Abstract 14304: Feasibility of Automated Function Imaging Based on Myocardial Strain Echocardiography in Rats: A Study Using Myocardial Ischemia/Reperfusion Model with and without Adrenomedullin
Background: Automated function imaging (AFI) is a clinically useful tool providing a panoramic view of left ventricular (LV) contraction based on myocardial strain. However, few studies demonstrate its value in small animals. We investigated the feasibility of AFI to assess cardiac function in rats undergoing myocardial ischemia/reperfusion. Adrenomedullin (AM), potential attenuator of myocardial ischemia/reperfusion injury, was used to alter the infarct size.
Methods: Wistar rats (n=10) were randomly assigned to control (n=5) and AM (n=5) groups. Rats underwent left anterior descending coronary artery occlusion for 60 minutes followed by reperfusion. Saline (1.0 ml) or AM (3.0 μ g/kg) were given in each group at reperfusion. Echocardiography was performed at baseline, during coronary occlusion and 1, 3 and 7 days post-reperfusion. At 7 day post-reperfusion, the heart was excised and was sliced transversely into 3 pieces. Each slice was stained with hematoxylin and eosin to analyze its infarct size. Peak global longitudinal strain was calculated and change of LV function was assessed by the percent change of global longitudinal strain (%GLS). At each slice, the correlation between infarct size and averaged value of peak systolic longitudinal strain in 6 segments was assessed.
Results: AFI demonstrated serial changes of LV contraction. In AM group, %GLS was improved significantly at 7 day compared with 1 day post-reperfusion demonstrating infarct reduction. Peak systolic longitudinal strains correlated well with the infarct size at each slice (r=0.72, P<0.0001).
Conclusion: AFI is feasible to assess LV function serially in rats clearly demonstrating the cardioprotective effect of AM. AFI may be a promising tool in basic research using small animals.
- © 2011 by American Heart Association, Inc.