Heart rate variability biofeedback for critical illness polyneuropathy: a randomized sham-controlled study

Area of Science:

• Neuroscience
• Cardiology
• Rehabilitation Medicine

Background:

• Critical illness polyneuropathy (CIP) is associated with autonomic nervous system dysregulation and neurocardiac dysfunction, increasing mortality risk.
• Understanding and improving neurocardiac function is crucial for managing CIP patients.

Purpose of the Study:

• To evaluate the efficacy of heart rate variability (HRV) biofeedback in improving neurocardiac function in patients with CIP.
• To assess the impact of HRV biofeedback on autonomic nervous system balance and functional recovery.

Main Methods:

• A randomized controlled trial allocated 30 CIP patients to HRV biofeedback or sham biofeedback for 14 days.
• Neurocardiac function was assessed using standard deviation of normal-to-normal intervals (SDNN) and HRV frequency domains.
• Functional recovery was measured by the Barthel index and sympathetic skin function tests.

Main Results:

• HRV biofeedback significantly increased SDNN and high-frequency HRV, indicating enhanced parasympathetic activity, sustained at 4-week follow-up.
• Patients receiving HRV biofeedback showed a significantly higher adjusted Barthel index, indicating improved functional recovery.
• No significant differences were observed in low-frequency HRV or sympathetic skin function between groups.

Conclusions:

• HRV biofeedback shows promise as a therapeutic intervention for CIP patients.
• The intervention improves neurocardiac function, particularly parasympathetic modulation, and aids in functional recovery.
• Further research is warranted to confirm these pilot findings and explore long-term effects.