Postural orthostatic tachycardia syndrome is an under-recognized condition in chronic fatigue syndrome. Journal: QJM. 2008 Sep 19. [Epub ahead of print] Authors: Hoad A, Spickett G, Elliott J, Newton J. Affiliations: From the Northern CFS/ME Clinical Network, Equinox House, Silver Fox Way, Cobalt Business Park, Newcastle upon Tyne ME NorthEast, Bullion Hall, County Durham and Falls and Syncope Service, Institute of Cellular Medicine, Newcastle University, Newcastle, UK. NLM Citation: PMID: 18805903 BACKGROUND: It has been suggested that postural orthostatic tachycardia syndrome (POTS) be considered in the differential diagnosis of those with chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME). Currently, measurement of haemodynamic response to standing is not recommended in the UK NICE CFS/ME guidelines. Objectives: To determine prevalence of POTS in patients with CFS/ME. Design: Observational cohort study. METHODS: Fifty-nine patients with CFS/ME (Fukuda criteria) and 52 age- and sex-matched controls underwent formal autonomic assessment in the cardiovascular laboratory with continuous heart rate and beat-to-beat blood pressure measurement (Task Force, CNSystems, Graz Austria). Haemodynamic responses to standing over 2 min were measured. POTS was defined as symptoms of orthostatic intolerance associated with an increase in heart rate from the supine to upright position of >30 beats per minute or to a heart rate of >120 beats per minute on standing. RESULTS: Maximum heart rate on standing was significantly higher in the CFS/ME group compared with controls (106 +/- 20 vs. 98 +/- 13; P = 0.02). Of the CFS/ME group, 27% (16/59) had POTS compared with 9% (5) in the control population (P = 0.006). This difference was predominantly related to the increased proportion of those in the CFS/ME group whose heart rate increased to >120 beats per minute on standing (P = 0.0002). Increasing fatigue was associated with increase in heart rate (P = 0.04; r(2) = 0.1). CONCLUSION: POTS is a frequent finding in patients with CFS/ME. We suggest that clinical evaluation of patients with CFS/ME should include response to standing. Studies are needed to determine the optimum intervention strategy to manage POTS in those with CFS/ME.