The Significance of HRV in Long COVID
HRV Insight: Why HRV Can Play a Crucial Role in Long COVID Management!
In our HRV Insight series, Dr Alfred Lohninger, CEO and Medical Director of Autonom Health GesundheitsbildungsGmbH, explores and documents various HRV-related topics, including current research areas. In this blog post, we delve into the highly relevant subject of Long COVID.
We have thoroughly examined the latest research on Long COVID, maintaining active dialogue with recognised experts in the field. Through our analysis of “COVID measurements” in our database, we have identified fascinating HRV patterns. Below, we present a concise overview of current findings. The statements referenced here draw from German and Austrian guidelines, cite the most significant scientific works to date, and provide insight into the various theories being discussed regarding the development and treatment of Long COVID.
WHAT IS LONG OR POST COVID?
To date, there is no universally accepted definition of Long/Post COVID. The World Health Organisation (WHO), the CDC (Centers for Disease Control and Prevention), and the RKI all reference the proposal put forward by the British National Institute for Health and Care Excellence (NICE).
This definition states: The nature of the condition lies in the persistence of symptoms following SARS-CoV2 infection or vaccination against the pathogen, similar to other infectious diseases. Symptoms persisting beyond four weeks post-infection are classified as Long COVID, while those lasting more than twelve weeks are termed Post COVID syndrome.
Causes
The precise causes remain undetermined. The persistence of the virus or viral components within the body may play a significant role. Potential mechanisms include tissue structures damaged by Covid-19, particularly damage to blood vessel linings resulting in disrupted blood circulation and coagulation. Other factors include immune system dysfunctions leading to autoimmune responses, excessive inflammatory reactions, disturbances in fluid and mineral balance, and possible side effects from COVID-19 treatments. The prolonged presence of viral components in the body over weeks or months could be particularly significant.
HOW COMMON IS LONG COVID?
According to the Robert Koch Institute’s (RKI) analysis of 23 review papers (scientific publications summarising current research) and 102 original research papers (studies aimed at generating new insights), the findings are noteworthy. Among adults who did not require hospitalisation for Covid-19, between 7.5% and 41% experienced long-term effects. For hospitalised adults, 37.6% reported ongoing health consequences.
HOW DOES THE ILLNESS PROGRESS?
All three components of the Autonomic Nervous System – the sympathetic, parasympathetic, and enteric nervous systems – evidently play a confirmed role in Long COVID’s progression. Dysautonomia emerges as a central pathophysiological mechanism, becoming a crucial signpost for research.
- The virus leads to DYSFUNCTION of organs
- This dysfunction impacts the Enteric, Parasympathetic and Sympathetic Nervous Systems, resulting in DYSAUTONOMIA
- Persistent dysautonomia leads to EXHAUSTION or
- Anxiety, uncertainty, and feelings of abandonment intensify FATIGUE
- Dysautonomia triggers further DYSREGULATION of organ functions
- The dysregulation of organ functions and dysautonomia cause Long COVID SYMPTOMS
- Dysautonomia alters HEART RATE VARIABILITY
Diagnosis
The diagnosis of Long/Post COVID Syndrome cannot be confirmed through a single laboratory test or a panel of laboratory values. Similarly, normal laboratory results do not rule out Long/Post COVID Syndrome. Long COVID is primarily diagnosed clinically, based on presenting symptoms.
Symptoms
There are numerous symptoms associated with the condition. A significant proportion of the most common symptoms can be definitively verified through HRV. These include:
- Performance and activity limitations, characterised by exertion-induced symptom deterioration
- Breathlessness and shortness of breath (both at rest and during activity)
- Non-restorative sleep/sleep disorders
- Altered breathing patterns
- Stress
- Tachycardia.
Common symptoms that cannot be verified through HRV analysis:
- Headaches
- Loss or disturbance of smell, altered taste perception
- Coughing
- Depressive moods
- Anxiety
- Post-traumatic stress disorder symptoms
- General pain symptoms
- Cognitive impairments
- Compulsive behaviours
- Hair loss
Primary Symptom
Patients with Long/Post COVID most frequently report ‘fatigue’ as their most characteristic and defining symptom. This manifestation occurs following various viral infections and is termed Chronic Fatigue Syndrome or Chronic Exhaustion Syndrome. Those versed in autonomic function diagnostics understand that these terms should not be used interchangeably.
Exhaustion is characterised by a complete breakdown of autonomic regulation, evidenced by an HRV decline exceeding 85 percent across all frequency ranges compared to daily averages, accompanied by elevated heart rates throughout most or all of the measurement period, and/or inappropriate responses to relatively minor exertion. Unlike burnout syndrome, Long COVID exhaustion symptoms manifest even with good to excellent sleep quality.
