Venous denervation and increased venous pooling may contribute to symptoms of orthostatic intolerance. We examined venous compliance in the calf and forearm in 11 orthostatic-intolerant patients and 15 age-matched controls over a range of pressures, during basal conditions and sympathetic excitation. Occlusion cuffs placed around the upper arm and thigh were inflated to 60 mmHg and deflated to ...

Methods We reviewed the records of 138 patients with primary systemic amyloidosis seen at the Mayo Clinic from 1935 through 1964. In all instances, the presence of amyloidosis was proved by tissue biopsy or postmortem examination. The criteria for the diagnosis of orthostatic hypotension included a decrease in the standing blood pressure from the recumbent blood pressure of 30 mm Hg systolic an...

BACKGROUND In this report, we provide the first normative reference data and prevalence estimates of impaired orthostatic blood pressure (BP) stabilization, initial orthostatic hypotension, and orthostatic hypotension based on beat-to-beat blood pressure methods in a population-representative sample. METHODS AND RESULTS Participants were recruited from a nationally representative cohort study...

Individuals with spinal cord injury (SCI) above the T6 spinal segment suffer from orthostatic intolerance. How cerebral blood flow (CBF) responds to orthostatic challenges in SCI is poorly understood. Furthermore, it is unclear how interventions meant to improve orthostatic tolerance in SCI influence CBF. This study aimed to examine 1) the acute regional CBF responses to rapid changes in blood ...

The relation of orthostatic blood pressure decrease, or increase, with occurrence of ischemic stroke subtypes has not been examined. We investigated the association of orthostatic blood pressure change (within 2 minutes after supine to standing) obtained at baseline (1987 to 1989) in the Atherosclerosis Risk in Communities Study with incidence of ischemic stroke subtypes through 2007. Among 12 ...

Interest in the association between serum 25-hydroxyvitamin D (25OHD) and blood pressure has increased because recent research showed a close relationship between them, but there is still little information on the possible association between 25OHD and orthostatic hypotension. The aim of this study was to explore the relationship of 25OHD levels with any presence of orthostatic hypotension in a...

Orthostatic challenge produced by upright posture may lead to syncope if the cardiovascular system is unable to maintain adequate brain perfusion. This review outlines orthostatic intolerance related to the aging process, long-term bedrest confinement, drugs, and disease. Aging-associated illness or injury due to falls often leads to hospitalization. Older patients spend up to 83% of hospital a...

Although orthostatic hypotension is a common clinical syndrome after spaceflight and its ground-based simulation model, 6 degrees head-down bed rest (HDBR), the pathophysiology remains unclear. The authors' hypothesis that a decrease in sympathetic nerve activity is the major pathophysiology underlying orthostatic hypotension after HDBR was tested in a study involving 14-day HDBR in 22 healthy ...