hyper-POTS…

Edit: I have been trying to read as much as I can about hyper-POTS, and feel I should update this post because it isn’t entirely accurate. A number of POTS experts describe hyperadrenergic POTS as just a characterization of POTS, not a separate subtype, just as hypovolemic may be a characteristic of POTS. Norepinephrine levels in POTS patients may rise and fall throughout the illness, although I suspect my NE levels are actually lower now than when I was first diagnosed, as I don’t feel the same amount of adrenaline now as I did back then. – L

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Well, as you probably know from my previous post, it’s official….I am a participant in a clinical trial that studies the effects of ivabradine on hyperadrenergic postural orthostatic tachycardia syndrome, or hyper-POTS. I haven’t talked much about the study thus far because, up until a month ago, I didn’t even know I had hyper-POTS and didn’t think I would qualify for the study. Next post I will talk more about the study, but for now I’d like to discuss hyper-POTS.

Hyper-POTS is a sub-type of POTS characterized by high norepinephrine and epinephrine (noradrenaline and adrenaline) levels when standing. The exact diagnostic criteria for hyper-POTS varies from specialist to specialist. In this article in the Cardiology Journal, hyper-POTS is defined by 1)  an increase in systolic blood pressure of ≥ 10 mm Hg while standing, and 2) standing norepinephrine (NE) levels of ≥ 600 pg/mL. Some hyper-POTS definitions require not just an increase in blood pressure, but hypertension (high blood pressure) when standing.

Since I developed POTS, I often feel like I have a lot of adrenaline. In particularly difficult circumstances, such as prolonged standing or high-stress situations, I may begin to shake from the adrenaline. My first response is to search for the nearest exit and plan my daring escape, although on most occasions I just suffer in silence. I’m not an especially violent or confrontational person, so the “fight” extent of my fight-or-flight response is limited to dramatic but persistent eyerolls. On the average day, if you’re at about eye-level, you may find yourself the latest victim. But because I had never had the NE test, I just assumed that was a normal part of POTS.

Some of the people I know  with hyper-POTS , and no offense to anyone reading this that has hyper-POTS, are kind of hyper.  I think of myself as being pretty laid back, and have been told  that’s the image I project, at least outwardly. When I heard about the study, I called to find out more information to share with some POTSie friends, expecting that I wouldn’t qualify. The researcher offered to bring me in for the NE test and, although I didn’t expect that my NE levels would meet the threshold, I thought it sounded like an interesting way to spend a morning and earn a couple bucks.

The qualifying criteria for the study is standing NE levels ≥ 600 pg/mL. The NE test compares norepinephrine supine (lying down) and standing. For a great description of the NE test, check out Jackie at Lethargic Smiles’ post. No blood pressure requirement for the study, although at every visit thus far my systolic blood pressure has risen at least 10 mm Hg when standing, although it’s still in the low or normal range. My supine NE level was nearly 600 pg/mL, and, needless to say, my standing levels are significantly higher. I’m like this big spoonful of meth.

So, yeah, I qualify. And at least according to some definitions, I have hyper-POTS. So, other than high norepinephrine, what does hyper-POTS look like? According to this article from Dr. Grubb et al, hyper-POTS is less common (occurring in ~ 10% of POTS patients) than other types of POTS, because….of course. Sometimes I’m disappointed that I always end up in the unlikely scenarios, but my mama did tell me I’m special.

The above article by Dr. Grubb also characterizes hyper-POTS as:

• difficult to treat
• portrayed by significant tremor, anxiety, and cold sweaty extremities when upright,
• attributed to a genetic mutation (at least as suggested by current research) which causes a dysfunction of the norepinephrine reuptake transporter.

I’m a little confused as to why I wasn’t given an NE test years ago. It would have been nice to know about my high norepinephrine levels when I was first diagnosed. I have spent the last 7 years learning about and trying to treat the wrong kind of POTS.

Although it’s rarity adds an elevated dimension to my POTS, I’m kind of relieved with the hyper-POTS diagnosis. Suddenly everything I have ever doubted about myself can be explained by one test. Suddenly it all makes sense.

I’m just bursting with adrenaline.

Interestingly, in addition to my high norepinephrine, I have high dopamine and low epinephrine. I’m not positive, but I’m pretty sure that, collectively, all of that means I’m crazy.

“We have two lives, and the second begins when we realize we only have one.” – Jack Gilbert

Smell ya later.
– Linds