Deanfield J E, Selwyn A P
Am J Med. 1986 Apr 30;80(4C):18-24. doi: 10.1016/0002-9343(86)90448-1.
Measures of the severity of angina pectoris, coronary anatomy, and left ventricular function are widely used to assess prognosis and determine management in patients with ischemic heart disease. However, recent evidence suggests that myocardial ischemia, with or without angina, is also a reliable prognostic sign. Studies using ambulatory ST-segment monitoring of patients with chronic stable angina out of the hospital have shown that the majority of episodes of transient myocardial ischemia are silent and surprisingly prolonged. Most episodes occur without the increase in heart rate noted during physical exertion. Characteristic abnormalities of regional myocardial perfusion have been observed using positron tomography during both painful and painless episodes of ischemia. Among these abnormalities is an absolute reduction in the perfusion to the poststenotic ischemic segment of myocardium. Episodes of ischemia can be induced in the hospital by a number of ordinary daily activities, including mental stress, cold, and cigarette smoking, and they often resemble episodes recorded from patients out of the hospital. These observations suggest that both an increased myocardial demand and a reduction in coronary blood flow may be important in the genesis of ischemia out of the hospital. If prospective studies confirm that myocardial ischemia is damaging, even in the absence of angina, investigation and treatment policies may need to be reevaluated. Results of ongoing clinical studies will show whether control of the total ischemic burden can prevent myocardial damage and improve the prognosis.
心绞痛严重程度、冠状动脉解剖结构及左心室功能的测量方法被广泛用于评估缺血性心脏病患者的预后并确定治疗方案。然而，最近的证据表明，无论有无心绞痛，心肌缺血也是一个可靠的预后指标。对院外慢性稳定型心绞痛患者进行动态ST段监测的研究表明，大多数短暂性心肌缺血发作是无症状的，且持续时间惊人地长。大多数发作发生时没有体力活动时出现的心率增加。在缺血的疼痛发作和无痛发作期间，使用正电子断层扫描观察到了局部心肌灌注的特征性异常。这些异常包括心肌狭窄后缺血节段灌注的绝对减少。在医院里，一些日常普通活动，包括精神压力、寒冷和吸烟，都可以诱发缺血发作，而且这些发作往往与院外患者记录的发作相似。这些观察结果表明，心肌需求增加和冠状动脉血流减少在院外缺血的发生过程中可能都很重要。如果前瞻性研究证实心肌缺血具有损害作用，即使在没有心绞痛的情况下，也可能需要重新评估调查和治疗策略。正在进行的临床研究结果将表明，控制总的缺血负荷是否能够预防心肌损伤并改善预后。
