Objective: The purpose of this study was to investigate the right ventricular function and hemodynamic changes by Doppler echocardiography in rabbits with monocrotaline (MCT)-induced chronic pulmonary hypertension (CPH).
Methods: The CPH model was created in 13 rabbits induced by the injection of MCT. Eight rabbits injected with Dulbecco's phosphate-buffered solution (D-PBS) severed as controls. The pulmonary acceleration time (AT), ejection time (ET) and pre-ejection period (PEP) were measured with Doppler echocardiography. Tei index was calculated by tissue Doppler imaging on the lateral side of the tricuspid annulus. Comparisons were made between the CPH group and the control group, and within the CPH group before and 28 days after the MCT injection.
Results: The CPH model was created successfully in all the 13 rabbits that proved by the right heart catheterization with the pulmonary arterial mean pressure greatly increased compared to the control group (41.18±11.17 mmHg vs. 18.50±2.86mmHg, p<0.00001). The AT and ET decreased and PEP and PEP/AT increased significantly, both of the tricuspid inflow velocity E/A ratio and the tricuspid annulus velocity Em/Am ratio decreased dramatically due to the increased A and Am velocity, and the Tei index became much higher (1.51±0.28 vs. 0.92±0.29, p<0.00001) in the CPH model rabbits, indicating the right ventricular function impaired 28 days after the MCT injection.
Conclusion: Doppler echocardiography can be used for assessing the right ventricular function in the rabbit model of chronic monocrotaline-induced pulmonary hypertension.