Background: Kawasaki disease (KD) is known as systemic vasculitis, and more than half of the patients with KD have myocarditis, which can induce ventricular dysfunction. In this study, we evaluate left ventricular (LV) dysfunction in patients with KD based on the myocardial performance index (MPI) using pulse Doppler (PD) and tissue Doppler imaging (TDI), from the acute to convalescent phases.

Methods: We retrospectively studied 89 children diagnosed with KD from January 2010 to August 2012. We assessed the presence of coronary artery lesions (CALs) and the LV ejection fraction, PD-MPI, and TDI-MPI at diagnosis, and 2, 14, and 56 days after intravenous immunoglobulin (IVIG) treatment. We enrolled 70 healthy children as a control group.

Results: The ejection fraction in patients with KD at diagnosis (67.3 ± 0.9%) was lower than that in the control group (69.8 ± 0.8%, P = 0.035), and the LV TDI-MPIs for patients with KD at diagnosis (0.49 ± 0.01) and 2 days after IVIG treatment (0.48 ± 0.01) were higher than those in the control group (0.45 ± 0.01, P = 0.002, P = 0.033, respectively). No significant differences were found in the LV dysfunction between the patients with complete and incomplete KD. Septal TDI-MPIs in patients with KD with CAL at diagnosis (0.52 ± 0.02) were higher than those in patients with KD without CAL (0.47 ± 0.01, P = 0.019).