SEX DIFFERENCES IN REPOLARIZATION AND EARLY REPOLARIZATION (AIM 3)

本子项目是利用由NIH/NCRR资助的中心赠款提供的资源的众多研究子项目之一。子项目和研究者（PI）可能已经从另一个NIH来源获得了主要资金，因此可以在其他CRISP条目中表示。列出的机构是中心的，不一定是研究者的机构。在这个项目中，我们假设性激素水平是心肌复极（ST段高度）的主要决定因素。支持这项研究的基本原理是，对某些心律失常（心律不齐）的易感性存在重要的性别差异，这表明男性和女性之间存在基本的电生理差异。为了验证我们的假设，我们将在接受激素替代治疗的无心脏病和未接受正常替代治疗的混合人群（年轻和老年男性和女性）中检查ST段高度和性激素水平之间的关系。具体来说，受试者将被给予超声心动图（一种使用声波勾勒出心脏大小并确定心脏功能的测试），被要求在固定自行车上做运动测试（记录受试者踩踏板时心脏的电活动），如果女性月经周期正常，则接受排卵期预测测试，并提供20毫升血液以确定几种性激素水平。我们将根据正常月经周期不同阶段和长期性激素治疗后的激素水平变化，试图确定ST变量变化的幅度。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. In this project, we hypothesize that the level of sex hormones is a major determinant of myocardial repolarization (ST height). The rationale supporting this study is that there are important sex differences in susceptibility to certain arrhtyhmias (irregular heartbeats), suggesting the existence of fundamental electrophysiologic distinctions between males and females. To test our hypothesis, we will examine the relationship between ST height and sex hormone levels in a mixed population of subjects (young and old men and women) without heart disease undergoing hormonal replacement therapy and in subjects not undergoing hormal replacement therapy. Specifically, subjects will be given an echocardiogram (a test using a sound wave that outlines the size of the heart and determines how well the heart is functioning), asked to do an exercise test on a stationary bicycle (which records the heart's electrical activity while the subject is pedaling), undergo, if females with regular menstrual cycles, a urinary ovulation predictor test and give 20 ccs of blood to determine several sex hormone levels. We will seek to determine the magnitude of changes in ST variables according to hormone levels changes occuring during the different phases of a normal menstrual cycle and following a long-term sex hormones therapy.