Orthostatic intolerance (OI) is defined as the development of symptoms when standing upright that are relieved when reclining Orthostatic intolerance
Conditions
Interventions
None listed
Sponsors
Amsterdam UMC
Eligibility
Age
18 Years to 64 Years
Inclusion criteria
Inclusion criteria: In order to be eligible to participate, a participant must meet all of the following criteria:The ability to provide informed consent.A willingness and ability to comply with all aspects of the protocol, including physical assessments.Aged between 18-65 yearsAbility to stand for 10 minutesIn addition to the general inclusion criteria, PC controls must meet the following criteria:Fulfilment of WHO criteria for a PC diagnosisNo symptoms present before confirmed diagnosis of severe acute respiratory coronavirus 2 (SARS-cov-2)In addition to the general and additional inclusion criteria for PC controls, PC OI patients must additionally meet the following criteria: Report orthostatic symptoms, as assessed via clinical interview and/or questionnaires
Exclusion criteria
Exclusion criteria: A potential participant who meets any of the following criteria will be excluded from participation in this study:Taking immune modulatory drugs in the past 3 months.In line with the WHO criteria for post-COVID, a serious medical condition that may explain PC-like symptoms, such as cancer, coronary heart disease, uncontrolled diabetes, chronic infection (hepatitis B and C, tuberculosis, HIV), inflammatory disorders, autoimmune diseases (e.g. rheumatoid arthritis, lupus, or polymyositis), severe COPD or other severe ongoing respiratory disease, severe anaemia, kidney failure, Addison’s or Cushing’s disease, or serious neurological disorder (e.g. Parkinson’s Disease).Unwillingness to stop consumption of alcohol and recreational drugs for at least 48 hours prior to the study visit.Unwillingness or contra-indication to stop OI medication five days prior to the testing day.A diagnosis of ongoing mood disorder or other psychiatric diagnosis. Pregnant or breastfeeding in the past 12 months.BMI > 40.
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| All participants will be assessed for phenotypic characterization. We will collect self-report (demographic, behavioral, symptoms), clinical/medical data and physiological reactions. As primary parameters will be evaluated the responses to orthostatic challenge on:Change in cerebral blood flow (%?CBF upright–supine, determined by extracranial doppler) and cerebral Oxygenation (%?rScO2 upright–supine, using Near-Infrared Spectrometry, NIRS)Blood pressure, heart rate derived vagal function (Respiratory Sinus Arrythmia, RSA), baroreflex sensitivity, and log-ratio method estimation (to derive the relative contribution of cardiac output, peripheral resistance, and stroke volume to blood pressure). Orthostatic response in baroreflex sensitivity is assessed as: ?BRS upright–supine, expressed in ms/mmHg (spectral method). The log-ratio approach summarising the relative contribution of cardiac output (CO) versus total peripheral resistance (TPR) (CTCR). CTCR = log(CO_upright/CO_supine) divided by log(TPR_upright/TPR_supine). | — |
Secondary
| Measure | Time frame |
|---|---|
| Secondary outcome measures:Cardiac-autonomic responses to autonomic function tests: 1) 1-minute paced breathing (cardio-vagal regulation), 2) 20-second Valsalva maneuver (mixed cardio-vagal and sympathetic), 3) sudomotor evaluation (postganglionic sympathetic, to determine if symptoms of OI are linked to small fiber neuropathy in part of patients).pCO2 during posture change (to determine if symptoms of OI are linked to hyperventilation in part of patients) expected to be significantly different from healthy controls and clinical cut off score24h HR and HR variability adjustments Autonomic or cardio-respiratory symptoms during testing and in daily life (to compare subjective experience with physiological responses)e.g., habitual and TTT-induced headache, brain fog, dizziness, dyspnea, palpitations eye blackening, skin discoloration, physical activity | — |
Countries
Netherlands
Contacts
Public ContactJA Bosch
Amsterdam UMC
Outcome results
None listed