(NOTE: If you don't know what Orthostatic Intolerance (OI) is or you have CFS but think you don't have OI, then please read this introductory OI post first. Briefly, OI is an umbrella term that includes two conditions (and several variations): Postural Orthostatic Tachycardia Syndrome (POTS), where the heart rate goes up when upright, and Neurally Mediated Hypotension (NMH), where the blood pressure falls when upright. Over 97% of ME/CFS patients have some form of OI, either POTS or NMH or some rarer type of dysautonomia - many people with CFS have both POTS and NMH. To understand how a high heart rate can contribute to post-exertional crashes, read this post. And to understand how beta blockers help and what my experience has been with beta blockers, read this post. There, that should bring you up to date!)
Even though I have had ME/CFS for 10 years and learned about and was diagnosed with OI about 8 years ago, I was never actually tested for OI. My son and I went to see Dr. Bell in 2004; he diagnosed my son with CFS and confirmed my CFS diagnosis, made by my primary care doctor. Dr. Bell asked me if I knew about OI, and I said I had read about it but was sure that neither Jamie nor I had it, since we'd never felt dizzy or fainted. Dr. Bell did an in-office OI test on Jamie, and I was stunned by the results - within 10 minutes of standing still, Jamie's heart rate went sky high, his blood pressure plummeted, and he felt horribly sick. Dr. Bell explained that most people with CFS don't actually faint from OI (though some do) - we just get sicker and all of our CFS symptoms get worse. He explained to me that, based on my symptoms and his exam, I definitely also had OI, but if he tested me right then, I would get too sick to get the two of us back home on the plane. After today's test, I now better understand what he meant!
In reviewing my Social Security application with my lawyer recently (I've been denied twice), I noticed that one reviewer of my case had written "self-reported Orthostatic Intolerance but no medical evidence." Obviously, their reviewers don't know much about CFS! Since OI is behind most of the symptoms of ME/CFS and is one of the primary reasons why I can't work (can't stay upright for 8 hours, even just sitting), I decided to ask my doctor to make my OI diagnosis official with a simple in-office test, like the one Dr. Bell did for my son.
In preparation, I did not take my beta blocker this morning, since my purpose is to confirm the diagnosis itself (beta blockers help with POTS but they don't remove it completely - with the meds in my system, it just would have taken much longer for the test to show POTS). I knew the beta blockers were helping to keep my heart rate down and allowing me to be much more active, but going without it this morning was eye-opening. I strapped on my heart rate monitor as soon as I woke up and was stunned by what I saw for the next few hours.
Just walking to the bathroom, getting dressed, brushing my teeth, all raised my heart rate up into the 120's and 130's. I was exhausted before I left my bedroom! I tried to take it easy this morning, so as not to trigger a crash tomorrow, but even lying on the couch, my "resting" heart rate was between 105 and 115! Since my anaerobic threshold is about 103, I was in a constant state of over-exertion, even while lying down! I used to feel like this all the time, before beta blockers - I was constantly triggering a post-exertional crash.
I finally got to the doctor's office at 10 am, feeling like my heart was going to explode from the high heart rate and tachycardia. The doctor who was going to do the test met with me and brought a med student along - I think it was an eye-opening experience for them both! The test calls for the patient to lie still for several minutes, then stand up, leaning against a wall, without moving at all - no twitches, no wriggling of toes, no tensing muscles. The med student took my heart rate and blood pressure measurements once a minute, and the doctor recorded them.
Since my "resting" heart rate started at 110, it was already sky high when I first stood up. Even though I've understood OI for 8 years, I was still amazed by the effects of just standing still for 10 minutes. My heart rate creeped up higher each minute. By the 5-minute mark, I was starting to feel hot all over, flushed, and light-headed. My fingers started to feel tingly and numb. I was feeling more and more sick as the minutes ticked by.
And it's HARD to stand that still! Your body just naturally wants to compensate for what is happening; I had a horrible urge to move, to flex my muscles, to crouch down. It made me realize how much I do compensate for OI in my normal daily life, without thinking about it. Moving around, switching from foot to foot when I have to stand in line, sitting as soon as I start to feel bad, etc.
We got to 10 minutes, which was as far as the form went, and I felt horribly, horribly sick, but the official diagnostic criteria for POTS is an increase in heart rate of 30 bpm, and I was still just a bit shy of that (of course, I'd started at 110!), so I asked if we could continue for a few more minutes, and the doctor reluctantly agreed. He later told me that I looked so bad if I had asked for another minute, he would have said no!
My final heart rate, at 15 minutes, was 142 bpm, so my POTS diagnosis was confirmed. However, my blood pressure hadn't dropped the way it has previously (my doctor can often see a big drop with a single BP measurement upon standing). In fact, it went up a bit. My regular doctor came in to discuss the results and thought it might have something to do with my body getting used to the beta blockers. Or it could be that we needed to continue the test for longer to show NMH - which sometimes doesn't show up in people with CFS until after 20 minutes of standing - but my POTS was so severe that we couldn't do that (I probably would have fainted if we'd continued). In any case, the POTS diagnosis alone proves that I can not stay upright for very long without getting sick, and my doctor wrote a note about her previous observations of NMH in me.
When the test was finally completed (longest 15 minutes of my life!), I crouched down close to the floor and sat on a little step, with my knees up, took 2 of my beta blockers, and chugged a can of V-8 I brought with me (lots of salt and fluids for increasing blood volume). I felt very sick and was shaking all over. Once I was able to get up from that position, I climbed up on the table to lie down and rest. I still had my heart rate monitor on, and my heart rate stayed above my AT for another 15-20 minutes before the beta blockers started to work and it finally began to come down.
Even though I already knew I had OI and understood it intellectually, the testing was an emotional and eye-opening experience for me. I was all excited about it afterward, feeling like there is finally some hard outside evidence of how bad I feel on the inside! I want to make copies of my test results and hand them out to every person who tells me how good I look or who misunderstands how debilitated I really am. I was telling my husband about the test at dinner and asked him why he was so quiet. He said the test results made him feel sad - more proof of how sick I was. I can see his point, too, but I still want to hand out copies of my test results to everyone who thinks that CFS is just feeling tired.
P.S. I can't find Dr. Rowe's instructions and forms for the in-office OI test anywhere online, but I have a copy he e-mailed to me that I used today. So, if anyone wants a copy for their own doctor, just e-mail me, and I will send it. Click on "View my complete profile" on the left-hand side of this blog and then on "E-mail."