HRV - CV and Autonomic nervous system

CARDIOCLOUD – HEART RATE VARIABILITY (HRV) – Optimizing Clinical Performance

“Your brain is the motherboard that controls everything!  Evaluating the messages your brain is sending to your cardiovascular system is the best way to detect problems LONG BEFORE your heart is actually affected.”  ~ Dr. Lisbeth Roy

    A Doctors Studio HRV (Heart Rate Variability) CardioCloud test offers an incredibly convenient, non-invasive & technologically advanced means of gauging the health of your cardiovascular system & of your overall biological health. As recent research tells us, ‘Healthy biological systems exhibit complex patterns of variability that can be described by mathematical chaos’! One way of easily capturing that mathematical chaos that can tell us SO much about your health & wellness? An HRV test!

    It really is true – the brain is the motherboard of the body & HRV screening offers an easy, convenient means of learning exactly how efficiently that motherboard is functioning! It is a quick test, straightforward to administer, which outputs clear, interesting graphs & data that are easy-to-read and which provide an awesome snapshot of health, stress levels & functionality. It serves as a great ‘early warning system’ that enables us to pick up on physiological, endocrinological, or physiological dysfunctions early, giving us time & opportunity to reverse any negative practices or lifestyle habits that might eventually cause serious long-term illness.

    What is HRV?

    HRV, or Heart Rate Variability, is a measure of the variation in the time that falls between each heartbeat. Heart rate is controlled by a part of our nervous system called the Autonomic Nervous System (ANS), a part of our physiological machinery that automatically takes care of our heart rate, blood pressure, internal organs, oxygen delivery to the brain, breathing, hormone release, homeostasis, digestion, & about every other function of the body that you can think of. It is basically the system that does all the hard work to keep our body ticking along efficiently while we take care of the tasks that require our conscious attention (e.g., driving to work, deciding which book to read, taking part in an exercise class). While HRV might, on the face of it, look like a basic test, the inferences about your health that we can take from your HRV reading – principally about the health of your ANS – can be profound.

    The SNS & the PNS: Your Nervous System

    In actuality, the ANS includes two main systems; the Sympathetic Nervous System (SNS), which you’ll probably have heard of as the ‘fight or flight’ reflex (a system that powers us up ready to face a challenge), and the Parasympathetic Nervous System (PNS), sometimes referred to as the ‘relaxation response’ (because it calms us down).

    The reason for the dry mouth & shaking hands you might experience just before a major presentation is that the SNS immediately signals to the endocrine system to release ‘stress hormones’ (cortisol, adrenaline) which in turn affects heart rate (which we test with HRV screening). Now, in the short-term, that response is super useful, with the ANS immediately signaling to the body to power up the SNS until the immediate threat has passed (your HR would also shoot up at this stage), keeping you pumped, alert & super-focused to threats.

    But after the threat has been dealt with, the ANS immediately mobilizes the PNS to calm you down again. Your body is constantly engaging the SNS and PNS in this way to maintain homeostasis (balance) which your body needs for optimized health, a healthy body & a healthy emotional state.


    So far, so good. But what if the ANS malfunctions? It often does – and that’s usually a result of us placing our bodies under constant, chronic stress. A study by the American Psychological Association in 2019 reported that 80% of Americans reported feeling stressed at work – so you might well fall into this statistic, too!

    The effect of chronic stress on our ANS is profound. When we remain under constant stress (e.g., an almost impossible daily pressure to juggle childcare, sleep deprivation & work when children are very young, or having to deal with bullying at work), the SNS keep pumping out stress hormones without a break, causing the PNS to remain immobilized. This can lead to a constantly elevated HR, high blood pressure (a risk factor for heart attacks), muscle loss (catabolism), increased fat storage, anxiety, stress, depression, burnout & adrenal fatigue, amongst other major issues. 

    An HRV test can alert us to these effects straight away, as stress (& inhibition of the PNS) majorly influences your HRV.

    Healthy PNS engagement is critical because it governs the endocrinological activity that enables your body to power through some really healthy, constructive physiological activity, such as restorative cellular repair, rest & rejuvenation, muscle building (anabolism), the release of muscle-building hormones, great sleep, the release of hugely powerful restorative hormones such as GH (growth hormone), DHEA, melatonin, testosterone, & estrogen, & healthy digestion that the PNS facilitates. In short, if your ANS is functioning sub-optimally, you need to know about it.

