PROGNOSTIC SIGNIFICANCE OF T WAVE ALTERNANS

描述(逐字摘自申请人摘要)：心源性猝死 在美国每年大约有40万人死亡，而且仍然是 流行比例的健康问题。大多数心脏猝死是由 由致命性室性心律失常引起。一项旨在初级预防的努力 心脏性猝死需要有效地识别处于 发生这些心律失常的风险足够高，足以保证积极 预防性治疗。一些最近完成的随机临床试验 试验表明，植入式心脏除颤器(ICD)可以 在高度精选的高危患者组中预防心脏性猝死。 当将这些试验放在一起观察时，唯一的患者 预防性植入ICD已被证实有益于这些患者 由记录在案的、自发的或可诱导的、持续的心室识别 心律不齐。 两个随机治疗试验(MADIT II，SCD-HeFT)目前正在测试 假说植入ICD将降低慢性阻塞性肺疾病患者的死亡率 充血性心力衰竭和左心功能不全 进一步的风险分层。然而，这两个因素的影响 在每个CHF患者身上植入ICD的试验不太可能 要么被医学界接受，要么被医疗保健支付者接受。更多 必须采用有效的风险分层方法来识别这些风险 最有可能从预防性治疗中受益的CHF患者 带着ICD。 最近有研究表明，在运动过程中测量的T波交替(TWA) 与诱导性单态CVT和随后的 自发性心律失常事件。这些初步数据表明，环球航空可能是一种 高效非侵入性电生理检测代用品的筛选 可能是心脏性猝死高危人群。 本研究的目的是评价TWA对急性髓细胞白血病患者预后的影响。 一项前瞻性的流行病学自然历史研究。归根结底，规划 一项随机治疗试验，利用TWA和其他药物的某种组合 选择心源性猝死高危患者的危险因素需要 一项不偏不倚的自然历史研究对一些问题的回答。什么 是TWA发生心律失常事件风险增加的幅度 到场了吗？对于那些患有缺血性心脏病的患者来说，风险的增加是否类似 和非缺血性心肌病呢？环球航空公司和环球航空公司之间有什么关系？ 其他危险因素(EF、nsVT和RR变异性)？是指两者之间的关联 TWA和心律失常事件与这些其他危险因素无关？什么是 临床上最有效的结合危险因素来识别群体的方法 发生心律失常事件的高危患者的比例？这项研究描述了 在这项拨款申请中，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.