MED: impressions of Cheney, part 2 (down cardiac heart cancer cardiomyopathy)
I posted some thoughts maybe ten days ago on the first part of the tape -- which deals specifically with the diastolic cardiomyopathy. Here are some reactions on the next section.
There is an old parable about several blind men trying to describe an elephant. One feels the trunk, another feels the leg, one feels an ear, another feels the tusk, etc. They give wildly different descriptions of what an elephant is like because they haven't grasped the whole picture. Watching Cheney's new lecture is a little like that. He'll talk about cardiomyopathy and its ramifications, and then the slide switches to something about peroxynitrite, or exercise ergometry with gas ****ysis, and so on. These are all aspects of the CFS elephant, apparently, but it is hard to get a coherent picture of the relationship between these elements -- at least it is hard for me.
Although he started out talking about cardiomyopathy -- the type that is found in CFIDS and the evidence for it -- in the second part it seems to me he is talking about the pathology that underlies the heart dysfunction.
It boils down to mitochondria malfunction. This malfunction seems to cause an increase in the superoxide radical. Normally this radical is kept in check by SOD (which should be familiar to anyone reading my posts lately -- it is the most abundant antioxidant enzyme in the body, if I'm not mistaken) and another substance with which I am unfamiliar. When the SOD + ? system fails, then superoxide can get outside the cell and combine with nitric oxide to produce peroxynitrite, which is a very powerful very damagine free radical. Cheney feels that our cells are shutting down energy production, shutting down oxygen consumption, as much as possible in order to minimize superoxide release, because that is normally the rate limiter in the production of peroxynitrite.
When the mitochondria reduce their energy production, cardiomyopathy is one result. There are many other consequences. If this scenario is correct, I still think it might be difficult to say just how much each factor is responsible for the symptoms we suffer. Certainly the reduced microcirculation in capillaries -- a compensation for low cardiac output -- could cause many symptoms by itself. Is the mitochondrial dysfunction only in certain cells, or is it in every cell? If the latter, it could have wide ranging effects apart from the poor microcirculation.
Here is the point: Lance Armstrong can reach a peak cardiac output of 35 liters/minute. This is why he can do the amazing things he has done. I would also like to point out that it is probably why he survived a toxic chemothe****utic regimen for his cancer that permanently debilitates or kills other patients. Other athletes might get 25 liters/minute of output. A normal person, when standing, puts out 7 liters/minute, but when reclining, will put out 5 liters per minute.
But CFIDS patients have a cardiac output of 5 liters or less when standing. Some will put out much less. He had one patient with a cardiac output near 2 liters/per minute, which was less than Cheney had before his heart transplant. He could not figure out how this patient could stay alive.
Since cardiac output drops even lower when a patient stands (if he/she can stand up -- but most of us can, I think) the situation is much worse. It is very hard to keep adequate blood flowing to all the organs, the skin, the brain, under these cir***stances. Something has to suffer somewhere. Some body part always gets the blood supply cut off a little bit.
Less blood flowing to an area means less oxygen, less signalling molecules like hormones, less waste removal, and a host of bad things. With more cardiac output, that is to say with more blood flow to all areas, no doubt many of our symptoms would resolve or be mitigated just by that fact alone.
Since the root cause seems to be the mitochondria, that has to be part of the focus of treatment. And also, to improve the filling of the ventricle. There are some ways that we might accomplish each of these goals, but I will have to view and review a bit more before I understand what he is recommending in these areas.
Again -- I am trying to report and summarize what Cheney said. I may have got some things a bit wrong, and even if I report 100% accurately, that does not mean that everything Cheney said is correct. But with those caveats, this general outline seems to be how Cheney views CFS.
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