Abstract 711: Diagnosis of Acute Myocardial Ischemia by Speckle Tacking Echocardiography -A Comparative Animal Study-
Since the subendocardium is known to be more vulnerable to ischemia than the subepicardium, indexes of subendocardial function are expected to be more sensitive than indexes of whole LV wall. The aim of our study is to compare the diagnostic values of systolic and diastolic indexes measured by 2D speckle tracking echocardiography in an animal experiment. The proximal left circumflex coronary artery was balloon-occluded for 3 minutes in 14 pigs. LV short-axis view was recorded at rest and 30 minutes after release of the occlusion by transthoracic 2D echocardiography except for one pig with ventricular fibrillation. Peak circumferential and radial strain (CR, RS), peak systolic and diastolic strain rate (CSR-S′ and CSR-E′), time from QRS to peak CS and RS, time from QRS to E′, and the incidence of post-systolic shortening (PSS) were measured in the subendocardium of the LV posterior wall. ROC curve analysis of these indexes was done for the diagnosis of acute myocardial ischemia followed by reperfusion. Only 5 indexes showed significant change before and after the occlusion. ROC curve revealed that CSR-E′ had the highest predictive value for detecting the ischemic memory, followed by peak CS, and CSR-S′. Peak early diastolic circumferential strain rate of the subendocardium was the most powerful index for diagnosing ischemic memory after acute coronary occlusion.