In this third part of our iMRS Prime Review, we’re focusing on a key aspect of our physiology with profound importance for every type of therapy and therapeutic technology: Heart Rate Variability (HRV) and the Autonomic Nervous System (ANS). As explained in part 2 of the review, these are the basis for the type of biofeedback used in the Prime.
The ANS essentially sits in the background, a collection of physiological components that control important functions such as heartbeat and breathing, how we respond to threats and stress, without us even noticing.
What is HRV and Why is it Important?
Our hearts do not beat at regular intervals although it may seem like that. Even when at rest, there are tiny variations in the time interval between consecutive beats. This variation is measured in milliseconds and current research suggests that it could be extremely important for our health, wellbeing and longevity. Contrary to what you might expect, greater variability is actually a good thing.
There is growing evidence that low heart rate variability can be an indicator of underlying physical and emotional illness. A paper published by the American Heart Foundation back in 2000 (1) found that:
“In a population-based study of middle-aged men and women, high heart rate and, especially, low HRV were predictive of increased mortality rates. For HRV, this relation could not be attributed to cardiovascular risk factors or underlying disease. It may be hypothesized that low HRV is an indicator of poor general health.”
Heart rate variability is affected by a wide range of factors. When you breathe in, the interval between beats tends to get shorter, and when you breathe out it lengthens. Exercise and exertion, normal hormonal reactions and even emotional changes caused by stress can all have an impact.
The Role of the Autonomic Nervous System
Heart rate variability is controlled by our autonomic nervous system. This is the part of the nervous system that regulates involuntary physiological processes such as digestion, blood pressure, heart rate and respiration.
The two key parts of the autonomic nervous system are called parasympathetic and sympathetic:
- The parasympathetic system allows us to ‘power down’ and recover, for example, after we’ve been for a run or faced a challenging situation.
- The sympathetic prepares us for the flight/fight response, activating stress hormones and increasing heart rate.
These two systems work synergistically. Which is in control at any particular time will affect heart rate variability.
HRV is generally higher when we are relaxing, sleeping or in a cognitive state like meditation. This is under the control of our parasympathetic system. When our heart beats more rapidly during exercise or in a stressful situation, HRV is much lower and controlled by the sympathetic system.
While the autonomic nervous system works without our input most of the time, we can have a conscious impact with the help of biofeedback techniques. To lower our heart rate and raise our HRV level, we can use meditation, deep relaxation and breathing exercises. A better diet and more physical exercise will also help.
There is a consensus that ANS activity degrades as we age. Some research suggests that maintaining a healthy ANS, perhaps through HRV biofeedback, and making the right lifestyle choices, can boost our lifespans and our health in later life.
The HRV Pioneers: HeartMath Institute
After being founded in 1991, the best-known pioneer in real-time HRV measurement has been the HeartMath Institute. Over the past 30 years, this non-profit organisation developed various self-regulation tools and techniques and carried out cutting edge research into the effect biofeedback and relaxation techniques have on improving health with a particular focus on positive thinking.
At the Life Mat Company, our own journey with HRV began in 2000 with the HeartMath computer app and later using their pocket sensor device. Each product uses a sensor which is an early version of the type used in the iMRS Prime.
HeartMath contends that the heart is much more than a simple pump. Not only does the brain send signals to the heart but the heart sends them back to the brain as well, changing and influencing our perceptions and emotions moment by moment, involved in everything from cognitive functions such as memory and problem solving to our attention levels and focus on the world around us.
If we’re under stress, for example, our heart is beating faster and HRV can be erratic, which in turn has a direct impact on brain function, making it more difficult for us to make good decisions and think clearly. If we manage our heart rate variability, through techniques such as meditation, this can often have a profound impact on our cognitive processes.
HeartMath Institute Research Findings
Psychophysiological coherence arose out of the notion that beneficial physiological changes can be encouraged through positive emotions and linking them to biofeedback. We see this for short periods when we sleep or have a positive emotional experience but it is rarely sustained for a long time. The challenge is generate this process for sustained periods where it can really influence a person’s physiology.
The HeartMath team found that (2)
“By using practical, positive emotion refocusing techniques designed to enhance states of appreciation, individuals can learn to self-orchestrate coherence with increased consistency, thereby reducing stress and enhancing health, emotional stability, performance and quality of life.”
Using these approaches and combining them with biofeedback helps individuals to develop skills that allow them to improve and maintain health and wellbeing. A further study published in Frontiers in Psychology in 2014 (3) suggests:
“Numerous studies have provided evidence that coherence training consisting of intentional activation of positive and calming emotions paired with HRV coherence feedback facilitates significant improvements in wellness and well-being indicators in a variety of populations.”
Psychophysiological coherence is monitored most easily by measuring heart rate variability. A positive change is visualised as a smooth, sine wave pattern that has been associated with several different physiological changes, including:
- The parasympathetic and sympathetic parts of the ANS synchronising better with each other.
- Other biological systems also synchronise and reach homeostasis leading to improved health outcomes.
This mode can be achieved using a range of different techniques. For example, the Quick Coherence® Technique is designed to allow an individual to achieve coherence in just a few minutes using meditation. It helps participants control stress reactions.
In research conducted in 2009, HeartMath researchers found that heart rate variability coherence training and feedback could help returning veterans cope with PTSD better.
