PROGNOSTIC SIGNIFICANCE OF T WAVE ALTERNANS

描述（申请人摘要中的逐字记录）：心脏性猝死病例 美国每年约有40万人死亡， 流行病程度的健康问题。大多数心脏性猝死都是由 致命的室性心律失常一项旨在初级预防 心源性猝死需要有效识别处于 心律失常的风险很高， 预防性治疗一些最近完成的随机临床试验 试验已经证明，植入式心脏除颤器（ICD）可以 预防高风险患者的心脏性猝死。 当这些试验放在一起看时， 已证明植入ICD的预防性治疗对这些患者有益 通过记录的、自发性或诱导性、持续性心室 心律不齐 两项随机治疗试验（MADIT II，SCD-HEFT）目前正在测试 植入ICD将降低患者死亡率的假设 充血性心力衰竭（CHF）和左心室功能障碍， 进一步风险分层。然而，这两个问题的含义 试验-在每一个CHF患者中植入ICD-不太可能 被医学界或医疗保健支付者所接受。更 有效的风险分层方法将是必要的，以确定这些 最有可能从预防性治疗中获益的CHF患者 植入了ICD 最近的研究表明，在运动过程中测量的T波交替（TWA） 与诱导型单形性CVT以及随后的 自发性的精神病事件这些初步数据表明，TWA可能是一个 用于电生理测试的有效和非侵入性替代物， 心脏性猝死的高危患者。 本研究的目的是评估TWA在预后中的意义， 一项前瞻性流行病学自然史研究。最终，规划 一项随机治疗试验，使用TWA与其他 选择心源性猝死高危患者的风险因素 对一项无偏见的自然历史研究中的一些问题的回答。什么 是如果TWA 存在吗？缺血性心脏病患者的风险增加是否相似 和非缺血性心肌病环球航空公司与 其他风险因素（EF、NSVT和RR变异性）？是两者之间的联系 TWA和脑卒中事件独立于这些其他风险因素？是什么 结合风险因素以确定一个组的最有效的临床方法 有高风险的病人发生过过敏反应吗描述的研究 在这个补助金申请将提供必要的数据来回答这些问题 问题.

DESCRIPTION (Verbatim from Applicant's Abstract): Sudden cardiac death accounts for approximately 400,000 deaths each year in the United States and remains a health problem of epidemic proportions. Most sudden cardiac deaths are caused by fatal ventricular arrhythmias. An effort aimed at the primary prevention of sudden cardiac death requires efficient identification of patients who are at high enough risk for having these arrhythmias to warrant aggressive prophylactic therapy. A number of recently completed, randomized clinical trials have demonstrated that an implantable cardiac defibrillator (ICD) can prevent sudden cardiac death in a highly selected group of high-risk patients. When these trials are viewed together, the only patients in whom the prophylactic implantation of an ICD has proven benefit are those patients identified by documented, spontaneous or inducible, sustained ventricular arrhythmias. Two randomized treatment trials (MADIT II, SCD-HEFT) are currently testing the hypothesis that implantation of an ICD will reduce mortality in patients with congestive heart failure (CHF) and left ventricular dysfunction without any further risk stratification. However, the implications of these two trials-implantation of an ICD in every patient with CHF-are unlikely to be accepted either by the medical community or by health care payers. More efficient methods of risk stratification will be necessary to identify those patients with CHF who are most likely to benefit from prophylactic treatment with an ICD. It has recently been shown that T Wave Alternans (TWA) measured during exercise is strongly associated with inducible monomorphic CVT and with subsequent spontaneous arrhythmic events. This preliminary data suggest that TWA may be an efficient and non-invasive surrogate for electrophysiologic testing to screen patients who may be at high-risk for sudden cardiac death. The purpose of this study is to evaluate the prognostic significance of TWA in a prospective epidemiologic natural history study. Ultimately, the planning of a randomized treatment trial that utilizes TWA in some combination with other risk factors to select patients at high-risk for sudden cardiac death requires answers to a number of questions from an unbiased natural history study. What is the magnitude of the increase in risk of having an arrhythmic event if TWA is present? Is the increase in risk similar for those patients with ischemic and non-ischemic cardiomyopathy? What is the relationship between TWA and the other risk factors (EF, NSVT, and RR variability)? Is the association between TWA and arrhythmic events independent of these other risk factors? What is the most clinically efficient method of combining risk factors to identify a group of patients at high-risk for having an arrhythmic event? The research described in this grant application will provide the data necessary to answer these questions.