Instantaneous cross sectional flow velocity profiles from early mitral flow in 10 healthy men were constructed by time interpolation of the velocity data from each point in sequentially delayed two dimensional digital Doppler ultrasound maps. This interpolation allows correction of the artificially produced skewness of velocities across the flow sector caused by the time taken to scan the flow ...

In diabetic patients, vascular disease and autonomic dysfunction might compromise cerebral autoregulation and contribute to orthostatic intolerance. The aim of our study was to determine whether impaired cerebral autoregulation contributes to orthostatic intolerance during lower body negative pressure in diabetic patients. Thirteen patients with early-stage type 2 diabetes were studied. We cont...

The effects of loud sound on the microvasculature of the cochlea are not well characterized or understood. Morphological changes in the stria vascularis and changes in blood flow are known to occur during or following sound stimulation, however, the effects on cochlear blood flow appear to be complex. Studies have shown that noise exposure may produce increases in blood flow, decreases in blood...

We investigated the effects of vigorous exercise on blood flow in the macular vasculature. The velocity and density of entoptically viewed leukocytes in the paramacular retinal capillaries were measured with an Oculix BFS-2000 blue field simulator in 18 healthy adults first at rest, and then after 20 min of exercise. Exercise typically increased the density of leukocytes with more variable effe...

BACKGROUND AND PURPOSE The aim of our study was to evaluate by transcranial Doppler ultrasonography the dynamics of blood flow velocity changes in the middle cerebral artery during and after hypocapnia-induced vasoconstriction in untreated essential hypertensive patients. METHODS Sixteen hypertensive patients (10 men and six women, 29-62 years of age) and 10 healthy control subjects (six men ...

We noninvasively evaluated the effects of nicardipine on cerebral vascular responses to hypocapnia and blood flow velocity in the middle cerebral artery of 10 patients aged 17-60 (mean +/- SD 46.1 +/- 11.8) years. During fentanyl/diazepam/nitrous oxide anesthesia, mean blood flow velocity in the middle cerebral artery was measured and cerebral vascular reactivity to hypocapnia induced by hyperv...

AIM To study continuously cerebral blood flow velocity in the middle cerebral artery before, during, and after tube feeding in neonates. METHOD Cerebral blood flow velocity was measured in 14 neonates using a Doppler ultrasound device. Blood pressure, respiration, and oxygen saturation were monitored. RESULTS Mean blood flow velocity decreased from 37 cm/s before feeding to 33 cm/s (P < 0.0...