Chronic orthostatic intolerance, sometimes known as the postural tachycardia syndrome (POTS), is the most common disorder among patients seen at several centers specializing in diseases of the autonomic nervous system. It affects an estimated 500,000 people in the United States alone. POTS (excessive increase in heart rate \[\>30 min-1\] on standing associated with orthostatic symptoms \[including palpitation, chest pain syndrome, dyspnea on standing, mental clouding and difficulties with concentration\], in the absence of orthostatic hypotension) can produce substantial disability among otherwise healthy people. Patients with POTS typically feel tired and run down. Many also report a myriad of symptoms that are hard to categorize, often involving fatigue. One study, from the Mayo Clinic, found that patients with POTS had a diminished quality of life when measured using a standard health status instrument (SF-36).
In this pilot study, we will test the hypothesis that breathing through an inspiratory resistance device will improve orthostatic tolerance and reduce orthostatic tachycardia in patients with postural tachycardia syndrome.
