Friday, October 28, 2011

#10 Mending a Broken Heart with Heart Rate Variability Feedback

Sometimes it’s hard for people to believe that breathing with feedback (HRV-F with the StressEraser or emWave) could result in significant, enduring changes in the body.  “Dude, it’s just breathing, I do that pretty much every day." 
But imagine if you could heal a broken heart with HRV-F.  Not poetically or metaphorically, but literally.  This is the subject of some cutting edge research at the Cleveland Clinic.

Like many chronic health conditions heart failure results from a progressive downward spiral.  The Sympathetic Nervous System (SNS), or "fight or flight response", gets turned up to compensate for the failing heart’s inadequate output.  Initially this helps, but it also makes the heart work harder.This increases the demand for oxygen, and the only way to meet this demand is to turn up the SNS even more!  Combined with inflammation, this vicious cycle leaves many people needing a new heart i.e. a transplant. 
Often a mechanical pump called a “ventricular assist device” is implanted to rest the heart, and buy some time, until a new heart is available.  With the rest provided by this pump, evidence of healing can be seen in the heart when it is removed for transplant.
Knowing the effects of HRV-F raises an interesting possibility.  HRV-F turns up the Parasympathetic Nervous System or "rest and digest" response.  It also turns down the SNS, and reduces inflammation. (Future Post). Could HRV-F help the failing heart?
Using a stress management program that includes HRV-F as a core component, researchers at the Cleveland Clinic are testing this hypothesis.  Preliminary results show positive changes in the heart tissue comparable to those seen with implantation of a ventricular assist device. HRV-F causes enduring changes in the body that can be measured, and seen on the microscopic level.
"Whoa, dude. Science Rocks."

Moravec, C. S. and M. G. McKee (2011). "Biofeedback in the treatment of heart disease." Cleve Clin J Med 78 Suppl 1: S20-23.

Thursday, April 7, 2011

#9 Zen and the Mind Mirror

Some days it’s hard to accept what I see in the mirror.   A blemish, a new wrinkle or some other indignity of aging.  Hair growing out my ear?  Really?  Why?

In those moments the challenge is to accept what is.  So I repeat my mantra:  “This is how I am now”.  And if I persevere, some days I can get beyond my ego and enjoy being alive, even with hair growing out of my ear.

 HRV Feedback (HRV-F) has a remarkable property that makes it a “Mind Mirror”.  Most people learn the mechanics of the rhythmic breathing relatively quickly. After that the feedback from the device shifts from being primarily a reflection of how you are breathing, to a reflection of what is happening in your mind.  If your mind is tranquil, that will be reflected by a nice smooth, regular heart-wave (See Post #6.).  And if you are angry and your thoughts scattered, the heart-wave will be jagged and irregular. Sorry, no exceptions.

The Heart-wave reflects the state of the mind because of a direct connection between the emotional right hemisphere of the brain, and the SA node in the heart.  This connection occurs via the Autonomic Nervous System (ANS) which serves to coordinate brain and body states.  If you are angry because someone just stole your food, your body needs to be in a state that supports “angry behaviors” e.g. grabbing   the food back.  And if you are sharing a tender moment with your lover, the body needs to be in a relaxed, open, receptive state.  The ANS makes this happen.

Some days it’s hard to accept what I see in the Mind Mirror.  After weeks of getting a nice smooth heart-wave I am rather proud of my skill.  Like a little boy who has  grown confident that his finger-painting is great because his mother tells him so every time. But today my heart-wave looks like an ugly, jagged coastline.  I try pleading my case-“I don’t feel that bad, the wave shouldn’t look like that.”   And when that doesn’t work I protest in frustration-“but I’m really good at this!”.  The wave gets even more irregular and ugly.  Now I’m really angry.  Fortunately, just before I throw the damn thing against the wall I have a thought:
                                                "This is how I am now."

As I focus on accepting how I am right now (jagged heart-wave with hair growing out of my ear) my mind begins to settle.  The heart wave begins to settle.  The process continues and my capacity to stand back and observe increases.  The hair growing out of my ear is kind of funny.  But it’s also a little sad.  I’m aging.  And apparently I’m not totally okay with that.  The more I accept my feelings, the more the energy associated with them dissipates, and the smoother the wave gets. Thoughts of aging drift away and a new thought comes to the surface:  I really am good at finger painting.  Always have been.

Saturday, March 26, 2011

#8 Fear of becoming an HRVF Junkie

People are frequently surprised by how powerful Heart Rate Variability Feedback (HRVF) can be.  In the words of one client “this is more powerful than any medication I’ve been on…it leaves me really calm, but awake”.  Apparently because of this type of natural, spontaneous  comparison to drugs, people experience fear of becoming addicted or dependent on HRVF.  Wait a second, you mean addicted to breathing? Like drugs?

