PHYSIOLOGY OF HEART RATE RECOVERY AFTER SUBMAXIMAL EXERCISE IN SUBJECTS WITH CAD

该子项目是利用 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个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 研究中心，而研究中心不一定是研究者所在的机构。 运动期间和运动后猝死的风险增加。 静息副交感神经张力降低也与死亡率增加相关。 最近，运动后心率恢复减弱已被证明可以预测死亡率，但没有关于运动和副交感神经张力对心脏电生理的相互作用的信息。 本研究的目的是检验以下假设：a）在冠状动脉疾病和左心室功能不全的受试者中，副交感神经再激活对心率和QT间期恢复的影响减弱。 这将通过在伴有和不伴有中度至重度左心室功能障碍的冠状动脉疾病受试者中进行有和无副交感神经阻滞的连续运动试验进行评估; B）恢复期间心率变异性的新的非侵入性指标与副交感神经再激活对心率和QT间期恢复的影响相关。 这项研究将为副交感神经张力减弱与猝死风险之间的病理生理联系提供重要的见解。 这些结果可能支持使用特定的指数的副交感神经张力在运动和/或恢复作为预后指标，而不是指数在休息时得出的。

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. The risk of sudden death is increased during and following exercise. Diminished resting parasympathetic tone is also associated with increased mortality. Recently, attenuated heart rate recovery after exercise has been shown to predict mortality yet, no information is available regarding the interaction between exercise and parasympathetic tone on cardiac electrophysiology. The aim of the proposed study is to test the following hypotheses: a) there is diminished effect of parasympathetic reactivation on recovery of heart rate and QT interval in subjects with coronary artery disease and left ventricular dysfunction. This will be assessed by sequential exercise testing with and without parasympathetic blockade in subjects with coronary artery disease with and without moderate to severe left ventricular dysfunction; b) new non-invasive indices of heart rate variability during recovery are correlated with the effects of parasympathetic reactivation on recovery of heart rate and QT interval. This study will provide important insight into the pathophysiologic link between diminished parasympathetic tone and the risk of sudden death. The results may support the use of specific indices of parasympathetic tone during exercise and/or recovery as prognostic markers rather than indices derived at rest.