Introduction: This study aimed to assess the impact of resistance to intravenous immune globulin(IVIG) on left ventricular(LV) myocardial deformation in children with Kawasaki disease(KD) during the acute and convalescent phases of illness. Few studies have elucidated the impact of resistance to IVIG on the progressive changes of myocardial mechanics over time in patients with KD.
Methods: We studied 26 patients with KD and 8 normal control subjects. Of the 26 patients, 16 were IVIG non-responders. Echocardiograms were obtained during the acute and convalescent phases of KD. Standard echocardiographic data and peak systolic global LV longitudinal strain[strain(ε)] were obtained using vector velocity imaging.
Results: During the acute phase of KD, peak systolic global LV longitudinal ε decreased significantly in both IVIG non-responders(-21.18 % ± 3.97) and responders(-20.94 % ± 3.15) compared to controls(-24.99 % ± 2.23). Although in the acute phase, LV ejection fraction(EF) was significantly higher in the IVIG non-responders(55.38 % ± 5.14) compared to the responders(50.2 % ± 6.53), peak systolic global LV longitudinal ε was not significantly higher in the IVIG non-responders compared to the responders. During the convalescent phase, peak systolic global LV longitudinal ε tended to increase in non-responders(-21.62% ± 3.98) and responders(-21.83% ± 2.61) compared to the acute phase, but remained significantly decreased in both groups compared to controls. The increment of peak systolic global LV longitudinal ε from acute to convalescent phase tended to be smaller in the IVIG non-responders compared to the responders. The proportion of patients with coronary dilatations in both IVIG non-responders(4 of 16) and IVIG responders(2 of 10) did not differ significantly.
Conclusions: The increment of peak systolic global LV longitudinal ε over time tended to be smaller in the IVIG non-responders compared to the IVIG responders. Resistance to IVIG may delay normalization of myocardial mechanics in IVIG non-responders. Further studies with larger number of patients, as well as long-term follow-up of myocardial deformation in KD are necessary.