Abstract:Objective: To assess the left ventricular regional rotation of rabbit in early phase of acute coronary occlusion by speckle tracking imaging(STI), in order to investigate the sensibility of this method to evaluate the regional function of left ventricle. Methods: Forty-six healthy New Zealand rabbits had opened had chest operation to establish acute coronary occlusion model by ligating the anterior branch of the left coronary artery. Dynamic two-dimensional image of parasternal left ventricular long-axis, apical four-chamber and two-chamber view, mitral valve, papillary muscles and apex level in short-axis view were acquired twice pre-operation and 10 minutes post-operation. General parameters such as left ventricular end-diastolic diameter(LVEDD), end-systolic diameter(LVESD), fraction shortening(LVFS), end-diastolic volume(LVEDV), end-systolic volume(LVESV), ejection fraction(LVEF) were measured. Rotation angle of 18 regions in three level of left ventricle were analysed by STI. Results: ①There was no statistical difference between post-operation and pre-operation in LVEDD, LVESD, LVFS, LVEDV, LVESV, LVEF(P>0.05). ②On mitral valve level rotation angle was the maximum in inferior and posterior-septum, but the smallest in anterior and lateral pre-operation. There was no statistical difference of rotation angle among every region post-operation on mitral valve level, pre-operation and post-operation on papillary muscles and apex level(P>0.05). ③Rotation angle of anterior-septum, posterior-septum, inferior and posterior on mitral valve level were obviously decreased post-operation(P<0.05), and there was no statistical difference of anterior and lateral on mitral valve level, every region on papillary muscles and apex level between post-operation and pre-operation(P>0.05). Conclusion: Assessment of left ventricular regional rotation in early phase of acute coronary occlusion by STI can sensitively reflect the change of regional function of left ventricle.