Grant: Research Tools and Instruments

The overall objective of my NSERC-funded research program is to understand factors determining diffusing capacity and pulmonary gas exchange at rest and during exercise. Exercise represents a stress to the pulmonary system to maintain adequate gas exchange and oxygenation for the working muscles. Diffusion capacity within the lung increases from rest to peak exercise due to capillary recruitment/distention secondary to increased pulmonary arterial pressure. A secondary benefit of capillary recruitment/distention may be an improvement in cardiac mechanics. Despite the rise in diffusion capacity, most healthy humans show an impairment in gas exchange during exercise, which may be due to: 1) a diffusion limitation secondary to high cardiac output, 2) the recruitment of anatomical intra-pulmonary arteriovenous anastomoses (IPAVAs) which bypass the gas exchange units within the lung. The requested ultrasound system (EPIQ CVx Ultrasound System) is necessary to support the proposed NSERC Discovery Grant which aims at investigating these mechanisms over the next 5 years. The cardiac ultrasound device will be used at rest and during exercise to: 1) detect IPAVAs using saline contrast echocardiography, 2) determine pulmonary artery pressure by cardiac Doppler, and 3) assess cardiac output by Doppler echocardiography. Further, this new device allows for 3D imaging as well as determination of myocardial strain. These new techniques will allow for a more comprehensive evaluation of cardiac mechanics/strain both at rest and exercise and provide greater insight into the relationship between diffusion capacity recruitment and cardiac mechanics. The advanced image quality of this device will also allow us to explore the use of artificial intelligence in cardiac evaluation. My laboratory is unique as it is the only laboratory in the world capable of conducting both exercise diffusing capacity and the multiple inert gas elimination technique to evaluate ventilation-perfusion matching and diffusion limitation. These two pulmonary techniques, combined with a new cutting-edge cardiac ultrasound device, would allow for an unparalleled laboratory to examine cardiopulmonary physiology in Canada, which would provide a rich environment to conduct innovative research and train the next generation of scientists in physiology.