Fraker T D, Nelson A D, Arthur J A, Wilkerson R D
Am J Cardiol. 1984 Jun 1;53(11):1699-702. doi: 10.1016/0002-9149(84)90605-2.
P6 area of increased acoustic reflectance was readily observed by 2-dimensional echocardiography (2-D echo) in the acutely ischemic canine myocardium. Fifteen mongrel dogs subjected to closed-chest coronary artery occlusion were used to test the hypothesis that these areas of altered acoustic reflectance were predictors of subsequent myocardial infarction (MI). Each dog was studied by 2-D echo in short-axis views of the left ventricle at 4 levels before and after coronary artery occlusion. The dogs were killed after 48 hours and heart sections were stained with triphenyltetrazolium chloride to identify the areas of necrosis. Four sections were then selected, approximating the same location within the left ventricle as the short-axis views taken for 2-D echocardiographic analysis. The in vivo 2-D echocardiographic examination revealed alteration of acoustic reflectance immediately after coronary occlusion, which detected the presence of MI with a sensitivity of 92% and a specificity of 90%. The extent of altered acoustic reflectance seen by echo correlated closely (r = 0.81) with the extent of MI detected by triphenyltetrazolium staining of the excised heart. Altered acoustic reflectance seen by 2-D echo immediately after coronary artery occlusion reflects acute ischemic changes and may be an early predictor of MI size.
通过二维超声心动图（2-D回声）很容易观察到急性缺血犬心肌中声学反射增强的P6区域。使用15只接受闭胸冠状动脉闭塞的杂种狗来检验以下假设：这些声学反射改变的区域是后续心肌梗死（MI）的预测指标。在冠状动脉闭塞前后，通过二维超声心动图在左心室的4个水平的短轴视图中对每只狗进行研究。48小时后处死狗，心脏切片用氯化三苯基四氮唑染色以识别坏死区域。然后选择四个切片，其在左心室内的位置与用于二维超声心动图分析的短轴视图大致相同。体内二维超声心动图检查显示冠状动脉闭塞后立即出现声学反射改变，检测到MI的敏感性为92%，特异性为90%。回声所见声学反射改变的程度与切除心脏的氯化三苯基四氮唑染色检测到的MI程度密切相关（r = 0.81）。冠状动脉闭塞后立即通过二维超声心动图看到的声学反射改变反映了急性缺血变化，可能是MI大小的早期预测指标。