Advanced HRV Software Solutions
It is only recently that people could enjoy the benefits from HRV entrainment outside laboratory or hospital facilities. The latest devices measure HRV accurately and AI-powered software provides real-time diagnostic tools.
One of the leading pioneers in HRV applications is Kubios, the Finnish company that our manufacturer partnered with for the analysis of data collected by the iMRS Prime. Their software can be used with a broad range of measuring devices in GP surgeries, hospitals, sports centres and therapist offices. Their cardiology-level products are used in scientific research, by the wellness community and by professional athletes.
HRV measurement plays an intrinsic role in medical research and yet there’s a lot we don’t yet know about its relationship to our overall health.
One key finding from recent research using Fitbit data has suggested that there is a more rapid decline in the parasympathetic than that sympathetic response as we get older. The study, published in the Lancet, looked at the data from some 8 million users and hinted that HRV could be improved for most people into later life by using exercise.
Another finding is that Type 2 diabetes is associated with low HRV, so HRV monitoring may have a role as both a diagnostic tool and in implementing lifestyle changes.
The most obvious and frequent use of HRV-based biofeedback software is to help monitor and reduce stress, while its accuracy in measuring the cardiovascular system means it can also be used for HRV-based recovery monitoring for trainers and sports scientists.
HRV and PEMF: Creating a Biofeedback Loop
HRV monitoring on its own simply provides data that gives us a snapshot of how our autonomic nervous system is working. For it to have any value, users need to combine it with methods that induce change: such as someone with chronic stress investigating how well their meditation practice is working. When combined with PEMF, or pulsed electromagnetic field therapy, we have a very special approach.
PEMF is already approved for pain relief, increasing circulation and improving blood oxygenation, boosting bone healing, enhancing muscle function and even reducing stress and severe depression. And plenty of research shows how PEMF affects cell activity, the autonomic nervous system and blood flow, so it’s not surprising to see that one study has already found that (8):
“20 minutes’ exposure to PEMF resulted in more rapid recovery of heart rate variability, especially in the very low-frequency range after physical strain.”
With a PEMF machine like the iMRS Prime, we can generate a biofeedback loop where HRV is monitored in real-time and used to raise and lower the PEMF field intensity minute by minute. Indeed, there could be a wide range of different ANS-related therapeutic solutions using a combination of PEMF and HRV. Further improvements (beyond what basic PEMF can already deliver) seem possible in microcirculation, hypertension and many other health issues. HRV continuous biofeedback becomes the element that personalises the treatment to the individual user’s needs.
Some Caveats of HRV Monitoring
There are still some notable caveats for people who want to work on their HRV and what the data means:
- Just because someone has a high or low HRV does not necessarily mean there is a medical or emotional problem.
- HRV varies considerably during the day and it’s not unusual to get strong readings one way or another.
- Various things can affect the consistency of HRV results, especially when using a wearable device. That could include simply sitting or standing or if you’ve had a cup of coffee before exercising.
- Stress is generally cumulative and it’s important not to just measure things when there is an important event going on. HRV can change over time and a global view of what is going on for a particular individual is more accurate than taking snapshots at certain times.
- HRV data always needs to be viewed in context and it can take a lot of work to interpret what’s going on. Wellness experts and medical professionals will often collect objective data and combine this with subjective reports from their clients or patients to get an overall picture.
In conclusion, it’s clear that we’re only touching the tip of the iceberg when it comes to HRV and biofeedback. It has the potential to be one of the most important health metrics of all. As the technology improves and our understanding grows, it could well present several avenues to greatly improve personal health and wellbeing as people move into later life, even heading off potentially harmful conditions before they become less treatable.
1. Jacqueline M. Dekker, Richard S. Crow, Aaron R. Folsom et al. Low Heart Rate Variability in a 2-Minute Rhythm Strip Predicts Risk of Coronary Heart Disease and Mortality From Several Causes Circulation, 2000
2. J.P. Ginsberg, Ph.D.; M.E. Berry, M.A.; D.A. Powell, Ph.D. Cardiac Coherence and Posttraumatic Stress Disorder in Combat Veterans Alternative Therapies 2010
3. Rollin McCraty, Ph.D. Psychophysiological Coherence: A Proposed Link Among Appreciation, Cognitive Performance, and Health Institute of HeartMath, 2001
4. Aravind Natarajan, PhD et al Heart rate variability with photoplethysmography in 8 million individuals: a cross-sectional study Lancet, 2020
5. Alex W Thomas, Karissa Graham, et al A randomized, double-blind, placebo-controlled clinical trial using a low-frequency magnetic field in the treatment of musculoskeletal chronic pain NCBI, 2007
6. Ziying Wu, Xiang Ding et al Efficacy and safety of the pulsed electromagnetic field in osteoarthritis: a meta-analysis British Medical Journal, 2018
7. Klaus Martiny, Marianne Lunde, and Per Bech Transcranial Low Voltage Pulsed Electromagnetic Fields in Patients with Treatment-Resistant Depression Biological Psychiatry, 2010
8. Grote, V., Lackner, H. Short-term effects of pulsed electromagnetic fields after physical exercise are dependent on autonomic tone before exposure Human Research, 2007