冠脉血流显像技术对急性主动脉瓣反流时冠脉血流储备的实验研究

摘要

目的　探讨急性主动脉瓣反流对冠脉血流储备（CFR）的影响。方法　应用彩色多普勒冠脉血流显像技术（CDCFI）检测7条开胸杂种犬作为对照组及由猪尾管造成的轻、中、重度急性主动脉瓣反流各组，静脉注射潘生丁前后心外膜冠脉血流的变化。CFR以用药后与用药前冠脉血流的速度时间积分比和峰值血流速度比来计算。结果　最大血流变化出现在注药开始后4～6 min，平均5 min；用药后与用药前速度时间积分比与峰值血流速度比均随着主动脉瓣反流程度的增加而逐渐减小；各组之间的CFR（速度时间积分比和峰值血流速度比）差异均有显著性意义（P<0.01）；相关分析显示，两种方法计算的CFR与主动脉瓣反流程度的增加均呈高度负相关，相关系数分别为-0.969 和 -0.978。各组CFR之间差异均有显著性意义（P<0.01）。两种方法计算的CFR差异无显著性意义（P>0.05）。结论　随着主动脉瓣反流程度的加重，CFR逐渐降低。%Objective　To explore the effects of graded temporary acute aortic regurgitation (AR) on coronary flow reserve (CFR) in opened-chest dogs.Methods　Graded temporary acute aortic regurgitation was produced with pigtail catheter in 7 healthy mongrel opened-chest dogs. Using coronary flow imaging, the peak velocity (CPV) and the velocity time integral (VTI) in left anterior descending artery flow were measured at basal state and during dipyridamole-induced hyperemia under control conditions and each grade of acute AR. The grade of AR was performed according to the ratio of regurgitant jet original color height (JH) to left ventricular outflow tract height (LVOTH) in parasternal long-axis view. CFR was defined as the ratios of CPV and VTI respectively,between after and before administration of dipyridamole.Results　A significant increase of CPV and VTI were observed in all groups, but the increasing extent was lower in the AR, consequently, CFR was lower in the AR than in the control. Under control conditions, analysis of variance revealed significant difference in CFR between control and each grade of AR (P<0.01). There is a high negative correlation between CFR (CPV-D/R) and graded temporary acute aortic regurgitation, and so is CFR (VTI-D/R), the correlation coefficients were -0.97824 and -0.96921 respectively.Conclusions　This study demonstrates a marked decline in coronary flow reserve with increasing degrees of acute aortic regurgitation.