Testing and Diagnosis for Postural Orthostatic Tachycardia Syndrome (POTS)

What is Postural Orthostatic Tachycardia Syndrome?

Postural orthostatic tachycardia syndrome (POTS) is a disorder of the autonomic nervous system that regulates involuntary functions like heart rate. In people with POTS, this system does not properly constrict blood vessels when standing up. This causes blood to pool in the legs rather than returning to the heart. As a result, the heart beats faster to compensate, sometimes increasing by over 30 beats per minute after standing.

Causes & Symptoms of Postural Orthostatic Tachycardia Syndrome

The exact cause of postural orthostatic tachycardia syndrome (POTS) is not fully understood, but it is thought to be caused by a combination of factors. POTS can manifest through a wide range of symptoms, often overlapping with other conditions. These symptoms typically worsen when transitioning from lying down to an upright position. Daily functioning becomes impaired due to the unpredictability of symptoms.

Postural Orthostatic Tachycardia Syndrome (POTS) Causes

• Dysfunction of the Autonomic Nervous System
  POTS is closely linked to a malfunction of the autonomic nervous system, which regulates vital functions like blood pressure and heart rate. Irregularities in this system can disrupt normal circulatory responses.


• Autoimmune Response
  Emerging research suggests that an autoimmune process may affect blood vessels, causing excessive dilation when transitioning to an upright position.


• Deconditioning
  Extended periods of inactivity and muscle weakness can play a role in the development of POTS, contributing to symptoms.


• Genetic Predisposition
  While not directly inherited, certain gene variants may predispose individuals to developing POTS.


• Triggers
  POTS can be triggered by various factors, including viral illnesses, surgical procedures, pregnancy, injury, or trauma.

Postural Orthostatic Tachycardia Syndrome (POTS) Symptoms

• Lightheadedness, Dizziness, or Fainting
  When transitioning from lying down to an upright position, individuals with POTS often experience a sudden drop in blood pressure, leading to lightheadedness, dizziness, and in severe cases, fainting (syncope).


• Heart Palpitations
  POTS frequently results in a rapid heart rate, with the heart often beating more than 100 beats per minute upon standing. This palpitation is one of the defining characteristics of the condition.


• Fatigue
  Profound and persistent fatigue is a hallmark symptom of POTS, often disproportionate to an individual's level of physical activity. This fatigue can significantly affect daily functioning.


• Cognitive Dysfunction
  Many individuals with POTS report cognitive difficulties, including brain fog, difficulty concentrating, and memory problems.


• Gastrointestinal Distress
  Symptoms such as nausea, abdominal pain, bloating, and diarrhea can be troublesome for those with POTS.


• Respiratory Issues
  Shortness of breath and occasional chest pain may occur, particularly during upright posture.


• Mental Health Symptoms
  Anxiety, tremors, and sleep disturbances are common in individuals with POTS. The chronic nature of the condition, along with its unpredictable symptoms, can contribute to anxiety and emotional distress.


• Thermal Regulation Issues
  POTS can disrupt the body's ability to regulate temperature, leading to heat and cold intolerance. Excessive sweating may also be observed.

Testing & Diagnosis for Postural Orthostatic Hypotension Syndrome (POTS)

Postural orthostatic tachycardia syndrome (POTS) shares symptoms with other medical conditions, such as dehydration, anemia, heart conditions, and anxiety disorders. Since POTS symptoms can be similar to other conditions, a full evaluation is needed to confirm a diagnosis. Some of the key tests used include:

• Tilt Table Test
  This is a specialized diagnostic test used to confirm POTS. During this test, you will be securely strapped to a table that can be tilted to various angles. Your heart rate and blood pressure are monitored continuously as you change positions from lying down to an upright tilt. An abnormal increase in heart rate upon standing is a defining characteristic of POTS.


• Active Stand Test
  This is similar to a tilt table test but simpler. You sit down for 5-10 minutes, then stand up unaided for 10 minutes while your heart rate and blood pressure are checked multiple times.


• Physical Exam
  Your doctor will listen to your heart, check your blood pressure lying down and standing, assess reflexes, muscle strength, and coordination.


• Blood Tests
  These help rule out other causes like anemia or thyroid disorders. Common blood tests include complete blood count, metabolic panel, erythrocyte sedimentation rate, and thyroid levels.


• Autonomic Reflex Screening
  This assesses how your involuntary nervous system responds to certain stimuli like breathing exercises or the Valsalva maneuver. Abnormal responses may indicate dysautonomia.


• Heart Rate Monitor
  This is a specialized test to evaluate your heart rates continuously over a few days.

Postural Orthostatic Tachycardia Syndrome (POTS) Treatments

While no single cure exists for postural orthostatic tachycardia syndrome (POTS) yet, various treatments can help manage symptoms. The goal is to improve circulation and relieve tachycardia associated with standing. Common treatments include:

• Increasing Fluid and Salt Intake
  Extra fluid and sodium intake can help increase blood volume and prevent blood from pooling in the legs upon standing. Drinking 2-3 liters of water and consuming 10-12 grams of sodium daily is often recommended.


• Compression Garments
  Specialized compression stockings, leggings, or abdominal binders can help prevent blood from pooling in the lower body and improve circulation back to the heart. They should be worn daily.


• Exercise Training
  Low-intensity exercises like swimming, rowing, or recumbent biking can help strengthen leg and core muscles. This improves venous return and stamina. It’s important to avoid overexertion.


• Medications
  Drugs like beta blockers, alpha-2 agonists, fludrocortisone, ivabradine, or pyridostigmine can help control heart rate and improve blood pressure regulation.


• Head of Bed Tilt
  Elevating the head 8-12 inches while sleeping allows gravity to encourage blood flow to the chest and head rather than pooling downward.


• Avoiding Triggers
  Things like hot showers, alcohol, large meals, and prolonged standing should be limited to prevent exacerbating symptoms.