While this seems absurd I hear it often enough to recognize that it is a common concern which needs to be addressed.

When a person trains with HRVF they are using the feedback to consciously control their breathing, and their autonomic nervous system.  Feeling stressed they consciously decide to use HRVF which changes their physiological and mental state.  Because they have feedback, as opposed to simply deep breathing, their learning is much faster and more efficient.   Like learning piano with a teacher vs. learning from a book with no correction for mistakes.

And like any skill, breathing at your resonant frequency with HRVF becomes more automatic with practice.  And that means that it becomes unconscious.  The more you practice, the less you need the feedback.  The result is that with time when a person becomes stressed, they unconsciously change their breathing and pull themselves back into a relaxed, balanced state without any thought or effort.  Far from being dependent, the person who is trained in this way is much more autonomous.

The road to true independence requires strategic, time-limited dependence on good teachers.  And HRV feedback is a great teacher.

#7 HRV Feedback is not Meditation

People exploring Heart Rate Variability Feedback (HRVF) often come to the incorrect conclusion that HRVF is “just meditation”.  As Llyod Bentsen said to Dan Quayle in the Vice Presidential Debates:  Senator I served with Jack Kennedy… I knew Jack Kennedy… Jack Kennedy was a friend of mine…Senator,  you’re no Jack Kennedy.

Saying that HRVF is “just meditation” short changes both HRVF and meditation.  In the mid 70’s I caught the wave when Maharishi Mahesh Yogi was touring the US and took a course in Transcendental Meditation (TM).  While I have my doubts that the mantra I was given was specifically chosen for me by the Mahrishi as promised, I still use it to this day. I have found TM to be a very useful tool for relaxation, and have practiced it regularly for decades.

The underlying physiology of meditation has been elucidated by the work of Herbert Bensen MD on what he calls the “Relaxation Response”.  The most important effect is an increase in the Parasympathetic (calming) to Sympathetic (arousing) nervous system ratio.    While the ratio is increased, the overall output of the autonomic nervous system is turned down. (There are contradictory findings on this fact which I believe can be explained by the pattern of breathing employed in the meditation.)  This can be demonstrated by meditating while using an HRV device to monitor your heart rate.

Typically what happens when you meditate while monitoring heart rate, is that there is a significant decrease in heart rate variability.  As the parasympathetic/sympathetic ratio increases, the individual relaxes and breathing becomes more shallow.  This causes HRV to decrease. This leads you to a state which is more relaxed, but not particularly “ready”.  It’s great for shutting down your mind before bed, but lousy if you are headed to a party where you want to be vivacious and scintillating. (My goal, not always realized.)

HRVF in contrast leads to a very different physiological and mental state.  While the ratio of Parasympathetic to Sympathetic nervous system output is increased as with meditation, the overall output of the autonomic nervous system is maintained or even increased.  You will see an increase in the variability of the heart rate.  And mentally you will be in a “Relaxed and Ready” state.  It is a fluid state where you can shift to quiet contemplation, or to socially engaged and dynamic.  For that reason it tends to be much more useful during the day when a person needs to get “balanced” before a demanding activity like a presentation.

Understanding the difference between HRVF and meditation illustrates why the picture above is after the big meeting- calming down and digesting the experience with meditation.
(As opposed to preparing for the meeting, when HRVF would be more useful.)

HRVF and meditation both lead to very useful but distinct physiological and mental states.  In an echo of Lloyd Bentsen:  I know meditation…meditation is a friend of mine…but HRVF is not meditation.

For readers interested in a contemporary view of meditation check out:  Buddha’s Brain:  the practical neuroscience of happiness, love and wisdom by Rick Hanson PhD.

Thursday, March 10, 2011

# 6 What is “Coherence” and how does the emWave™ or StressEraser™ measure it ?

Coherence is a tricky concept to master because it is used in several different ways in the literature of HRV.  To facilitate understanding I’ll explain “coherence” from the perspective of someone opening up and beginning to use an emWave/StressEraser.

Auto-coherence of the Heartwave. – Breathing deeply and rhythmically, the display of the heart-rate will be a smooth, regular, undulating wave.  A  “sine-wave”.

Given it’s regularity the parts of the wave are all “organized, consistent, and logical” with each other.  It is coherent with respect to itself, or “auto-coherent”.  The HRV device calculates exactly how regular or “auto-coherent” the waveform is.  This gets represented as low (red on the emWave, one box on the StressEraser), medium (blue/two boxes) or high (green/three boxes) “Coherence”.  Achieving “High Coherence” (Auto-coherence) means that there is the potential to achieve other types of Coherence that have profound effects on the mind and body. But you’re not there yet.

