AGE-ASSOCIATED CHANGES IN CARDIAC RHYTHM AND CONDUCTION

A.确定PR间期延长的部位 在161例老年人中，我们进行了信号平均的高分辨率体表心电图。 临床健康的巴尔的摩老年纵向研究(BLSA)志愿者 房室传导正常。PR间期的增加 随年龄增长在男女中均可发现，并局限于His近端 束去极化，但在P波铭文的远侧，提示 房室交界处内的阻塞；类似的性质相似但更多 7例老年男性患者在希氏束近端有明显的延迟。 一级房室传导阻滞。 B.我们已经确定了运动性运动的患病率和意义 频发或重复室性早搏(VEB) 健康的BLSA志愿者。在1974至1984年间，1160名 无症状的受试者出现频繁的VEB(10%)或Salvos(&gt；3)。 至少进行一次最大跑步机运动试验。这80名受试者 比没有这样的更大的群体年龄要大得多 运动性VEB(63.8+/-12.5vs50.0+/-16.1，p&lt；0.0001)。只有9个人 80例(11%)运动后出现缺血性ST段反应。超过一年 平均随访4.6年；仅发生8次心脏事件，而10次 80名年龄和性别匹配的对照受试者没有这种复杂的事件 运动性VEB(p=NS)。 C.24小时动态心电记录的预后意义是 在100名60岁的健康BLSA志愿者中进行了评估。超过了小气 随访10年，10例受试者发生冠状动脉事件。这个 室上性心动过速(SV)和室性心动过速(V)的患病率和复杂性 异位搏动在有无CE组中相似。不过，行政长官 ST段平坦或下斜者5例中有2例(40%) 压低或=1.0 mm，而95例无ST段改变者中仅有8例(8%)。

A. To determine the site of the PR interval prolongation associated with aging, we performed signal averaged high resolution surface ECGs in 161 clinically healthy Baltimore Longitudinal Study of Aging (BLSA) volunteers with normal atrioventricular (AV) conduction. An increase in PR interval with age was found in both sexes and was localized proximal to the His bundle depolarization but distal to the P wave inscription, suggesting block within the AV junction; a similar qualitatively similar but more pronounced delay was noted proximal to the His bundle in 7 older men with first degree AV block. B. We have determined the prevalence and significance of exercise-induced frequent or repetitive ventricular ectopic beats (VEB) in apparently healthy BLSA volunteers. Between 1974 and 1984, 8O of 1160 such asymptomatic subjects developed frequent VEB (> 10%) or salvos (> 3 in a row) on at least one maximal treadmill exercise test. These 80 subjects were significantly older than the larger group without such exercise-induced VEB (63.8 +/- 12.5 vs 50.0 +/- 16.1, p<.0001). Only 9 of 80 (11%) demonstrated an ischemic ST segment response to exercise. Over a mean followup of 4.6 years; only 8 cardiac events have occurred versus 10 events in 80 age- and sex-matched control subjects without such complex exercise-enduced VEB (p = NS). C. The prognostic significance of 24-hr ambulatory ECG recordings was assessed in 100 healthy BLSA volunteers > 60 years old. Over a mean followup of 10 years, coronary events (CE) developed in 10 subjects. The prevalence and complexity of both supraventricular (SV) and ventricular (V) ectopic beats were similar in the groups with and without CE. However, CE occurred in 2 of 5 subjects (40%) with flat or downsloping ST segment depression > or = 1.0 mm versus only 8 of 95 (8%) without such ST changes.