Time-course study on left ventricular function in a rabbit model of ischemia-reperfusion injury with morphine preconditioning.

Aims: To analyze the left ventricular longitudinal function in a rabbit model of myocardial ischemia reperfusion with morphine preconditioning through strain rate imaging and to evaluate the effect of morphine preconditioning. Methods: A myocardial ischemia-reperfusion model was induced by occlusion and recanalization of the coronary artery in 40 male New Zealand white rabbits, which were divided into a sham group, morphine group, and vehicle control group. Routine echocardiography data were recorded 1 day before and within 28 days after the operation. Dynamic images were also collected and analyzed off-line using Doppler tissue imaging software. Results: On the first day after the operation, the global and regional systolic functions of the left ventricle in the morphine and vehicle control groups were lower than those in the sham group. After ischemia reperfusion, some of the values of the above-mentioned parameters decreased over time, which was more obvious in the vehicle control group at each examined time point. Conclusions: The current study revealed that detection of changes in regional myocardial function after myocardial ischemia reperfusion by strain rate imaging is objective and accurate. In addition, our results indicated that morphine preconditioning significantly attenuates myocardial ischemia-reperfusion injury in rabbits.