Physiological Coherence-The body contains many oscillators, that is, systems that cycle.  For example the heart beat, breathing, blood pressure and brain waves. When two or more systems are synchronized they are said to be “coherent”. When many systems in the body are synchronized the person is in a state of “physiological coherence”.  To achieve this state takes ten to twenty minutes for most people beginning to use HRV.  Why?

Imagine a middle school orchestra.  If the conductor  keeps regular time (auto-coherence) then as the orchestra continues to play, the instruments will fall into synch.  The drums get in synch with the conductor which helps the bass get in synch  which helps the strings get into synch etc. until the entire orchestra is synchronized or “coherent”.

In the body, the heart and respiration get in synch which then allows the pressure sensitive baro-receptors to get in synch which then allows the brain (thalamus and cortex) to get in synch.  This is a sequential process that occurs over time.

Individual Coherence- After Physiological coherence has been achieved it is possible to see the manifestations at the behavioral level.  The person is more “coherent” –e.g. ideas are expressed more clearly, actions are more fluid and take less energy, and life in general proceeds more smoothly.

Take Home Point. – When you start to score “High Coherence” in an HRV session your mind-body is not yet in a state of “Coherence”.   If you continue to score “High Coherence” and allow the different “players” in your body to sequentially get in synch over ten to twenty minutes you will then be in the “Coherent” state.  And you will know that not because of a score, but rather because of how you feel.

Tuesday, March 1, 2011

#5 How does the StressEraser or the emWave measure the function of the Sympathetic and Parasympathetic Nervous Systems?

How does the Stress Eraser or the emWave measure the function of the Sympathetic and Parasympathetic Nervous Systems? Short Answer: It doesn’t. (Not directly.)

The Stress Eraser and the emWave are the Heart Rate Variability (HRV) Feedback devices currently available on the consumer level. I’m generally a big fan of the user reviews on Amazon, however with these devices there is a lot of confusion. Consider the following excerpt from a retired physician:

“based on the “feedback” it gives the user, I really don’t understand what it is measuring. It simply can’t be sensitive enough to detect what it purports to detect without being very much more complex than it is.”

The Stress Easer and emWave measure one thing, and one thing only- the inter-beat interval. That is, the time between heart beats. With this one measure it is possible to calculate the heart rate which is constantly changing. For example if the inter-beat interval is 10 seconds the heart rate is 6 beats per minute. If the next interval is 15 seconds the rate has dropped to 4 beats per minute. (Unrealistic numbers chosen to simplify the math.) So how does it measure the output of the Autonomic Nervous System (ANS)?

The devices don’t measure directly the output of the ANS. Using the inter-beat interval data, and the mathematical technique of Fast Fourier Transform, the rate of change of the heart rate is calculated, on the fly, in real time. This is the “magic” of the technology.

Sometimes the heart rate is changing quickly, and sometimes slowly.

Fast changes in rate are caused by shifts in parasympathetic tone (by opening an ion channel which is virtually instantaneous).

Slow changes in rate are caused by shifts in sympathetic tone (linked by a second messenger system which is relatively slow taking roughly 4 seconds to change the rate).

So the rate of change of the heart rate, fast or slow, is a fairly accurate reflection of the activity of the ANS (particularly the parasympathetic system), even though it is not measured directly.

Next time we’ll look at “coherence” and see how that is measured (or not).

Saturday, February 19, 2011

#4 Antidepressant effects on HRV

I’ve often wondered if the effects of HRV training were compromised with
patients taking Tricyclic Antidepressants (TCA’s). TCA’s are anticholinergic, thus interfering with the parasympathetic nervous system which uses acetylcholine as its neurotransmitter. TCA’s usually increase resting heart rate, but do they interfere with the ebb and flow of vagal (parasympathetic) tone that gives rise to HRV?

A recent study suggests that TCA’s may interfere with HRV training. Why?

“Reduced cardio-respiratory coupling after treatment with nortriptyline in contrast to S-citalopram.” J Affect Disord. 2010 Jun 8.

Major Depressive Disorder increases cardiac mortality, with decreased HRV estimated to explain 30% of the increased risk. This study measured HRV before and after treatment with an antidepressant-either the TCA nortriptyline or the SSRI s-citalopram.

The results demonstrated decreased HRV and cardio-respiratory coupling, (consistent with interference in parasympathetic regulation) by nortriptyline, but not the SSRI s-citalopram. These results have implications for the treatment of clinical depression in patients who already have a higher risk for cardiovascular disease. That is, use of TCA’s to treat the depression may increase cardiovascular risk relative to use of the SSRI’s via its effect on HRV.

In addition one can speculate that given the decreased cardio-respiratory coupling associated with TCA use, that training with HRV Feedback would be less effective for someone on a TCA. An idea that certainly needs more observation and study.