Any Insight for someone with POTS?

[POTsy]

Hello everyone. I am a 26 year old woman who’s been suffering with POTS (Postural orthostatic tachycardia syndrome) for the past 10 years, since approximately age 16. A few months after I became symptomatic I was diagnosed with Epstein Barr Virus, so I believe there might be a connection there. With my POTS, I also have severe heat intolerance and poor body temperature regulation. I can easily overheat in a warm room becoming symptomatic even while sitting.

I am currently on hydrocortisone and florinef which have helped with adrenal insufficiency symptoms, but not with the POTS. I was really hoping the AI was the underlying cause of POTS, but this hasn’t been the case at all. This makes me question whether I should have been put on HC at all.

I have been to 2 doctors who both diagnosed me with POTS via head-up tilt (HUT) table test. I failed both miserably, but did not faint nor have any significant orthostatic hypotension throughout the test. During the first HUT my blood pressure actually increased to 140/80 while tiled. During the second HUT, my BP was more normal for me in the 108/60 range, but it did drop a bit for a few minutes, but always came back up only causing temporary lightheadedness.

I had plasma catecholamine levels tested while supine and 10 minutes into the HUT. Here are the results from that.

Supine
Dopamine <20
Epinephrine <10
Norepinephrine 125

Tilt
Dopamine <20
Epinephrine 22
Norepinephrine 613

I am having quite a NE response to standing/tilting. The doctor said this was very abnormal and is likely causing the heart problems. When these catecholamines were tested my BP was 104/68 HR was 135. My HR continued to climb throughout the test, reaching 153 at its highest which is rather typical for me. I’ve captured standing HR’s as high as 175.

As soon as I was tilted back down, my HR went from 150 to 77 within seconds. My heart had a hard time adjusting to that lower rate and I had a lot of PVC’s at the end of the test.

I am looking for some insight into what I should further investigate. What tests should I have done? Am I missing something really obvious?

Thyroid meds only make my HR’s even higher, so that’s not an option for me. I had a NutrEval test done, which showed elevations in certain amino acids and organic acids. Unfortunately I don’t have a doctor who knows how to interpret them. I tried increasing florinef, salt-intake, taking midodrine, DDAVP and beta blockers. The beta blockers were the most helpful of anything I’ve taken, but once the weather warmed up, the beta blockers were unable to keep my HR’s from increasing when standing. I was experiencing 140 HR’s while on the beta blocker, but also had negative side effects from the drug. I am no longer on them.

My POTS doctors have no more ideas for me. I’d really like to try to wean off the HC at some point, but there’s NO way I can even attempt to do that with my HR’s so high every single day. It’s putting a tremendous amount of stress on my poor body.

Thanks.

[POTsy]

Maybe I am overlooking it, but I couldn’t find a way to edit my post. I just wanted to add the results to a 24 hour urinary catecholamine too for comparison.

Epinephrine 4 (0-32)
Norepinephrine 27 (0-140)
Dopamine 241 (65-610)

[Figuring]

That is definitely really high NE, it seems I have the opposite problem.

Could that be caused by an infection?

[DrMariano2]

Here is an interesting article: http://emedicine.medscape.com/article/1154266-print about autonomic failure syndromes.

Here is an interesting circuit fact from the article:

Both sympathetic and parasympathetic preganglionic synapses use acetylcholine (ACh) as the major neurotransmitter; postganglionic parasympathetic synapses and sympathetic sweat synapses also use acetylcholine. Other postganglionic sympathetic synapses use noradrenaline.

Generally, changes in blood pressure (and heart rate – which affects blood pressure) are monitored by the baroreceptors. These are neurons that sense stretch in various areas such as the carotid arteries. When activated by high blood pressure, they signal circuits in the brain which lead to a simultaneous decrease in sympathetic nervous system signaling and an increase in parasympathetic nervous system signaling. This leads to a lowering of heart rate or blood pressure. When relaxed, as in low blood pressure, which can occur as one stands up, the opposite occurs – increased sympathetic nervous system signaling and decreased parasympathetic nervous system signaling. Thus blood pressure or pulse can increase.

