Heart Rate Variability (HRV) Testing Is A Measure Of Nervous System Balance

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What is Heart Rate Variability (HRV):

The autonomic nervous system (ANS) mediates the body’s initial response to physical, physiological, or psychological stress. The ANS is a component of the peripheral nervous system. It is responsible for involuntary and reflexive bodily function. The ANS controls many body organs such as the heart, adrenal gland, and gastrointestinal (GI) tract. It plays an important role in an individual’s overall health and ability to handle stress. The ANS is composed of the sympathetic and parasympathetic nervous system. The sympathetic nervous system (SNS) produces the “fight or flight” response in stressful situations. It quickly mobilizes energy while increasing blood pressure, heart rate, and blood flow to muscles which are all necessary for responding to short-term stressors. SNS tone is a biological marker of age. As we age, our production of adrenalin decreases and cortisol increases but eventually both decrease.

Conversely, the parasympathetic nervous system (PSNS) allows us to “rest and digest” in non-stressful situations. It counters the effects of the SNS and conserves the energy stores of the body. PSNS promotes relaxation following a stressful event. It is most active during sleep, meditation, or other restful states. PSNS is a biological marker for health reserves and adaptive capacity. It promotes relaxation and is important for sleep.

There is a constant interplay between the SNS and PSNS and each balances the other. For example, during a short-term stressful event, the SNS increases blood pressure, heart rate, and breathing while decreasing GI function. Subsequently, after the stressor subsides, the PSNS decreases heart rate, breathing, blood pressure, and restores digestion allowing the body to return to a restful state.

Heart Rate Variability (HRV) reflects the simultaneous affect of the SNS and PSNS on the heart, which results in a beat-to-beat variability on an electrocardiographic (ECG) rhythm strip. A change in the normal autonomic regulation of heart rate may reflect the impact of a stressor on the body and can detect the early signs of pathologic developments or functional disorders, which may not be detected with routine physical or laboratory examinations.

HRV analysis provides a visual representation of heart rate referred to as the “method of rhythmography” or electrocardiograph (ECG). The lines on the ECG are longer (taller) under the influence of the PSNS and shorter (smaller) when under the influence of the SNS. HRV is performed in a supine position to promote PSNS tone, which occurs during relaxation and an upright position to stimulate SNS tone, which simulates a short-term stressor. HRV is a measurement of SNS and PSNS tone and respectively one’s ability to adapt to stress and relax.

Assessment of the Physical Fitness Level

HRV Overview Tulsa Functional Medicine









Fig 1   Normal Transition Period and Fitness Level Graph

Assessment of the transition period:

The period of transition occurs when an individual goes from a lying to a standing position. Normally when one stands, the heart rate increases to compensate from a drop of blood pressure that occurs upon standing. The assessment of the transition period graph should show a dip (represents faster heart beats) reflecting an increase in heart rate upon transitioning from a supine to an upright position. The ability to increase heart rate upon standing reflects the overall adaptability of an individual.

Chronotropic Reaction measures one’s adaptability (SNS tone) and should range from 0.59-0.63.

Compensation Response measures one’s fitness (PSNS tone) and measures how well one recovers from a stressor (standing up). It should range from 0.59-0.63 or slightly higher.

Ortho-Test Ratio measures the ratio of heart rate upright to heart rate supine. The ratio should be close to 1.00. When one is not fit, chronotropic reaction level (level of adaptability or SNS tone) and compensation response (level of fitness or PSNS tone) ratio is greater than 1.00 and there is no dip during the transition period.


  • If chronotropic reaction is above normal, consider Revolution.calm & L-Theanine
  • If chronotropic reaction is below normal, consider NeuroMax
  • If compensation response is below normal, consider Revolution.calm, Serenity Now & ProbioHealth.

Your chronotropic reaction is: _____normal  ______above normal   ______below normal

Your compensation response is: ____normal  _____above normal   ______below normal

Graphic Presentation of the Physical Fitness (see Figure 1 above)

Physical fitness level measures one’s level of wellness (compensation response or PSNS tone) versus their adaptability (chronotropic reaction or SNS tone). The lower the number on the level of wellness and adaptability axis, the better the individual’s physical fitness. Conversely, the higher the numerical number on the level of wellness and adaptability axis, the worst the individuals physical fitness. Well-trained athletes usually fall in the upper left quadrant or 1/1 ranges of the graphical presentation of physical fitness. Those of average fitness fall in the middle or 7/4 ranges of the graph. Those who fall in the lower right quadrant in the 13/7 ranges (below the red line in figure 1 of graphic presentation of the physical fitness) are considered to exhibit the worst physical fitness.

