Resting and exercise echocardiology

我的NSERC资助的研究项目的总体目标是了解在休息和运动时决定弥散能力和肺气体交换的因素。 运动代表了对肺系统的压力，以维持工作肌肉的足够气体交换和氧合。由于肺动脉压升高继发的毛细血管募集/扩张，肺内的扩散能力从休息到峰值运动增加。毛细血管募集/扩张的第二个益处可能是心脏力学的改善。尽管扩散能力增加，但大多数健康人在运动期间显示出气体交换受损，这可能是由于：1）继发于高心输出量的扩散限制，2）绕过肺内气体交换单元的解剖学肺内动静脉栓塞（IPAVA）的募集。 所申请的超声系统（EPIQ CVx超声系统）是支持拟议的NSERC发现资助所必需的，该资助旨在未来5年内研究这些机制。心脏超声器械将在静息和运动时用于：1）使用生理盐水超声造影检测IPAVA，2）通过心脏多普勒测定肺动脉压，3）通过多普勒超声心动图评估心输出量。此外，这种新设备允许3D成像以及心肌应变的确定。这些新技术将允许在休息和运动时对心脏力学/应变进行更全面的评价，并提供对扩散能力募集和心脏力学之间关系的更深入了解。该设备的先进图像质量也将使我们能够探索人工智能在心脏评估中的应用。 我的实验室是独一无二的，因为它是世界上唯一能够进行运动弥散能力和多种惰性气体消除技术来评估通气-灌注匹配和弥散限制的实验室。这两种肺部技术，再加上一种新的尖端心脏超声设备，将使加拿大能够建立一个无与伦比的实验室来研究心肺生理学，这将为进行创新研究和培养下一代生理学科学家提供一个丰富的环境。

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.