From the Guidelines
POTS (Postural Orthostatic Tachycardia Syndrome) is a condition characterized by a heart rate increase of at least 30 beats per minute within 10 minutes of standing, without a significant drop in blood pressure, and is often accompanied by symptoms such as lightheadedness, palpitations, tremulousness, generalized weakness, blurred vision, exercise intolerance, and fatigue. According to the 2017 ACC/AHA/HRS guideline for the evaluation and management of patients with syncope 1, POTS is defined as a clinical syndrome usually characterized by all of the following: 1) frequent symptoms that occur with standing; and 2) an increase in heart rate of ≥30 bpm during a positional change from supine to standing; and 3) the absence of OH (>20 mm Hg reduction in systolic BP).
The pathophysiology of POTS is quite varied, but it is thought to be related to the autonomic nervous system's failure to properly regulate blood vessel constriction when standing, causing blood to pool in the lower body and reducing blood flow to the brain, which triggers a compensatory heart rate increase to maintain blood pressure, resulting in symptoms like dizziness, fatigue, brain fog, and sometimes fainting 1.
Some key points to note about POTS include:
- The primary symptom is a heart rate increase of at least 30 beats per minute within 10 minutes of standing, without a significant drop in blood pressure 1.
- Symptoms associated with POTS include those that occur with standing, such as lightheadedness, palpitations, and those not associated with particular postures, such as bloating, nausea, diarrhea, abdominal pain, and systemic symptoms like fatigue, sleep disturbance, migraine headaches 1.
- Treatment typically includes increased fluid intake, increased salt consumption, compression garments for the lower body, and a structured exercise program focusing on recumbent exercises 1.
- Medications may include beta-blockers like propranolol, fludrocortisone to increase blood volume, or midodrine to constrict blood vessels 1.
It's worth noting that while syncope can occur in patients with POTS, it is relatively infrequent, and there is little evidence that the syncope is due to POTS 1. However, treatments that improve symptoms of POTS might decrease the occurrence of syncope, although this is unknown 1. For further guidance on the management of POTS, we refer readers to the Heart Rhythm Society consensus statement 1.
From the Research
Definition of POTS
- Postural Orthostatic Tachycardia Syndrome (POTS) is defined by a heart rate increment of 30 beats/min or more within 10 minutes of standing or head-up tilt in the absence of orthostatic hypotension 2
- The standing heart rate is often 120 beats/min or higher 2
Pathophysiology of POTS
- The pathophysiology of POTS is heterogeneous and includes impaired sympathetically mediated vasoconstriction, excessive sympathetic drive, volume dysregulation, and deconditioning 2
- Three primary POTS phenotypes have been identified: hyperadrenergic, neuropathic, and hypovolemic, each requiring tailored management strategies 3
Symptoms of POTS
- Symptoms of POTS include cerebral hypoperfusion and excessive sympathoexcitation 2
- Patients with POTS often experience symptoms such as fatigue, exercise intolerance, and gastrointestinal distress 4
- Other symptoms may include headaches, chest pain, shortness of breath, and brain fog 5
Diagnosis and Management of POTS
- The evaluation of a patient with suspected POTS should seek to establish the diagnosis, identify co-morbid conditions, and exclude conditions that could cause or mimic the syndrome 4
- Management of POTS typically begins with patient education and non-pharmacologic treatment options, and may include medications to address specific symptoms 4
- A multidisciplinary approach to control symptoms is crucial, given the heterogeneous nature of POTS 5