The Test: Impedance Cardiograph
Hi Jim,
I think the actual test is called "Impedance Cardiograph" test; could also be called "Idiopathic Cardiomyopathy" test. It supposedly used to test for a condition called "Compensated Idiopathic Cardiomyopathy".
I had thought about getting this test in the past, even discovered that it is covered by Medicare. I think I slipped into an abyss for a while and never followed up on it. It would probably be a good idea for me to do so at some time.
I found this by Carol Sieverling, who has transcribed a number of Cheney presentations. I'll post the beginning below; the entire article can be accessed at:
http://www.dfwcfids.org/medical/cheney/hrt04lng.htm
Best, Wayne
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09-12-2005
By Carol Sieverling PREFACE
The following is my interpretation of transcripts and tapes of conversations that took place between Dr. Paul Cheney and two different patients, including myself, during September and November of 2004. Any treatments mentioned are highly individualized and should not be generalized to all CFS patients. Dr. Cheneys treatment approach is rapidly evolving as new information and insights unfold.
Certain broad concepts central to Dr. Cheneys understanding of this illness are generally much more constant (such as decreased cardiac output, HPA axis involvement, the role of glutathione, etc.). Its essential to note that a set Cheney protocol applicable to most patients does not exist, given that his treatment protocol is extremely individualized and constantly evolving.
Quotes are from Dr. Cheney or, where noted, from a patient. Statements in brackets were added by me to provide clarification or context. All other comments are statements from Dr. Cheney that have been slightly paraphrased, but, to the best of my knowledge, maintain his original meaning.
The focus of this article and much of Dr. Cheneys current work is based on the following publication: Abnormal Impedance Cardiography Predicts Symptom Severity in Chronic Fatigue Syndrome. Peckerman, et al: The American Journal of the Medical Sciences. 2003; 326(2):55-60
A synopsis of this article and an interview with Dr. Peckerman was published in the Fall 2003 issue of The CFS Research Review by the CFIDS Association of America. It can be found online at cfids.org > archives > Research Review > 2003 > fall. You can also google Peckerman and find another article on WebMD.
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PECKERMANS ARTICLE
Dr. Cheney stated, This is the best, most important publication in 20 years. [On the topic of CFS.] This was published the year I left practice, 2003. The senior author is Natelson, and the principal author is Arnold Peckerman. What this very impressive article says is that, without exception, every disabled CFS patient is in heart failure.
CFS Compensates for Idiopathic Cardiomyopathy
Let me first of all define heart failure. There are two kinds of heart failure. Theres the kind that any cardiologist can diagnose in about a minute. That you do NOT have. Which is why cardiologists missed this. What you have is Compensated Idiopathic Cardiomyopathy. [Idiopathic = cause unknown; cardiomyopathy = structural or functional disease of heart muscle] And your primary means of compensation now this is the big twist are you ready? Have you got your seat belt on? The primary methodology for compensation for this disorder is in fact CFS itself.
Patient responds, I see. So, this is the bodys way of saving us from dying of cardiomyopathy.
Yes. From dying of cardiomyopathy. What is ironic about this is that I had Idiopathic Cardiomyopathy (ICM). But I never had CFIDS.
In the medical literature, at least 35% of those with a diagnosis of ICM will die within 5 years unless they receive a transplant. [That, of course, was Dr. Cheneys experience a heart transplant.] Ive been following CFS patients for 20 years and never seen one case of CFIDS go on to transplant or ever even heard of one going on to transplant.
Now if your diagnosis is ICM, why arent you dead? Why hasnt one patient in 20 years needed a transplant? Its because you had CFIDS, and I didnt. I even suspect the mechanism, and that has been published too.
The disease [CFS] itself is protecting you from a deeper problem that has been totally missed, including me. I missed it, too. Because its so well hidden.