Your fitness level is ________Normal (left side of red line) _______Low Normal (right side of red line) _______Athletic Zone ________Below Normal

Recommendations for Average to Below Normal Fitness:

  • Revolution Essentials
  • Increase exercise, relaxation and deep breathing techniques.

Assessment of ANS Functional State Based on Heart Rate Variability Analysis

Electrocardiogram Rhythm Strip

Electrocardiographic rhythm strip or rhythmogram provides an assessment of the PSNS and SNS function in a supine and upright position. See figure 2 below.

HF (high frequency or taller lines on the ECG) reflects PSNS function and acetylcholine production.

LF (low frequency or shorter line) represents the combined affect of SNS activity and adrenal cortisol output.

LF1 reflects epinephrine and norepinephrine production by the SNS

LF2 represents cortisol hormone production by the adrenal gland

Orthostatic pattern correction (OPC) on the ECG rhythm strip refers to a pattern, which occurs during the transition from supine to standing position.  OPC reflects how well one responds to stress. It measures whether the body responds appropriately to a short-term stressor, i.e. standing up with a short-term increase of SNS tone and epinephrine and norepinephrine production. This event typically results in a dip in the ECG rhythm strip. If the body responds to the stress of standing with cortisol hormone production, there is no dip in the ECG strip. This condition is indicative of adrenal and SNS dysfunction. It represents that there is no short-term adaptability or SNS reserve.

Normal HRV Tulsa Functional Medicine


Supine (PSNS Influence)                                                                    |      OPC       |           Upright (SNS Influence)

Fig 2    Healthy ECG Rhythm Strip

Normal Rhythm Strip should show multiple variations and looks like “uncut grass on waves”

Normal Supine – multiple, high frequency “uncut grass-like” patterns

Normal Upright – lower frequency “wave-like” patterns (SNS) with high frequency pattern (PSNS) on top

Your rhythm strip shows: ______very good variability  __________average variability  ______little or flat variability  ________Spikes & Dips (____few _____multiple)

The sharper and more regular the fluctuation pattern, the healthier the ECG rhythm strip. The PSNS and the SNS activity have different influences on a normal rhythmogram. A healthy PSNS rhythm strip contains numerous, high frequency variations, while a SNS influenced strip typically has a more “wavy” patter, like waves on water, than uncut grass-like pattern. During the OPC, SNS initially predominates to increase heart rate and blood pressure, which results in a brief dip. The strip recovers as the PSNS balances the effects of the SNS.

HRV Adrenal Fatigue Tulsa Functional Medicine










Supine (PSNS Influence)         |          OPC       |           Upright (SNS Influence)

Fig 3    Typical “Cortisol Pattern”

If cortisol production is predominant instead of epinephrine and norepinephrine (SNS) and acetylcholine (PSNS), there is no variability of the ECG strip or dip during the OPC period and the strip becomes flattened. This indicates chronic stress.


  • Revolution.calm
  • NeuroMax
  • Revolution C
  • Serenity Now
  • L-Theanine

HRV ectopic Tulsa Functional Medicine



Supine (PSNS Influence)                         |          OPC       |           Upright (SNS Influence)

Fig 4    Ectopic Beat Pattern

An ECG rhythm strip can detect conductive problems with the heart muscle pacemaker cells. An ectopic beat pattern occurs when dips in the strip are followed by “spikes” which represent ectopic beats. When this pattern appears frequently throughout the strip, a referral to a cardiologist may be recommended.

If there are only a few spikes and dips present, it may just be an artifact or may represent a stressful state in which case further evaluation by a cardiologist may not be needed. HRV should be repeated to assess if the treatment of the stressful state resolves the spikes and dips. If the spikes and dips worsen, do not resolve with treatment, or if the patient is symptomatic, a referral to a cardiologist should be considered.

ANS Balance HRV Tulsa Functional Medicine

Graphical Presentation of the ANS Condition:

This graph depicts the activity of the PSNS and SNS when going from a supine to an upright position.

Supine: When lying down, the point should be positive number on PSNS axis reflecting normal PSNS activity, which occurs during relaxation. If the point has a negative value, PSNS activity is diminished which means that the ability to rest, relax, and digest is sub-optimal.

Upright: The point should remain positive on PSNS axis and at the most decrease by one point when going from a supine to an upright position. The SNS tone should remain on the positive SNS axis and increase by only one. If SNS tone increases by more than one it indicates that the body is experiencing stress and is in a stressful state. If SNS tone decreases on standing, it may mean that the individual suffers from pain with laying, is obese, or feels vulnerable lying down. If the point remains in the same position, there is no SNS reserve and it may be indicative of adrenal fatigue. Abnormal PSNS tone occurs if it decreases upon standing by more than one or if it has a negative value.

