Is orthostatic hypotension a part of long COVID (Coronavirus Disease 2019)?

Orthostatic Hypotension in Long COVID

Yes, orthostatic hypotension is a recognized component of long COVID, defined as a drop in systolic blood pressure of at least 20 mm Hg or diastolic blood pressure of at least 10 mm Hg within 3 minutes of standing. 1

Prevalence and Relationship to Long COVID

• Orthostatic intolerance, including orthostatic hypotension (OH), is highly prevalent in long COVID patients, with recent multicenter studies showing approximately 8% of long COVID clinic patients meeting criteria for OH 2
• Cardiovascular autonomic dysfunction (CVAD), which includes orthostatic hypotension, may affect up to one-third of highly symptomatic COVID-19 patients 3
• Orthostatic hypotension can develop early during or after acute COVID-19 infection, similar to patterns seen in myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) 4

Pathophysiological Mechanisms

• The American College of Cardiology recognizes orthostatic hypotension as part of the post-acute sequelae of SARS-CoV-2 infection (PASC) cardiovascular syndrome 1
• Potential mechanisms include:
  • Vascular dysfunction affecting the capacitance vessel system, which is critical for orthostatic regulation 4
  • Microcirculatory disturbances resulting from endothelial dysfunction, microthrombus formation, and rheological disturbances of blood cells 4
  • Autonomic nervous system dysregulation, potentially due to neuroinflammation 1
  • Immune dysregulation with possible autoimmune components 1

Clinical Presentation and Diagnosis

• Orthostatic hypotension in long COVID often presents with symptoms including:
  • Lightheadedness upon standing
  • Dizziness
  • Weakness
  • Fatigue
  • Blurred vision 1
• Diagnosis requires measurement of orthostatic vitals:
  • Blood pressure and heart rate should be measured while supine and at 2,5, and 10 minutes after standing 1
  • A drop in systolic blood pressure ≥20 mm Hg or diastolic blood pressure ≥10 mm Hg within 3 minutes confirms orthostatic hypotension 1

Evolution Over Time

• Interestingly, the hemodynamic profile of long COVID patients changes over time:
  • In the first 12 months after infection, postural orthostatic tachycardia syndrome (POTS) is more common
  • After 24 months, more patients show either normal hemodynamic responses or orthostatic hypotension 5
• Cerebral blood flow abnormalities improve over time but remain abnormal even after hemodynamic parameters normalize 5

Relationship to Other Post-COVID Conditions

• Orthostatic hypotension in long COVID often overlaps with:
  • Postural orthostatic tachycardia syndrome (POTS) 1, 6
  • Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) 1
  • Inappropriate sinus tachycardia 1
• Around half of individuals with long COVID are estimated to meet criteria for ME/CFS, which commonly features orthostatic intolerance 1

Clinical Implications and Management

• The American College of Cardiology recommends evaluation of orthostatic vitals in patients with long COVID who report symptoms of orthostatic intolerance 1
• A National Aeronautics and Space Administration Lean Test (NLT) is recommended for all patients attending long COVID clinics, as approximately 45% of patients with abnormal orthostatic testing may not report prior symptoms 2
• Management should be multidisciplinary, involving specialists in cardiology, neurology, and rehabilitation medicine 6

Pitfalls and Caveats

• Not all patients with orthostatic hypotension in long COVID report typical symptoms, making objective testing crucial 2
• Orthostatic hypotension must be distinguished from POTS, which is defined by an increase in heart rate ≥30 beats per minute without hypotension 1
• Symptoms may be mistaken for deconditioning alone, but the pathophysiology appears more complex 1
• Orthostatic testing should be performed for the full recommended duration (10 minutes), as some patients develop delayed orthostatic changes 1