Postural tachycardia syndrome (POTS) is a chronic syndrome in which the heart beats too quickly when standing. POTS primarily affects young women. People with POTS also experience symptoms such as feeling faint, fatigue, nausea, and mental clouding or "brain fog." “Brain fog” is one of the most bothersome symptoms of POTS and it is unknown why people with POTS experience this symptom. Some studies have shown that POTS patients have problems with attention, memory and executive function (ability to plan, organize information, and adapt to changes) while seated and when upright. In this study, we will evaluate how brain function during mental tasks is affected in people with POTS compared to healthy volunteers. All volunteers will complete mental tasks while lying down and standing. If eligible, we will measure brain activity using functional magnetic resonance imaging (fMRI).The findings from this study will increase our understanding of the mental complaints in people with POTS, to hopefully help with development of new treatments.

There will be three in person visits for this study. At the screening visit, participants will undergo a detailed medical history and physical examination and then will complete a mental test while lying down and standing. If eligible based on the results of the mental test, participants will undergo a pregnancy test if female and of childbearing potential, measurements of blood pressure and heart rate and blood draws while lying down and standing up, and a test to determine if they can tolerate being in a lower body negative pressure (LBNP) device that distributes more blood to the legs to mimic standing. If eligible based on the results of the screening visit, participants will be asked to complete an online questionnaire and two study visits that are separated by at least one week. At these study visits, they will perform a mental test in a magnetic resonance imaging (MRI) scanner. The LBNP device will also be used while in the MRI scanner to distribute more blood to the legs to mimic standing.

$25 per hour; additional $25 for completion of online questionnaire