Impaired central hemodynamics in chronic obstructive pulmonary disease during submaximal exercise

Area of Science:

• Cardiovascular Physiology
• Pulmonary Medicine
• Exercise Science

Background:

• Chronic obstructive pulmonary disease (COPD) can cause cardiac structural changes and pulmonary issues, potentially affecting exercise response.
• The impact of these alterations on central hemodynamics during exercise in COPD patients remains unclear.

Purpose of the Study:

• To investigate central hemodynamic responses during submaximal exercise in COPD patients compared to healthy controls.
• To determine if static hyperinflation and intrathoracic pressure relate to impaired cardiac function in COPD during exercise.

Main Methods:

• Clinically stable COPD patients (n=13) and controls (n=10) performed constant workload exercise at a similar absolute oxygen consumption (~1.3 L/min).
• Measurements included cardiac output (acetylene rebreathe), stroke volume, heart rate, lung volumes (inspiratory capacity maneuvers), and esophageal pressure.

Main Results:

• COPD patients exhibited significantly lower cardiac output (11.0±1.6 vs. 12.2±1.2 L/min) and stroke volume (107±13 vs. 119±19 mL) at similar oxygen consumption.
• No significant difference in heart rate response was observed between groups.
• FEV1, inspiratory capacity to total lung capacity ratio (IC/TLC), and esophageal pressure were positively related to stroke volume and cardiac output.

Conclusions:

• COPD patients demonstrate attenuated cardiac output and stroke volume responses during exercise compared to controls.
• Greater static hyperinflation and more negative inspiratory intrathoracic pressures are associated with more impaired central hemodynamic responses in COPD patients during exercise.