PURPOSE We aimed to determine the correlation between flow characteristics of the proximal pulmonary arteries and vena cava obtained by 3.0 T phase-contrast magnetic resonance imaging (MRI) and hemodynamic characteristics by right heart catheterization in patients with chronic thromboembolic pulmonary hypertension. MATERIALS AND METHODS Twenty consecutive patients with chronic thromboembolic ...

BACKGROUND The problems of patients with erectile dysfunction have been recognized, leading to the emergence of sildenafil, which has led to successful treatment in many cases. The purpose of this study is to examine the effect of sildenafil on the pulse wave velocity of patients with erectile dysfunction. METHODS Fifteen patients with erectile dysfunction were enrolled for this study. The br...

Instantaneous velocity of pulmonary artery blood was measured using a thin-film resistance anemometer mounted on a hypodermic needle. Studies were performed, at thoracotomy, in five dogs and five patients. Instantaneous blood velocity was recorded at several sites across die transverse axis of the main pulmonary artery to determine the shape of the velocity profile. We found the velocity profil...

Methods Vascular ejection efficiency (VEE) is proportional to the dimensionless ratio of aortic diameter to wavelength of the transmitted blood pulse. The wavelength of ejected blood is proportional to blood wave velocity divided by blood wave frequency measured using phase velocity mapping (PVM) applied to the ascending aorta. Left ventricular function and aortic PVM data were retrospectively ...

In cremaster muscle of pentobarbital-anesthetized rats, temporary occlusion of an arteriole increased red blood cell velocity (mean increase, 8.2 +/- 1.0 mm/sec from a control velocity of 7.9 +/- 0.7 mm/sec) in proximal parallel arteriolar branches (mean control diameter, 19.4 +/- 0.6 microns). Increases in flow velocity were consistently followed by proportional delayed (6-15 seconds) increase...

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...

AIMS/BACKGROUND While the retinal lesions of sickle cell retinopathy have been well documented, their pathogenesis remains unclear. The purpose of this study was (1) to compare macular blood flow velocity in patients with sickle cell disease and controls, and (2) to determine in sickle cell patients the relation between macular blood flow velocity and red blood cell density. METHODS Macular b...

The goal of this study was the development of a simple bedside test to assess cerebrovascular reserve capacity using transcranial Doppler sonography. We studied 33 normal persons at rest and after stimulation of cerebral blood flow with 1 g acetazolamide. Their mean +/- SD increase in blood flow velocity in 54 middle cerebral arteries 10 minutes after stimulation was 24.4 +/- 9.2 cm/sec. We tri...