Sex Differences in Early Myocardial Repolarization

早期心肌复极的性别差异

• 批准号: 7086950
• 负责人: Alan H Kadish
• 金额: $ 36.21万
• 依托单位: NORTHWESTERN UNIVERSITY AT CHICAGO
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-07-01 至 2009-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7086950
• 关键词: androgens; arrhythmia; clinical research; electrocardiography; estrogens; gender difference; heart electrical activity; heart rate; heart ventricle; hormone regulation /control mechanism; hormone therapy; human subject; idiopathic dilated cardiomyopathy; menstrual cycle; myocardial infarction; myocardium; progesterone

DESCRIPTION (provided by applicant): Sex differences in the QT interval have been known since the early 1900s. In contrast, sex differences in the ST segment consisting of a higher ST height and elevated J point have only recently been studied in detail. There are sex differences in clinical arrhythmias that may be associated with the sex ECG differences. Ventricular tachycardia is inducible in 35-40 percent of men but only 20 percent of women with coronary artery disease and LV dysfunction. Women are only half as likely as men to develop VF as a cause of cardiac arrest are. The fact that there are important sex differences in susceptibility to certain arrhythmias suggests the existence of fundamental electrophysiologic distinctions between males and females that remain to be elucidated. The overall hypothesis of the present study is that sex differences in early myocardial repolarization are rate dependent, are due to effects of sex hormones and alter the propensity to clinical arrhythmias. The following specific hypotheses will be tested. 1) A major determinant of ST height is the level of sex hormones. We will also seek to determine whether the ST elevation seen most often in athletic males sometimes called "early repolarization" is a distant clinical syndrome. 2) Sexrelated differences in myocardial repolarization are dependent on both heart rate and autonomic tone. This aim will be accomplished by examining the heart rate dependence of ST height before and after autonomic manipulations in both men and women. 3) Androgens but not estrogens or progesterone modulate early repolarization. This aim will be accomplished by studying subjects who will undergo sex hormone therapy. 4) ST elevation that has previously been characterized as benign based on incomplete data alters the propensity to arrhythmias under appropriate pathologic conditions. In this aim, the relationship between ST elevation on the resting ECG and ventricular tachycardia and ventricular fibrillation will be examined. Studies will be performed in patients with acute and healed myocardial infarction and in patients with non-ischemic dilated cardiomyopathy. It is hoped that the results of this study will improve the understanding of myocardial physiology and improve risk stratification and therapy for arrhythmias by uncovering important sex related differences.

描述（由申请人提供）：自1900年代初以来，QT间隔中的性别差异就已经知道。 相比之下，直到最近才详细研究了由ST高度和升高J点组成的ST段的性别差异。 临床心律不齐的性别差异可能与性心电图差异有关。 患有35-40％的男性，但只有20％的冠状动脉疾病和LV功能障碍的女性可诱导心室心动过速。 女性发展为心脏骤停的原因的可能性只有男性的一半。 对某些心律不齐的敏感性存在重要的性别差异的事实表明，男性和女性之间存在基本的电生理学区别，但仍有待阐明。 本研究的总体假设是，心肌复制早期的性别差异取决于速率，这是由于性激素的影响并改变了临床心律不齐的倾向。 将测试以下特定假设。 1）ST高度的主要决定因素是性激素的水平。 我们还将寻求确定在运动雄性中最常看到的ST高度是否有时称为“早复极化”是一种遥远的临床综合征。 2）心肌重极化的性别差异取决于心率和自主语调。 该目标将通过检查男性和女人的自主性操纵前后ST高度的心率依赖性来实现。 3）雄激素，但不能调节雌激素或孕激素的早期复制。 这个目标将通过研究将接受性激素治疗的受试者来实现。 4）先前基于不完整数据的良性表征的ST升高改变了适当的病理条件下心律失常的倾向。 在此目标中，将检查静息心电图与心室心动过速的ST升高与心室纤颤之间的关系。 研究将对急性和愈合心肌梗塞的患者以及非缺血性大扩张性心肌病的患者进行研究。 希望这项研究的结果能够通过发现重要的性别相关差异来改善对心肌生理的理解，并改善心律不齐的风险分层和治疗。