Postural Orthostatic Tachycardia is an age dependent manifestation of Ehlers-Danlos Syndromes. C. Slemenda1, B.F. Griswold2, L. Sloper2, C.A. Francomano3, N.B. McDonnell2 1) LI, NIA/NIH, Baltimore, MD; 2) LCI, NIA/NIH, Baltimore, MD; 3) GBMC, Baltimore, MD.

   Postural Orthostatic Tachycardia (POTS), defined as a heart rate increase greater than thirty beats per minute from supine to standing, has been reported to be associated with joint hypermobility. We studied the prevalence of POTS among 61 consecutive patients with hypermobile and classical forms of Ehlers Danlos syndrome seen at the National Institutes of Health. Supine, sitting, and standing heart rate measurements were obtained for each subject with five minutes of rest between each position. Thirty eight percent (23/61) of the subjects met criteria for POTS. The condition was significantly more common (p<0.001) in patients under the age of 25, with 72% of such patients being affected, as compared to 13.9% of persons over the age of 25. The presence of POTS was associated with a reduction in quality of life, including inability to maintain gainful employment or attend school. The etiology and natural history of POTS in this cohort is not well understood and merits further investigation.