As much as 50% of cardiac output can be distributed to the skin in the hyperthermic human, and therefore the control of cutaneous vascular conductance (CVC) becomes critical for the maintenance of blood pressure. Little is known regarding the magnitude of cutaneous vasoconstriction in profoundly hypotensive individuals while heat stressed. This project investigated the hypothesis that leading u...

The head-upright tilt-table (HUT) test is used primarily for the investigation of orthostatic symptoms. Although this test is frequently the gold standard for the evaluation of neurocardiogenic syncope, dysautonomia and postural orthostatic tachycardia syndrome, there is a debate over its diagnostic value and method. The authors review the physiologic basis of the HUT test, the method, patterns...

Orthostatic dizziness is feeling dizzy or lightheaded when standing up. Hemodynamic orthostatic can be caused by autonomic dysfunction such as hypotension postural tachycardia syndrome. The interpretation of the function test results in patients with crucial for diagnosing and managing underlying condition. head-up tilt Valsalva tests are especially important evaluating adrenergic hemodynamic d...

Objective. The aim of this study was to identify patients with Parkinson's disease who showed loss or decrease of nocturnal blood pressure fall (nondipper patients) as a marker of autonomic dysfunction. Presence or absence of orthostatic hypotension was considered to investigate whether alterations in circadian blood pressure pattern are associated with posture-related dysregulation of blood pr...

PURPOSE Orthostatic intolerance is more prevalent in women. The purpose of this investigation was to evaluate the physiological responses of orthostatic tolerant and intolerant females to progressive lower body negative pressure (LBNP) and to identify predictors of orthostatic tolerance. METHODS Following baseline measurements, eleven healthy, moderately active women (mean age 24 ± 3 yr) unde...

BACKGROUND Children presenting to the Pediatric Emergency Department (PED) with fever often describe symptoms such as lightheadedness, dizziness, fatigue, and weakness, and may appear pale. They may also present with a chief complaint of syncope. Such symptoms may result from orthostatic hypotension. OBJECTIVE To determine whether children with an acute febrile illness have a higher incidence...

The clinical presentation of autonomic failure is orthostatic hypotension. Severely affected patients require pharmacological treatment to prevent presyncopal symptoms or frank syncope. We previously reported in a proof of concept study that pediatric doses of the norepinephrine transporter blockade, atomoxetine, increases blood pressure in autonomic failure patients with residual sympathetic a...