Purpose：Dilated cardiomyopathy (DCM) is a most common cause of cardiac transplantation in children. However, little is known about the disease progression process of DCM in children. In this study, we explored the disease progression of DCM during early postnatal stages, using a knock-in mouse model for human DCM caused by ΔK210 mutation in the cardiac troponin T gene.
Methods：Cardiac functions were evaluated at 15 and 30 days old, using M-mode echocardiography and color Doppler.
Results：BW of mice at 30 days old was about 2-fold greater than at 15 days old. At 15 days old, HW of HM mice were already greater than WT. At 30 days old, HW of heterozygous (HT) mice also became greater than WT. LVIDd of DCM mice was significantly greater than WT both at 15 and 30 days old. LV wall thickness was not different between DCM and WT mice at 15 days old, but thinner in DCM mice at 30 days old. EF and FS declined in HM but maintained in HT at both ages. Fibrosis was observed only in 30 days old HM mice.
Conclusions：LV dilation and systolic dysfunction occur at a very early postnatal stage before weaning in this DCM mouse model, suggesting that this model is useful for the exploration of pathogenic mechanisms and therapeutics for very early onset DCM.