Syndromes of orthostatic intolerance and syncope in young adults

Abstract

ObjectiveTo explore the clinical and neuroendocrine characteristics of syndromes of orthostatic intolerance and syncope in young adults.MethodsTwo hundred and thirty-six patients aged 18–40 years with orthostatic intolerance and/or syncope were examined by head-up tilt test (HUT). Plasma levels of epinephrine, norepinephrine, renin, C-terminal-pro-arginine-vasopressin (CT-proAVP), C-terminal-endothelin-1 and mid-regional-fragment of pro-atrial-natriuretic-peptide (MR-proANP) were analysed. Patients’ history, haemodynamic parameters and plasma biomarkers were related to main diagnoses such as vasovagal syncope (VVS), postural tachycardia syndrome (POTS), orthostatic hypotension (OH) and negative HUT.ResultsNo self-reported symptom of orthostatic intolerance was highly specific for any diagnosis. Patients with VVS (n=103) were more likely to be men (p=0.011) and had lower resting heart rate (HR; 66±11) compared with POTS (73±11; n=72; p=0.001) and negative HUT (74±11; n=39; p=0.001). Patients with POTS demonstrated greater rise in norepinephrine (p=0.008) and CT-proAVP (p=0.033) on standing compared with negative HUT, and lower resting MR-proANP compared with VVS (p=0.04) and OH (p=0.03). Patients with OH had lower resting renin (p=0.03). Subjects with a resting HR <70 and MR-proANP >45 pm/L had an OR of 3.99 (95 % CI 1.68 to 9.52; p=0.002) for VVS compared with subjects without any of these criteria; if male sex was added the OR was 21.8 (95% CI 3.99 to 119; p<0.001).ConclusionsSyndromes of orthostatic intolerance and syncope share many characteristics in younger persons. However, patients with VVS are more likely to be men, have lower HR and higher MR-proANP at rest compared with POTS, which might be taken into account at an early stage of evaluation.

Postural orthostatic tachycardia syndrome: clinical presentation, aetiology and management

“…A characteristic patient with POTS is a young woman about 25 years old, reporting first symptoms at age around 15 years, although the range of disease onset may extend until fifth decade of life and one‐fifth are men . In a specialized syncope unit, almost one‐third of patients aged 18–40 years with a history of unexplained syncope and pronounced orthostatic intolerance may meet the diagnostic POTS criteria .…”

“…A characteristic patient with POTS is a young woman about 25 years old, reporting first symptoms at age around 15 years, although the range of disease onset may extend until fifth decade of life and one‐fifth are men . In a specialized syncope unit, almost one‐third of patients aged 18–40 years with a history of unexplained syncope and pronounced orthostatic intolerance may meet the diagnostic POTS criteria . Importantly, symptoms of orthostatic intolerance and number of syncopal events do not well discriminate between POTS and other syncope‐related dysautonomic conditions, orthostatic hypotension and recurrent vasovagal syncope .…”

“…In a specialized syncope unit, almost one‐third of patients aged 18–40 years with a history of unexplained syncope and pronounced orthostatic intolerance may meet the diagnostic POTS criteria . Importantly, symptoms of orthostatic intolerance and number of syncopal events do not well discriminate between POTS and other syncope‐related dysautonomic conditions, orthostatic hypotension and recurrent vasovagal syncope . The onset of POTS may be precipitated by typical immunological stressors such as viral infection, frequently of the upper respiratory or gastrointestinal tract, vaccination, trauma, pregnancy, surgery or even a period of intensive psychosocial stress .…”

Susceptibility to diarrhea is related to hemodynamic markers of sympathetic activation in the general population

“…The ANS governs the most important life-supporting and adaptive functions in humans. Dysfunction of the ANS is probably best seen in cardiovascular autonomic disorders, including clinical manifestations of disturbed heart rhythm and blood pressure regulation, such as orthostatic hypotension and postural orthostatic tachycardia syndrome (POTS) [6,7]. Impaired autonomic control of the gastrointestinal (GI) system is usually more discrete [8].…”

Dysregulation of the “inflammatory reflex” with abnormal neurohumoral activation may contribute to proinflammatory activity driving the progression of COPD

“…Since microneurography as a gold standard for the evaluation of sympathetic activity is a challenging method and has never been performed in a population-based cohort, it is not possible to prove this assumption. However, in other diseases, such as heart failure and obstructive sleep apnoea, the concept of neurohumoral activation and autonomic nervous system imbalance with increased sympathetic activation and reduced parasympathetic activity has long been recognised, and is related to increased resting heart rate, as well as increased morbidity and mortality [6,7].…”