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

到目前为止，经外周静脉超声心动图检查仅限于右心。用手搅拌法制造的微泡相对太大，不能通过肺毛细血管床。因此，左心混浊一直是一个梦想。后来发现，超声处理的人血清白蛋白在10微米以下有大量的小微泡，可以穿过肺毛细血管床。使用这种试剂，左心肯定是浑浊的。但由于自制方法得到的气泡大小不一，其混浊效果并不是恒定的。随着心肌声学造影技术的发展，对心肌血流灌注的评价不仅需要定性的，也需要定量的。为了满足这些要求，需要均匀的和大小确定的微泡。自从最初的研究通过冠状动脉内注射以来，静脉心肌声学造影术一直是人们所希望的。几个ATEM…已经做出了更多的评论。然而，即使左室腔过度混浊，流入冠状动脉的微泡数量也太少，不能清楚地显示心肌混浊。当将造影剂注入左房腔时，左室壁显影良好。但左心室腔内的造影剂显著减弱了从后面发出的回声。虽然彩色编码图像有助于显示低度混浊的室壁，但人们一直认为使用常规造影剂静脉注射很难使心肌混浊。最近，一种相当新的造影剂已经被开发出来。即沸点低于体温、血液中气泡稳定性高的药剂，称为QW3600注射剂。该助剂由碳氟化合物和表面活性剂组成。该试剂在室温下为液体状态，但注入体内后沸腾形成微泡。大剂量静脉注射0.5 mg/kg以上可使犬心肌明显混浊。心肌混浊消失后，心肌混浊持续时间较长，可能是由于微泡在循环过程中变大所致。大剂量组出现低血压、低氧血症等不良反应。但该试剂在静脉心肌声学造影中有很好的应用前景。较少

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