Postural Orthostatic Tachycardia Syndrome

POTS: Professional Off-Tilting Specialist, er Postural Orthostatic Tachycardia Syndrome

Not enough credit goes to your neurological system. If you have a gastrointestinal disorder, you have a gastrointestinal disorder (and sometimes an immune one). If you have a cardiac condition, you have a cardiac condition. Skin blemish? It is usually just on your skin. However, if you develop a neurological illness you may have all the above problems plus endocrine, muscular and sensory ones.

Postural orthostatic tachycardia syndrome (POTS) is one of those multi-systemic illnesses that stem from miscommunication within the nervous system, also known in general terms as dysautonomia or autonomic dysfunction. The autonomic nervous system regulates everything in your body you cannot consciously control, such as heart rate, blood pressure, digestion, body temperature, how sensitive your eye sight and hearing are, adrenaline, and even hormone regulation.

Named for the primary diagnostic symptom, people with POTS have an abnormally enthusiastic response from their heart when they stand or even sit upright—a cardiac issue. Usually when standing after lying down, a normal person’s heart will increase 10 to 20 beats per minute for maybe a few minutes before stabilizing around 10 bpm or less more than their prone heart rate. A POTS patient will have 30 bpm or more in that same scenario.

How exactly can an elevated heart rate hurt you? You can have your heart rate over 200 bpm without “anything bad happen,” but that depends on what else is going on in your body.

Say you went exercising and worked up a great sweat and a high heart rate. How do you feel? Depending on how you mentally feel about exercise, you may either feel exhilarated or exhausted. A POTS person, or POTSy as many affectionately refer to themselves, might be on the ground passed out. While their hearts run rampant their vascular system does not compensate. When upright your blood vessels constrict to force circulation back up, against gravity.

Since POTS is a neurological disorder, the neural cue to tell the vessels to constrict fails. Blood collects in the lower legs and feet, the brain is oxygen deprived, and they either pass out or feel so lightheaded they may as well pass out. The heart makes things worse, because it will increase in response to the literally dropping blood pressure, thus pushing it down faster. The less blood to the brain the harder the heart tries and the worse things get—a normal mechanism with a disastrous outcome all because the vessels do not tighten.

In theory, a POTSy’s nervous system is in overdrive. The “fight or flight” or sympathetic autonomic nervous system has more control than it should and the “rest and digest” or parasympathetic autonomic nervous system does not have enough control. This may be a result of an over-activation of the sympathetic ANS or an under-activation of the parasympathetic ANS. Either way, the POTSy is trapped in a physiological stress state. They feel stressed all the time and the body grows weaker from it. Many of these people become bed ridden, too symptomatic to take care of themselves. Some medical clinic sites describe the syndrome as debilitating as congestive heart failure.

autonomic nervous system
Everything that can go wrong. I can come with three different “everything”s that can apply: just about every important part of your body can be involve, just about anything abnormal can happen to that part of the body, and general just about everything can happen simulaneously. (Photo courtesy of Dysautonomia International)

On top of that, POTSies are in a chronically dehydrated state. Their kidneys do not produce enough of the hormone aldosterone, which tells the body to retain fluids and electrolytes inside the blood stream. If you are dehydrated, maybe lightheaded and have a headache, you drink more and restore the fluids in your bloodstream. With lower aldosterone, a POTSy urinates far more per fluid intake than a healthy individual. No matter how much they drink they do not get to rehydrate the bloodstream or alleviate the lightheadedness or that headache. They must consume high amounts of sodium, usually 3,000 to 10,000 mg per day along with 4 to 8 liters of fluids in order to truly rehydrate. If you do not have to do that to be healthy, you should thank your aldosterone-producing kidneys.

renin angiotensin aldosterone diagram
Something along here goes wrong and makes everything else go wrong…. (Photo courtesy of A. Rad on Wikipedia)

POTS patients have a hard time with digestion, considering that part of their system remains less active than it should. Many have gastroparesis, a condition where the pace maker for the stomach fails and the stomach muscles do not contract to move food into the intestines. Again, this is a physical issue that has no justice in words. The nerves in the stomach wall become extremely overactive, causing extreme pain. Food sitting in the stomach, or even just reaching the inert stomach, can lead to nausea, vomiting, heartburn, and dizziness due to blood leaving the brain to gather at the stomach to aid digestion. All this pain alters the person’s diet and many develop nutritional deficiencies, including those important for helping neurologic function. Hello vicious circle.

Most, around 80 percent, of POTSies are female and age between puberty and menopause. That might make it seem like the condition is hormonal, especially since many have “developmental POTS” which occurs in teenagers after a growth spurt. However, the nervous system is the master regulator. It regulates the hormones to a degree—and by that I mean the body has back-up mechanisms and the hormones should have a second-in-command, but in this case do not.

Many POTSies also have autoimmune diseases. When the immune system is in overdrive it can send antibodies to attack native cells, even destroy whole organs. If your antibodies attack your thyroid you have Hashimoto’s thyroiditis. If they attack your adrenal glands you have Addison’s disease. Celiac disease and Crohn’s disease are both serious gastric autoimmune conditions. Lupus is a connective tissue disorder that inspired the Spoon Theory, and multiple sclerosis is an example of neurological autoimmune disease. Once you have one kind of autoimmunity, you may develop another. They are also far more common in women than men. Current research in POTS has found autoantibodies attacking the adrenergic receptors on cells that tell blood vessels to constrict. These same receptors are necessary for aldosterone activity.

Officially, POTS has no known cause and is often called a heterogeneous syndrome, as different patients may have different underlying reasons for their illness. Those with developmental POTS usually recover within three to five years. Those who started symptoms suddenly after a viral infection, pregnancy or trauma may get better. Some people have a genetic predisposition and are not likely to fully recover. However, many people have relapse-remission phases throughout their lives (after the initial illness), and new relapses occur after stressful events (not unlike the initial illness).

Maybe we should ask how we can reboot the circuitry.


One thought on “Postural Orthostatic Tachycardia Syndrome

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s