Campbell S, Rocco M B, Nabel E G, Barry J, Rebecca G S, Deanfield J E, Selwyn A P
Am J Med. 1986 Apr 30;80(4C):9-17. doi: 10.1016/0002-9343(86)90447-x.
Transient regional myocardial ischemia appears to underlie symptoms such as angina pectoris and represents a key pathophysiologic step, since it is an objective marker of disease activity and is capable of causing disabling symptoms and damage to left ventricular myocardium. A study of the characteristics of transient ischemia in and out of the hospital has shown that symptoms are an inconsistent underestimation of these events. Ischemia is generally prolonged, mostly asymptomatic, and usually accompanied by a regional decrease in myocardial perfusion. Studies out of the hospital have also shown that these episodes are frequently triggered by a wide range of ordinary everyday activities. These new features of transient ischemia are worth noting when searching for relevant causes that are present during everyday life and when trying to choose more rational therapy. More detailed studies of patient activity have shown that different levels of mental arousal are the most common triggering mechanism causing ischemia out of the hospital. In addition, the occurrence of transient ischemia during everyday life displays a circadian rhythm, with an increase and peak occurrence between 6:00 A.M. and 12 noon each day. The day-to-day variability of ischemia is marked, indicating functional disturbances of coronary stenoses against a background of a severe reduction in cross-sectional area. The examination of proximal stenoses has shown that the reduction in cross-sectional area is usually underestimated by conventional angiography; pressure gradients across coronary stenoses are common and, with reduced poststenotic blood pressure, can jeopardize perfusion; disturbances of vessel caliber and antegrade flow can accompany many of the ordinary everyday activities known to trigger ischemia detected in Holter tapes studied out of the hospital; and there is clear-cut evidence of endothelial dysfunction in these patients, with reversal of the normal dilator response to acetylcholine and paradoxical constriction of stenoses. This evidence of endothelial dysfunction in humans could be central to the problems of atheromatous narrowing, thrombus, and disturbed vasomotion.
短暂性局部心肌缺血似乎是心绞痛等症状的基础，并且代表了一个关键的病理生理步骤，因为它是疾病活动的客观标志，能够导致功能障碍性症状以及对左心室心肌造成损害。一项关于院内外短暂性缺血特征的研究表明，症状对这些事件的评估往往不一致且存在低估。缺血通常会持续较长时间，大多无症状，且通常伴有局部心肌灌注减少。院外研究还表明，这些发作常常由各种日常普通活动引发。在寻找日常生活中存在的相关病因以及试图选择更合理的治疗方法时，短暂性缺血的这些新特征值得关注。对患者活动的更详细研究表明，不同程度的精神兴奋是院外引发缺血最常见的触发机制。此外，日常生活中短暂性缺血的发生呈现昼夜节律，每天上午6点至中午12点发生率增加并达到峰值。缺血的每日变异性很显著，这表明在冠状动脉狭窄横截面积严重减小的背景下存在功能紊乱。对近端狭窄的检查显示，常规血管造影通常会低估横截面积的减小；冠状动脉狭窄处的压力梯度很常见，并且随着狭窄后血压降低，会危及灌注；血管口径和正向血流的紊乱可能伴随许多已知能触发院外动态心电图监测中缺血的日常普通活动；并且有明确证据表明这些患者存在内皮功能障碍，对乙酰胆碱的正常舒张反应发生逆转，狭窄处出现反常收缩。人类内皮功能障碍的这一证据可能是动脉粥样硬化性狭窄、血栓形成和血管运动紊乱问题的核心所在。
