OBJECTIVETo determine the feasibility and accuracy of high-frequency ultrasound in evaluating the left ventricular (LV) structure and function in normal and pressure overload rats and to examine the changes of the left ventricle during its transition from hypertrophy to heart failure.

METHODSThirty-eight female rats were randomly assigned to normal (n = 10), operated (n = 16) and sham-operated (n = 12) groups. Parasternal long axis and short axis images were acquired by a 7.5 mHz linear ultrasound probe at 12 weeks and 20 weeks after the operation respectively.

RESULTSLeft ventricular structure and function could be satisfactorily imaged for dimensions and mass. Compared to the sham-operated groups, at 12 weeks after the operation, the operated rats had increased LV wall thickness and mass (P < 0.01) with normal cavity and FS% (P > 0.05). At 20 weeks after the operation, the LV wall thickness showed no further progressive change and the LV mass increased greatly with slightly dilated LV cavity and decreased FS% (P < 0.05).

CONCLUSIONSHigh-frequency echocardiography provides a useful means to noninvasively evaluate LV dimensions, mass and function in rats. It will have great value for evaluating LV remodeling during the transition from LV hypertrophy to heart failure, as well as the effects of intervening drugs.