Klein A L, Bailey A S, Moura A, Murray R D, Morehead A J, Brum J, Pearce G, Stewart W J, Thomas J D
Department of Cardiology, Cleveland Clinic Foundation, Ohio 44195-5064.
J Am Coll Cardiol. 1993 Dec;22(7):1983-93. doi: 10.1016/0735-1097(93)90788-3.
The purpose of this study was to assess the reproducibility and pitfalls of intracoronary and aortic root sonicated albumin injections, using time-intensity curves, in a large sample of normal dogs.
The utility of a new myocardial contrast echocardiographic agent, sonicated serum albumin (Albunex), is currently under investigation. However, the reproducibility, injection techniques and general pitfalls of this contrast agent have not been well characterized.
We administered sequential intracoronary and aortic root injections (518 injections) of sonicated albumin in 25 closed chest normal dogs to measure the effectiveness and reproducibility of this product. Time-intensity curves, as a measure of myocardial perfusion, were derived and quantified using an on-line videodensitometric analysis system and two-dimensional echocardiography. Measurements included peak intensity, area under the curve, half-time of descent, alpha-parameter and transit time within a 31- x 31-pixel "region of interest" in the anterior septum. Analyses provided 80% power and a type I error protection of 95%.
The best reproducibility of the variables was half-time of descent for aortic root injections (coefficient of variation [CV] 20%) and peak intensity for intracoronary injections (CV 25%), whereas aortic root area under the curve showed the most variability (CV 41%). Analysis of variance for repeated measures of serial intracoronary and aortic root injections showed no significant systematic variability within subjects for the measured variables. In a comparison between intracoronary and aortic root injection sites, paired t tests showed no significant difference for mean values between these two techniques. There was also no statistically significant difference between manual versus power intracoronary injections. Finally, there was no significant difference among three injection rates (1, 2 and 3 ml/s) in paired intracoronary injections, nor was there a difference among injection rates in paired aortic root injections, except for a lower peak intensity with a 1-ml/s injection rate compared with a 2-ml/s injection rate (p = 0.01). Potential pitfalls include preparation of sonicated albumin, delivery techniques and measurement variables.
We conclude that the results of serial injections of sonicated albumin show no systemic change or trend in normal dogs. Both intracoronary and aortic root injections at standard injection rates by hand or power injector can be used to quantify time-intensity curves, as measure of myocardial perfusion, with similar variability ranging from 20% to 41%. These results are important in the human model, especially after coronary interventions.
本研究旨在评估在大量正常犬样本中，使用时间-强度曲线进行冠状动脉内和主动脉根部超声处理白蛋白注射的可重复性及存在的问题。
一种新型心肌对比超声心动图剂——超声处理血清白蛋白（Albunex）的效用目前正在研究中。然而，这种造影剂的可重复性、注射技术及常见问题尚未得到充分描述。
我们对25只开胸正常犬进行了冠状动脉内和主动脉根部的序贯注射（共518次注射），以测量该产品的有效性和可重复性。使用在线视频密度分析系统和二维超声心动图得出并量化作为心肌灌注指标的时间-强度曲线。测量包括前间隔内一个31×31像素“感兴趣区域”的峰值强度、曲线下面积、下降半衰期、α参数和通过时间。分析的检验效能为80%，I型错误保护为95%。
各变量的最佳可重复性为主动脉根部注射的下降半衰期（变异系数[CV]为20%）和冠状动脉内注射的峰值强度（CV为25%），而主动脉根部的曲线下面积变异性最大（CV为41%）。对冠状动脉内和主动脉根部序贯注射的重复测量进行方差分析显示，所测变量在受试者内部无显著的系统变异性。在冠状动脉内和主动脉根部注射部位的比较中，配对t检验显示这两种技术的平均值无显著差异。手动与电动冠状动脉内注射之间也无统计学显著差异。最后，在配对的冠状动脉内注射中，三种注射速率（1、2和3 ml/s）之间无显著差异，在配对的主动脉根部注射中注射速率之间也无差异，但1 ml/s注射速率的峰值强度低于2 ml/s注射速率（p = 0.01）。潜在问题包括超声处理白蛋白的制备、给药技术和测量变量。
我们得出结论，在正常犬中，超声处理白蛋白的系列注射结果未显示出系统性变化或趋势。手动或电动注射器以标准注射速率进行的冠状动脉内和主动脉根部注射均可用于量化作为心肌灌注指标的时间-强度曲线，变异程度相似，范围在20%至41%之间。这些结果在人体模型中很重要，尤其是在冠状动脉介入治疗后。
