冠状动脉微栓塞后冠脉血流储备及心肌血流量的变化及其机制

目的:经导管建立冠状动脉微栓塞模型，测定微栓塞后冠脉血流储备及心肌血流量的变化情况，并探讨其机制。方法:12只小型猪，通过导管方法建立急性冠脉微栓塞模型，观察急性期（基础、微栓塞后2 h、6 h）及慢性期（基础、微栓塞后1周）冠脉血流储备和心肌血流量的变化情况，并测定血清中内皮素-1（ET-1）浓度变化。结果:急性期冠脉微栓塞后冠脉血流储备在基础、微栓塞后2 h、6 h分别为2.10±0.60、1.40±0.10及1.10±0.10（微栓塞后2 h及6 h与基础相比，均P<0.01），慢性期实验中，冠脉血流储备在微栓塞前及微栓塞后1周分别为2.03±0.43及1.58±0.22（微栓塞后1周与基础相比,P<0.05）。但前内侧和后内侧心肌血流量以及它们的比值在微栓塞后没有显著变化。测定血清ET-1浓度显示微栓塞后2 h开始升高，但只有微栓塞后6 h较基础有明显增加(P<0.05)，微栓塞后6 h及1周心脏标本NBT染色均未见梗死灶。结论:冠脉微栓塞后冠脉血流储备呈现先下降后恢复的趋势，这种变化与内皮功能变化一致，冠脉血流储备和心肌血流量变化不同步。

Changes of coronary flow reserve and myocardial blood flow after coronary microembolization

AIM:To investigate the changes of coronary flow reserve (CFR) and myocardial blood flow (MBF) after coronary microembolization (CME).METHODS:The left anterior descending coronary artery of 12 pigs was embolized by injection of 42 μm microspheres with a total of 120 000.Study was divided as acute study (base, 2 h and 6 h) and chronic study (base and 1 week).CFR was measured using Doppler wire.Regional myocardial blood flow (MBF) was detected using colored microspheres.Serum endothelin-1(ET-1) was determined by ELISA.RESULTS:CFR decreased significantly after CME at acute phase (2.10±0.60 at baseline, 1.40±0.10 at 2 h and 1.10±0.10 at 6 h, 2 h and 6 h compared with base, P<0.01, respectively).At chronic phase, CFR was 2.03±0.43 at base and 1.58±0.22 at 1 week after CME.No changes were found for MBF at acute and chronic study.Serum ET-1 only elevated at 6 h after CME.CONCLUSION:CFR decreases with time at acute phase after CME and resumes 1 week later.Changes of CFR correlate with changes of endothelial function.Changes of CFR and MBF are mismatched after CME.