    You might already have tried relaxation techniques in the past when you were feeling stressed – such as meditation, deep breathing, diaphragmatic breathing, or progressive muscular relaxation. In reality, what you were doing was trying to mobilize your PNS. When we are chronically stressed, that mobilization becomes harder & harder.

    What Can I Expect from my CardioCloud HRV test?

    So what exactly can you expect from your HRV test? Well, what we’ve covered so far is the basics of the stress response and how it can affect HRV – which means that the HRV test can be used as an excellent means of understanding more about the health of your body. When you receive your results, you’ll receive a whole host of interesting, insightful data about your overall health.

    In the sample report above, for example, you can see a Cardiovascular Report that provides a detailed insight into the HRV, & what that means for the patients’ health, the different waveform patterns (Types 1-7) that we might observe in your HRV (& why), insight into that patients’ risk of arteriosclerosis (hardening of the arteries), & the health of the ANS (including the effects it can mete out on the functioning of the adrenal glands, hypothalamus, testes or ovaries, dependent on gender, pancreas, parathyroid, pineal gland, pituitary gland, thymus & thyroid).

    HRV & Dysfunction

    One thing we look out for is potential dysfunction and an excellent insight that we can gain from HRV tests is to find out whether there is any dysfunction of the ANS. Undecided about whether the HRV test is right for you? Take a look at the table of potential ANS dysfunction symptoms  (below) – and if any of the side-effects listed seem familiar, you’ll know that it is likely to be a great choice!

    Chronic stress and overstimulation of the SNS can compromise insulin production, leading to insulin resistance & making you feel tired, fatigued & lethargic (&, over time, contribute to the onset of Type II Diabetes). Cortisol constantly pumped out by the ANS can disrupt sleep, & damage brain neurons, contributing to depression, osteoporosis & a whole host of other illnesses & dysfunctions. It can even contribute to IBS (Irritable Bowel Syndrome) and weight gain! The effects of ANS dysfunction – which we can measure with HRV tests – can be profound and serious.

    So while our society tends to encourage us to just ‘get on with it when we experience stress, because ‘that’s just how life is, the reality is that we need to treat stress seriously because it can prompt major biological shifts that can lead to really major long-term problems that can end up being costly, painful & difficult to treat.

    In Search of a High HRV

    So what are we hoping to see in an HRV test?

    What we are really looking for in a healthy individual is a high HRV. Why? Because the fitter you are, the more physiologically adaptable, flexible & resilient to stress your cardiovascular system & ANS is. An optimal HRV reading is one where it reflects flexibility & adaptiveness, where the ANS is able to rapidly cycle between the PNS and SNS as required.

    What Does the Test Include?

     The non-invasive, convenient, quick HRV test includes:

    • An HR (Heart Rate) or BPM (Beats Per Minute) test over a 3-minute period, that outputs a graphical & numerical score
    • A Plethysmograph (PTG) allows us to check the pulsation of the chest wall and arteries, followed by the heartbeat, picking up the pulse wave from your heartbeat through your fingertip in real-time
    • An Accelerated Plethysmography (APG) allows us a “final analysis” waveform reading, which measures blood circulation state and aging level of blood vessels
    • HRV (Heart Rate Variability) Tachogram displays the HRV information collected during the three-minute period
    • HR (Heart Rate) Variability: A graphical representation of heartbeats. The more they are dispersed and spread out in a group, the more adaptable (& healthy) your cardiovascular system.
    • DPI – Differential Pulse Wave Index:  A DPI represents the overall health of the cardiovascular system.  DPI is the main indicator that represents aging vascular health
    • EC – Eccentric Constriction:  represents the contraction power of vessels from the left ventricle.
    • AE – Arterial Elasticity:  Analyzes the blood circulation, vascular elasticity, and resistance of the vessels. It detects early cardiovascular diseases like atherosclerosis and peripheral circulation dysfunction.
    • RBV – Remaining Blood Volume:  The remaining blood volume in the vessels after systolic contraction on the heart. If the blood vessels are healthy, there is little remaining blood volume. If the vascular state improves, the remaining blood volume will decrease. This will be reflected as an improved remaining blood volume score.

