多巴酚丁胺负荷乳酸/羟基乙酸共聚物心肌造影下二维应变定量评价犬存活心肌的研究

摘要

Objective To explore the accuracy of assessing viable myocardium by two -dimensional strain analysis combined with PLGA contrast enhanced low dose dobutamine stress echocardiography.Methods Thirty cute ischemia reperfusion canine models were reproduced successfully. Then myocardial contrast(enhanced with PLGA contrast agents) was performed through aortic root,images were acquired and saved at baseline,rest,and the period with low dose dobutamine administration.The dimentional strain parameters of myocardial segments were acquired by measurements of regional peak -systolic strain in longitudinal(LS),radial(RS)and circumferential(CS)motion on all segments respectively under different condition.Results The parameters of 24 dogs were measured successfully.Compared with nonviable myocardial segment,LS,RS and CS of viable segment increased significantly during dobutamine stress,there was significant difference (P<0.05),however,LS,RS and CS of the former did not present significant variance at the same time .The myocardial specimen staining results were selected as the gold standard, the LS,RS,and CS were selected as evaluation parameters,the sensitivities for LS,RS and CS were 81.03%,77.59% and 72.41%, the specificities were 81.30%,84.00% and 78.00%,respectively.Conclusion Two-dimensional strain analysis combined with low dose dobutamine stress echocardiography enhanced with PLGA contrast agent can improve the quality of ultrasound image,and also can improve the accuracy of assessing viable myocardium with acquired dimensional strain parameters.%目的：探讨乳酸/羟基乙酸共聚物（PLGA）经主动脉心肌造影联合多巴酚丁胺负荷条件下，二维应变评价犬节段心肌存活性的准确性。方法30只犬成功建立急性心肌缺血再灌注模型，经主动脉根部行 PLGA 心肌造影，通过多巴酚丁胺负荷试验，获取心肌节段二维应变参数：收缩期峰值纵向应变（LS）、径向应变（RS）及圆周应变（CS）。结果共计24只犬完成实验。多巴酚丁胺负荷实验后，非存活心肌节段的收缩期二维峰值应变较静息时无明显升高；存活心肌节段的二维应变值随多巴酚丁胺剂量增加而升高，与非存活心肌节段比较差异有统计学意义（P<0.05）。以心肌标本染色结果作为金标准，分别以收缩期峰值 LS、RS 及 CS 作为评价参数，其检测存活心肌的敏感性分别为81.03%、77.59%及72.41%，特异性分别为81.30%、84.00%及78.00%。结论 PLGA 心肌造影联合多巴酚丁胺负荷实验可以提高超声图像质量，获取二维应变参数，提高评价犬心肌存活的准确性。