Kawasaki disease is an immune mediated vasculitis of the medium and large arteries. Its cardiac manifestations include coronary artery ectasia and aneurysms, pericarditis, myocarditis, pericardial effusion and/or valvulitis (most commonly of the mitral valve). In the setting of coronary artery involvement, the proximal segments and branching points of the coronary arteries are most commonly involved. Coronary aneurysms may be fusiform, saccular, cylindrical or segmented. Patients with coronary artery aneurysms are at risk of stenosis or thrombosis which can cause myocardial ischemia or infarction. Echocardiograms play an important role in the assessment of these patients and are typically obtained at the time of diagnosis, two weeks and 6-8 weeks and potentially more frequently should coronary artery ectasia or aneurysms be identified. Should the coronary arteries be affected with either dilation or aneurysm, the most common sites of coronary involvement in include the right coronary artery (~78%), left anterior descending coronary artery (~88%). In addition the circumflex (~26%) and left main coronary artery (~12%) may also be involved.
Criteria for Echocardiographic Abnormality in Kawasaki Disease
LAD or RCA Z score ≥ to 2.5
Coronary artery diameter >3 mm in children <5 years or >4 mm in children ≥ to 5 years
Lumen diameter ≥1.5 times adjacent segment
Coronary lumen is clearly irregular
Newburger et al. Ciculation 2004, Japanese Ministry to health, Kitamura et al 1994