应用冠脉血流显像技术检测猪心外膜和心肌内冠脉血流特征的实验研究

目的：应用冠脉血流显像技术检测猪的冠脉血流，初步探讨心外膜和心肌内冠脉的时相性灌注特点及其在冠脉扩张状态下的变化。方法：5条实验小型猪，在麻醉状态下应用超声冠脉血流显像技术探测不同节段心外膜冠脉和左室心肌内的冠脉血流信号，记录其血流频谱曲线。观察心外膜及心肌内冠脉的时相灌注特点，测定冠脉血流速度，计算右冠脉和前降支的舒张期／收缩期峰值血流速度比值。观察静脉推注潘生丁（0．56mg/kg）后前降支和心肌内冠脉血流信号及其频谱曲线特点的变化。结果：所有动物均可检测较清晰的心外膜和心肌内冠脉血流信号；心外膜冠脉为全心动周期前向灌注，右 冠脉的收缩期血流速度明显高于前降支；心肌内冠脉的时相灌注特点为收缩期出现低速的逆向血流；静 注潘生丁使心外膜与心肌内冠脉的血流均明显增强，但灌注模式未变。结论：彩色多普勒冠脉血流显像技术为研究冠脉血流的时相性灌注特点提供了很好的无创性检测手段。

Assessment of epicardial and intramyocardial coronary flow using a new echocardiographic system in a closed chest swine model

Objectives This study was performed to determine the phasic perfusion character of epicardial and intramyocardial coronary blood flow and the changes of that during dipyridamole administration using coronary flow imaging. Methods In five juvenile swines, coronary flow imaging system were used to visualize the different segments of epicardial coronary arteries and intramyocardial arteries. Pulsed - Doppler spectrums were analysised respectively and the diastolic/systolic velocity ratio of the right coronary artery and the left anterior descending branch was calculated. The left anterior descending and intramyocardial coronary blood flow signals and related pulsed - Doppler spectrums were recorded at baseline and during dipyridamole administration. Results The epicardial and intramyocardial coronary arteries could be visualized by coronary flow imaging. The systolic component of coronary flow in RCA was greater than that in LAD. The intramyocardial blood flow was characterized by persistent retrograde blood flow velocity during systole. Vasodilation with dipyridamole produced exaggerated differences of the phasic pattern of coronary blood flow in epicardial and intramyocardial vessels. Conclusions The color Doppler coronary flow imaging provided a noninvasive method to study the phasic character of coronary blood flow.