Heart-lung interactions and the effect on cardiac and vascular mechanics

心脏、肺和血管都是相连的，它们对维持血压和血液流动至关重要，从而向器官和工作肌肉输送氧气和燃料。从历史上看，研究人员已经使用动物和人体实验来研究肺部的变化如何影响心脏，主要是通过压力的机械变化和强迫呼吸。相比之下，我们实验室的长期目标是加强对肺、心脏和血管在自主呼吸过程中如何相互作用的理解，并研究一个或多个关键系统的变化如何影响其他系统的机械和功能特性。我的实验室和受训者之前已经研究了胸腔负压的变化、肺容量的变化和肺部血管大小的变化是如何影响心脏及其产生的血流的基本方面。然而，对于心脏如何对这些压力源做出机械反应，血管内的血液流动是否会影响它们的功能，以及当心脏和肺部同时承担单独的负荷时，血管的变化是否会改变它们之间的相互作用，目前所知甚少。利用复杂的成像技术，我们可以看到心脏是如何旋转填充和收缩的，我们将研究心脏的机制如何对肺部和血管施加的压力做出反应。此外，我们将利用一系列的研究来改变：1)心脏中的血液量，2)心脏收缩和增加心率的能力，3)血管对心脏的负荷，试图确定心脏机械地适应肺部不同生理变化的具体机制。这项拟议的研究将大大提高我们对三个基本系统如何协同工作以及心脏如何机械地适应来自肺和血管的生理压力的认识。通过这些研究，我们也希望能够确定当人体长期受到挑战时，心脏和血管发生变化的潜在新机制，并为研究生提供一个高质量的学习环境，以加强他们在人类生物学方面的训练。

The heart, lungs and blood vessels are all connected and are critical to maintain blood pressure and blood flow for the delivery of oxygen and fuel to the organs and working muscles. Historically, researchers have used animal and human experiments to look at how changes in the lungs may affect the heart, primarily through mechanical changes in pressure and with forced breaths in or out. In contrast, a long-term goal of our laboratory is to enhance understanding of how the lungs, heart and blood vessels interact during spontaneous breathing and to examine how a change in one or more of these critical systems influence the mechanical and functional properties of the others. My laboratory and trainees have previously investigated fundamental aspects of how changes in negative pressures that occur in the chest, changes in lung volumes and changes in the size of blood vessels within our lungs influence the heart and the blood flow it generates. However, little is currently known regarding how the heart mechanically responds to these stressors, whether blood flow within the blood vessels effect how they function and whether changes in our blood vessels alter how the heart and lungs interact when they also impose a separate load to the heart. Utilizing sophisticated imaging techniques that allow us to look at how the heart rotates to fill and contract, we will examine how the mechanics of the heart respond to stressors imposed by the lungs and blood vessels. Furthermore, we will utilize a series of studies that alter: 1) the amount of blood in the heart, 2) the ability of the heart to contract and increase heart rate and 3) the load that the blood vessels place on the heart to try and determine the specific mechanisms by which the heart mechanically adjusts to different physiological changes within the lungs. The proposed research will greatly enhance our knowledge of how three essential systems work together and how the heart mechanically accommodates physiological stresses imposed from the lungs and blood vessels. Through these studies we also hope to identify potential new mechanisms that contribute to the changes in heart and blood vessels that occur when the human body is chronically challenged, as well as provide a high-quality learning environment for graduate students to enhance their training in human biology.