History of POTS with Phillip Low, MD
Mr. Al Ruechel: Hi everybody, I’m Al Ruechel. Thank you for joining us here on our webcast as we continue to talk about dysautonomia. And we are honored today, and I mean that really, to have Dr. Philip Low who joins us and we’ll tell you why we’re honored in just a second. Dr. Low, thank you for stopping by, I appreciate you being here. Tell me a little bit about your background if you would before we start talking about POTS, which is really cool. Go ahead.
Dr. Phillip Low: Yes, I graduated in medicine in Sydney, Australia and came over to the Mayo Clinic in 1976. I got interested in the autonomic nervous system because of my research in Australia. I have subsequently become boarded in neurology and clinical neurophysiology. I founded the autonomic laboratory, the first of its kind, at the Mayo Clinic in 1983. At that time, I was interested in the autonomic disorders. It was a called a Cinderella of medicine because it was so neglected.
Mr. Ruechel: Oh Gosh!
Dr. Low: At that time, there was only myself, Roger Bannister – the runner in England, and also David Robertson at Vanderbilt. So, we developed this field and I’m pleased that the American Autonomic Society has become a large and active organization.
Mr. Ruechel: Well, I can see why they call you the father of POTS, because you were so involved so early on. So, for our audience most doctors already know, but tell me what is POTS. Define it for me.
Dr. Low: POTS is a condition or syndrome consisting of orthostatic intolerance meaning that patients develop symptoms of lightheadedness and other symptoms when they stand up coupled with an increase of heart rate by at least 30 beats per minute for adults. So that’s what defines POTS.
Mr. Ruechel: Well defined, but in the early years, how did you come up with that particular name for it? Was it because most of the patient you were seeing had those symptoms or is it the other way around where take the symptoms and then you fit them to the patient?
Dr. Low: The condition itself probably has been present for a long-long time. During the first and second world wars, there were soldiers who went by different names. They called it effort syndrome because they couldn’t exert themselves. There was soldier’s heart, because their hearts would beat too fast, etc. But the term postural orthostatic tachycardia had been mentioned in a couple of publications prior to my getting involved. For instance, there was paper by Phillip Cryer and also another one by Bob Holky, who were endocrinologist, diabetologist, who got interested in orthostatic intolerance in those conditions and there was also someone else at the Cleveland Clinic, Dr. Fuad who interested in hypovolemia, low blood volume. But I got interested in it together with my fellow, Ron Schondorf, because we were dealing with autonomic neuropathies, especially autoimmune autonomic neuropathies where patients have damage to the autonomic nervous system. Some of them, when they stood up, they had a heart rate as high as 160 beats per minute with orthostatic hypotension. So, we reasoned that what if you had autonomic failure of lesser degree where they would still have the tachycardia, but without the orthostatic hypotension; those patients, let’s call them POTS, postural orthostatic tachycardia syndrome. So, we were interested in a subset of POTS with autonomic neuropathy.
Mr. Ruechel: Now, I’ve heard some people and some of the doctors talked about using the word postural and then orthostatic tachycardia, sometimes you leave off the postural because it’s like, well maybe the other two words actually define it better.
Dr. Low: Right, I think that most of us would prefer to leave the term postural, so we don’t always put in the term orthostatic, that’s assumed.
Mr. Ruechel: Okay.
Dr. Low: So, you assume that when postural means when you go from lying or sitting to standing.
Mr. Ruechel: So, since it was named, you worked on it many-many years, what kind of advancements have been made in terms of treatment.
Dr. Low: There has been about three or four major advances. One of them is the demonstration that these patients have hypovolemia, meaning their blood volume is reduced. Any normal person who has low blood volume would have orthostatic tachycardia, someone who has a viral illness with vomiting and diarrhea; if you go to bed and you stand up, you get lightheaded, but you understand why. These patients don’t have an otherwise explainable mechanism, but their volumes are down. So that’s one advance that was found. Second advance is the recognition that some patients are hyperadrenergic, the sympathetic nervous system is in overdrive. That’s a second group of patients. Third finding is that deconditioning plays a major role in much of the symptomatology of POTS.
Mr. Ruechel: So, define deconditioning, what does that mean?
Dr. Low: Deconditioning is a condition where you’re not on your feet for a significant period of time. One extreme example I can provide are excellent astronauts. These are fit persons who go into space and then they come back and they can’t stand on their feet, they are severely orthostatic because they are deconditioned. They haven’t been standing on their feet.
Mr. Ruechel: Okay, that makes sense.
Dr. Low: In fact, working with NASA researchers, we were able to show that if you put a normal person to bed for more than two weeks and then they stand up, they have POTS.
