Let me first start with my disclaimer that I am not a doctor and I have no medical training. All advice I give is in the context of what I have read, what I learned from my doctor, and my own personal experiences.
It has now been about 2.5 years since I first became debilitated by this condition and I am pleased to say that after 3 months of debilitating hell, followed by another 6 months of treatment refining, that I have been very stable ever since. Because this is such a tricky condition to get diagnosed and to treat, I am posting my advice in the hopes that it may help someone some day that is looking for answers.
First, it is important to understand the terminology:
POTS - a symptom of many different possible underlying conditions that results in a sustained elevated heart rate while standing.
Hyperadrenergic POTS - a sybtype of POTS that results in high adrenaline / norepinephrine surges that can potentially send blood pressure to very high levels.
Low Flow POTS - the name that Julian Stewart (the leading expert on this type of POTS) uses instead of Hyperadrenergic POTS, but is also more specifically focused on low blood volume / hypovolemia than the common descriptions of hyperadrenergic POTS.
RAAS disfunction - the RAAS is the complicated system of the body that is responsible for the regulation blood volume.
ACE2 deficiency - a rare, specific type of RAAS dysfunction and causes a high amount of Angiotensin II.
Before visiting a doctor, make sure that know your own symptoms and that they compare with the combined symptoms of POTS, Pheochromocytomas (since the hyperadrenergic pots adrenaline storms present in a similar manner), and frequent urination. It would be worth doing the poor man's tilt table test before visiting your doctor. Buy a pulse oximeter and heart rate monitor, lie down for 10 minutes, take your heart rate and blood pressure, then stand up and measure your heart rate after 1 minute, 5 minutes, and 10 minutes. If your heart rate stays elevated by more than 30 beats per minute or if your heart rate is higher than 120, then you probably have POTS. If your blood pressure is significantly elevated as well, then you may have hyperadrenergic POTS. Keep in mind though that you may get somewhat different results throughout the day depending upon your recent food and fluid intake as well as your anxiety levels.
There are very few doctors that can diagnose and have experience treating this condition. Finding a doctor that can help will be frustrating and difficult. There is a list of doctors on dinet.org's website that are experienced treating POTS, but also understand that there are some really good doctors that are more accessible than the experts that will appreciate the challenge of helping you figure it out. Look for doctors that will listen to you when you show them your research, are receptive to your treatment option suggestions, that may do research on their own between appointments, and won't be in a rush to push you out the door so that they can move on to their next patient. You may need to try out 10-20 different doctors until you find one that can genuinely help.
Second, ask your doctor to perform a tilt table test and a catecholamines blood test that compares your norepinephrine after 10 minutes of laying down vs after 10 minutes of standing up. The tilt table test can be used to diagnose POTS and hyperadrenergic pots in some cases, and the catecholamines blood test can be used to diagnose hyperadrenergic POTS. Specifically, if your norepinephrine is relatively normal while supine after 10 minutes but is more than 3 or 4 times higher after standing for 10 minutes.
Unfortunately, there is no commonly available test that can be done to confirm that you have the dysfunctional RAAS / ACE2 deficiency subtype of hyperadrenergic POTS. There is however a commonly available RAAS test that measures the ratio of Renin to Aldosterone that your doctor will probably perform if you suggest that your RAAS might be dysfunctional. This test however will likely give misleading results. The ACE2 deficiency results in a paradoxically high amount of Angoitensin II (which the test doesn't specifically measure), but a relatively normal Renin to Aldosterone ratio. If you are male, you should also ask to have your testosterone checked since low
male testosterone is common with POTS, and in my opinion is a very good
indicator of the dysfunctional RAAS / ACE2 deficiency subtype when combined with the other hyperadrenergic pots symptoms and frequent urination.
If you do have a deficient ACE2, the main treatment is to prevent your RAAS from activating, which means that you can NEVER let yourself become dehydrated and you might need to supplement with additional fluids and salt. If you are in a debilitated state due to your symptoms, then you are probably in a constant hypovolemic state with a frequently activated RAAS. The only way to get your broken RAAS to deactivate is to get your blood volume up through fluids and salt - which I know seems somewhat counter intuitive considering that you are likely dealing with scary blood pressure surges. The amount varies from person to person, but I would recommend that you increase fluids and salt through Gatorade, Propel, Nuun Tablets, and/or Pedialyte. Salt sticks and/or sodium chloride tablets combined with increased water works as well. Don't assume that you can achieve the needed salt by putting more salt on your food. Everyone needs to play around with it until they figure out their sweet spot. If you go too high, your blood pressure will rise from having too much blood volume, so what you're looking for is the sweet spot where your blood pressure and tachycardia stable out, but before your blood pressure starts to rise. Because you can do real damage to your body if your blood pressure gets too high, you should go slowly, and I once again drop my disclaimer that you should consult your doctor before doing this. My recommendation is to keep a very detailed diary of fluid and salt intake keeping in mind the sodium that you are consuming through food, and then increase by 1 gram of salt per week. If the trend of your blood pressure immediately rises during the first week or two, then you probably aren't hypovolemic and probably don't have an ACE2 deficiency. If the trend of your blood pressure over the week stays flat or lowers, then you could very well be hypovolemic. Keep increasing slowly each week until the overall trend of your your blood pressure starts to rise. When it does start to rise, then you know you've gone too far, and you should go back to the previous week's supplementation levels. It takes some time to find that sweet spot. I only need an additional 1-2 grams of salt per day, but I think that some people need as much as 8-10.
Appropriate medications are also extremely helpful. Losartan is great as it suppresses the effects of the Antiotensin II, which is what ultimately causes a lot of the symptoms. I take 100mg per day. Lisonopril should theoretically provide the same benefits as Losartan. Clonidine is a life saver during the adrenaline storms. I take .1 mg every night before bed, and I'll take another .1 or .2 during the storms, but fortunately I haven't had a storm in a long time. The clonidine pills are extremely powerful, but relatively short lasting so it can be a bit ticky to keep a leveled dosage in your body. The Clonidine patches can be used to keep you a bit more level. I haven't tried beta blockers myself, but most doctors will probably start with them because they are known to reduce tachycardia and blood pressure. I however recommend against them because Dr. Grubb's research has shown a paradoxical effect where it can actually increase blood pressure for some of those with this condition due to unopposed alpha receptors, and I have also spoken to several of potsies that confirm this problem. Dr Grubb has suggested that alpha-beta blockers can be an effective alternative to beta blockers, although I have not tried them myself. I also recommend an ssri to help prevent some of the anxiety driven adrenaline storms because even a little bit of anxiety can trigger some crazy adrenaline storms. I recommend taking some anti-oxidant supplements because Julian Stewart has done some studies where it has shown some positive benefits since high Angiotensin II levels promote oxidative stress. I also highly recommend getting your testosterone levels checked if you are male and supplement if you are low. Testosterone supplements probably won't help much with this condition specifically, but will make you feel better overall. And of course, a strong healthy heart makes a huge difference, so daily cardio exercise is crucial even though it is the last things in the world that you want to do. Rowing machines, recumbant exercise bikes, and possibly even swimming are good ways to do cardio while minimizing POTS symptoms.
