Dysfunction of the autonomic nervous system plays a critical role in long covid and can be targeted for symptom management, new research suggests.
Slow breathing for 10 minutes, twice a day, could help alleviate symptoms of long covid, a small feasibility study has found.
A UK research team investigated a heart rate variability biofeedback intervention on patients with long covid. Patients were instructed to use a slow breathing technique for 10 minutes, twice a day, in conjunction with heart rate variability monitoring.
At the end of the four-week intervention, there were statistically significant improvements across a variety of symptom, disability and quality of life measures. Patients reported sleeping better and feeling less fatigued, less stressed and more relaxed.
“A diaphragmatic breathing technique using heart rate variability biofeedback is feasible to be used in a home setting by individuals with long covid and the intervention seems to have a potential effect on improving long covid symptoms,” wrote the authors in Advances in Rehabilitation Science and Practice.
In the trial, the slow breathing was undertaken in conjunction with heart rate variability biofeedback using a heart rate monitor, a Fitbit and a phone app. However, study lead Professor Manoj Sivan told ARR that the biofeedback wasn’t necessary for patients to benefit.
“The breathing technique is good on its own as well,” said Professor Sivan, a specialist in rehabilitation medicine at the University of Leeds.
“The biofeedback is an added advantage as the individual is getting to see that the re-tuning of the autonomic nervous system is happening and that motivates them to do it more regularly and effectively.”
The study of 13 people with long covid included instruction on the breathing technique – a four-second inhale and six-second exhale through the nose for 10 minutes twice a day. Heart rate variability was displayed in real time on the app, and participants aimed to increase it during the breathing exercise.
The primary outcome measure was the Covid-19 Yorkshire Rehabilitation Scale modified version, a validated condition-specific patient-recorded outcome measure for long covid.
Fitbit heart rate and sleep data were collected, as well as patient reported outcome measures including symptom score and quality of life measures.
Statistically significant improvements were shown across all outcome measures. Overall, the intervention was judged to be feasible for patients with long covid in a home-based setting.
The breathing technique has been shown in previous research to improve heart rate variability, which in turn has been linked with the autonomic nervous system.
“Many [long covid] symptoms such as palpitations, dizziness, fatigue, pain and breathlessness can be explained by dysfunction of the autonomic nervous system, or dysautonomia,” explained the authors.
“Lower heart rate variability has been observed to be associated with fatigue and pain symptoms of chronic fatigue syndrome/myalgic encephalomyelitis and fibromyalgia, as well as other chronic physical and mental health pathologies including asthma, anxiety and stress.”
Associate Professor Marc Russo, an anaesthetist and pain medicine specialist with the University of Newcastle, has done research on heart rate variability and the autonomic nervous system. He told ARR that he’d actually used the slow breathing technique himself to treat inappropriate sinus tachycardia after having covid.
He said in terms of long covid, we don’t have definitive, known effective treatments because we’re still trying to work out the pathophysiology.
“And it’s likely, of course, that there’s multiple aspects of disturbed pathophysiology, so no one treatment is going to help everyone,” said Professor Russo.
“But there is evolving evidence that the commonality is a disturbed autonomic nervous system and that covid can interact with that in an adverse manner.
“Heart rate variability is a good way to measure the overall health of the autonomic nervous system. And the best way to improve it is by slow breathing, also called resonant breathing, where you use a breathing technique of typically between six to 10 breaths per minute, usually with double the expiratory time compared to the inspiratory time.
“It doesn’t work straight away, it takes practice. But it’s free, there are no side effects as far as we can determine, and it can be profoundly effective.”
Marie-Claire Seeley, an Adelaide-based clinical nurse with expertise in dysautonomia and long covid, agreed the slow breathing technique was definitely worth trying.
“It’s pretty clear by now that long covid is very dominated by autonomic nervous system dysfunction,” she told ARR.
“So it’s obviously a really good target for therapy in long covid, given that there’s no curative treatment known for autonomic nervous system dysfunction. It’s all about symptom management at this point in time.”
However, she pointed out, it isn’t really understood how well and how long it will last, and that symptom modulation seems to be quite temporal. What happens longer term is unclear.
Advances in Rehabilitation Science and Practice 2024, online 28 January
