Clinical challenges in the diagnosis and management of postural tachycardia syndrome Jones PK1, Shaw BH2, Raj SR3. Author information 1Department of Neurology, UT Health Science Center San Antonio, San Antonio, Texas, USA. 2Cumming School of Medicine, University of Calgary, Calgary, Canada. 3Department of Cardiac Sciences, Libin Cardiovascular Institute of Alberta, Cumming School of Medicine, University of Calgary. http://www.ncbi.nlm.nih.gov/pubmed/27660311 Abstract Postural tachycardia syndrome (POTS) is a multifactorial clinical syndrome defined by an increase in heart rate of ≥30 bpm on standing from supine position (or ≥40 bpm in children). It is associated with symptoms of cerebral hypoperfusion that are worse when upright and improve when in supine position. Patients often have additional symptoms including severe fatigue and difficulty concentrating. There are several possible pathophysiologic mechanisms including hypovolaemia, small-fibre peripheral neuropathy and hyperadrenergic states. POTS can also be associated with several disorders including mastocytosis, Ehlers-Danlos syndrome (hypermobility type) and autoimmune disorders. The treatment is focused on symptom relief and not solely on reducing tachycardia. Given its varying presentations, it is important to employ a practical, mechanism-focused approach to the diagnosis and management of POTS.