Overnight Trials to Compare the Effects of Controlled Heat Stress Versus Sham Control on Nocturnal Supine Hypertension in Autonomic Failure Patients
Vanderbilt University Medical Center
Summary
Patients with autonomic failure are characterized by disabling orthostatic hypotension (low blood pressure on standing), and at least half of them also have high blood pressure while lying down (supine hypertension). Exposure to heat, such as in hot environments, often worsens their orthostatic hypotension. The causes of this are not fully understood. The purpose of this study is to evaluate whether applying local heat over the abdomen of patients with autonomic failure and supine hypertension during the night would decrease their nocturnal high blood pressure while lying down. This will help us better understand the mechanisms underlying this phenomenon, and may be of use in the treatment of supine hypertension.
Description
Primary autonomic failure is a neurodegenerative condition characterized by loss of efferent sympathetic function and severe baroreflex impairment. The clinical hallmark of autonomic failure is disabling orthostatic hypotension, but at least half of patients are also hypertensive while lying down. This supine hypertension can be severe and associated with end-organ damage and worsening of orthostatic hypotension due to increased pressure natriuresis. It also complicates the management of these patients by limiting the use of daytime pressor agents for the treatment of orthostatic hypotension.…
Eligibility
- Age range
- 18–80 years
- Sex
- All
- Healthy volunteers
- No
Inclusion Criteria: * Male and female patients, between 18-80 yrs., with primary autonomic failure (Parkinson Disease, Multiple System Atrophy, and Pure Autonomic Failure) and supine hypertension. Supine hypertension will be defined as SBP≥150 mmHg. * Patients able and willing to provide informed consent. Exclusion Criteria: * Pregnancy * Significant cardiac, renal or hepatic illness, or with contraindications to administration of pressor agents or with other factors, which in the investigator's opinion would prevent the subject from completing the protocol including clinically significant…
Interventions
- OtherHeating pad
Heat stress applied on the trunk for up to 8 hours
- OtherSham control
heating pad turned off applied on the trunk for up to 8 hours
Location
- Autonomic Dysfunction Center/ Vanderbilt University Medical CenterNashville, Tennessee