Postural Orthostatic Tachycardia Syndrome (POTS) has gained increasing recognition as a condition that can emerge following a COVID-19 infection. Recent research indicates a notable rise in POTS diagnoses in the wake of the pandemic, shifting from approximately 4 new cases per month before COVID-19 to over 22 new cases per month afterward.
Understanding POTS
POTS is categorized as a form of dysautonomia, a disorder of the autonomic nervous system. This involuntary nervous system regulates bodily functions such as heart rate, blood pressure, digestion, and temperature control.
Under normal circumstances, when a person stands up, gravity pulls blood downwards, and the autonomic nervous system responds by constricting blood vessels in the lower body. This constriction helps to maintain adequate blood flow to the brain and upper body. In individuals with POTS, this automatic constriction of blood vessels in the lower extremities does not occur effectively. Consequently, blood pools in the legs and abdomen, reducing the volume of blood returning to the heart and, subsequently, to the brain. To compensate for this reduced blood flow, the heart begins to beat much faster and harder, attempting to deliver more oxygen to the brain and other organs. This compensatory tachycardia is a hallmark of the syndrome.
The Connection Between COVID-19 and POTS
The emergence of POTS following a COVID-19 infection has become a focus of scientific inquiry, with several theories attempting to explain this connection. One prominent theory suggests an autoimmune reaction, where the body’s immune system, after fighting the SARS-CoV-2 virus, mistakenly begins to attack healthy tissues, including components of the autonomic nervous system. This misdirected immune response could disrupt nerve signaling and function.
Another proposed mechanism involves direct viral damage to nerve cells or the tiny blood vessels that supply them. The SARS-CoV-2 virus is known to affect multiple organ systems, and direct cellular damage could impair the intricate network responsible for regulating heart rate and blood pressure. Persistent inflammation resulting from the infection is also considered a contributing factor. Chronic inflammation could affect the function of the autonomic nervous system, leading to its dysregulation.
Common Symptoms of Post-COVID POTS
Beyond an elevated heart rate upon standing, individuals with post-COVID POTS often experience other symptoms, including:
Severe fatigue, significantly impacting daily activities.
“Brain fog,” characterized by difficulties with concentration, memory lapses, and slowed processing of information.
Dizziness or lightheadedness upon changing positions.
Headaches, sometimes presenting as migraines or a pressure-like sensation.
Exercise intolerance, where even mild physical exertion can exacerbate symptoms and lead to profound exhaustion.
Nausea, palpitations, and tremors.
The Diagnostic Journey
Diagnosing POTS involves a medical evaluation. The process usually begins with consulting a healthcare provider who considers the patient’s symptoms and medical history. A key initial assessment is the Active Stand Test, where a patient’s heart rate and blood pressure are measured while lying down and then again after standing for a specific period, usually 10 minutes. A sustained increase in heart rate of at least 30 beats per minute (bpm) for adults, or 40 bpm for adolescents, without a significant drop in blood pressure, strongly suggests POTS.
For a more definitive diagnosis, a Tilt Table Test is often performed. During this test, the patient lies flat on a table that then slowly tilts upright to a 60- to 70-degree angle while heart rate and blood pressure are continuously monitored. This controlled environment allows doctors to observe the body’s response to gravity and confirm the characteristic heart rate increase and other symptoms. Ruling out other conditions, such as anemia, dehydration, or thyroid dysfunction, is important.
Managing Daily Life with Post-COVID POTS
Managing post-COVID POTS involves lifestyle adjustments and, when necessary, medical interventions. Increasing fluid intake, typically 2-3 liters of water or electrolyte-rich beverages daily, helps expand blood volume. Simultaneously, increasing dietary salt intake, usually 8-10 grams per day, helps the body retain fluids and maintain blood pressure.
Wearing compression garments, such as abdominal binders and compression stockings that extend to the waist or thighs, can help prevent blood from pooling in the lower body. Specific exercise programs, like the modified Levine protocol or the CHOP (Children’s Hospital of Philadelphia) protocol, are often recommended. These programs gradually introduce recumbent exercises like rowing or cycling before progressing to upright activities, helping to recondition the cardiovascular system without exacerbating symptoms.
While lifestyle strategies are primary, healthcare providers may also prescribe medications such as fludrocortisone to increase blood volume, or beta-blockers to help control heart rate.