Sympathetic nervous systems in chronic cor pulmonale.

Area of Science:

• Cardiology
• Pulmonology
• Neuroendocrinology

Background:

• Chronic hypoxic states can significantly impact sympathetic nervous system (SNS) activity.
• Cor pulmonale, a complication of chronic respiratory failure, may be associated with altered SNS function.
• Understanding sympathetic activity is crucial for managing chronic respiratory conditions.

Purpose of the Study:

• To investigate sympathetic nervous activity in patients with chronic respiratory failure and hypoxia.
• To specifically assess SNS activity in chronic cor pulmonale.
• To evaluate the effects of oxygen inhalation on sympathetic markers.

Main Methods:

• Studied 23 patients with chronic respiratory failure and 30 healthy controls.
• Measured plasma concentrations of norepinephrine (NE), dopamine-beta-hydroxylase (DBH), cyclic adenosine 3',5'-monophosphate (cyclic AMP), and cyclic guanosine 3',5'-monophosphate (cyclic GMP).
• Measurements were taken before and after oxygen inhalation.

Main Results:

• Patients with chronic respiratory failure exhibited significantly higher plasma NE and cyclic AMP concentrations compared to controls.
• Elevated NE levels were observed in patients with right ventricular hypertrophy (RVH), a marker of cor pulmonale.
• Oxygen inhalation led to a significant decrease in plasma NE concentrations in patients with RVH.

Conclusions:

• A substantial number of patients with chronic respiratory failure, particularly those with cor pulmonale, present with hyper-adrenergic states.
• Hypoxia appears to be a contributing factor to this heightened sympathetic activity.
• Findings suggest that managing hypoxia may help mitigate excessive sympathetic drive in these patients.