provide quantitative information about myocardial fibrosis using cardiac integrated backscatter in Han race Kawasaki disease patients.

Methods

Ninety Kawasaki disease patients and 90 healthy control subjects were recruited. Based on Kawasaki disease status, the patients were categorized into 3 groups: acute, subacute, and convalescence phase. Based on coronary artery status, the Kawasaki disease patients were categorized into 3 groups: without coronary artery lesions, with coronary artery dilation, and with coronary artery aneurysms. All subjects underwent two-dimensional and Doppler examinations to measure clinical echocardiographic parameters. Myocardial fibrosis was detected with calibrated integrated backscatter imaging.

Results

Left ventricle systolic functions were normal in both the Kawasaki disease and control participants. The myocardial calibrated integrated backscatter values of the left ventricles of the acute (p < 0.001), subacute (p < 0.001) and convalescence phase (p < 0.001) Kawasaki disease patients were significantly greater than those of the healthy controls. The left ventricle myocardial calibrated integrated backscatter values were significantly smaller in the Kawasaki disease patients without coronary artery lesions than in the Kawasaki disease patients with coronary artery dilations and coronary artery aneurysms in different phases. The left ventricle myocardial calibrated integrated backscatter results were positively correlated with coronary artery status in the acute (r = 0.331, p < 0.001), subacute (r = 0.456, p < 0.001) and convalescence phases (r = 0.407, p < 0.001) of Kawasaki disease.

Conclusion

Our findings may suggest that myocardial fibrosis occurs during early episodes of Kawasaki disease given uncertainties that exist regarding correlations of calibrated integrated backscatter and myocardial fibrosis.