About Valsalva Wave Pro (Internet)
December 28, 2010
Welcome to Valsalva Wave Pro, by Stephen Elliott, President COHERENCE
I'm very pleased to announce that we are now able to observe the effect of respiration on the action of the blood. In my research of the last 5 years or so, I've been able see this wave action in both blood pressure and blood volume, but not conveniently. Valsalva Wave Pro addresses this need, allowing us to monitor the blood effects of breathing clearly and easily. It also makes clear the relationship between respiration and heart rate, i.e heart rate variability (HRV).
The illustration below presents 60 seconds of the "Whole" Valsalva Wave while breathing "coherently" as measured at the right ear lobe. The slow wave (dotted line) is the Valsalva Wave proper, "respiratory modulation" of blood volume in both the arterial tree and the vena cava. The faster pulses that appear to be riding on the slower wave are individual heart beats that rise and fall in amplitude with the Valsalva Wave. Note that the pulse rate becomes slower (farther apart) as the Valsalva Wave crests and faster (closer together) as the Valsalva Wave troughs.
Exactly how much of a role breathing plays in the circulation we don't fully understand, and may never without invasive measurement. The typical human body contains about 5 liters of blood. This volume is thought to circulate about one time each minute. It is also understood that during vigorous exercise, this may increase to 6 times per minute. My current estimate is that when we breathe "coherently" the rate of blood flow doubles, i.e. it increases from 5 liters per minute to 10 liters per minute. This is reasonable, as Coherent Breathing may simply be seen as a very specific "form of exercise".
The "Whole" Valsalva Wave While Breathing "Coherently"
The slow deep blood wave action that we see in this illustration is all but absent during typical breathing. It is a consequence of the "thoracic pump", the sealed thoracic cavity bounded on 3 sides by the rib cage and the diaphragm at the bottom in which both lungs and heart reside. The process that generates this wave is described in the graphic below (from Coherent Breathing - The Definitive Method).
The long and short of it is that breathing plays a vital role in moving the blood in the body, i.e. the circulation. I refer not to the matter of "gas exchange" but literally to the "pumping" of the blood in the circulatory system.
Here, there is a major missing link in our understanding of "respiration"...
When we inhale, the lungs fill with air - but they also fill with blood. When we exhale, the lungs empty of air - but they also empty of blood. The whole idea of this "design" is that air and blood meet across the extremely think alveolar surface of the lung in a very coordinated way, optimizing gas exchange. When we inhale, air and blood meet; when we exhale they part.
The motive influence behind the movement of both air and blood is the pressure in the thoracic cavity - "intrapleural pressure". Intrapleural pressure is a function of volume which is ultimately a function of diaphragm position. When the diaphragm moves down, pressure becomes relatively negative. (This the same thing that happens when we raise the handle of a simple bicycle pump.) When the diaphragm moves up, pressure becomes relatively positive (what happens when we push the bike pump handle down).
When we breathe shallowly and without rhythm, this pumping action is defeated. Shallow irregular respiration contributes little to the movement of air in the windpipe and conducting airways and little to movement of blood in the pulmonary arteries and veins. The bottom line is that we receive enough air and blood to survive but not to thrive.
Possibly as important....
The diaphragm is a large, thick, strong muscle. When it is not contributing to the "work" of moving the blood, the entire job of circulation falls to the heart and vascular system, smaller and less robust than the diaphragm. I believe this issue is most problematic in the venous circulation, i.e. movement of the blood from the extremities back to the lungs. When the diaphragm is not contributing to this effort, the heart must generate the vacuum that draws the blood through the veins.
This represents a dramatic increase in "work load" on both the heart and the vascular system which must bear the entire burden of "circulation". To accommodate this burden, the autonomic nervous system ratchets up "activity", i.e sympathetic emphasis. This increase in sympathetic activity, combined with suboptimal circulation and aeration is the ultimate basis of many present day maladies, both acute and chronic. This sympathetic "bias" can be observed via numerous biometrics, specifically heart rate variability, electrodermal response, brainwaves, hand temperature, and muscle tension. These biometrics can also be observed to change dramatically within minutes of breathing "coherently". I believe that this dramatic change is ultimately an outcome of the diaphragm contributing to "circulation".
Regarding heart rate variability...
The phenomenon of heart rate variability (HRV) has been of fascination for over 3 decades. Even so, as of now we have little appreciation for what heart rate variability actually "is". Here again there seems to be a "missing link". While we've understood for decades (actually for 5000 years) that breathing has a major influence on heart rate, this understanding seems to be all but lost in the present. Technically, heart rate variability is variation of the heart rate for any reason. Recognizing this, the fact is that heart rate is under fine autonomic control where the ultimate goal is maintenance of viable blood flow and pressure. Huang Ti, circa 2500 B.C. said, "Health results when breathing and blood flow are harmonized and mutually supportive. Alternatively, disease reults from their disharmony." (From Coherent Breathing - The Difinitive Method.)
About the name "Valsalva Wave"...
In medical literature there is a term given to the understood but little recognized wave action as observed in the arterial system as a function of breathing. It is called the "respiratory arterial pressure wave". There is also a relatively obscure term for a wave phenomenon in the venous system - the "venous wave". However, there is no term for the wholistic "circulatory" phenomenon, arterial and venous emphasis alternating with exhalation and inhalation, respectively. Antonio Valsalva (circa 1600), an early physiologist, is said to have observed changes in the jugular vein as a function of respiration, making him one of the earliest recorded observers of the interaction between breathing and blood flow. As the phenomenon is both "arterial" and "venous", the initials "A" and "V" help remind us of the wholistic nature of body in which we live.
Copyright 2009 COHERENCE LLC
(V1.0, May 2009)