What causes Postural Orthostatic Tachycardia Syndrome (POTS)?

From the Guidelines

POTS is primarily caused by a combination of deconditioning, immune-mediated processes, excessive venous pooling, and a hyperadrenergic state, as proposed in the pathophysiology of the condition 1. The exact cause of POTS is debated and likely heterogeneous, but it is frequently associated with various factors such as recent infections, chronic fatigue syndrome, joint hypermobility syndrome, and a spectrum of non-specific symptoms like headache and chest pain. Some key points to consider in the diagnosis and management of POTS include:

• A marked orthostatic heart rate increase of >30 b.p.m., or >120 b.p.m. within 10 min of standing or head-up tilt in the absence of orthostatic hypotension (OH) 1
• Symptoms that typically develop upon standing, are relieved by sitting or lying, and may be worse in the morning, with heat exposure, and after meals or exertion, such as dizziness, light-headedness, weakness, fatigue, and palpitations 1
• The importance of history taking in patients with orthostatic intolerance to reveal underlying conditions that may be contributing to POTS, such as autoimmune disorders or Ehlers-Danlos syndrome. It is essential to note that several drugs can cause bradyarrhythmias and tachyarrhythmias, and the pathophysiology of POTS is complex and multifactorial, involving various physiological mechanisms, including autonomic nervous system dysfunction and vascular abnormalities 1.

From the Research

Causes of POTS

The causes of Postural Orthostatic Tachycardia Syndrome (POTS) are complex and multifaceted. Some of the key factors that contribute to the development of POTS include:

• Autonomic nervous system dysfunction 2, 3
• Immunological stressors, such as viral infections 3
• Autoimmune disorders, such as Hashimoto's thyroiditis, rheumatoid arthritis, and systemic lupus erythematosus 4
• Central nervous system disorders, with evidence suggesting that POTS may be a CNS disorder in addition to a peripheral nervous system disorder 5
• Genetic factors, with genomic research potentially elucidating the underlying mechanisms of POTS 6

Pathophysiology of POTS

The pathophysiology of POTS is not fully understood, but it is thought to involve a combination of factors, including:

• Dysautonomia, which affects the autonomic nervous system's ability to regulate heart rate and blood pressure 6
• Thoracic hypovolemia, which refers to a decrease in blood volume in the thoracic cavity 6
• Autonomic neuropathies, which affect the nerves that regulate the autonomic nervous system 6
• Sympathetic denervation, which affects the nerves that regulate the sympathetic nervous system 6
• Autoimmune responses, which can contribute to the development of POTS 4

Triggers for POTS

Some common triggers for POTS include:

• Orthostatic stress, such as standing or changing positions 2, 3
• Immunological stressors, such as viral infections 3
• Hormonal changes, such as those that occur during menstruation or menopause 3
• Environmental factors, such as heat or stress 3