EFFECT OF AGING ON MYOCARDIAL REPOLARIZATION

本研究的目的是检查年龄对QT间期的影响 自主神经电生理检查前后两种性别的间期和QT离散度 封锁随着年龄的增长，原始AT逆变器的性别差异已经被证实。 但性别和年龄对QT离散度的相互作用， 未知。40名年轻受试者和40名老年受试者， 心脏病将在综合临床研究中心进行评估， 西北纪念医院受试者将接受筛选访视， 确保没有结构性心脏病或系统性疾病， 禁忌自主神经阻滞在随后的访视中，受试者 将在几个阶段进行常规12导联ECG和体表标测： (1)休息时;（2）阶段性自行车运动测试期间;（3） 双重自主神经阻滞方案的第一种药物（阿托品或 普萘洛尔）;（4）第二种药物（普萘洛尔或阿托品）后;（5） 在给予双自主神经后的运动试验期间， 封锁将以标准方式测量QT间期。Qt 12导联EKG上的离散度将通过手动和 使用先前开发的算法的计算机化方法。 将使用定制设计的方法分析体表标测图上的QT离散度。 这些算法将作为研究的一部分开发。重复测量 方差分析将用于检查绝对值的差异 青年人与老年人术前及术后QT间期及QT离散度比较 在自主神经阻滞后。此外，性别影响也将 考察

The purpose of this study is to examine the effects of aging on the QT interval and QT dispersion in both genders before and after autonomic blockade. Gender differences in the raw AT inverval with aging have been described but the interaction of gender and aging on QT dispersion are unkown. Forty young and 40 elderly subjects without evidence of structural heart disease will be evaluated in the General Clinical Research Center at Northwestern Memorial Hospital. Subjects will undergo a screening visit to ensure the absence of structural heart disease or systemic diseases which would contraindicate autonomic blockade. On a subsequent visit, subjects will undergo routine 12 lead ECG and body surface maps at several stages: (1) At rest; (2) During staged bicycle exercise testing; (3) After the first drug of a double autonomic blockade protocol (atropine or propranolol); (4) After the second drug (propranolol or atropine); (5) During exercise testing after the administration of double autonomic blockade. The QT interval will be measured in the standard fashion. QT dispersion on the 12 lead EKG will be determined by both manual and computerized methods using algorithms that have been previously developed. QT dispersion on body surface maps will be analyzed using custom designed algorithms which will be developed as part of the study. Repeated measures of analysis of variance will be used to examine differences in the absolute QT interval and in QT dispersion between the young and elderly before and after autonomic blockade. In addition, gender effects will also be examined.