To Compare the Cardiac Output Response and Severity in COPD Patients when Subjected to a Submaximal Upper Limb Exercise

Patients with Chronic obstructive pulmonary disease (COPD) are exposed to expiratory loads and dynamic hyperinflation as a consequence of expiratory flow limitation. So the alterations in lung mechanics might affect cardiac function. This altered haemodynamic response in COPD patients are more pronounced during physical activity than at the resting state. This is one of the main cause of exercise intolerance. This study tries to correlate the severity of COPD with exercise induced cardiac output response.

This study was carried out in two groups with 30 in each group, Group A as controls and Group B with established COPD patients. Group B were again subdivided into Mild subgroup, Moderate subgroup and Severe subgroup depending on their FEV1% which is commonly used to assess the severity of COPD. Pulmonary function tests parameters (mainly FEV1%, FEV1/FVC%,) were assessed by Spirometer. The cardiac output and stroke volume were measured by the Cardiac Output Monitor using bio-impedance method initially in the resting subject. Then the subject was asked to perform handgrip at fifty percent of the maximum strength for thirty seconds and peak cardiac output and stroke volume was measured again without altering the posture of the volunteer.

As the Severity of COPD increases, Basal cardiac output was at a higher level compared to controls and raise in cardiac output during exercise was less when compared to controls. We conclude that the cardiac parameters limit the exercise endurance in the moderate and severe COPD patients.