Nesto R W, Phillips R T
Am J Med. 1986 Oct 20;81(4A):12-9. doi: 10.1016/0002-9343(86)90973-3.
A great deal of interest is being generated by the possibility that patients with coronary artery disease and typical angina pectoris may also experience periods of ischemia during activities of daily living that are not necessarily associated with angina or increased myocardial oxygen demand. It might be that the majority of ischemic episodes during daily life are not preceded by increases in myocardial oxygen demand, and are probably related to dynamic changes in coronary blood flow. Questions still remain, however, regarding the prevalence of asymptomatic ischemia in patients who present with effort angina and positive results on exercise tolerance tests. Therefore, in susceptible patients with coronary artery disease, calcium channel blockers, especially nifedipine, may be of particular benefit since they decrease myocardial oxygen demand during effort and may increase coronary blood flow, thereby aborting asymptomatic ischemia, which tends to occur at low levels of cardiac oxygen demand. It appears that a greater awareness of the total ischemic burden, i.e., the sum total of symptomatic and asymptomatic and exertional and nonexertional ischemia, may facilitate individualization of therapy for patients with coronary artery disease. Agents that both reduce myocardial oxygen demand and improve coronary blood flow, such as nifedipine, may particularly benefit individuals whose ischemia may be both asymptomatic and symptomatic, and who seem to constitute the majority of patients with coronary artery disease.
冠状动脉疾病和典型心绞痛患者在日常生活活动期间可能也会经历缺血期，而这些缺血期不一定与心绞痛或心肌需氧量增加相关，这种可能性正引发了人们极大的兴趣。可能日常生活中的大多数缺血发作之前并无心肌需氧量增加的情况，且可能与冠状动脉血流的动态变化有关。然而，对于出现劳力性心绞痛且运动耐量试验结果呈阳性的患者，无症状缺血的患病率仍存在疑问。因此，对于易患冠状动脉疾病的患者，钙通道阻滞剂，尤其是硝苯地平，可能具有特殊益处，因为它们在运动时可降低心肌需氧量，并可能增加冠状动脉血流，从而终止往往在低心脏需氧量水平时发生的无症状缺血。看来，提高对总缺血负荷（即有症状和无症状、运动性和非运动性缺血的总和）的认识，可能有助于冠状动脉疾病患者治疗的个体化。既能降低心肌需氧量又能改善冠状动脉血流的药物，如硝苯地平，可能对那些缺血可能既有症状又无症状的个体特别有益，而这些个体似乎构成了冠状动脉疾病患者的大多数。
