Effect of impairement in left ventricular filling pressure on exercise tolerance in patients with chronic obstructive pulmonary disease

Background Chronic obstructive pulmonary disease (COPD) is a progressive irreversible obstruction in the airways that could be preventable. It has some significant extrapulmonary adverse effects that add to severity of the disease. Impaired left ventricular filling is commonly associated with patients with COPD. Objective To detect the relationship between COPD severity and diastolic dysfunction grading and their effect on exercise tolerance. Patients and methods The study was conducted on 70 patients with stable COPD, excluding those with known cardiac diseases and those having any known contraindication to cardiopulmonary exercise test. Chest radiograph, computed tomography chest, ECG, spirometry, cardiopulmonary exercise test, and echocardiography were done for all included patients. Results Left ventricular diastolic dysfunction (LVDD) was found in all COPD study cases. There is a statistically significant inverse relation between LVDD severity and COPD severity among study cases (r=-0.566, P=0.000). Grades of diastolic dysfunction had statistically significant inverse correlation with amount of oxygen consumption (VO2 ml/kg/min) at anaerobic threshold, maximal exercise, and percentage of functional capacity (VO2 max/predicted %), represented by r=-0.332, P=0.005; r=-0.398, P=0.001; and r=-0.404, P=0.001, respectively. There was a significant negative correlation between severity of LVDD in patients with COPD and oxygen pulse (VO2/heart rate) at anaerobic threshold (r=-0.473, P=0.000) and at maximal exercise (r=-0.81, P=0.000). Conclusion There is increased prevalence of diastolic dysfunction of left ventricle in patients with COPD. Both COPD and LVDD can aggravate each other. Presence of LVDD in patients with stable COPD impairs their functional capacity even in mild grades of LVDD.