Heart rate is controlled by a balance of sympathetic nervous system signaling (which raises heart rate) and parasympathetic nervous system signaling (which reduces heart rate).

POTS can be triggered by infections. The infection would increase immune system inflammatory signaling. In some people, this may also trigger an autoimmune response, which causes the immune system to think parts of the body are foreign. Thus the immune system may then make antibodies against these parts and may attack them, causing dysfunction.

One such autoimmune problem can be antibodies against acetylcholine receptors. When these are present, then the parasympathetic control over heart rate is impaired. This causes the sympathetic nervous system signaling to be exaggerated – resulting in POTS.

If parasympathetic nervous system signaling is impaired, then one possible treatment is to increase its signal – acetylecholine. This may be done by prolonging the signal using an anticholinesterase inhibitor – e.g. Pyridostigmine bromide (Mestinon) or even Donazepil (Aricept).

Heat intolerance is a possible additional symptoms. If sympathetic tone is unbalanced because parasympathetic tone is impaired, then a person can feel hotter than normal, making additional environmental heat intolerable. Also, increased temperature triggers sympathetic nervous system signaling in order to trigger sweating. However, if acetylcholine receptors are impaired by antibodies, then sweating may be impaired. This impairs temperature regulation, again making additional environmental heat intolerable.

There may be other factors involved which can exaggerate sympathetic nervous system signaling.

For example, if adrenal insufficiency or dysregulation is present, then sympathetic signaling (norepinephrine signaling) is less controlled. Norepinephrine and Corticotropine Releasing Hormone are in a positive feedback circuit. CRH increase norepinephrine. Norepinephrine increases CRH. Adequate cortisol production – which is triggered by norepinephrine signaling, leading to ACTH production – is necessary to help block this positive feedback circuit. Without adequate cortisol, then norepinephrine signaling becomes exaggerated or out of control.

Norepinephrine signaling has numerous control signals – which essentially gang up to control it and various locations in the nervous system. These signals include serotonin, dopamine, estrogens, testosterone, DHEA, progesterone, GABA, adenosine, cortisol, acetylcholine, anti-inflammatory cytokines, etc. etc. One or more of these signals may be impaired in production, leading to an increase in norepinephrine signaling.

Metabolic problems can lead to an increase in norepinephrine signaling. For example, various nutritional deficiencies (such as iron, vitamin A, tryptophan, B-vitamins, selenium, etc.) can lead to increased sympathetic nervous system signaling (norepinephrine signaling).

Beta blockers work by blocking norepinephrine receptors, thus blunting the norepinephrine signal. Some, such as Atenolol, don’t affect brain function as much (e.g. not causing sedation) because they don’t readily cross the blood brain barrier.

When the systolic blood pressure is under 115, I wonder if a person has problems causing low blood pressure, such as adrenal dysregulation. The causes of low blood pressure may also give one a clue as to why exaggerated norepinephrine signaling may be present.

Infections activate immune system pro-inflammatory signaling. This can lead to higher norepinephrine signaling. Pro-inflammatory signaling can also lead to lowering of blood pressure by increasing nitric oxide production from white blood cells.

Thyroid hormone can either have anti-inflammatory effects or pro-inflammatory effects depending on the situation. When already in a pro-inflammatory state, thyroid hormone may become intolerable, even if a person is hypothyroid, if it stimulates pro-inflammatory signaling. Again, pro-inflammatory signaling can increase norepinephrine signaling.

When there is an excess of pro-inflammatory signals, it may be important to consider both medicinal, hormonal (signal), and nutritional interventions to help reduce pro-inflammatory signals. Hydrocortisone is an antiinflammatory signal. However, its dosing is limited, generally, to subphysiologic dosing since adverse effects at supraphysiologic doses are themselves pose significant risks (e.g. diabetes, obesity, muscle atrophy, etc.).

It may be important to use several measures in order to have an adequate effect. This is particularly true when attempting to control norepinephrine signaling – which can be like attempting to control a bucking bull.

Increasing serotonin signaling – such as with a serotonin reuptake inhibitor (e.g. antidepressant) – can be done to help tone down norepinephrine – essentially reducing exaggerated responses – such as in anxiety disorders.

[Author]

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