RecruitingBehavioural interventionPhenotyping Resting and Exertional Right Ventricular Dysfunction Among Patients With Chronic Obstructive Pulmonary DiseaseThis study plans to learn about heart function among individuals with chronic obstructive pulmonary disease (COPD). In particular, the investigators want to understand the different patterns of right ventricular response during rest and moderate- vs high-intensity exercise. By identifying patterns of right ventricular dysfunction, this study will help identify better treatments for patients with COPD in the future.