Efficacy of Intravenous Ultrasonic Contrast Agent for Diagnosing Ischemic Heart Disease.

超声心动图是诊断缺血性心脏病不可缺少的工具。到目前为止，超声心动图提供了重要和有用的信息，如室壁运动异常、心功能、心肌梗死引起的解剖和功能并发症等。然而，超声心动图尚未阐明心肌血流灌注情况。本研究探讨了冠状动脉内注射心肌声学造影技术检测犬冠状动脉狭窄和梗阻的可行性。联合应用血管扩张剂，冠状动脉狭窄的危险区域不显影，而未加扩张剂的冠状动脉狭窄，心肌显影良好。对静脉注射心肌声学造影剂的效果进行了检测。超声造影剂经静脉注射对心肌也有良好的显影效果。二次谐波成像的联合应用对显示心肌显影清晰、减少造影剂用量非常有用。实验装置与冠状动脉内注射方法基本相同，心肌显影清晰，低灌注区未见混浊。两者的视频强度对比明确，提示静脉心肌声学造影术对诊断缺血性心脏病有一定的价值。

The echocardiography is an indispensable tool for diagnosing ischemic heart disease.So far, echocardiography provides important and useful information such as wall motion abnormalities, cardiac function, anatomical and functional complications etc due to myocardial infarction.Nevertheless, myocardial perfusion has not been elucidated using echocardiography.Myocardial contrast echocardiography is a promising tool ; especially intravenous method is available.In this research, we examined the feasibility of myocardial contrast echocardiography for detecting coronary obstruction and stenosis in canines using intracoronary injection method.The area at risk covered by stenotic coronary artery was not opacified using combination with vasodilating agent, while the myocardium was well opacified despite coronary stenosis without vasodilating agent.Consequently, we examined the efficacy of intravenous myocardial contrast echocardiography.The ultrasonic contrast agent opacified myocardium well even via venous injection.The combination use of second harmonic imaging was extremely useful for visualizing myocardial opacification clearly and reducing the dose of contrast agent.The experimental setup was almost same as that for the intracoronary injection method.The myocardium was clearly opacified and the low perfused area was not opacified.The contrast of videointensity between was definite and leads the conclusion that the intravenous myocardial contrast echocardiography is useful for diagnosing ischemic heart disease.