Development and evaluation for volume overload-induced and pressure overload-induced cardiac hypertrophy in rats

AIM: To compare the evaluations for the structure and function of the hypertrophic hearts induced by volume overload or pressure overload in rats. METHODS: Volume overload-induced cardiac hypertrophy was established by abdominal aortacaval fistula (ACF) and pressure overload-induced cardiac hypertrophy was developed by constriction of aorta (CA). The cardiac structure and function were analyzed by echocardiography, hemodynamic determination, heart weight measurement and histological examination. RESULTS: Heart weight of rats in all the operated groups was increased compared to the sham-operated groups. In 1-week ACF group, the internal diameter ［(0.67±0.03)cm vs (0.60±0.02)cm, P<0.01］ and volume of left ventricle increased ［(0.69±0.10)mL vs (0.50±0.04)mL, P<0.01］，relative wall thickness (RWT) decreased (0.46±0.05 vs 0.55±0.05, P<0.01), compared with the sham-operated group. In 1-week CA group, interventricular septal thickness ［(0.20±0.03)cm vs (0.16±0.02)cm, P<0.05］, left ventricular posterior wall thickness ［(0.20±0.03)cm vs (0.16±0.02)cm, P<0.01］, RWT (0.71±0.17 vs 0.56±0.12, P<0.05) and +dp/dtmax (4 886±1 304 vs 3 674±325, P<0.05) were all increased compared with the sham-operated group. In 2-week-groups, these parameters changed more significiantly. CONCLUSION: Cardiac structure and function could be evaluated by echocardiography and hemodynamic determination. RWT is a sensitive index for the cardiac hypertrophy induced by both volume overload and pressure overload.