Sympathetic nervous systems in chronic cor pulmonale

Twenty-three patients with chronic respiratory failure and 30 normal subjects were studied to assess the sympathetic nervous activity in chronic hypoxic states, especially in chronic cor pulmonale. Of the 23 patients, 13 had a right ventricular hypertrophy (RVH) pattern on the electrocardiogram. Plasma norepinephrine (NE), dopamine-beta-hydroxylase (DBH), cyclic adenosine 3',5'-monophosphate (cyclic AMP) and cyclic guanosine 3',5'-monophosphate (cyclic GMP) concentrations were measured before and after oxygen inhalation. Plasma NE concentrations were 0.57 +/- 0.07 ng/ml in patients with chronic respiratory failure and 0.22 +/- 0.02 ng/ml in controls (p less than 0.001). Moreover, plasma NE concentrations were higher in patients with RVH than without (p less than 0.05), and these concentrations decreased significantly (p less than 0.05) in the former patients after oxygen inhalation. Plasma cyclic AMP concentrations were 31.2 +/- 2.6 pmol/ml in cases of chronic respiratory failure and 17.4 +/- 0.7 pmol/ml in controls (p less than 0.001) with no difference in plasma cyclic GMP and DBH concentrations. These results suggest that a significant proportion of patients with chronic respiratory failure, especially with cor pulmonale, were in hyper-adrenergic states partially due to hypoxia.