Challenges in Diagnosing Orthostatic Intolerance

I have written often here about the significant role that Orthostatic Intolerance (OI) plays in ME/CFS and how treating OI has led to life-changing improvements for my sons and I, allowing us to live active lives again. OI is an integral part of ME/CFS - one study showed that 97% of the patients studied had it - and it is also very common in those with fibromyalgia, Lyme and other tick infections, and MCAS. Basically, any disease that affects your autonomic nervous system can cause OI. OI is an umbrella term encompassing several conditions where the body can not maintain a steady blood pressure (BP) or heart rate (HR) while upright (standing or even sitting). If you feel worse after standing and better when you are lying down, that is OI at work. Some people faint from OI but many with ME/CFS just feel sicker when upright.

The two most common types of OI in ME/CFS are Neurally Mediated Hypotension (NMH), where the BP drops when you are upright, and Postural Orthostatic Tachycardia Syndrome (POTS), where the HR goes up when upright. Rarer forms of OI - like where the BP goes up or the HR goes down or HR and/or BP jump all over the place - also exist. The good news is that there are many inexpensive treatments available for OI, and treating it usually brings dramatic improvement in all symptoms - it's what got both of my sons back to school full-time and allows me to now exercise again, walking for up to 90 minutes at a time, with no crash afterward!

This blog post describes OI - particularly NMH and POTS - in more detail, including how to diagnosis and treat it and our own experiences. I also wrote two articles for the ProHealth website, Part 1: Diagnosing OI and Part 2: Treating OI. These two articles will be particularly helpful in sharing with your doctor(s) because they are heavily footnoted with references listed at the bottom from scientific studies and papers, in case your doctor wants proof and/or to read more. Finally, Dr. Peter Rowe is the top expert worldwide in OI as a part of ME/CFS, and his summary brochure on OI is also helpful for reading yourself and sharing with your doctor(s). He includes a review of available treatments.

Even with all this information available, though, I have found in helping hundreds of other patients get treatment for OI that most people still run into some challenges in diagnosis and/or treatment. I'll cover diagnosis today and treatment next week.

Here is an overview of the most common challenges you might encounter in diagnosing OI and how to overcome them:

Challenges in Diagnosing OI:

• Finding a doctor. Some patients have trouble finding a doctor who is knowledgeable about OI. You have two basic options: a cardiologist, who will most likely run a tilt table test, or your primary care doctor, who can do a simple standing test in the office (see below). The cardiologist is helpful for ruling out other cardiac conditions, but even this specialist may not be familiar with NMH and POTS and is almost certainly unfamiliar with these conditions as a part of ME/CFS (which is different than when they occur alone). Once we had a cardiologist rule out other problems for our son, we just went with standing tests in our family doctor's office.
• Which test? You need a test that will show precisely what is happening to your HR and BP while you are standing. Cardiologists will tend to run all sorts of ruling-out tests, like EKGs and 24-hour monitors, but there are only two ways to diagnose OI: a tilt table test or a 10-minute standing test (instructions and forms at the link). The tilt table test is much, much more expensive, requires special equipment at a separate location, and can end up making the patient very ill and badly crashed, since it is intentionally trying to cause OI and lasts up to an hour or more. The standing test can be done in about 30 minutes in any doctor's office, with a nurse or doctor with a blood pressure cuff and watch (I wore my own heart rate monitor which made it even easier), so it only costs as much as a doctor's visit. It is still triggering OI so will still make the patient crash, but not as much usually since it doesn't last as long. Here's the surprising part: one study actually found the simpler standing test is MORE effective at diagnosing OI than the expensive tilt table test.
• Stand VERY still. During the standing test, the patient leans against a wall for stability but then must stand absolutely still - not even wriggling fingers or toes. This is hard to do! Our bodies naturally want to compensate for the plunging BP and/or the rising HR, and they normally do this by moving around to keep blood circulating and not pooling in the feet and lower legs. Don't move, and let the nurse or doctor take the BP and HR measurements.
• 10-minute standing test, not 1-minute. Those instructions linked above describe a test where the patient stands, leaning against a wall, for a full 10 minutes (or until the criteria is met, at which point the test can immediately end) after 10 minutes of lying down. I have lost count of the number of times I have heard that a doctor took a patient's BP while sitting, then immediately upon standing and announced they do not have OI. This is most likely due to confusion between Orthostatic Hypotension (OH), in which the BP falls immediately upon standing, and NMH, where the BP drop can take a while to fully develop. In fact, one doctor found that NMH can take up to 50 minutes to fully develop in ME/CFS patients, though most of us can't tolerate standing that long. It's the same with POTS. If your POTS is severe, it could show up immediately, but for most of us, up to10 minutes of standing is required for it to fully develop.
• Watch for trends. Continuing along those same lines, be aware that your NMH or POTS or other form of OI might not fully develop, even during a full tilt table test. For that reason, the forms for the standing test have room to record symptoms. You and your doctor should look at the full picture after the test to determine if you have OI. So, if your HR went up 25 bpm in the 10-minute standing test, but the criteria says you need a 30 bpm increase to have POTS, you probably do have it, and it just didn't fully develop in that time. It's not normal for your HR to jump so high just from standing; a normal healthy person's body can hold their BP and HR pretty steady while standing still. Similarly, if you didn't meet the criteria for NMH or POTS but felt very sick during and after the test. So, you would still benefit from OI treatment.
• Check BP as well as HR.  I honestly don't understand why, but I hear over and over again from patients whose doctors (often well-trained cardiologists) diagnose them with POTS but don't look at what their BP did while standing or on the tilt table - or measured their BP but then ignored it. I guess POTS is a more common condition, so they are more aware of it. But the other side of the OI equation is just as important, so ask your doctor what your BP did while upright, either during a 10-min standing test or a tilt table test.
• One test might not be enough. I knew OI testing wasn't foolproof, but I was still stunned to read this study that showed that only 65% of POTS patients (already diagnosed with POTS) had their POTS show up with a single test. 65%! So, be aware that it might take multiple tests, and show your doctor this study if you think you need a second test. The study found the tests were more accurate in the morning, so that could help. If you have symptoms of OI (feel worse when standing, better when lying down) but your standing test doesn't show OI, come back another day (preferably in the morning) and try it again. This is another case where it's important to look for trends - if your BP or HR is trending up or down but doesn't quite meet the criteria - and to record symptoms during the test. When my son was tested, his feet turned purple and after about 7 minutes of standing, he felt horribly sick, was sweating (in a very cold office in January), and had pale, blotchy skin. Clearly his body could not tolerate standing!

All of this might seem like a lot of trouble to go through to get more diagnoses, but these are conditions that are measurable (a nice change of pace for us) and very, very treatable. Treating OI can lead to dramatic improvements in all symptoms and in quality of life. It's a big part of what got my sons and I back to living semi-normal, active lives again.

Up next week: Challenges in Treating OI, to help you get the same kinds of improvement we've gotten from OI treatment, which - like all aspects of ME/CFS - can require some trial and error to get right.

Have you encountered other challenges or problems in diagnosing OI that I haven't covered here? If so, please leave a comment below, and I will respond.