POTS, or postural orthostatic tachycardia syndrome characterized by dysregulation of the autonomic nervous system. It causes symptoms like a fast heart rate, muscle weakness, and feeling light-headed, dizziness and/or fainting when standing.
Although the exact cause of this dysregulation is not fully known, it is most common in women between 15 and 50 years old and more likely to occur after viral infections, accidents or surgeries.
Patients who suspect they may have POTS should consult a cardiologist. Treatment may involve physical conditioning exercises, measures like increasing fluid intake and wearing compression garments, and medication to manage more specific symptoms.
Common symptoms
The main symptoms of POTS are:
- Increased heart rate
- Weakness or tiredness
- Dizziness and/or nausea
- Lightheadedness
- Bloating and/or abdominal pain
- Difficulty reasoning
- Fainting
POTS symptoms can begin to manifest after pregnancy, surgery, accident or viral infection. Episodes commonly appear within 10 minutes of standing up and improve after lying down.
POTS episodes also tend to worsen in hot environments, when exercising, and with illnesses such as colds and flu. In some women, symptoms may be more frequent in the days prior to a period.
Confirming a diagnosis
A POTS diagnosis is usually confirmed by a cardiologist after noting an increase in heart rate that is equal to or greater than 30 beats per minute within 10 minutes of standing up or of performing a tilt test. A drop in blood pressure should not be noted.
The doctor may also order other tests, such as a TSH and T4 test, ECG or a 24-hour Holter to rule out problems such as arrhythmias and hyperthyroidism, which can present with similar symptoms.
Possible causes
The exact cause of POTS is not known. However, it is believed that there are several factors that contribute to it such as a difficulty in blood return from abdominal vessels and the lower limbs to the heart, excess activation of the sympathetic nervous system and a reduced volume of circulating blood.
It is also known that POTS is more common in women between 15 and 50 years old with autoimmune diseases, such as Sjogren's syndrome, lupus and celiac disease. It can also develop after serious or viral infections, pregnancy, accidents and surgeries.
Treatment options
POTS treatment is initially done with exercises that improve physical fitness. They should be guided and carried out with a health care professional, and started gradually due to the risk of symptoms emerging.
Measures such as wearing compression clothing and increasing fluid intake are also recommended to stimulate blood circulation and prevent dehydration. The doctor may also recommend reducing caffeine and alcohol intake, and avoiding hot environments.
In more serious cases that do not respond to initial treatment, the doctor may prescribe medications, such as fludrocortisone, clonidine or propranolol, with the aim of managing symptoms and allowing the person to start exercises to improve their stamina.