Tomita F
Department of Cardiovascular Medicine, Hokkaido University, School of Medicine, Sapporo, Japan.
Hokkaido Igaku Zasshi. 1990 Nov;65(6):583-94.
The purpose of this study was to clarify the clinical and prognostic significance of silent myocardial ischemia (SMI) in patients with proven ischemic heart disease using ambulatory electrocardiographic monitoring (AEM). A total of two hundreds and ninety one patients, including 131 patients with stable effort angina (EA), 125 with previous myocardial infarction (MI), 21 with variant angina (VA), and 14 with unstable angina (UA) were examined. In 141 (EA 65, MI 41, VA 21, UA 14) of these 291 patients, we investigated the frequency and characteristics of SMI. During daily activities, 47% (125/268), 73% (99/136), 71% (140/196), and 69% (102/147) of all transient ST-segment deviations observed was asymptomatic in patients with EA, MI, VA, and UA, respectively. When patients exhibiting only symptomatic episodes were compared with those exhibiting only asymptomatic ones, asymptomatic episodes tended to be associated with the greater duration and magnitude of ST-segment deviation. On the other hand, in patients exhibiting both symptomatic and asymptomatic episodes, the duration and magnitude of ST-segment deviation were greater for symptomatic than asymptomatic episodes. In addition, we also investigated the relation between the result of AEM after standard medical therapy and long-term prognosis in 208 (EA 99, MI 109) of 291 patients. In MI, during the mean follow-up period of 41.2 months, cumulative cardiac event rate was significantly higher in patients with only asymptomatic episodes (SMI group) as well as patients with symptomatic episodes (angina pectoris, AP group) than in patients without any ischemic episodes (Control group). There was no statistically significant difference in prognosis between AP group and SMI group in MI, or among the three groups in EA. These results lead us to conclude that: (1) SMI is observed frequently in patients with ischemic heart disease during daily activities. (2) Asymptomatic episodes are not necessarily less severe in myocadial ischemia than symptomatic episodes. (3) The presence of SMI, as well as angina pectoris, may identify a high-risk group for the development of subsequent unfavorable outcomes while on standard medical therapy.
本研究旨在通过动态心电图监测（AEM）阐明确诊为缺血性心脏病患者无症状心肌缺血（SMI）的临床及预后意义。共检查了291例患者，包括131例稳定劳力型心绞痛（EA）患者、125例既往心肌梗死（MI）患者、21例变异型心绞痛（VA）患者和14例不稳定型心绞痛（UA）患者。在这291例患者中的141例（EA 65例、MI 41例、VA 21例、UA 14例）中，我们研究了SMI的发生频率及特征。在日常活动期间，EA、MI、VA和UA患者中所有观察到的短暂性ST段偏移分别有47%（125/268）、73%（99/136）、71%（140/196）和69%（102/147）是无症状的。将仅表现为有症状发作的患者与仅表现为无症状发作的患者进行比较时，无症状发作往往与更长的ST段偏移持续时间及更大的偏移幅度相关。另一方面，在同时有症状性和无症状性发作的患者中，有症状发作时ST段偏移的持续时间和幅度大于无症状发作时。此外，我们还研究了291例患者中208例（EA 99例、MI 109例）在标准药物治疗后AEM结果与长期预后之间的关系。在MI患者中，平均随访41.2个月期间，仅有无症状发作的患者（SMI组）以及有症状发作的患者（心绞痛，AP组）的累积心脏事件发生率显著高于无任何缺血发作的患者（对照组）。在MI中，AP组和SMI组之间的预后无统计学显著差异，在EA中三组之间也无统计学显著差异。这些结果使我们得出以下结论：（1）在日常活动期间，缺血性心脏病患者中经常观察到SMI。（2）无症状发作时心肌缺血的严重程度不一定低于有症状发作时。（3）在标准药物治疗期间，SMI的存在以及心绞痛可能识别出随后发生不良结局的高危人群。
