منابع مشابه
Head-up tilt testing in children.
The article by Kouakam et al. in issue 22/17 is a prospective observational study of syncope recurrence in 101 children (mean age 12·6 3; range 7–18 years) undergoing head-up tilt testing for investigation of recurrent unexplained syncope or presyncope. Data are presented for patients recruited between 1990 and 1998, and followed-up for an average of 4 years. Head-up tilt was initially positive...
متن کاملPatient-specific modelling of head-up tilt.
Short-term cardiovascular responses to head-up tilt (HUT) involve complex cardiovascular regulation in order to maintain blood pressure at homoeostatic levels. This manuscript presents a patient-specific model that uses heart rate as an input to fit the dynamic changes in arterial blood pressure data during HUT. The model contains five compartments representing arteries and veins in the upper a...
متن کاملLeg intravenous pressure during head-up tilt.
Leg vascular resistance is calculated as the arterial-venous pressure gradient divided by blood flow. During orthostatic challenges it is assumed that the hydrostatic pressure contributes equally to leg arterial, as well as to leg venous pressure. Because of venous valves, one may question whether, during orthostatic challenges, a continuous hydrostatic column is formed and if leg venous pressu...
متن کاملPrior head-down tilt does not impair the cerebrovascular response to head-up tilt.
The hypothesis that cerebrovascular autoregulation was not impaired during head-up tilt (HUT) that followed brief exposures to varying degrees of prior head-down tilt (HDT) was tested in 10 healthy young men and women. Cerebral mean flow velocity (MFV) and cardiovascular responses were measured in transitions to a 60-s period of 75° HUT that followed supine rest (control) or 15 s HDT at -10°, -...
متن کاملEffects of lower body positive pressure on muscle sympathetic nerve activity response to head-up tilt.
The present study was performed to test the hypothesis that application of lower body positive pressure (LBPP) during orthostasis would reduce the baroreflex-mediated enhancement in sympathetic activity in humans. Eight healthy young men were exposed to a 70 degrees head-up tilt (HUT) on application of 30 mmHg LBPP. Muscle sympathetic nerve activity (MSNA) was microneurographically recorded fro...
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ژورنال
عنوان ژورنال: Journal of the American College of Cardiology
سال: 2000
ISSN: 0735-1097
DOI: 10.1016/s0735-1097(99)00500-8