Heart rate variability biofeedback in patients with functional dizziness, 2025, Simon et al

Andy

Retired committee member
Abstract

Background
Functional dizziness is one of the most common causes of chronic dizziness. Associated psychiatric diseases such as depression and anxiety lead to significant impairment, possibly due to autonomic nervous system imbalance. We investigated whether heart rate variability (HRV) biofeedback can modulate autonomic function in patients with functional dizziness.

Methods
We performed a randomized controlled study in 24 patients diagnosed functional dizziness for the first time. Patients received six 20 min sessions of HRV biofeedback or no intervention. We assessed HRV (time and frequency domains), sympathetic vasomotor function, sympathetic skin response and psychometric assessments at baseline, immediately post-intervention (or control period) and another 3 and 6 weeks later.

Results
Patients in the HRV biofeedback group showed improved cardiac autonomic function with elevated HRV time-dependent parameters immediately post-intervention [Root Mean Square of Successive Differences (RMSSD): 71.2 ms ± 38 ms vs. 38.2 ms ± 18.5 ms, p = 0.014; Standard Deviation of all NN Intervals (SDNN): 78.3 ms ± 35.9 ms vs. 48.1 ms ± 20.5 ms, p = 0.001], increased HRV frequency-dependent parameter [Low Frequency (LF): p = 0.001], as well as reduced depressiveness (BDI-II: p = 0.0236). None of these parameters were changed in control patients (p = ns). Dizziness-associated symptoms and sympathetic function of vasculature and sweat glands were unaltered in both study arms.

Conclusion
In a randomized controlled pilot study, HRV biofeedback led to improved autonomic cardiac function and alleviated symptoms of depression in patients with functional dizziness, most likely mediated by a predominantly parasympathetic effect.

Open access
 
415_2025_12988_Fig2_HTML.png
 
So they did a test of a treatment for dizziness and it made no difference to the dizziness. So a fail then.

But instead they focus the conclusion on other things that did show some between group differences, and don't mention dizziness.
Yes. I have not been able to find the protocol to check if there was any outcome switching.
 
From those graphs, it looks like the treatment group had a significant change at 14 days that was gone by the later days. So a transient change in HRV that wore off fast.

I wonder if something about the hope and trying to be well rested at the start of a new treatment affects HRV, and wears off as they reailse it's making no difference to their dizziness.
 
From those graphs, it looks like the treatment group had a significant change at 14 days that was gone by the later days. So a transient change in HRV that wore off fast.

I wonder if something about the hope and trying to be well rested at the start of a new treatment affects HRV, and wears off as they reailse it's making no difference to their dizziness.
HRV can be affected by so many things, so the changes might be due to the intervention.

But that also means that changes to HRV can be completely insignificant for you condition. As observed here.
 
Back
Top Bottom