Mor-Avi V, Shroff S G, Robinson K A, Cholley B P, Ng A F, Lang R M
Department of Medicine, University of Chicago Medical Center, Chicago, IL 60637, USA.
J Am Soc Echocardiogr. 1996 Jul-Aug;9(4):452-61. doi: 10.1016/s0894-7317(96)90116-9.
The effects of Albunex (Molecular Biosystems, Inc., San Diego, Calif.) and a second generation contrast agent, FS069, on left ventricular (LV) contractility were evaluated using an isolated rabbit heart model under constant loading conditions and heart rate. Contrast injections (2 ml total volume) were performed in two separate protocols (N1 = 6, N2 = 6). In protocol 1, various doses of Albunex (0.1 to 2.0 ml in saline solution) were used, and paired control injections of a matched dose of 5% solution of human albumin in saline solution were administered. In protocol 2, LV contractility was assessed during injections of the following solutions: (1) 1:250 suspension of FS069 in saline solution, which caused optimal myocardial contrast enhancement; (2) a 1:25 suspension of FS069; (3) a 1:25 suspension of FS069 prefiltered using an 8 microns pore filter; and (4) 2 ml saline solution as a control. Instantaneous LV pressure was analyzed for variations in peak systolic pressure (peak P) and maximum pressure derivative (peak P'), both indices of LV contractility under conditions of fixed heart rate and chamber volume. Albumin alone caused a transient, dose-dependent depression of LV contractility, reflected by decreases in both peak P and peak P' values. These decreases presumably were caused by the decreasing availability of ionized calcium as a result of calcium binding. No further decrease in contractility was noted when Albunex microspheres were present in the solution. Saline injections caused a transient minor increase in LV contractility, reflected by increases of 4.5% +/- 1.1% and 10.6% +/- 3.8% in peak P and peak P' values, respectively. These levels returned to baseline levels within 2 minutes. A similar response was observed when a 1:250 suspension of FS069 was used. The 1:25 suspension of FS069 caused a bimodal response, with initial rises in peak P and peak P' levels (5.2% +/- 3.6% and 12.8% +/- 6.5%, respectively), followed by minor reductions in contractility (2.0% +/- 2.4% and 1.7% +/- 2.1%, respectively). The latter decrease in contractility caused by the 1:25 suspension of FS069 was eliminated by filtering. The isolated rabbit heart model is a highly sensitive tool that allows accurate and direct assessment of possible adverse effects of intravascular contrast agents on LV contractility. Using this model, we showed that neither Albunex microspheres nor FS069 microspheres impaired myocardial contractility.
使用离体兔心模型，在恒定负荷条件和心率下，评估了Albunex（分子生物系统公司，加利福尼亚州圣地亚哥）和第二代造影剂FS069对左心室（LV）收缩性的影响。造影剂注射（总体积2 ml）分两个独立方案进行（N1 = 6，N2 = 6）。在方案1中，使用了不同剂量的Albunex（在盐溶液中为0.1至2.0 ml），并给予配对的盐溶液中5%人白蛋白匹配剂量的对照注射。在方案2中，在注射以下溶液期间评估左心室收缩性：（1）FS069在盐溶液中的1:250悬浮液，其可引起最佳心肌造影增强；（2）FS069的1:25悬浮液；（3）使用8微米孔径滤器预过滤的FS069的1:25悬浮液；（4）2 ml盐溶液作为对照。分析瞬时左心室压力的收缩压峰值（峰值P）和最大压力导数（峰值P'）的变化，这两个指标均为固定心率和心室容积条件下左心室收缩性的指标。单独的白蛋白引起左心室收缩性的短暂、剂量依赖性降低，表现为峰值P和峰值P'值均降低。这些降低可能是由于钙结合导致离子钙可用性降低所致。当溶液中存在Albunex微球时，未观察到收缩性进一步降低。盐水注射引起左心室收缩性短暂轻微增加，表现为峰值P和峰值P'值分别增加4.5%±1.1%和10.6%±3.8%。这些水平在2分钟内恢复到基线水平。当使用FS069的1:250悬浮液时观察到类似反应。FS069的1:25悬浮液引起双峰反应，初始时峰值P和峰值P'水平升高（分别为5.2%±3.6%和12.8%±6.5%），随后收缩性轻微降低（分别为2.0%±2.4%和1.7%±2.1%）。FS069的1:25悬浮液引起的收缩性降低通过过滤消除。离体兔心模型是一种高度敏感的工具，可准确、直接评估血管内造影剂对左心室收缩性可能的不良影响。使用该模型，我们表明Albunex微球和FS069微球均未损害心肌收缩性。
