EXPERT SERIES 1

Heart Rate

Variability Training

Donald Moss, Ph.D.

In this interview, Dr. Don Moss andDr. Fred Shaffer bring the insightsthat they have acquired throughtheir many years of research andpractice to other health profession-als and introduce some of the keytechniques being used in Heart RateVariability (HRV) biofeedbacktraining. The body’s autonomicnervous system (ANS) governsmany of the body’s internal func-tions, through its two branches: thesympathetic branch of this ANSactivates or increases the heart’saction, while the parasympatheticbranch acts as a brake slowing theaction of the heart. The vagus nerveplays a role in the parasympatheticbraking action. The balance be-tween this throttle and brake systemproduces an ongoing oscillation, anorderly increase and decrease inheart rate. These autonomic inputsare mediated by two “pacemakers”in the heart, the sinoatrial (SA) andatrioventricular (AV) nodes, whichare responsible for heart rhythms.The SA node initiates an electricalsignal which begins each cycle ofthe heart’s pumping action. Thissignal passes through the AV nodewhich spreads the electrical currentthrough the ventricles of the heart. Avariety of factors, including breath-ing, pressure sensors (barore-ceptors) in the arteries, the body’sthermal regulation, and anxiousthinking, increase specific rhythmsin heart activity. The overall processof heart function is the end productof these component rhythms. Higherheart rate variability seems toindicate an optimal cooperationbetween the sympathetic andparasympathetic nervous system.

The Biofeedback Foundation ofEurope is a non-profit organizationlocated in the Netherlands. Formore information on the BFE“Foundation for Learning” initiative,conferences, workshops, protocolsand online education opportunitiesplease visit www.bfe.org.

Donald Moss, Ph.D., is adjunct graduatefaculty in Health Psychology at SaybrookGraduate School in San Francisco, California,and a partner in three outpatient behaviouralhealth clinics in western Michigan. He isEditor of the Biofeedback Magazine, Associ-ate Editor for Applied Psychophysiology andBiofeedback, and Consulting Editor for theJournal of Neurotherapy and the Journal ofPhenomenological Psychology. Dr. Moss hasover 50 publications in the fields of psycho-physiology, biofeedback, and mind-bodytherapies, including an edited book (Hand-book of Mind Body Medicine for PrimaryCare, Sage, 2003).

Fred Shaffer, Ph.D. is Professor of Psychol-ogy at Truman State University and foundedan innovative biofeedback and applied psy-chophysiology program in 1977. He was a2005 recipient of the AAPB Sheila AdlerDistinguished Service Award. He is theproducer and author of Biofeedback Tutor, amultimedia training program developed for theBCIA General Examination in Biofeedback.His research interests focus on heart ratevariability and respiratory self-regulation.

What is Heart Rate Variability?By variability we mean changes in the interval or distance between onebeat of the heart and the next. The interbeat interval (IBI) is the timebetween one R-wave (or heart beat) and the next, in milliseconds. The IBIis highly variable within any given time period. Multiple biological rhythmsoverlay one another to produce the resultant pattern of variability.Interbeat interval variations, or heart rate variability, have relevance forphysical, emotional, and mental function. Many people confuse HeartRate with Heart Rate Variability. The human heart is a bio-electrical pumpbeating at an ever changing rate: it is not like a clock that beats at asteady, unchanging rate. This variability in heart rate is an adaptivequality in a healthy body.

How is Heart Rate Variability measured?One measure of heart rate variability is the difference between the highestheart rate and the lowest heart rate within each cardiac cycle, measuredin beats per minute. This index is called “HR Max – HR Min.” A second

Fred Shaffer, Ph.D.

Photo Courtesy of the Biofeedback Tutor

index of Heart Rate Variability,widely used in medical researchis the Standard Deviation of theN-to-N interval. The N-to-Ninterval is the “normalized” beat-to-beat interval. The SDNN isthe standard deviation of thoseintervals, a measure of theirvariability. The SDNN is ex-pressed in milliseconds (ms).Finally, a third index of variability,more reliable in the short term, iscalled pNN50. This index meas-ures what percent of theInterbeat Intervals differ fromneighboring intervals by 50milliseconds or more. ThepNN50 is expressed in percent-ages.

Can we train individuals toincrease the variability of theirHeart Rate and is there anideal value for HRV?Scientific study of the variabilityin heart rate is fairly recent, andonly in the past ten years did itbecome possible to train humanbeings to change the variability inheart rhythms. Biofeedbackpractitioners have found thatbiofeedback training can in-crease HRV, through severalparallel training pathways. Thepractitioner initially guides thesubject to acquire three basicskills: 1) relax physically andemotionally, 2) reduce anxiousthoughts and negative emotions,and 3) engage in smooth fulldiaphragmatic breathing. Next,

“The human heart is abio-electrical pumpbeating at an everchanging rate: it is notlike a clock that beatsat a steady, unchang-ing rate.”

the trainee learns torecognize and pro-duce the smoothsinusoidal waveforms (RSA wave-forms) in whichrespiration and heartrate co-vary in anear-phase orcomplete phaserelationship. HRVbiofeedback canreinforce breathingin the 5-7 breathsper minute range,and reinforce theproduction of adominant spike inHRV at around 0.1Hz.

