Shapiro J R, Reisner S A, Amico A F, Kelly P F, Meltzer R S
Department of Anesthesiology, University of Rochester, New York.
J Am Coll Cardiol. 1990 Mar 1;15(3):602-9. doi: 10.1016/0735-1097(90)90634-2.
To determine whether myocardial contrast echocardiography is quantitatively reproducible, repeated intracoronary injections of sonicated albumin (5%) were performed in eight open chest dogs. Paired injections were performed at baseline, during ischemia produced by ligation of a coronary artery, and during hyperemia induced by intravenous infusion of 0.75 mg/kg body weight of dipyridamole. Contrast washout curves were generated for the left anterior descending coronary artery territory (ischemic area) and left circumflex coronary artery territory (nonischemic area) by beat per beat analysis of frozen end-diastolic frames of left ventricular short-axis views. Peak contrast intensity, contrast washout half-time and area under the curve were derived from these curves. A total of 75 contrast washout curves were analyzed for the study of interinjection, intraobserver and interobserver reproducibility. The correlation coefficients between measurements obtained from paired injections of the echocardiographic contrast agent (interinjection reproducibility) ranged from 0.78 for peak contrast intensity to 0.87 for area under the curve. Percent error varied between 14.7% and 24.7%. The intraobserver variability in measurements was less than the interinjection variability, with a cumulative mean percent error of 17.8% and correlation coefficients of 0.72 (peak contrast intensity), 0.95 (area under the curve) and 0.96 (washout half-time). Interobserver correlation for all indexes was high (r = 0.92 to 0.96). It is concluded that peak contrast intensity, contrast washout half-time and the area under the curve derived from myocardial contrast washout curves can be measured reproducibly from videotapes. In addition, the variability between two injections attempted under identical conditions is greater than reader variability from videotapes.
为确定心肌对比超声心动图是否具有定量可重复性，对8只开胸犬进行了重复冠状动脉内注射超声处理的白蛋白（5%）。在基线状态、冠状动脉结扎产生缺血期间以及静脉输注0.75mg/kg体重双嘧达莫诱导充血期间进行配对注射。通过对左心室短轴视图的舒张末期冻结帧逐搏分析，生成左前降支冠状动脉区域（缺血区）和左旋支冠状动脉区域（非缺血区）的对比剂清除曲线。从这些曲线得出对比剂峰值强度、对比剂清除半衰期和曲线下面积。共分析了75条对比剂清除曲线，以研究注射间、观察者内和观察者间的可重复性。超声心动图对比剂配对注射获得的测量值之间的相关系数（注射间可重复性）范围为，对比剂峰值强度为0.78，曲线下面积为0.87。误差百分比在14.7%至24.7%之间。观察者内测量值的变异性小于注射间变异性，累积平均误差百分比为17.8%，相关系数分别为0.72（对比剂峰值强度）、0.95（曲线下面积）和0.96（清除半衰期）。所有指标的观察者间相关性都很高（r = 0.92至0.96）。得出结论，心肌对比剂清除曲线得出的对比剂峰值强度、对比剂清除半衰期和曲线下面积可从录像带中进行可重复测量。此外，在相同条件下进行的两次注射之间的变异性大于录像带读者间的变异性。
