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

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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.