Heart-Lung Interactions & Cardiovascular Insufficiency

我们将利用心肺相互作用的临床分析作为培养博士后候选人的载体。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，并要求受训者学习使用最先进的成像技术，广泛应用于手术室、ICU、综合医院病房和门诊。通气和通气操作具有深刻的血流动力学影响，但通常知之甚少，特别是在心肺衰竭的情况下。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。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)通风引起的左室前负荷和后负荷的变化在强力和放松自发和正压吸气之间是非线性的。2)低呼气末正压水平通过增加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（声学量化和组织多普勒成像）进行左室表现的复杂分析，并使用简单的主动脉脉冲多普勒和动脉压力波形分析来评估预负荷反应性、收缩储备和动脉张力，以获得临床有用的信息。

We shall use the clinical analysis of heart-lung interactions as the vehicle 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 imaging techniques with broad applications to the operating room, ICU, general hospital ward and out- patient clinic. Ventilation and ventilatory maneuvers have profound and often poorly understood hemodynamic effects especially in the setting of cardio-respiratory failure. Although numerous investigators have studied heart-lung interactions, an accurate clinical application has been lacking. 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 echocardiographic clinic and the cardiac surgery suite. To accomplish these goals we are testing three hypothesis: 1) Ventilation-induced changes in LV preload and afterload are non-linear between forceful and relaxed spontaneous and positive- pressure inspiration. 2) Low levels of positive end-expiratory pressure improve 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 (acoustic quantification and tissue Doppler imaging) for complex analysis of LV performance and simple aortic-pulsed Doppler and arterial pressure waveform analysis to assess preload-responsiveness, contractile reserve and arterial tone to derive clinically useful information.