Slow-Paced Breathing and Autonomic Function in People Post-stroke.

Area of Science:

• Cardiovascular Physiology
• Neurology
• Respiratory Medicine

Background:

• Stroke survivors often experience autonomic dysfunction, impacting cardiovascular regulation.
• Baroreflex sensitivity (BRS) and heart rate variability (HRV) are key indicators of autonomic function.
• Impaired autonomic function post-stroke is linked to increased cardiovascular risk.

Purpose of the Study:

• To investigate the acute effects of slow breathing at 6 breaths/min on BRS, HRV, and blood pressure (BP) in adults post-stroke.
• To compare the effects of slow breathing (6 breaths/min) with a typical breathing rate (12 breaths/min).

Main Methods:

• Twelve adults post-stroke participated in a randomized crossover study.
• Participants performed 15-minute breathing exercises at 6 breaths/min (slow) and 12 breaths/min (control).
• Continuous BP and heart rate (HR) were monitored, with BRS, HRV, and BP analyzed pre-, during-, and post-exercise.

Main Results:

• Slow breathing increased BRS by 10% and BRS response to BP elevations (BRSup) by 30%.
• Both breathing conditions led to acute decreases in HR and systolic BP.
• Heart rate variability (HRV) measures, including total power, low frequency power, and SDNN, increased during slow breathing.

Conclusions:

• Acutely, slow breathing (6 breaths/min) may enhance BRS, particularly BRSup, in individuals post-stroke.
• Paced breathing, at both slow and typical rates, offers acute benefits by reducing BP and HR and improving HRV.
• These findings suggest breathing exercises as a potential non-pharmacological intervention for cardiovascular regulation post-stroke.