The Research
[Lets take a closer look at the study, beginning with the researchers.] This group is at the New Jersey Medical Center. Its a major medical school. Dr. Natelson is a neurologist and professor of neurology. Hes a very good researcher; quite a bright and accomplished scientist. Dr. Peckerman, the lead author, is a cardiac physiologist or cardiopulmonary physiologist. About five years ago the NJ Medical Center received a multi-million dollar grant from the NIH (National Institutes of Health). To get the grant, Dr. Natelson wrote a proposal to find a physiological parameter that could be objectively measured and would correlate with disability.
Find an Accurate Measure of Disability
Their job was not to find the etiology, pathophysiology or treatment for this disorder. Their job was to find a measurable number that could accurately demarcate those with [CFS] that are disabled vs. those that are not, so that we could resolve some of the disability adjudication problems [that affect so many CFS patients], where people dont believe that you have a problem and its hard for you to get objective proof that will satisfy critics as to your disability.
As clinicians we know that not everyone with CFIDS is disabled, and there are many people with CFIDS that are disabled. We know these extremes exist. What we know less about is where to draw the line, because thats a harder thing to do. And the government is just nuts about this, because some circles feel that too many people are getting access to SSDI that shouldnt, and on the other side there are people who feel that there are some who arent getting it who deserve it. We need to resolve this in a compassionate and fair manner.
That was [Natelsons] proposal and it was funded, fully. [The NJMC was named a CFS Cooperative Research Center.] And you can guess why. The government has a vested interest in knowing that were not raiding the treasury unfairly, but they dont want to be accused of knocking people off [SSDI] who later turn out to be disabled.
A Q Problem
So the NJ team looked at many things, and they found something: a Q problem. Q stands for cardiac output in liters per minute. Q in CFIDS patients correlated with great precision with the level of disability as judged by a validated clinical questionnaires that asked about activities of daily living. What can you do, (bathe, dress, cook, etc) and how hard is it (no problem, little bit of a problem, moderate problem, lot of problem)?
Question after question after question. Then they have a score, and those with the highest score were the most disabled, and those with the lowest score were the least disabled. And then they gave the same questionnaire to normal sedentary controls.
The Test: Impedance Cardiograph
Then they measured Q, using impedance cardiography, which is a technology that allows one to accurately measure the cardiac output, using the idea that the resistance a current has, passed through your chest, is a function of the blood flow through it. Its actually inversely proportional. The greater the blood flow, the lower the impedance. The less the blood flow, the greater the impedance. Because blood is water, water passes current better. Its a simple idea. Put an electrode on your front and your back, and pass the current through, and if it goes quickly through, theres a lot of blood going through the chest, and if theres resistance, theres less.
They used a thoracic algorithm, developed at the University of Minnesota some 30 years ago. The algorithm allows many factors to be part of determining Q, including chest and body size. Using it, you can compare the Q of big people to the Q of small people and still be comparing apples to apples.
The University of Minnesota algorithm has been approved by the FDA as a valid measurement of Q. The point is that Medicare pays for this; its been clinically validated by a government agency; its not considered experimental or research as long as you use this algorithm. Thats important, because whenever this filters back to a cardiologist, the first thing many say is, well, but, you know, thats not accurate. And indeed it may not be accurate depending on the machine and the algorithm that it uses.
By the way, theres one other important detail. Unlike all other measures of cardiac output, this is the only one that can be done in the upright position. Which, as youll find out in a second, was a critical step. Absolutely critical. All other cardiac output measurements are done in the supine position laying down.
Now, do CFIDS patients prefer to stand up or lie down? Of course they prefer to lie down. Do you know why? Do you know what your cardiac output does when you stand up? It drops 30%. In all humans without exception. So very critical to this technology is that its the only one that could be done upright. And what they found is absolutely astonishing, truly astonishing. When [disabled CFIDS patients] stand up, [theyre] on the edge of organ failure due to low cardiac output.
The study involved 38 CFIDS patients and 27 matched sedentary controls a reasonable sample to get convincing statistics. The CFIDS patients were subdivided into 18 severe cases, and 20 that were less severe. When they looked at the statistics, disability correlated with Q!
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The above article continues at:
http://www.dfwcfids.org/medical/cheney/hrt04lng.htm
