Cardiovascular Limitation in Chronic Obstructive Pulmonary Disease Patients Using Cardiopulmonary Exercise Test

ORIGINAL ARtIcLein COPD patients using CPET and correlated the cardiovascular response with transthoracic echocardiography findings. Materials a n d MethodsThis study was conducted in the Department of Pulmonary and Critical Care Medicine at Metro Hospitals and Heart Institute, Noida, India.This was a retrospective cross-sectional study, and the sample size was calculated using the Daniel 1996 formula, 12 introduction Cardiopulmonary exercise test (CPET) provides an integrative assessment of the cardiovascular, respiratory, skeletal muscle, and metabolic functions of the body. 1 CPET is performed using either a treadmill or a cycle ergometer to evaluate exercise tolerance, undiagnosed exercise intolerance, or patients presenting with respiratory symptoms. 1CPET is clinically useful in patients with chronic obstructive pulmonary disease (COPD) to assess factors, other than respiratory, that may be contributing to their exercise limitation. 2 Moreover, as COPD and heart failure share common risk factors, such as cigarette smoking, they are likely to be present together in a patient. 3 COPD prevalence ranges from 23 to 33% in heart failure patients, 4 whereas heart failure is present in 5-41% of COPD patients. 5Moreover, a reduced forced expiratory volume in 1 second (FEV 1 ) is an independent risk factor for ischemic heart disease 6 due to an increase in systemic inflammation in patients with COPD. 7xygen pulse in CPET expresses the volume of oxygen ejected from the ventricles with each systole and is defined as oxygen uptake (V O2 ) divided by heart rate. 1 Oxygen pulse significantly correlated with stroke volume (SV) at rest and at peak exercise on a cycle ergometer in healthy controls and only at rest in patients with heart failure with preserved ejection fraction.8 Oxygen pulse also correlated with SV obtained by radionuclide testing in patients with ischemic heart disease.9 Furthermore, oxygen pulse is often reduced in patients with COPD due to dynamic hyperinflation.Dynamic hyperinflation (by increasing intrathoracic pressure) can impair cardiac function, either by reducing blood return to the right ventricle or by increasing the afterload of the left ventricle.10 Oxygen pulse obtained at maximum exercise is also a predictor of survival in patients with COPD. 1 In this study, we evaluated the cardiovascular response 1,