Effects of acute hypoxia on left and right ventricular contractility in chronic obstructive pulmonary disease

Abstract

The purpose of this investigation was to assess the effects of acute hypoxia on left (LV) and right ventricular (RV) contractility in clinically stable chronic obstructive pulmonary disease (COPD) patients. Eleven male patients (mean age 52.4 ± 12.6 years) who were diagnosed to have COPD were included into the study. All of the patients underwent left and right heart catheterization. RV contractility was measured according to the method of Ferlinz and LV contractility according to the method of Kennedy and colleagues using indirect digital substraction angiography. Mean pulmonary artery pressures (Mean P_PA) and oxygen saturation of the pulmonary artery (S_aO₂) were measured before and at each stage of graded hypoxic exposure 14%, 12%, and 10% of O₂. Right atrial pressures (P_RA,syst, P_RA,diast, P_RA,mean), RV pressures (P_RV,syst, P_RV,diast, P_RV,mean, P_RV,end-diast), RV and LV end-diastolic volume index (EDVI), end-systolic volume index (ESVI), stroke volume index (SVI), cardiac index (CI), ejection fraction (EF), and heart rate (HR) were calculated before and after breathing a hypoxic mixture of 10% of O₂ for 30 minutes. Acute hypoxia induced significant elevation of mean P_PA, P_RA,syst, P_RA,diast, P_RA,mean, P_RV,syst, P_RV,mean, P_RV,end-diast, RV EDVI, RV ESVI, LV EDVI, LV ESVI, decreased significantly after acute hypoxia confidence interval, and HR (p < 0.05). Whereas S_aO₂ (p < 0.05). These findings suggest that the systolic performance of the right and left ventricles were well-maintained during acute hypoxia in patients with COPD.

Keywords:

• acute hypoxia
• obstructive pulmonary disease
• ventricular contractility