Cardiac and Pulmonary Response to Peak Exercise in Patients with Chronic Obstructive Pulmonary Disease / 中国运动医学杂志

ABSTRACT

Objective To study the effects of cardiac and pulmonary response in pailents with chronic obstructive pulmonary disease(COPD) on their exercise capacity.Methods Thirty four patients with COPD(including 8 patients in stage Ⅰ,15 patients in stage Ⅱ,10 patents in stage Ⅲ and 1 patent in stage Ⅳ and 24 healthy controls performed incremental exercise testing.Oxygen uptake(VO_2) and carbon dioxide output(VCO_2)were measured breath-by-breath.Arterial blood samples were drawn both at rest and peak exercise.Results The VO_2 at peak exercise was significantly lower in COPD group than in control group(15.81±3.65ml/min/kg vs 18.96±6.10ml/min/kg,P=0.042).The respiration reserve was lower in COPD patients compared to controls.The rBorg dyspnea score at the peak exercise for COPD patents was 4.24±2.01,significantly higher than that for controls(1.754±1.50).Oxygen pulse and heart rate reserve had not statistically difference between COPD group and control group.Significant increase of PO_2 and PCO_2 were found during exercise,which were 26.374±15.40 vs 10.26±22.65 mmHg and 42.33±3.65 vs 40.29±4.46 mmHg respectively compared to at rest.Conclusion Abnormal pulmonary response to exercise might be the main cause inducing exercise intolerance in patents with COPD.