02/21 AG).įorty-one participants met the inclusion criteria (29 females age 29.74☑0.61 years, mean±SD), and the control group consisted of 10 healthy individuals (6 females, age 24.25☒.25 years). All participants signed informed-consent forms approved by the Ethical Committee of University Hospital Center Zagreb (approval no. Furthermore, age- and sex-matched healthy controls who had no previous history of events that could be associated with any kind of orthostatic intolerance were included. 6 Exclusion criteria were the presence of any underlying condition that might influence the results in the tilt-table test such as hypertension, diabetes or polyneuropathy. This was a prospective study that was conducted from April 2016 to November 2017 in the Referral Center for Autonomic Nervous System Disorders at University Hospital Center Zagreb.Įligible participants were consecutive patients referred to the center for tilt-table testing and who had a sustained HR increment of ≥30 beats/min within 10 min of standing or during head-up tilting in the absence of orthostatic hypotension with or without characteristic symptoms for POTS in the baseline examination.

Based on the hypothesis that food intake prior to tilt-table testing can influence the criteria used to diagnose POTS, the aim of this study was to determine the effect of food intake on the current criteria applied for the diagnosis of POTS. 11 However, current POTS criteria do not define whether food intake should be taken into account while interpreting the results of tilt-table tests. 10, 11 One study has shown how food ingestion alters the HR and BP upon head-up tilting in POTS patients. 9 Since several neurological illnesses can influence the postprandial response, it is no wonder that gastroenterologic symptoms are common in the POTS, and postprandial worsening of orthostatic symptoms often occurs. 7, 8 This effect of the sympathetic nervous response seems to be even greater in young adults, which is the population mostly affected by POTS. Meal intake significantly influences the autonomic nervous system, and it is estimated that maintaining the postprandial BP requires a 200% increase in sympathetic nervous activity. 6 The tilt-table test is a common diagnostic tool for diagnosing POTS because it enables the positions of the patient to be readily altered between standing and supine while measuring the blood pressure (BP) and HR changes, which are major criteria for POTS. For individuals aged 12–19 years, the required minimum increment in HR is 40 beats/min. 5 A definitive diagnosis of POTS requires fulfillment of the following criteria reported in 2011 by Freeman et al., 6 a sustained HR increment of ≥30 beats/min within 10 min of standing or during head-up tilting in the absence of orthostatic hypotension and accompanied by characteristic symptoms that are relieved by recumbency.

1, 3, 4 The exact prevalence of POTS is unknown, mostly because many patients who suffer from this condition have unspecific symptoms, resulting in them being underdiagnosed or misdiagnosed and hence treated for some other condition instead. 1, 2 POTS is more common among females and either can appear in isolation or can overlap and be secondary to other conditions such as chronic fatigue syndrome, multiple sclerosis, inappropriate sinus tachycardia, and Ehlers-Danlos syndrome. 1 This abnormal response to orthostasis could be pathophysiologically explained by insufficient compensatory vascular constriction, excessive central sympathetic tone, hypovolemia with a defect in the renin-angiotensin-aldosterone system, deconditioning, and autoimmune causes, but the exact underlying mechanism remains unknown. The HR increase in POTS is accompanied by characteristic symptoms such as lightheadedness, weakness, and nausea, which are relieved by adopting a recumbent position.

Postural orthostatic tachycardia syndrome (POTS) is a form of orthostatic intolerance characterized by a sustained excessive increase in the heart rate (HR) after adopting an upright posture.

Pots symptoms checklist