ANS Assessment Based on Heart Rate Variability:

Supine/Average Quadrant Correction

  • Upper and Right Axis = Positive Axis
  • Lower and Left Axis = Negative Axis

Zone 1: Is seen when both the SNS and PSNS are firing at the same normal rate to match each other.

Zone 2: Is seen in trained athletes who are able to diminish their sympathetic firing while increasing their PSNS tone (firing) to promote relaxation and focus, which allows them to enter “the zone” and function at their best.

Zone 3: Is seen in individuals who are experiencing stress, i.e. mental, physiological, and physical stress, which increases the rate of SNS activity, while decreasing PSNS activity. Increased SNS activity may lead to anxiety, insomnia, and inability to relax. Increased SNS activity may worsen medical illness associated with stress, i.e. hypertension, palpitations, diabetes, attention deficit, anxiety, depression, insomnia, irritability, etc. While decreased PSNS activity may affect gastrointestinal functioning, i.e. digestion, immune function, and neurotransmitter production.

Zone 3 Recommendations:

  • Revolution.calm to promote calmness, healthy mood, mental focus, and inhibitory neurotransmitters (promote relaxation and calmness), i.e. serotonin & GABA
  • Melatonin is used to support sleep, relaxation, and healthy melatonin levels.
  • Giddy’up should be used to support a healthy cardiovascular system during periods of stress. Individuals with a history of certain conditions, which improve with vasodilation (i.e. hypertension, heart disease, migraine headaches or sexual dysfunction) may benefit from L-arginine supplementation, which may improve vasodilatation. Relaxation & deep breathing techniques to promote SNS & PSNS balance.

Zone 4: Is seen in individuals who are very sick. There is very little sympathetic or parasympathetic tone. Decreased SNS activity may result in fatigue, malaise, lethargy, difficulty concentrating, and weight gain. Epinephrine and norepinephrine production may be diminished.

Zone 4 Recommendations:

  • NeuroMax and Revolution Mineral are used to support ANS tone and nerve conductivity.
  • Phosphorylated Serine is used to support PSNS tone and hypothalamus sensitivity to cortisol.
  • Use NeuroMax to support adrenal function and epinephrine production by the adrenal gland.
  • ProbioHealth to support PSNS tone, GI health, and inhibitory neurotransmitter balance.
  • RevoFood to support GI health, detoxification, and immune function
  • Relaxation & deep breathing techniques.

Your ANS condition falls within Zone: _____Zone 1 _____Zone 2 _____Zone 3 _____Zone 4


Your ANS sub-zone falls within: _____Zone A _____Zone B _____Zone C _____Zone D _____Zone E


Subcategory Quadrant Correction Graph


A – This is an area of balance or ANS Equilibrium but actually, this is a point of zero SNS and PSNS activity. Follow Zone 4 treatment recommendations.

B – This is an area that represents individuals who are experiencing acute conditions, illness, or toxicity states. Area B represents very high SNS tone and very low PSNS tone. Follow Zone 3 recommendations.

C – This area represents individuals who are very sick with chronic conditions and serious illness. Area C represents very low SNS and PSNS tone. Follow Zone 4 treatment recommendations.

D – This area reflects very low PSNS tone and balanced SNS tone. It may represent very low potassium levels and/or low oxygen levels in the body. Consider checking potassium and oxygen levels. Revolution Essentials, Revolution.calm, ProbioHealth, and PrimeNZyme are recommended.

E – This area reflects very low SNS tone and balanced PSNS tone. It may represent very low calcium and low CO2 / high ammonia levels. Consider checking calcium, CO2, and ammonia levels. NeuroMax, Revolution Essentials, and Detox are recommended.


ANS Condition Abnormalities

 High SNS and Low PSNS Activity

  • Over 3 Point increase in SNS from supine to upright
  • Usually due to cortisol effect
  • May be due to hypothyroidism


  1. Lower cortisol levels & support adrenal function. Phosphorylated Serine to diminish the effects of cortisol on the hypothalamus and support adrenal function. Bio C 1:1 to diminish the effects of unhealthy cortisol levels.
  2. Improve PSNS activity with ProbioHealth, PrimeNZyme, and
  3. Meditation, Yoga, or Heartmath Coherence (biofeedback) Training to increase PSNS activity.
  4. Support thyroid function with Thyroid Support. Consider thyroid profile testing.

Low PSNS Activity

If the PSNS drops more than 3 points. It may suggest the presence of digestive problems.


  1. Support GI functioning with ProbioHealth, PrimeNZyme, and GI Max especially when the SNS increases as well.
  2. Support PSNS tone with Revolution.calm
  3. Support Liver & GI detoxification. The more the SNS goes up, the greater the need to look for toxicity and inflammation. Consider OptiCleans GHI or MedCaps DPO to aid with detoxification.

