The effect of paired associative stimulation with a high-intensity cortical component and a high-frequency peripheral component on heart rate and heart rate variability in healthy subjects

Front. Rehabil. Sci., 2023 · DOI: 10.3389/fresc.2023.1200958 · Published: July 26, 2023

Cardiovascular Science Physiology Rehabilitation

Simple Explanation

This study investigates the effects of a novel paired associative stimulation (PAS) protocol, called high PAS, on the cardiovascular system, specifically heart rate variability (HRV), in healthy individuals. High PAS combines high-intensity transcranial magnetic stimulation (TMS) and high-frequency peripheral nerve stimulation (PNS) and was developed for spinal cord injury rehabilitation. The study found that high PAS does not have sustained effects on cardiovascular functions and indicates higher parasympathetic activity during stimulation, plausibly due to participants being still during the session.

Study Duration

Not specified

Participants

17 healthy individuals (10 females, seven males, mean age 29 ± 7.8 years)

Evidence Level

Original Research

Key Findings

1
A significant decrease in low-frequency (LF) power and low-frequency to high-frequency (HF) ratio was observed during stimulation, indicating increased parasympathetic activity.
2
The changes in HRV were fully reversible immediately after stimulation, suggesting that the cardiovascular effects of high PAS are transient.
3
Sham stimulation exhibited a similar trend to active high-PAS stimulation, suggesting that being still and quiet during the stimulation session might contribute to the observed HRV changes.

Research Summary

This study evaluated the acute cardiovascular effects of a 20-min session of high PAS on 17 healthy individuals by measuring heart rate variability (HRV). The results showed a transient increase in parasympathetic activity during stimulation, as indicated by changes in HRV parameters such as LF power and HF power. The authors concluded that high PAS is safe and does not have sustained cardiovascular effects in healthy individuals, suggesting it's a promising therapy for neurological patients.

Practical Implications

Safety of High PAS

The study suggests that high PAS is a safe neuromodulation technique for use in healthy individuals.

Potential for SCI Rehabilitation

The lack of sustained cardiovascular effects supports the continued development of high PAS as a rehabilitation tool for spinal cord injury patients.

Influence of Sedentary Behavior

The study highlights the importance of considering the influence of sedentary behavior on HRV measurements during neuromodulation studies.

Study Limitations

1
The study was conducted on healthy individuals, and the results may not be generalizable to patient populations.
2
The sample size for the sham stimulation group was small (n=5), which may have limited the statistical power to detect significant differences.
3
The follow-up period was limited to 60 minutes, and longer-term cardiovascular effects of high PAS were not assessed.

Your Feedback

Was this summary helpful?

Back to Cardiovascular Science