DETECTION AND PROGNOSIS OF SILENT MYOCARDIAL ISCHEMIA

在726名表面健康的巴尔的摩老龄化纵向研究（BLSA）中， 男性和女性，他们经历了一系列的最大运动测试， 1969年，对那些最初 试验阳性（I组），由阴性转为阳性者 （第二组和那些在平均6.4年的随访中保持阴性的人） （第三组）。通过比例风险分析，第I组和第II组几乎 相同的心脏事件风险增加（RR为2.78和2.72 与第三组受试者相比。在无症状 志愿者，从阴性到阳性运动ECG的连续转换 对未来冠状动脉事件的预测价值与最初的 ECG反应阳性。 为了区分年龄和无症状心肌缺血（SI）的影响， 左心室（LV）对最大直立踏车运动的反应，我们 比较3组：8名临床健康老年人 既往ECG和铊扫描（TS）异常的男性（平均年龄-76岁） 对最大跑步机运动（OSI）的反应; 16名年龄匹配的男性， 正常ECG和TS反应（OC）; 21例年轻（平均年龄= 33岁）对照 （YC）.静息时左室射血分数（EF）、舒张末期容积指数（EDVI） 收缩末期容积指数（ESVI）3组间无显著性差异。与 YC组运动时LVEF显著增加，OC组次之， 在OSI。相反，运动诱发的左心室扩张（增加（ESVI）） 在OSI中最明显，OC增加较少; EDVI 在YC中通过最大努力实际上下降到基线值以下。因此，在本发明中， 年龄相关的心脏扩张和对直立骑行的EF反应迟钝 在运动诱发SI的老年受试者中被夸大。

Among 726 apparently healthy Baltimore Longitudinal Study of Aging (BLSA) men and women who have undergone serial maximal exercise testing since 1969, the risk of future cardiac events was compared in those whose initial test was positive (Group I), those who converted from negative to positive (Group II and those who remained negative over a 6.4 year mean followup (Group III). By proportional hazards analysis, Groups I and II had a nearly identical enhanced risk of a cardiac event (RR of 2.78 and 2.72 respectively) compared to Group III subjects. Thus, in asymptomatic volunteers, serial conversion from a negative to a positive exercise ECG has a similar predictive value for a future coronary event as an initially positive ECG response. To separate the effects of age and silent myocardial ischemia (SI), on the left ventricular (LV) response to maximal upright cycle ergometry, we compared 3 groups: 8 clinically healthy older men (mean age - 76) with prior abnormal ECG and thallium scan (TS) responses to maximal treadmill exercise (OSI); 16 age-matched men with normal ECG and TS responses (OC); and 21 young (mean age = 33) controls (YC). At rest LV ejection fraction (EF), end-diastolic volume index (EDVI) and end-systolic volume index (ESVI) were similar in the 3 groups. With cycle exercise LVEF increased markedly in the YC, less in the OC and least in the OSI. In contrast, exercise-induced LV dilatation (increased (ESVI) was most pronounced in the OSI with a lesser increase in the OC; EDVI actually declined below baseline values by maximal effort in the YC. Thus, age-related cardiac dilatation and blunted EF response to upright cycling are exaggerated in older subjects with exercise-induced SI.