conclusions results suggest that these methods cannot be interchanged, and vvi showed significantly lower lv peak twist, peak twisting rate and peak untwisting rate. however, when lv twist and lv twisting rates were normalized to lv length, values were comparable for both imaging techniques. results twist degree was significantly lower in the vvi group than in the tdi group (p = 0.008, r = 0.56...

background: pulse wave velocity (pwv) is widely used for estimating the stiffness of an artery. v arious invasive and non-invasive methods have been developed to determine pwv over the years. in the present research , the non-invasive estimation of the pwv of large arteries was used as an index for arterial stiffness. methods: a dynamic model based on the navier-stokes equations coupled to elas...

purpose: to compare ophthalmic artery velocity in eyes with nonarteritic anterior ischemic optic neuropathy (naion) with that of normal fellow eyes. methods: in this case-control study, 20 patients with unilateral naion and disease onset less than 8 weeks, were enrolled. using color doppler imaging, mean, maximum systolic and end diastolic ophthalmic artery velocities were evaluated. the result...

background: to determine whether islamic fasting would change cerebral blood flow during ramadan. methods: the study group comprised 20 subjects (16 males and 4 females) on a regimen of 1 month food and water intake restriction, according to islamic fasting ritual. subjects were evaluated for cerebral bolo flow through a middle cerebral artery (mca) by means of transcranial doppler (tcd), the d...

introduction : cerebral autoregulation (ca) and mean cerebral blood flow velocity in males and females are still under controversy. the present study was scheduled to address the effect of sex on these parameters. materials and methods : the present study was interventional and performed on 30 healthy volunteers (15 males aging from 20-30 yrs and mean age of 23.9±3 years old and 15 females agin...

The aim of this paper is to study the effect of slip velocity and shape of stenosis on non-Newtonian flow of blood through a stenosed arterial segment. Blood is modeled as Bingham-Plastic fluid in a uniform circular tube with a radially non-symmetric stenosis. The problem is investigated by a joint effort of analytical and numerical techniques. The influence of stenosis shape parameter, slip ve...

doppler ultrasound can provide important information about vascular problems through the analysis of blood flow wave-form. the purpose of this study was obtaining the normal images of color doppler and estimation of blood flow velocity parameters of femoral artery in rabbits. left and right femoral arteries of 8 healthy adult new zealand rabbits were evaluated. color and spectral doppler images...

Introduction: Nitroglycerin is a fast-acting drug that rapidly dilates coronary arteries and thus increases blood flow to these vessels, and increases the blood flow through the lateral vessels to low blood areas. It also reduces both end diastolic pressure and volume of the left ventricular. However, the effect of nitroglycerin on the circulation hemodynamic is not known. Caro...