A Novel Agent for Contrast Echocardiography and its Evaluation in a Distinctive Clinical Application.

到目前为止，经外周静脉造影的超声心动图仅限于右心。用手搅拌法制造的微泡相对太大，无法通过肺毛细血管床。因此，左心混浊一直以来都是一个梦想。结果表明，超声处理的人白蛋白有许多10微米以下的小微泡，这些微泡可以穿过肺毛细血管床。使用这种药物左心绝对是不透明的。但由于自制方法的气泡大小不一，其浊化效果并不稳定。随着心肌超声造影技术的发展，对心肌灌注的定性和定量评价都有了新的要求。为了满足这些要求，需要均匀且大小确定的微泡。自最初的研究以来，通过冠状动脉内注射进行静脉心肌对比超声心动图的研究一直很有必要。又做了几次尝试。然而，流入冠状动脉的微泡数量太少，即使左心室过度混浊，也无法清晰地混浊心肌。左房腔注射造影剂后，左室壁混浊良好。但在左心室腔内的造影剂能明显减弱后方的回声。传统的对比剂很难通过静脉注射使心肌混浊，尽管彩色编码图像有助于显示低级别的心室壁混浊。最近研制出了一种新型造影剂。即沸点低于体温，血液中气泡稳定性高的药剂；命名为QW3600注射。该剂由氟碳和表面活性剂组成。该药剂在室温下为液态，注射入体内后沸腾形成微泡。大剂量静脉注射大于0.5 mg/kg时，犬心肌明显浑浊。左室腔混浊消失后心肌混浊持续时间较长，可能与循环过程中微泡变大有关。大剂量时出现低血压、低氧血症等副作用。但这种药物在静脉心肌对比超声心动图上很有前景。少

So far, the contrast echocardiography via peripheral vein has been limited to the right heart. The microbubbles made by a hand agitation method are relatively too large to pass through the pulmonary capillary beds. Therefore, the opacification of the left heart has been a dream for a long time. Afterwards, it was revealed that sonicated human albumin has a lot of small microbubbles under 10 microns which can pass through the pulmonary capillary bed. The left heart is definitely opacified using this agent. But the effect of its opacification is not constant, because the bubble size by home made method is various. With the progression of the myocardial contrast echocardiography, not only qualitative but also quantitative assessment of myocardial perfusion are required. To satisfy such requirements, homogeneous and sized-determined microbubbles are needed. Intravenous myocardial contrast echocardiography has been desired since the initial studies via intracoronary injection. Several attem … More pts have been made. However, the amount of microbubbles flowing into the coronary arteries is too small to opacify the myocardium clearly, even if the left ventricular cavity is opacified excessively. When a contrast agent is injected into the left atrial cavity, the left ventricular wall is opacified well. But the contrast agent in the left ventricular cavity attenuates the echo from the behind significantly. It has been thought to be difficult to opacify the myocardium via intravenous injection using conventional contrast agents, although color-coded image will useful to visualize the low grade opacified ventricular wall. Recently, a quite new contrast agent has been developed. That is the agent with lower boiling point than body temperature and high stability of bubbles in the blood ; which is named QW3600 Injection. The agent consists of fluorocarbon with surfactant. The agent is liquid state under the room temperature, but boils forming microbubbles after injected into the body. Intravenous injection of high dose over 0.5 mg/kg opacified the myocardium clearly in canine experiments. The opacification of the myocardium remained longer after disappearance of the LV cavity opacification, probably because the microbubbles might become bigger during circulation. Some side effects such as hypotension and hypoxemia occurred using high dosage. But this agent is quite promising for intravenous myocardial contrast echocardiography. Less