Diurnal variability in orthostatic tachycardia: implications for the postural tachycardia syndrome.

Patients with POTS (postural tachycardia syndrome) have excessive orthostatic tachycardia (>30 beats/min) when standing from a supine position. HR (heart rate) and BP (blood pressure) are known to exhibit diurnal variability, but the role of diurnal variability in orthostatic changes of HR and BP is not known. In the present study, we tested the hypothesis that there is diurnal variation of orthostatic HR and BP in patients with POTS and healthy controls.

Sleep disturbances and diminished quality of life in postural tachycardia syndrome.

Study Objectives: Patients with postural tachycardia syndrome (POTS) commonly complain of fatigue, unrefreshing sleep, daytime sleepiness, and diminished quality of life. This study's objective was to assess the sleep quality and health-related quality of life in patients with POTS as compared with healthy control subjects.

Methods: Patients with POTS (n = 44) and healthy control subjects (n = 46) completed a battery of questionnaires including Medical Outcomes Study (MOS) Sleep Survey and the Epworth Sleepiness Scale to assess sleep, fatigue visual analogue scale (VAS) to assess fatigue, and the RAND-36 and EuroQol (EQ-5D) surveys to assess health-related quality of life.