An Experimental Study Of Detecting Hibernating Myocardium In Rabbits By Dobutamine Stress Echocardiography And Two-dimensional Speckle Tracking Technology

ObjectiveIn this investigation Dobutamine stress echocardiography (DSE) and Two-dimensionalspeckle tracking imaging (2D-STI) were combined to evaluate the diagnostic value ofhibernating myocardium.Methods28male New Zealand white rabbits underwent incompletely suture ligation of the leftanterior descending coronary artery via a left thoracotomy to induce ischemic cardiomyopathy,and the general situation of the rabbits was daily observed after surgery. A week later, therabbits whose short axis of left ventricle papillary level in myocardial segments existedmovement abnormalities by echocardiography would choose to continue feeding for threeweeks. Dobutamine stress echocardiography was performed at the end of the fourth week,two-dimensional images were recorded during preoperative, postoperative and load phase,then2D-STI was taken to get the message of systolic two-dimensional radial strain value(PRS), circumferential strain value (PCS) and the radial displacement (PRD) of themyocardial segments of the rabbits. SPSS17.0software was used for statistical analysis. Afterthe DSE was worked, the rabbits’ hearts were stopped, and then taken to perform triphenyltetrazolium chloride (TTC) and Hematoxylin-eosin (HR) staining, to detect the rabbits’myocardial pathological changes.ResultsThe PRS, PCS, and PRD of the all segments were normal before ligating (P>0.05). Aweek after operation, the PRS, PCS and PRD of anteroseptal, anterior and septal of themyocardial segments were obviously lower (P<0.05) then preoperative, which proved that theanteroseptal, anterior and septal of the short axis of left ventricle papillary level existencedregional ventricular wall motion abnormality.During the DSE, when the dobutamine stress was （5-10）μg/(kg min), the movement of the RWMA enhanced, PRS, PCS and PRD were significantly higher (P<0.05) than atbaseline. And when the dobutamine stress was10μg/(kg min), the RWMA had maximumdeformation, the sensitivity and specificity of PRS, PCS and the PRD were respectively（71.4%、81.4%）、（85.7%、58.6%）、（85.7%、65.7%）.The high dose dobutamine stress(40μg/(kg min)), PRS, PCS and PRD of the ischemic myocardium were significant lower(P<0.05) than the baseline and5μg/(kg min).TTC and HE staining showed the left ventricular myocardium of the rabbits’ were notinfarction.Conclusion2D-STI can analysis myocardial contraction, combined with dobutamine stressechocardiography can analysis the myocardial contractile reserve, and they could be useful todetecte hibernating myocardium.