Increased PSNS and Decrease SNS Activity

If the PSNS increases but the SNS decreases (or stays the same) it may be due to obesity, emotional distress, or physical pain while supine.


  1. Weight management
  2. Address source of physical pain
  3. Revolution.calm to promote relaxation
  4. Deep breathing and relaxation techniques.

No change in PSNS and SNS activity

It may represent poor adrenal gland reserve.


  1. Check BIA & phase angle
  2. Support adrenals with Adrenal Support
  3. Support PSNS and GI Function with ProbioHealth, PrimeNZyme, & GI Max
  4. Support SNS with NeuroMax

Decreased PSNS and SNS Activity

It may represent adrenal exhaustion


  1. Check BIA & Phase Angle
  2. Support adrenals with Adrenal Support
  3. Support PSNS and GI function with ProbioHealth, GI max, and PrimeNZyme
  4. Support SNS function with NeuroMax

Spectral Analysis of Heart Rate Variability:

  • Electrocardiographic Rhythm Strip
  • Interpretation of ANS Assessment based on Heart Rate Variability

 Spectral Summary:

Total Power (TP) reflects the power of one’s autonomic nervous system. It indicates how much power one’s body has to respond to stress, i.e. SNS Function and to relax and digest such as PSNS function and neurotransmitter production. The higher the TP, the better the SNS and PSNS function. If TP is low, less than 1000 supine or standing, it reflects that the SNS and PSNS are not functioning at their best. It may manifest as fatigue, insomnia, poor concentration, anxiety, depression, and poor digestion.

High Frequency (HF) reflects PSNS function

Low Frequency (LF) reflects SNS activity and adrenal cortisol output

LF1 reflects epinephrine and norepinephrine production

LF2 reflects cortisol output

When lying down HF should be higher than LF1 & LF2


LF1 or HF should be the highest number, which means that there is a quick burst of epinephrine and norepinephrine or PSNS activity (HF). LF2, which represents cortisol output, should not be the highest number. If this occurs, it may mean that there is excessive production of cortisol by the adrenal gland.

If LF2 is the highest number, the body is responding to short-term stressors with a long-term stress hormone, cortisol. It represents that epinephrine and norepinephrine levels are diminished therefore; the body has to use cortisol to adapt to stress. TP should be over 1000. Someone at age 21 will have a TP of 4000-7000, while older individuals are considered to have optimal TP if it is greater than 1000.

Your Total Power: _____greater than 1000 (normal for adults) _____4000-7000 (young adults) _____Below 1000

ECG Patterns:

Normal: Grass like lines with a sharp dip when standing that quickly returns to the same supine patterns within seconds.

Cortisol dominance: Flat non-grassy like pattern in both the supine and standing position with no drop. This pattern is usually seen in adrenal fatigue. There is no adaptability, which reflects decreased SNS function, or reserve.

If Total Power (TP) is les than 1000, amino acids and minerals are needed. Amino acids are the building blocks of neurotransmitters. Minerals are necessary for electrolyte balance.


  • NeuroMax provides the amino acids, which are the precursors for neurotransmitters that are needed to increase power.
  • Revolution Mineral provides the minerals needed for nerve conductivity.

Power Distribution:


The supine HF power should be higher than the LF’s with LF1 next and LF2 lowest. This represents that the PSNS (HF) activity is dominant over epinephrine and norepinephrine (LF1) and cortisol (LF2) production.


When upright, LF1 should be the highest number, HF should be next, and LF2 should be last indicating that the SNS (LF1) activity is dominant over PSNS (HF) and LF2 (cortisol) activity.


Your HP: ___________ Normal _____________ Below Normal ______________ Elevated

Your LF1: __________ Normal _____________ Below Normal ______________ Elevated

Your LF2: __________ Normal _____________ Below Normal ______________ Elevated


Your HP: ___________ Normal _____________ Below Normal ______________ Elevated

Your LF1: __________ Normal _____________ Below Normal ______________ Elevated

Your LF2: __________ Normal _____________ Below Normal ______________ Elevated

If HF is low supine and LF2 is higher than LF1 supine, consider elevated cortisol levels.


  • Revolution.calm, Phosphorylated Serine, and Vitamin C to lower LF2 (cortisol)
  • ProbioHealth to increase HF (PSNS function)
  • NeuroMax to improve LF1 (SNS function) and HF (PSNS function)

If both LF1 and LF2 are low:

  • NeuroMax to increase LF1 (PSNS function)
  • Adrenal Support to increase LF2 (SNS function)

If just LF1 is low:

Labs: check Thyroid


  • Thyroid Support to support thyroid gland function
  • Adrenal support to support adrenal function and energy levels.