28 Aug 2016

Study indicates deconditioning doesn't cause PoTS, but has a cardiac trigger

Study indicates deconditioning doesn't cause PoTS, but has a cardiac trigger

A very small, yet enlightening medical commentary about Postural Orthostatic Tachycardia syndrome (PoTS) has recently popped up.

PoTS is often -erroneously- put down to the result of deconditioning - i.e, not doing enough exercise.
It's one of the things that people with the condition (including me) find most upsetting, the thought - sometimes spoken, more often just reflected in someone's face, that it's really all our own fault.

While PoTS can be as the result of many things, for example, a chronic pain condition such as Ehlers Danlos syndrome, its effects can be utterly disabling. It ends up as a vicious circle of not being able to exercise or even stand up through the symptoms of dizziness, fainting, chest pain or nausea (among others) and that makes it even harder to get up because you're weaker through lack of moving about. This is called 'exercise intolerance'.

This explanation may be given to patients in a dismissive way - sort of, 'You've let yourself down by being lazy so just try harder, get up and you'll get better'. But how do you do that when you can't stand up in the first place? And what was the trigger for those people whose PoTS came on suddenly, at the same time as the other illness (as in my case) or just by itself out of the blue? Deconditioning does not explain this.

However two doctors have written to the journal, Pulmonary Circulation, as a follow up to another study that sparked their attention. Doctors, Svetlana Blitshteyn, MD of Buffalo's Dysautonomia clinic and David Fries, MD of the Sands-Constellation Heart Institute in Rochester, both in New York State, analysed this study on low ventricular filling pressures as a cause of exercise intolerance and dyspnea. They believe it sheds some light on the causes of PoTS saying:

Previously, a low stroke volume and decreased cardiac mass in patients with POTS have been attributed hypothetically to deconditioning. This study provides the first objective evidence that low ventricular filling pressures in patients with POTS are contrary to what would be expected in deconditioned patients—high filling pressures.

The doctors commented that the study (although small) could be applicable to the majority of PoTs patients in that, "exercise intolerance in POTS is not caused by a lack of maximum effort from the patient but that low ventricular pressures occur despite the maximum effort."

If they're lucky, patients with an autonomic dysfunction such as PoTS have non-invasive (i.e, not surgical) tilt-table tests or other cardiac stress tests, ECGs and perhaps blood tests to diagnose them. Unless you can pay privately, in the UK these tests have incredibly long waiting lists on the NHS, during which time patients are becoming more ill. Many such as myself often need to use a wheelchair to even leave the house.

My Automonic Testing

My own story illustrates how difficult life with this condition can be and I do, in fact, consider myself lucky that I am not a young woman, just setting out on life. It also shows why compassion and understanding is far more required than telling someone they just need to pull their finger out and get on the exercise bike. I'm not saying that doing nothing is the right thing either, but a huge amount of support is needed, especially if you are young with little experience of life.

For me, the wait was 18 months before I got an initial appointment. Then, a further three months before I got the tilt-table tests. Then, incredibly, TEN months before I got the results of the tests. All during this time, life was very difficult. I could only walk short distances without having to stop and sit down or, if there was nowhere to sit, to bend down to get my head as low as possible.

Of course family life continued around me, with me feeling like I was less relevant, less able to participate and altogether more useless by the day. It was probably my own fault for not trying hard enough, of course. I tried dying, but I didn't even manage to try hard enough at that. What a slacker.

When I went back, I was given a trial of Ivabradine, which had a very positive effect. My GP however, didn't want to dispense it as it was off-label and the specialist letter hadn't yet arrived (and didn't for some time). After I become quite upset, my GP relented and made out the prescription. 

Although I was told by the Autonomic clinic I would get a follow up appointment in three months, I didn't get any letters until I received one discharging me, as I had apparently failed to attend! Like I would fail to attend after all that waiting! The letter had simply not arrived.

Despite explaining this to them and speaking to my GP and to my EDS specialist, they have not yet sent me another appointment and we are now more than a year after the results appointment. In the meantime, I have taken it on myself to double the dose as it appears no one else gives a stuff whether it's working or not, so I'll just do it my way.

The Ivabradine certainly isn't perfect - not by a long shot. But it does give me more ability to move around and I have worked to increase my strength. Of course there is always the knock-on of fatigue but I'm doing as much as I can, paying for one-to-one Pilates to try to recover some strength. It's not easy, especially as I am no 20 or even 30-something, (barely even a 40-something now) and it often feels like you get through one door only to have it hit you in the back and knock you flat.

Deconditioning a result, not a cause

In their letter about the study, the doctors reiterated how people's responses to patients with this condition can often make it worse.

"Patients often feel frustrated and blamed for their illness and a lack of improvement or recovery when they are labeled as deconditioned or told that they are not putting their maximum effort, regardless of whether they are exercising routinely as part of their therapeutic regimen or have not been sick long enough to become deconditioned.
"Deconditioning can occur secondary to prolonged bed rest and chronic inactivity in patients with POTS, but appears to be not a primary underlying mechanism. Larger studies comparing the invasive cardiopulmonary exercise tests in a cohort of POTS patients vs. sedentary healthy individuals are needed to further delineate the pathophysiology and possible therapy for POTS, both in terms of tolerated exercise programs and pharmacotherapy."

This last bit means they need to do more research so they can shore up the findings and come up with improved treatment of both medication and suitable exercise programs.

Getting upright again can be done, but it is a slow progression and patients need lots of support and the funding to pay for it. For example, hydrotherapy is great, but in the NHS it usually comes in blocks as it's designed for injuries, not chronic conditions and is in short supply. I had it and it was indeed helpful but I needed someone to take me and bring me back and a day to recover as it was so exhausting. 

In my own case, and that of many others, this study's findings seem to be self-evident. In EDS, the veins and arteries don't snap shut quickly enough in standing, so blood starts to pool in the lower extremities and the heart must work harder with less blood to keep the body going. Ergo, low blood volume.

A new role

I'm delighted to say that I have taken on a new, volunteer role as UK and Europe Advisor to the new Ehlers Danlos Society, which has been formed from the US-based EDNF. Lara Bloom, formerly CEO of Ehlers Danlos UK, is jointly leading the new charity and the aim is to expand globally providing trusted information of use to patients wherever they live. I'm happy to be involved.