Fatigue, conversely, must be recognised as a vegetative signal, characterised by increased HRV, particularly in the HF range, elevated pNN50, the presence of RSA during daytime, and lower heart rates. The vagus nerve activates, shifting towards rest and resynchronising breathing and heartbeat. This process aims to restore order to the numerous self-organised rhythmically interacting processes within our bodies, as it consistently does to counteract inflammatory processes. This remarkably purposeful phenomenon has been prominently documented in scientific literature for two decades as the Inflammatory Reflex.
The vagus nerve’s role in Long COVID continues to expand with ongoing research. It is now identified as a potential pathway for virus (components) to enter the brain, as a nerve that can be functionally and even structurally damaged, and as hyperactive in Long COVID patients. The recently emerged concept of vagal imbalance in literature potentially holds a key to both differentiated diagnostics and treatment of Long COVID.
Parallels to Burnout
Similar to burnout, Long COVID appears to manifest in two forms: A classical type where the vegetative system switches to ‘standby mode’, downregulating both ergotropic and trophotropic systems. This means both sympathetic and parasympathetic systems become inactive, awaiting a ‘restart’, as documented in literature:
The second manifestation likely stems partially from the ‘Inflammatory Reflex’. This mechanism, first described by Kevin J. Tracey in the journal ‘Nature’ in 2002, centres on acetylcholine, the vagus nerve’s neurotransmitter, functioning as an anti-inflammatory molecule—particularly relevant given the persistent inflammation observed in Long COVID cases.
Additionally, there appears to be a correlation between the high prevalence of Long COVID among women and younger individuals and their naturally higher vagal tone. Both clinical observations and published research occasionally document an abnormally elevated vagal tone in Long COVID patients, manifesting as vagal rigidity. This appears to be the body’s attempt to create conditions conducive to self-healing processes.
This mechanism aims to utilise existing autonomic potential to contain ongoing inflammatory processes. This framework helps explain numerous Long COVID symptoms, including the sudden onset of elevated heart rates with minimal exertion (POTS – Postural Orthostatic Tachycardia Syndrome).
WHY ARE SO MANY YOUNG PEOPLE AFFECTED?
It logically follows that Long COVID generally—and particularly this form of vagal overactivation—occurs more frequently in younger individuals and notably in women, as these demographics naturally exhibit the highest vagal tone:
Medications
Medications successfully employed in Long COVID treatment—including amphetamines, antiepileptics, antihistamines, selective serotonin and serotonin-noradrenaline reuptake inhibitors, noradrenergic and specific serotonergic antidepressants, stimulants, and Parkinson’s disease medications—either inhibit noradrenaline reuptake or promote its release, thereby increasing sympathetic tone. Alternatively, they work anticholinergically, reducing vagal tone. Each medication utilised could ultimately serve to resolve the vagal rigidity.
The feasibility of discovering a universally effective medication for all Long COVID variants, whether driven by patient pressure or researcher optimism, will present a significant challenge for the scientific community.
Therapy
A Long COVID-induced chronic fatigue syndrome naturally follows different treatment principles compared to chronic fatigue syndrome. The therapeutic principle of pacing has proven not only effective but essential for both forms. This principle stipulates that careful management of personal resources is necessary, and overexertion must be strictly avoided. The goal is to minimise the frequency and severity of relapses (“crashes”). The less attention paid to pacing and the more patients are encouraged to increase their activity levels, the longer these relapses or crashes persist. Furthermore, overexertion risks deteriorating the general condition, subsequently further limiting patients’ quality of life.
Professor Dr Carmen Scheibenbogen, who researches and treats patients with Chronic Fatigue at Charité Berlin, has established a Post-Covid outpatient clinic. She summarises the significance of pacing for affected individuals: “Everyone must discover their current exertion threshold and remain below it for a certain period. Following this principle from the outset increases the likelihood of recovery from the illness.”
Finding one’s personal limits is remarkably straightforward with the My Autonom Health App. A performance test during a 24-hour measurement period, such as running or walking for 30 minutes or less at maximum capacity, helps define individual current stress thresholds. These thresholds, particularly the pulse rate at which the limit zone begins, are often surprisingly low. Any exceedance, even at a heart rate of 105 BPM in a young, otherwise athletic person affected by Long COVID, leads to an immediate significant decrease in Total Power compared to the daily average. Subsequently, by staying below one’s current crash threshold with ongoing support from the My Autonom Health App, the probability of complete recovery increases substantially.
Long Covid Care by Autonom Health
The Long COVID Care Programme developed by Autonom Health, as described in the chapter above, enables classification into respective forms of dysautonomia. The distinction between Chronic Fatigue or Exhaustion Syndrome allows for differentiated therapeutic strategies, which are developed into personalised recovery plans through individual coaching with specially qualified HRV professionals. Regular meetings for sharing and discussing specific knowledge, along with exchanges within the Autonom Health Community, provide individualised support and complete this unique care programme.