Mr. Ruechel: Oh gosh, something that simple. So, as you’re looking at this, everybody wants to know okay, great we now can recognize this. We now can recognize this but you know what the next question is, what causes it?
Dr. Low: I think that deconditioning affects, I think the, balance of your autonomic nervous system. What people have failed to realize is that chronic deconditioning has effects on your cardiovascular system. Dr. Ben Levine, in Texas, and the Mayo researchers were able to demonstrate that the heart becomes altered in patients with POTS. Ben Levine demonstrated, what he called cardiac atrophy, the heart actually got smaller and the Mayo Researchers demonstrated that the stroke volume, the amount of blood that the heart pumps with each effort, is reduced. So as a result, it’s a very inefficient system. But just as important indeed the fourth important advance I think is the demonstration that a program of exercise will reverse deconditioning and patients can lose much of their symptoms.
Mr. Ruechel: That always sounds unusual to me because when you’re not feeling like you can get up, when you’re feeling sick to your stomach, you may be vomiting, you may be fainting, so you say to yourself “Exercise? I mean I can hardly get out of bed and now you want me to exercise?”.
Dr. Low: That’s an excellent point and in fact it’s the biggest obstacle we have to patients who are extremely fatigued, the last thing they would like to think of is exercise. They say doctor, “When I exercise or even take a few steps, I get wiped out and I have a very slow recovery cycle and you’re asking me to exercise?”. So that is a major challenge and the way we try to overcome that is to have them take baby steps. What we tell them to do is, “I know what your goal is, I want you to be exercising at least four days a week for 30 minutes at 80% of maximum heart rate. I know you can’t do that, but I’m going to work you up over three months to do that, three months baby steps” .
Mr. Ruechel: So, that is something that is doable. So, where we are going in the future with this. What are you now keyed on? We know that exercise helps, but are we still trying to zero in on the mechanism that causes all of these. Is it the brain, is it the spinal cord, I mean what is it?
Dr. Low: Certainly, the brain is involved in at least a couple of ways. One is the hyperadrenergic state resides with the brain. So, you need a drug that acts centrally. Unfortunately, there’s also a second phenomenon that’s very active in someone with chronic POTS and that is central sensitization where patients are much more aware of their symptoms than you and I. So that dominates their life.
Mr. Ruechel: They think about it all the time.
Dr. Low: Right. I explain to patients that the brain has a gating mechanism and the gate is too wide open, you need to close it down a little and that is where training is very important.
Mr. Ruechel: Behavioral modification, then comes in.
Dr. Low: Behavior modifications sometimes with the help of psychology.
Mr. Ruechel: Yeah. Do you think there ever will be a day and of course, you say this is medicine, you can say this with any disease, when there’ll be a pill that will correct all of the stuff or is that ever going to happen?
Dr. Low: I think that it’s not the best way to explain that to the patient, because I think probably not. I say this carefully because POTS is a heterogenous group of conditions. There are different types of POTS. For instance, the patient with neuropathic POTS, you can treat the patient to improve the autonomic damage. If someone had an autoimmune disease, for instance an autoimmune autonomic neuropathy, you can try to use even the suppressive agents, etc., but that is probably a small subset. For most patients I think it is important for them to switch the emphasis from physician management to patient management. So that if you give the patients the tools, so that they understand their condition and if they know that there are certain tools that will improve aspects of their being, they can do a lot better.
Mr. Ruechel: And that’s exactly what we’re trying to do with this website and The Dysautonomia Project altogether. So, two last questions for you. Number 1: You’re talking to doctors right now, what key important thing would you tell the doctors in terms that they might be dealing with this?
Dr. Low: First of all, make the correct diagnosis. Secondly, try to define what is the major abnormality – is there autonomic failure, is there a hyperadrenergic state, is there bed deconditioning, and focus on the management of those particular aspects.
Mr. Ruechel: And now to patients that you’ve talked about hope in being patient, so if you’re talking to patients right now, what would you say?
Dr. Low: I say to the patient that based on what we know about the natural history of treated POTS, if you look at them a year after initiation of treatment, they are functionally improved. In fact, about 60% no longer fulfil criteria for POTS, but many of them still have some symptoms, so I emphasize to them that they should focus on function and not on symptoms and they should also be empowered, so that they can tackle the condition with the help of some physicians, but the patient takes charge.
Mr. Ruechel: Alright. Doctor, thanks so much. It’s an honor to work with you and talk with you right now. Thank you so much and hope to keep up the good work.
Dr. Low: Pleasure.
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Wolfgang Singer, MD
Associate Professor of Neurology
Mayo Clinic Rochester, MN