Pressor effect of hyperventilation in healthy subjects

Area of Science:

• Physiology
• Cardiovascular Research
• Psychophysiology

Background:

• Panic disorder frequently involves hyperventilation.
• A link between panic disorder and hypertension has been previously suggested.
• The direct effect of hyperventilation on blood pressure in healthy individuals requires clarification.

Purpose of the Study:

• To investigate the acute effects of hyperventilation on blood pressure (BP), heart rate, and electrocardiogram (ECG) in healthy subjects.
• To explore the relationship between the volume of air expired during hyperventilation and cardiovascular changes.
• To assess potential ECG alterations associated with hyperventilation.

Main Methods:

• A randomized, two-period, cross-over study design was employed.
• Twenty-six healthy subjects underwent periods of hyperventilation and normal breathing.
• Measurements included sitting BP, heart rate, and ECG over a 40-minute observation period.

Main Results:

• Hyperventilation induced significant increases in systolic BP (8.9 mm Hg), diastolic BP (8.2 mm Hg), mean arterial pressure (10.0 mm Hg), and heart rate (36 beats/min).
• Changes in diastolic and mean arterial pressure correlated with expired air volume but not with expired carbon dioxide levels.
• Inferior lead T wave changes were observed in 10 out of 26 subjects during hyperventilation.

Conclusions:

• Acute hyperventilation significantly elevates blood pressure and heart rate in healthy individuals.
• The findings support the need for further research into the role of hyperventilation in the association between panic disorder and hypertension.
• Hyperventilation may contribute to cardiovascular changes relevant to anxiety disorders.