Echocardiographic and electrocardiographic trends in children with acute Kawasaki disease

Kawasaki disease (KD), while primarily an acute, self-limited, multisystem vasculitis, is more appropriately described as a pancarditis, from a cardiac perspective. Many patients are noted to have ventricular dilation on initial echocardiography; however, functional and structural measurements may remain within the normal range.

The authors sought to determine echocardiographic and electrocardiographic trends after acute KD.

Clinical data were reviewed on all patients presenting with acute KD to the Hospital for Sick Children (Toronto, Ontario). Patients with at least three electrocardiograms and echocardiograms over the first year post-KD were eligible. Mixed linear regression analysis for repeated measures was used to determine trends over time and associated factors.

One hundred seventy-six eligible patients were reviewed. Mean initial coronary artery diameter Z-scores were increased, with 4% having aneurysms. The mean (+/- SD) initial Z-score of ejection fraction was 0.40+/-0.84 (P<0.001 versus normal) and left ventricular end-diastolic dimension (LVED) was 0.97+/-0.98 (P<0.001 versus normal). The initial mean QT dispersion was 54+/-23 ms (P<0.001 versus normal). Mixed linear regression analysis for repeated measures demonstrated that the LVED Z-score decreased significantly over time, and a greater Z-score was independently associated with a greater initial LVED Z-score. Increased QT dispersion was only related to higher initial dispersion, with no trend over time.

While systolic ventricular dysfunction may not be evident, subclinical myocardial involvement may be indicated by subtle ventricular dilation and repolarization abnormalities.