Postural orthostatic tachycardia syndrome (POTS) may be present when affected persons experience an elevated heart rate, dizziness and panic attacks when standing up. According to estimates by the Autonomic Dysfunction Center in Nashville, 0.2% of the population is affected, which corresponds to approximately 17,000 people in Switzerland. Most patients are between 15 and 50 years old, and more than 80% percent are women.
Simple diagnosis
POTS has been defined as an increase in heart rate of at least 30 beats per minute (40 beats/min in adolescents) within 10 minutes after standing up, with no drop in blood pressure. The increase in heart rate can be easily diagnosed by having the patient lie down for 10 minutes and measuring the heart rate over 10 minutes after standing up, or by a tilt table test. Other criteria for a successful diagnosis are frequent symptoms on standing up/sitting down or lying down (orthostatic intolerance) that have lasted ≥3 months and the absence of other conditions that could explain sinus tachycardia. It is estimated that POTS symptoms are due to a viral infection in approximately half of affected individuals.
The distinction between causes and symptoms is sometimes unclear
The causes of POTS are not clearly understood, and the delineation between causes and symptoms is sometimes diffuse. It is a disorder of the autonomic nervous system, meaning the processes that occur automatically and cannot be controlled voluntarily. This can trigger a variety of different dysfunctions, which are causally connected and influence each other.
What happens in POTS?
In POTS, the main problem is that the veins that pump blood from the legs to the head can no longer contract sufficiently. This causes blood to pool in the lower part of the body. To regulate and compensate for this disorder, the body increases the pulse to activate the heart (tachycardia), or it increases breathing (hyperventilation). Both help stabilize the circulation but lead to other problems as German physician Thomas Weiss explains in a video.
Tachycardia, or rapid heartbeat, leads to panic and stress. Hyperventilation takes in more oxygen, but also releases more carbon dioxide, which upsets the acid-base balance. The blood becomes too alkaline, and the increased mineral intake makes nerves and muscles more excitable. The consequences are restlessness, palpitations, tingling but also muscle twitching and muscle cramps.
POTS is associated with different symptoms and coexisting conditions
Postural orthostatic tachycardia syndrome can be associated with a variety of different symptoms, including lightheadedness, palpitations, tremors, general weakness, blurred vision, nausea, exercise intolerance, anxiety and panic, and fatigue. Even with varying symptom severity, POTS patients have one thing in common: symptoms are most severe in the upright position and those affected by POTS accordingly feel most comfortable when lying down. When getting up, the symptoms appear and, above all, a hardly controllable exhaustion sets in after a while. There are smooth transitions to other conditions such as chronic fatigue syndrome (CFS), concussion, migraine, fibromyalgia (chronic pain on the skin and in the muscles and joints), functional gastrointestinal disorders, anxiety and hypervigilance, autoimmunity, as well as hypermobility and Ehlers-Danlos syndrome.
POTS often occurs in association with COVID-19.
Since the onset of the Corona pandemic, an increase in patients with POTS symptoms has been observed, and several studies now support an association. After SARS-CoV-2 infection, approximately 2–14% of patients develop POTS and 9–61% experience POTS-like symptoms, such as tachycardia, orthostatic intolerance, fatigue, and cognitive impairment during the first 6–8 months after severe acute infection. A large-scale study of more than 280,000 participants from the United States also shows that there is an increased likelihood of developing POTS 90 days after COVID-19 vaccination or SARS-CoV-2 infection, with the likelihood being about 5 times higher after infection than after vaccination.
Sitting is the new smoking (should be the stated motto if you suffer from POTS, according to Dr. Thomas Weiss).
POTS can cause anxiety
Postural tachycardia syndrome is not a mental illness. However, the symptoms can trigger anxiety. Anxiety and panic, in turn, can exacerbate postural tachycardia syndrome symptoms because of hyperventilation. Many affected individuals also suffer from other functional disorders, such as migraines, irritable bowel syndrome, irritable bladder, pain, and sleep disturbances. Although affected persons feel most comfortable lying down, they should not always give in to the urge.
Rest leads to worsening
Resting usually contributes to further deterioration, explains Thomas Weiss, a physician from Germany. His main tips include avoiding stress, compression through stockings and wraps, cold baths, drinking more water and eating a high-salt diet to increase blood volume, respiratory therapy because of hyperventilation, and exercise to counteract inactivity and obesity. In fact, literature shows that of all things, unpleasant exercise can bring significant improvements.
Multimodal therapy according to Thomas Weiss
Four out of five persons suffering from POTS can achieve a significant improvement in their symptoms within 18 months with these measures. In a study with adolescent POTS patients, the symptoms had completely disappeared in 19% of the study participants after 5 years. Another 67% reported improved symptomatology or only intermittent symptoms. Anxiety and hyperventilation appear to be major factors leading to chronicity.
