What's causing my high heart rate and high serotonoin?

[Damien1983]

I'm a 33 year old Male, and for the last 18 months, I've had the following symptoms:

RANDOMLY SPIKING HEART RATES
resting pulse is normally high 60s. At least once every day, that rate jumps to somewhere in the 90s for a few hours - this appears to coincide with food intake, but can't be directly attributed to any particular kind of foods. And it doesn't always coincide with meals of any size
I've experienced a decent degree of orthostatic intolerance - First thing in the morning when i get out of bed my heart rate goes from 60 - 120+ , this can persist during the daytime, with a standing heart rate around 15-30bpm higher than sitting. But it doesn't happen all the time. Sometimes my standing heart rate is just fine and sits 1-5bpm over sitting.


CRIPPLING EMOTIONAL TROUBLE
Over the months I've become insanely neurotic about what could be causing it. I'm depsressed and anxious most of the time. I get paranoid about certain foods such as those high in Amines, or Serotonin (more on that later), I avoid eating too much salt.. so I end up losing a lot of weight due to not eating much.. When this first started, I lost 15kgs in the space of 2 months, and I wasn't fat to begin with. In fact when this all began, I was exercising 5 days a week (no enhancing drugs).

I'm debilitated by anxiety around medications. I've tried SSRI's which made me scarily sleepy and pushed up my heart rate (you'll see later this is unsurprising as my serotonin levels are extremely high). When I take drugs like Xanax my anxiety drops a bit but my heart rate goes HIGH even when im sleeping.. so on xanax, my sleeping heart rate is ~100 rather than 50-55 normally. Propranolol is the only drug I've taken that seems to help, but I have crushing anxiety because once my pulse is at its normal level, it already feels so low, so i worry that Propranolol will cause my heart to go to slwoly or have some other non-logical side-effect.

I get terribly depressed very easily. I have anxiety around my pulse most of the day every day.

I was exercising every day for 1 hour (mild walking exercise), and meditating 30 minutes every day, but neither had any appreciable impact.

It should be noted that before this all started, I had a history of panic attacks which were mostly well controlled by meditation/exercise/lifestyle.


FREQUENT URINATION
Now, this isn't the kind of frequent urination of a weak or small bladder. This is the kind of urination where my body just doesn't hold onto water. I can drink a glass of water, and 15 minutes later, urinate a huge amount out, almost completely clear.   My urine can be clear even if I'm just drinking 750ml of water a day. I don't feel thirsty ever, and have water around me all the time if I want it. I don't drink coffee, tea, or any other kind of diuretic.

This non-ability to hold onto liquids comes in phases, and generally (but not always) seems to coincide with my episodes of worse heart rate troubles.


WHAT HAVE I BEEN TESTED FOR
Not surprisingly, I've had a lot of tests.
1) Pheochromocytoma tested twice - negative
2) I've had 4 sets of 24 hour rate monitors, nothing interesting found
3) My thyroid profile is fine
4) My diatbetes test came back negative
5) My red/white blood cells are fine, but i do overproduce red blood cells but nothing to extreme
6) I've had a heart echo all fine
7) An endochrinologist then saw me and suggested i get tested for carcinoid -
So I had my urine 5HIAA tested which was negative,
but my serum serotonin was 2220 H  nmol/L when the upper limit for normal is 1200.
He then re-tested my serotonin suspecting a possible error, but this time it came back as 3730 H nmol/L which is over triple the upper limite. (yes I was on the correct diet beforehand)
He then tested my chromogranin A, which came back normal.
He then ordered an abdominal scan and a Dotatate PET scan and neither showed up anything.
8) My blood pressure is generally high. It's never low, and never extremely high. It sits around 130-140/80-95
9) My electrolytes were tested upon 2 hospital admissions and were fine both times


I have no idea what to do from here. I live around the world with my partner working online, my specialist is in Sydney, Australia. I can go back to him, but another appointment will be months away. I'm currently in Chiang Mai Thailand, and went to an Endochrinologist here who was clueless about serotonin issues and was using google to try to help. Obviously not the expert I need.

