Technology To Assess the Risk of Cardiac Arrhythmias

描述（由申请人提供）：心脏性猝死每年夺去大约30万美国人的生命。它的名字强调了迫切需要一种准确的方法来评估个体经历不稳定的心脏传播可能导致恶性心律失常的风险。我们的初步工作已经确定了一种廉价、敏感的诊断程序来进行评估。我们提出的研究将进一步探索不稳定的心电传播的生物物理特征，并提出可用于无创评估室性心律失常风险的标准。QT和RR间期的时空变化与心脏传导的稳定性密切相关。我们的初步理论和实验研究表明，稳定性可以通过测量心电图压力测试中收集的QT和RR间隔来评估，该测试采用专有的准静止运动方案（即逐渐改变运动负荷）。这是一个假设，我们建议通过研究QT间期波动和RR间期波动的相互依赖性来检验，它们伴随着准静止运动期间心率逐渐趋势的动态。我们将评估由物理学提出的不稳定心传导的定量标准，并可能作为评估心律失常风险的新的非侵入性诊断工具的基础。

DESCRIPTION (provided by applicant): Sudden cardiac death annually claims approximately 300,000 American lives. Its very name underscores the urgent need for an accurate methodology to assess an individual's risk of experiencing unstable cardiac propagation that may result in malignant arrhythmias. Our initial work has identified an inexpensive, sensitive diagnostic procedure to perform that assessment. Our proposed research will further explore the biophysical characteristics of unstable cardiac electrical propagation and suggest criteria useful for non-invasively assessing the risk of ventricular arrhythmias. QT and RR interval spatial and temporal variations are known to be intimately related to the stability of cardiac conduction. Our preliminary theoretical and experimental studies demonstrate that the stability can be assessed by measuring QT and RR intervals collected during an ECG stress test employing a proprietary quasi-stationary exercise protocol (i.e., with gradually changing exercise loads). This is a hypothesis that we propose to test by studying a mutual interdependence of the QT and RR interval fluctuations, which accompany the dynamics of the heart rate gradual trends during the quasi-stationary exercise. We will evaluate quantitative criteria for unstable cardiac conduction that are suggested by the physics and may serve as the basis for a new, non-invasive diagnostic tool for evaluating the risk of cardiac arrhythmias.