Evaluation of stunned and infarcted canine myocardium by real time myocardial contrast echocardiography

• Published in: Brazilian journal of medical and biological research Vol. 36; no. 11; pp. 1501 - 1509
• Main Authors: Dourado, P M M, Tsutsui, J M, Mathias, Jr, W, Andrade, J L, da Luz, P L, Chagas, A C P
• Format: Journal Article
• Language: English
• Published: Brazil Associação Brasileira de Divulgação Científica 01.11.2003
• Subjects: Animals; BIOLOGY; Coloring Agents; Contrast echocardiography; Contrast Media; Disease Models, Animal; Dogs; Echocardiography - methods; Fluorocarbons; MEDICINE, RESEARCH & EXPERIMENTAL; Myocardial infarction; Myocardial Infarction - diagnostic imaging; Myocardial Infarction - pathology; Myocardial perfusion; Myocardial stunning; Myocardial Stunning - diagnostic imaging; Myocardial Stunning - pathology; Risk Factors; Staining and Labeling; Tetrazolium Salts; Myocardial infarction; Myocardial stunning; Myocardial perfusion; Contrast echocardiography
• ISSN: 0100-879X; 1414-431X; 0100-879X; 1414-431X
• DOI: 10.1590/S0100-879X2003001100009

Differentiation between stunned and infarcted myocardium in the setting of acute ischemia is challenging. Real time myocardial contrast echocardiography allows the simultaneous assessment of myocardial perfusion and function. In the present study we evaluated infarcted and stunned myocardium in an experimental model using real time myocardial contrast echocardiography. Sixteen dogs underwent 180 min of coronary occlusion followed by reperfusion (infarct model) and seven other dogs were submitted to 20 min of coronary occlusion followed by reperfusion (stunned model). Wall motion abnormality and perfusional myocardial defect areas were measured by planimetry. Risk and infarct areas were determined by tissue staining. In the infarct model, the wall motion abnormality area during coronary occlusion (5.52 1.14 cm(2) ) was larger than the perfusional myocardial defect area (3.71 1.45 cm (2); P < 0.001). Reperfusion resulted in maintenance of wall motion abnormality (5.45 1.41 cm (2); P = 0.43 versus occlusion) and reduction of perfusional myocardial defect (1.51 1.29 cm (2); P = 0.004 versus occlusion). Infarct size determined by contrast echocardiography correlated with tissue staining (r = 0.71; P = 0.002). In the stunned model, the wall motion abnormality area was 5.49 0.68 cm (2) during occlusion and remained 5.1 0.63 cm (2) after reperfusion (P = 0.07). Perfusional defect area was 2.43 0.79 cm (2) during occlusion and was reduced to 0.2 0.53 cm(2) after reperfusion (P = 0.04). 2,3,5-Triphenyl tetrazolium chloride staining confirmed the absence of necrotic myocardium in all dogs in the stunned model. Real time myocardial contrast echocardiography is a noninvasive technique capable of distinguishing between stunned and infarcted myocardium after acute ischemia.