The last week or two have gotten much worse... my heart rate during the day stays around 80bpm sitting, and 100bpm standing (I know that's not crazy high, but it's higher than my normal levels). I feel tired a lot of the time,  and I occasionally get hot flashes where i feel hot even in an air con room, and start sweating.  I tried a small dose of propranolol yesterday, but it didn't seem to work at all, and it appeared to make my sweats and hot flashes worse.

I'm scared, and I really have no idea where to look next. I would pay for a specialist online or locally, but it appears that not many specialists know much about serotonin issues.

I have some questions I wish I could find answers to. They are.

1) Is it possible to be serotonin resistant? I have high serotonin levels, but my symptoms best match up with low serotonin problems. And cutting out serotonin foods or generally eating less seems to make things worse not better. I can't find anything much at all on it.

2) How can i have high blood serotonin, but not be secreting out much 5HIAA?  If it's not a carcinoid, what could cause that?

3) What else should I get tested? If my serotonin levels weren't so high I'd have to assume this was some extreme form of anxiety. But most of my research suggets chronic streess should lower my serotonin levels, not increase them.

3) Any ideas how I could get support without having to wait months for an appointment and pay to fly back to Australia?



Thank you so much to anyone who took the time to read this, and double thank you to anyone who can provide any kind of insight for me. Bit of a living hell right now.

[itdood]

Have you tried an SNRI instead?  people who do not tolerate SSRIs can usually bridge over to SNRIs.  Google Nefazodone, if it's available where you are it might be an option.    There were issues with liver function and it was taken off the market in some countries.  I live in the USA and it was taken off the market but you can still get generic from TEVA.   I've read many stories of people who couldn't touch anything else but this worked.    Like any drug there's risk to liver.

[Damien1983]

Thanks for the advice there mate. My Endochrinologist suggested that due to my high serotonin, I should avoid SNRI's as well.

[iPodClassic]

What if you ask your doctor to try Cyproheptadine?
I’m the complete opposite. I have undetectable serotonin levels in blood and gut.  I took it once and went insane.

[daveyboi1987]

a lot of the symptoms, apart from the high serotonin levels perhaps, could be indicative of POTS. the sweats, the anxiety, the changing heart rate, the urinary issues all fit with POTS. it  may be worth mentioning to either your doctor or arrange a meeting with a cardiologist for potential tests for that.

[tacolino]

Go to a site  worth a look;
Mayomedicallaborotories.com (Put it in google after High Serotonin) Its worth a careful read, its complex but informative

You should seek doctors help with considering taking a low dose of Beta Blockers for a few weeks. 2 weeks min would be necessary to get a clearer picture of whether it helps.

They usually slow the HR but come with side effects as usual.

You had the tests to outrule the carcinoid (Good insight in the article)

A few questions need to be asked;

Do you take any prescribed medications at all?

Do you take any over the counter meds from chemist?
(Painkillers, cough meds etc)

Do you take any type of recreational drugs?

Specifically what was the test you had for the Pheo?
Had you any Adrenal Gland tests?

You had anxiety issues in the past, could these be re surfacing in a different way?
It seems to be consuming you so much?

I just ask as I have has Tachy issues in the past and my HR was 170BPM at rest!
I was still functioning with this and my BP was crazy 280 / 160 at diagnosis !!!

I had all the Pheo and Adrenal testing done and its on going as they are hard to diagnose.

I think Pet scan is the preferred test these days.
When were you last tested for Serotonin levels? I suggest a re test promptly.

The high levels can cause on going issues as you know
I am based in Ireland but will look into UK based specialists and forward any findings to you. They are superior in the Endo side of things in London

I am aware of this through my research on Adrenal/ Aldosterone issues. Cambridge and Kings in London will have some expert on it im sure.
I will get back to you