Nichols W W, Nicolini F A, Yang B, Robbins W C, Katopodis J, Chen L, Saldeen T G, Mehta J L
Department of Medicine, University of Florida College of Medicine, Gainesville 32610-0277.
J Am Coll Cardiol. 1994 Sep;24(3):795-803. doi: 10.1016/0735-1097(94)90031-0.
We examined whether subtotal coronary artery occlusion and reperfusion alter coronary flow reserve and regional myocardial function.
Total coronary artery occlusion followed by reperfusion results in decreased coronary flow reserve and regional myocardial dysfunction.
Thirteen anesthetized dogs were subjected to subtotal occlusion of the left anterior descending coronary artery for 1 h, followed by reperfusion for 1 h. During subtotal left anterior descending occlusion, heart rate was increased by atrial pacing. After reperfusion, coronary flow reserve, indicated by reactive hyperemia, as well as coronary flow responses to acetylcholine and nitroglycerin, regional myocardial function and myocardial leukocyte accumulation were measured.
After reperfusion, coronary flow reserve was decreased in the ischemic left anterior descending but not the nonischemic circumflex coronary artery region. Myocardial function was also depressed in the left anterior descending coronary region and did not improve on reperfusion. Histologic study showed no leukocyte infiltration in the ischemic left anterior descending coronary region. Myeloperoxidase, an index of myocardial leukocyte accumulation, was similar in the left anterior descending and circumflex coronary regions. Sensitivity of epicardial left anterior descending coronary artery rings to the thromboxane A2 analog U46,619 was enhanced, and relaxation of these rings in response to endothelium-dependent relaxants was decreased.
Coronary flow reserve is reduced and regional myocardial function depressed after subtotal coronary artery occlusion and increased heart rate. A decreased synthesis or increased breakdown of endothelium-derived relaxing factor may be related to a decrease in coronary flow reserve. However, the reduction in coronary flow reserve appears to be unrelated to leukocyte accumulation in the reperfused region.
我们研究了冠状动脉次全闭塞和再灌注是否会改变冠状动脉血流储备和局部心肌功能。
冠状动脉完全闭塞后再灌注会导致冠状动脉血流储备降低和局部心肌功能障碍。
对13只麻醉犬进行左前降支冠状动脉次全闭塞1小时，随后再灌注1小时。在左前降支次全闭塞期间，通过心房起搏增加心率。再灌注后，测量反应性充血所指示的冠状动脉血流储备，以及冠状动脉对乙酰胆碱和硝酸甘油的血流反应、局部心肌功能和心肌白细胞聚集情况。
再灌注后，缺血的左前降支冠状动脉区域的冠状动脉血流储备降低，但非缺血的回旋支冠状动脉区域未降低。左前降支冠状动脉区域的心肌功能也受到抑制，再灌注后未改善。组织学研究显示，缺血的左前降支冠状动脉区域无白细胞浸润。心肌白细胞聚集指标髓过氧化物酶在左前降支和回旋支冠状动脉区域相似。心外膜左前降支冠状动脉环对血栓素A2类似物U46,619的敏感性增强，且这些环对内皮依赖性舒张剂的舒张反应降低。
冠状动脉次全闭塞和心率增加后，冠状动脉血流储备降低，局部心肌功能受到抑制。内皮源性舒张因子合成减少或分解增加可能与冠状动脉血流储备降低有关。然而，冠状动脉血流储备的降低似乎与再灌注区域的白细胞聚集无关。
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