An Appreciation of the Coronary Circulation
An Appreciation of the Coronary Circulation
复制标题
冠状动脉循环的认识
作者：
D. Sethna;E. Moffitt
用于评价冠状动脉血流和心肌代谢的冠状窦导管技术具有使用全局采样方法来评价局部疾病（冠状动脉疾病）的缺点。对冠状动脉循环的研究还受到以下事实的限制，即作用于冠状动脉床的干预可能同时改变冠状动脉血流的几个主要决定因素。结果也受到物种间差异的影响，以及冠状动脉血管床是正常的还是病理性狭窄。由于冠状动脉血流与心肌需氧量密切相关，因此将数值解释为异常需要同时评估心肌耗氧量的某些指标。在正常情况下，心肌血流主要是胆固醇，并受到胆固醇代谢因素的影响（例如，快速性心律失常）。自动调节在一定范围的灌注压（60-130 mm Hg）内维持恒定的冠状动脉血流，增加的血流需求通常通过冠状动脉血管舒张（冠状动脉血流储备）来满足。在近端冠状动脉狭窄中，这种额外血管舒张的能力可能显著降低，并且可以通过侧支维持流向狭窄之外的潜在缺血床的血流。在这种情况下，药物性冠状血管扩张可导致冠状动脉盗血。当灌注压降低到自动调节范围以下时，或者当冠状动脉血流储备早期耗尽时，如在冠状动脉狭窄中，血流变得依赖于机械因素，包括舒张持续时间和灌注压。在这些情况下，监测心率和舒张压可以合理评估冠状动脉血流和心肌灌注的充分性。
Coronary sinus catheter techniques for evaluation of coronary flow and myocardial metabolism have the drawback that a global sampling method is used to evaluate a regional disease (coronary artery disease). Studies on the coronary circulation are further limited by the fact that interventions acting on the coronary bed may simultaneously modify several of the principal determinants of coronary blood flow. Results are also influenced by differences among species, and whether the coronary vascular bed is normal or pathologically narrowed. Because coronary flow is intimately coupled to myocardial oxygen demand, interpretation of values as abnormal require simultaneous evaluation of some index of myocardial oxygen consumption. Under normal conditions, myocardial flow is predominantly in diastole, and is subject to compromise by factors that abbreviate diastole (e.g., tachyarrhythmias). Autoregulation maintains constant coronary blood flow over a range of perfusion pressures (60-130 mm Hg), and increased flow demands are normally met by coronary vasodilation (coronary flow reserve). In proximal coronary stenosis, this capacity for additional vasodilation may be significantly reduced, and flow to potentially ischemic beds beyond the stenosis may be maintained by collaterals. Pharmacologic coronary vasodilation in this situation can result in coronary steal. When perfusion pressure decreases below the autoregulatory range, or when coronary flow reserve is exhausted early, as in coronary stenosis, flow becomes dependent on mechanical factors including duration of diastole and the perfusion pressure. In these situations, monitoring heart rate and diastolic pressure would allow reasonable assessment of adequacy of coronary flow and myocardial perfusion.
影响因子：
15.9
作者：
KLOCKE, FJ;WEINSTEIN, IR;ECHT, MP
通讯作者：
ECHT, MP
冠状血管张力的局部和区域调节。
影响因子：
9.1
作者：
Bache,RJ;Dymek,DJ
通讯作者：
Dymek,DJ