Postural Orthostatic Tachycardia Syndrome (POTS) in Denmark: Increasingly recognized or new epidemic?

AIMS: The incidence of Postural Orthostatic Tachycardia Syndrome (POTS) has grown in recent years. Whether this is an emerging epidemic or increasing recognition is unclear. METHODS: We retrospectively examined 8790 tilt-table tests (HUT) performed between 1997 and 2014 in patients with orthostatic intolerance and/or suspected syncope. Tests were reclassified according to the current diagnostic criteria for POTS. The number of POTS diagnoses in proportion to the number of tilt tests performed per year was calculated. The number of papers published with the term "Postural Orthostatic Tachycardia Syndrome" 1997-2014 was retrieved from PubMed and related to yearly POTS incidence. RESULTS: Eight-hundred-and-seventy-five tests with suspected POTS were thoroughly evaluated. The reclassification of test results yielded 243 POTS diagnoses (age, 27.0 ±â€¯11.8 years). An increase in total number of POTS diagnoses was observed but the proportion of POTS-positive tests per year was relatively constant (≈2-3%) except for the period 2013-2014 (≈7%). The increase in POTS diagnoses was preceded by an increase in number of POTS-related papers in PubMed. CONCLUSION: The proportion of POTS diagnoses among patients investigated for suspected syncope and/or orthostatic intolerance was relatively constant 1997-2012. The growing number of POTS-related publications in PubMed preceded the steep increase in diagnostic rate of POTS observed after 2012.