Heart-Lung Interactions & Cardiovascular Insufficiency

描述（申请人提供）：我们将以心肺相互作用和收缩不同步的临床分析为载体，培养博士后候选人。这是一个极好的、被证明有效的指导途径，因为它基于临床相关的心肺生理学，要求受训者学习使用最先进的监测和成像技术，广泛应用于手术室、ICU、综合医院病房和门诊。尽管许多研究者研究了心肺相互作用，但缺乏准确的临床应用。通气和通气操作具有深刻的且最近才有文献记载的血流动力学效应，可用于定义心肺衰竭。我们的目标是开发和验证临床相关且易于应用的床边工具，用于快速明确诊断血流动力学不全的病因，以及通气和辅助心血管治疗对其的影响。我们使用ICU，超声心动图诊所和心脏外科套房作为我们的研究环境。为了实现这些目标，我们测试了三个假设：1)正压诱导的左室前负荷和后负荷的变化受到收缩性和有效循环血容量的不同影响。2)呼气末正压通过增加ITP减少心室相互依赖和左室射血不同步来改善左室功能。3)左室收缩储备和负荷前反应（通常是心功能谱的两端）和动脉张力可以很容易地通过分析动脉脉压对自发和正压通气的反应来识别。我们将使用最先进的超声心动图成像技术（斑点跟踪和组织多普勒成像）对左室表现进行复杂分析，并使用简单的主动脉多普勒和动脉压力波形分析来评估预负荷反应、收缩储备和动脉张力，以获得临床有用的信息。

DESCRIPTION (provided by applicant): We shall use the clinical analysis of heart-lung interactions and contraction dyssynchrony as the vehicles for training post-doctoral candidates. This is an excellent and proven productive pathway for mentoring because it is based in clinically relevant cardiopulmonary physiology and requires the trainee to learn to use state-of- the-art monitoring and imaging techniques with broad applications to the operating room, ICU, general hospital ward and out-patient clinic. Although numerous investigators have studied heart-lung interactions, an accurate clinical application has been lacking. Ventilation and ventilatory maneuvers have profound and only recently documented understood hemodynamic effects that can be used to define cardio-respiratory failure. Our goal is to develop and validate clinically relevant and easily applicable bedside tools for the rapid and unambiguous diagnosis of the etiology of hemodynamic insufficiency and the impact of ventilatory and adjunct cardiovascular therapies upon it. We use as our research environment, the ICU, echocardiographic clinic and the cardiac surgery suite. To accomplish these goals we are testing three hypotheses: 1) Positive-pressure induced changes in LV preload and afterload are differentially affected by contractility and effective circulating blood volume. 2) Positive end-expiratory pressure improves LV performance by minimizing ventricular interdependence and LV ejection asynchrony by increasing ITP. 3) LV contractile reserve and preload responsiveness (often opposite ends of the cardiac function spectrum) and arterial tone can be readily identified by analysis of the arterial pulse pressure responses to spontaneous and positive-pressure ventilation. We shall use state-of-the- art echocardiographic imaging techniques (speckle tracking and tissue Doppler imaging) for complex analysis of LV performance and simple aortic Doppler and arterial pressure waveform analysis to assess preload- responsiveness, contractile reserve and arterial tone to derive clinically useful information.