Objective To assess the regional systolic function of the left ventricle in rats with dilated
cardiomyopathy (DCM) after
administration of matrix metalloprotease (MMPs) inhibitor doxycycline by quantitative tissue velocity imaging (QTVI).Methods Eleven healthy rats,6 rats with DCM and 7 rats with DCM administered with doxycycline in early stage were studied.The longitudinal velocity during systole(Vs) of the two points at the mitral annulus (posterior inter-
ventricular septum and left ventricular lateral wall ) was measured by QTVI.Left ventricular end-diastolic dimension (LVEDd),fractional shortening (FS),and left ventricular ejection fraction (LVEF) were obtained by M-mode echocardiography.Results The echocardiographic data were significantly different between healthy and DCM rats (P<(0.05)).LVEF,FS and Vs in DCM rats treated with doxycycline were significantly higher than those of the untreated DCM rats,except lower LVEDd.Mean Vs of the two points mentioned above were closely correlated with LVEF (r=(0.86),P<(0.001)) and FS (r=(0.83),P<(0.001)).Conclusions QTVI can be used to non-invasively and accurately assess the effects of MMPs inhibitor doxycycline on preventing the left ventricle from remodeling and on improving the ventricular systolic function in DCM rats.