[CK] POTS Postural tachycardia syndrome.

Dx. head-up tilt testing: HR > +30 over baseline or to >120 bpm. 

  Dx. of exclusion: Dehydration, prolonged bedrest, medications, and other dysautonomia

Tx. not established. Same as orthostatic hypotension. 

  = Ex., IVF, fludrocortisone (0.05 to 0.2 mg per day) as the first line of therapy (Grade 2C). 

 Some patients may benefit from midodrine or BB.