    You’ll receive data readouts and graphs that show you EXACTLY what your HRV is (as shown in the example above), HR power readouts, your vascular rate of aging, the levels of physical & mental stress you are under, and your overall stress resistance, alongside DPI, EC, AE & RBV readings.

    Feel the Power!

    One important measure that we use in HRV testing is power readings. An optimal HRV means that we have great health & biological self-regulatory ability, that we have adaptability & resilience to stress, that we are capable of performance of executive functions like attention & emotional processing in the prefrontal cortex of the brain, that biologically we can engage in the autonomic (ANS) balance of our body, regulate blood pressure, engage in effective gaseous exchange (the exchange of oxygen & carbon dioxide throughout the body), maintain gut health & maintain vascular tone. In an optimized HRV reading, all power readings will fall clearly within the ‘I-Bar’ (as they do in the Healthy Reading example below).

    How – and why – do we measure power? We use a Frequency Domain Measurement (FDM) to measure LF (Low Frequency) and HF (High Frequency) oscillations. A frequency-domain graph allows us to measure the power of the signal within each frequency band, where TP (Total Power) is the sum total of the power reading of three frequencies:

    • Very Low Frequency (VLF): 0.0033 – 0.04 Hz: A low VLF has been associated with arrhythmic death, PTSD, high inflammation, and low levels of testosterone.  
    • Low Frequency (LF): 0.04 – 0.15 Hz: LF power may be produced by both the PNS and SNS.
    • High Frequency (HF): 0.15 -0.4 Hz: Reflects PNS activity and is also referred to as the respiratory band. Low HF correlates with stress, panic, anxiety & worry.   

    Using an LF/HF ratio (where LF power is interpreted to be generated by the SNS and HF generated by the PNS), we can see how well the ANS is reacting dynamically to stress, and to the complex biological demands of the body. This allows us to understand how well your body is able to maintain a healthy, optimized biological balance, & how well it is able to cope with stress.

    Reversing HRV & ANS Dysfunction

    While we often see dysfunction, sub-optimal HRV power scores, high Physical & Mental Stress readings, and low-Stress Resilience scores, the great news is that they are generally quite simple to reverse as long as you are ready to engage with the right therapies & lifestyle interventions.

    We can recommend adaptations to your lifestyle, for example (e.g., manipulating diet, mindfulness, sleep hygiene, meditation, nutritional supplementation, & exercise routines), &/or engage in other therapies or treatments to improve your HRV scores (e.g., hormonal treatments to reverse low testosterone which might be contributing to a sub-optimal HRV). We can then monitor physiological adaptations in your body over the course of any adaptive interventions or therapies that we prescribe to you, using HRV screening, which allows you to see the positive changes that you are facilitating in real-time! We find that this kind of concrete, real-time data & feedback makes patients feel empowered & motivated to continue to make the positive changes that they need, which can – and will – change their life.

    Why HRV Offers So Much Insight!

    Our autonomic, cardiovascular, central nervous, endocrine, and respiratory systems, baroreceptors, and chemoreceptors influence HRV over a short time period, which in turn influences very low (VLF) to high frequencies (HF) of the HRV spectrum. The functionality & efficiency of such complex interactions of major systems represented in one HRV reading is ultimately why HRV represents such a simple yet powerful diagnostic tool.

    HRV Testing at the Doctors Studio: Why Wait?

    At the Doctors Studio, we take a preventative approach to health & wellness, believing that optimization of health is key. We don’t expect you to accept ‘okay’ or ‘average’ when it comes to your health, which means that we also believe that early screening is the gold standard when it comes to healthcare. HRV screening offers us the ability to identify early signs of biological dysfunction & intervene with positive therapies or lifestyle interventions while they are still relatively easy to reverse.

    HRV screening ultimately offers us a powerful weapon in the war against stress & ill-health – giving you the tools that you need to emerge victorious from that fight looking & feeling younger, happier & more energetic than you have ever felt before!

     If you feel that you or someone you love would benefit from an HRV screening, contact the Doctors Studio today. We are ready to take your call!

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