Current research suggests thateach individual has a “resonantfrequency” at which heart ratevariability is the greatest, and thisresonant frequency can be meas-ured by biofeedback instruments.While there is no uniform “idealvalue” for all persons, this resonantfrequency is most frequentlyproduced by persons in a relaxedmental state, with a positive emo-tional tone, breathingdiaphragmatically at a rate of about5-7 breaths per minute. Relaxedbreathing at around six breaths perminute produces a spike of heartrate variability at around 0.1 Hz.Remember that one tenth of ahertz equals one tenth of a cycleper second, so that 0.1 Hz equalssix cycles per minute. The othermeasures of HRV also tend tomaximize when heart rate changeis dominated by rhythms in thisLow Frequency range. In this way,a trainee in HRV biofeedback canbe directly reinforced for increasingone of the variability indices (HRMax – HR Min, SDNN, or pNN50).

Is there any current or on-going research to support HRVbiofeedback?Psychophysiological researchsuggests that these frequencyranges reflect different biologicalinfluences. The high frequencyrange is associated withparasympathetic pathways, theinfluences of respiration in normalfrequencies on vagal tone. Thelow frequency range is associ-ated with the influence of bloodpressure (baroreceptors) on heartrhythms, and meditative/slowbreathing augments this range.The very low frequency range isassociated with sympatheticactivation, or more probably thewithdrawal of parasympatheticbraking, and also the influencesof visceral and thermal regulation.Rumination and worry augmentthis range. Finally, the ultra lowfrequency range is associatedwith the slower-acting biologicalinfluences. Several clinicalfindings show the importance ofthe heart’s variability. Changes inthe rhythms of the heart occurbefore a fetus goes into distress,

EXPERT SERIES 1

“Heart Rate VariabilityBiofeedback is a newtechnique for traininghuman beings tochange the variabilityand dominantrhythms in their heartactivity.”

and may predict sudden infantdeath. Lower variability in heartrate predicts a greater risk fordeath after a heart attack anddeath from all causes in adults,especially sudden death. Stud-ies have also shown that clinicaldepression lowers heart ratevariability.

What is the relationship be-tween Heart Rate Variabilityand Biofeedback?Heart Rate Variability Biofeed-back, or HRV biofeedback, is anew technique for training humanbeings to change the variabilityand dominant rhythms in theirheart activity. The use of HRVbiofeedback began in Russia,where it was applied to thetreatment of asthma and manyother conditions. Research isnow going on in many siteswithin the United States, applyingHRV biofeedback to a variety ofmedical and psychiatric condi-tions, including: anger, anxietydisorders, asthma, cardiovascu-lar conditions, chronic obstructivepulmonary disorder, irritablebowel syndrome, chronic fatigue,and chronic pain.

Biofeedback training can teachpatients to increase the percent-age of total HRV in specificfrequency ranges. To date, itappears optimal to increase theamount of heart rate change inthe Low Frequency Range.Evgeny Vaschillo, a Russianphysiologist, hypothesizes thatthere is a “resonant frequency,”native to each organism, which isoptimal for overall health. Formost persons that resonantfrequency involves a dominanceof heart rate change in the LowFrequency (LF) range, around0.1 Hz. HRV biofeedback cantherefore guide and reinforce

trainees for shifting their overallheart rate variability into the LFrange.

Can you tell me a little aboutyour BFE Suite on HRV Trainingand what makes it so useful toprofessionals that want to workwith Heart Rate Variability Bio-feedback?The Suite has been designed tohelp newcomers to the field toapply what has been demonstratedby both research and experience.It includes specialized softwaredisplay screens to support a varietyof convergent training strategies toproduce increased heart ratevariability. One of the things weare most pleased about with thesuite is that it also includes aclinical guide that clinicians canuse to get started right away in thisexciting field. The software anddocumentation in the suite teachthe techniques necessary forincreasing heart rate variability.HRV biofeedback can be of par-ticular value to psychologists andother health practitioners andtherapists.

Does Heart Rate Variabilitychange with age?

As human beings age or sufferillness, the total variability inheart rate is reduced, and therisk of illness and death in-creases. Twenty year olds oftenshow a swing of twenty or morepoints between the high and lowpoints in their heart rates. Per-sons over 50 often showchanges of ten beats or less.Persons who are more physi-cally active show a wider rangebetween their maximal andminimal heart rate. HRV bio-feedback can enable the indi-vidual to increase this variabilityin heart rate, sometimes produc-ing a range of fifty beats aminute during training. HRVbiofeedback training can focuson increasing the HR Max –HRMin index.

Distributed courtesy of an educational grant by Thought Technology Ltd.

The Physiology Suite containsa complete set of standardbiofeedback tools to get atotal physiological perspectiveon your client’s sympathetic

and parasympathetic processes, including: Temperature, Skin Conduct-ance, Surface EMG, Respiration and Heart rate variability (HRV).

The Physiology suite contains more than 80 screens and over 14 scripts,and provides you with advanced tools for assessment and follow-up:

• Pre/post baseline assessment• SC verbal Relaxation exercise• Training scripts (10 x 1 min trials)• A 7 activity stress assessment script that takes your client through

a sequence of stress/relax cycles and generates a report to rapidlyidentify hyper- or hypo-reactivity in each modality.

The Suite offers 17 new animations, 15 MP3 (music & ambiance),20 MIDI songs and many other new multimedia feedback options:

• DVD (4 action control: shrink, zoom, pause & sound)• Morphing animation sequences, 3 stage puzzles• Nature sound audio tracks• MIDI splitter

Physiology Suite features:Physiology Suite features:Physiology Suite features:Physiology Suite features:Physiology Suite features:• Skin-conductance driven relaxation script

with audio induction track• User-defined pre-labelled event-markers

(hot key activated)• Real-time epoch statistics for instant trend

graphing

NEW

Thought Technology Ltd.2180 Belgrave Avenue Montreal, QC, H4A 2L8, Canada

Tel: 1-800-361-3651 • 514-489-8251 Fax: 514-489-8255

http://www.thoughttechnology.com

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