Heart-Lung Interactions & Cardiovascular Insufficiency

我们将使用心肺相互作用的临床分析作为培养博士后候选人的工具。这是一种极好的和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，要求学员学习使用最先进的成像技术，并将其广泛应用于手术室、ICU、普通医院病房和门诊诊所。通风和呼吸机操作对血液动力学有深远的影响，但往往知之甚少，特别是在发生心肺衰竭时。尽管许多研究人员研究了心肺相互作用，但一直缺乏准确的临床应用。我们的目标是开发和验证临床上相关且易于使用的床边工具，以快速而明确地诊断血液动力学不全的病因以及呼吸机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手术套间作为我们的研究环境。为了实现这些目标，我们正在检验三个假设：1)机械通气引起的左心室前负荷和后负荷的变化在用力和放松的自发和正压吸气之间是非线性的。2)低水平的呼气末正压通过增加ITP来最大限度地减少心室相互依赖性和左心室射血不同步，从而改善左心室性能。3)通过分析自主和正压通气的动脉脉压反应，可以很容易地识别左心室收缩储备和前负荷反应性(通常是心功能谱的相反两端)和动脉张力。我们将使用最先进的超声心动图成像技术(声学定量和组织多普勒成像)来综合分析左心功能，并使用简单的主动脉-脉冲多普勒和动脉压波形分析来评估前负荷反应性、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.