Postural orthostatic tachycardia syndrome: diagnosis and management
If blood remains in the lower body instead of flowing as a person stands up, their heart rate will become irregular, with over 100 beats per minute. This condition is called Postural orthostatic tachycardia syndrome (POTS).
Orthostatic intolerance (OI) is the most common symptom of POTS. Usually, the autonomic nervous system balances the heart rate and blood pressure, to keep the blood flowing at a regular pace, no matter what position the body is in. Vice versa, OI is caused by an unusual change in blood flow rate as the person moves in and out of positions such as standing, sitting, or hanging upside down. If this occurs, the patient may experience:
The heart will beat faster in order to get more blood to the brain, and blood pressure will likely drop.
Patients with POTS can’t coordinate the balancing act of blood vessel constriction and heart rate response. This will cause a large variety of symptoms:
- Digestive symptoms: nausea, vomiting, bloating, diarrhea, constipation;
- Discomfort: severe sweating, fatigue, feeling hot or cold;
- Psychological symptoms: insomnia, anxiety, nervousness;
- Blurry vision;
- Brain fog;
- Neck pain, chest pain and headaches;
- Unusual coloring in hands and feet (pale face and purple discoloration of hands and feet);
- Blood pressure changes;
- Faster or slower heartbeat.
POTS symptoms may vary between different people and come and go over a period of years.
Causes and Risk Factors
The following conditions may increase the likelihood of POTS:
- Multiple sclerosis
- Click-murmur syndrome
- Autoimmune diseases (i.e. lupus, Sjogren’s syndrome, celiac disease)
- Chronic fatigue syndrome
- Lyme disease
- Hepatitis C
This condition is most common in subjects with a family history of POTS, and in women between 15 and 50 years of age. POTS may also follow pregnancies, severe infections or head injuries.
Patients may suffer from different types of POTS, such as:
- Hypovolemic – low blood levels;
- Neuropathic – damage in nerves leads to poor blood vessel muscles, especially in core and legs;
- Hyperadrenergic – the nervous sympathetic system is overactive, so higher levels of stress hormones are released.
POTS can be hard to diagnose, due to the many symptoms that can occur over time. The most effective assessment for it is the tilt-table test, which simulates standing up and measures heart rate changes. The test may cause the patient to faint so cautiousness is advised.
Beside the tilt-table-test, doctors may request some additional tests to confirm (or reject) a POTS diagnosis:
- Blood and urine tests for causes of POTS and conditions that mimic this syndrome;
- EKG and echocardiogram;
- QSART (Quantitative Sudomotor Axon Reflex Test), that measures the nerves that control sweating;
- Valsalva maneuver in order to act on the vagus nerve and slowing the heart rate;
- Autonomic breathing test, that measures your blood rate and pressure during exercise;
- Biopsy of the skin nerves.
While there’s no cure for POTS, treatment can help. This may include:
- Medication: fludrocortisone (increases salt retention and blood volume), midodrine (causes vasoconstriction), phenylephrine and beta-blockers (may reduce tachycardia).
- Movement: from workouts to walking and gentle yoga to stimulate blood flow.
- Diet: it must be rich in salt and water to retain fluids and raise the amount of blood in the body. Small, balanced meals are recommended.
- Lifestyle: learn to check your pulse and blood pressure regularly
- Regular sleep: a consistent sleep schedule and raising the head of the bed to facilitate mobility.
- Communication: A support group or therapist to confront feelings of depression and isolation.
- Compression stockings: a doctor will prescribe the most appropriate pair.