Search results for "Vascular resistance"
showing 10 items of 130 documents
Pulmonary vascular resistance as a potential marker of reactive pulmonary hypertension reduction following sildenafil therapy in patients disqualifie…
2019
Purpose:We sought to determine the predictors of restoration of heart transplantation (HTx) candidacy in pa-tients with systolic heart failure (HF) and reactive fixed pulmonary hypertension (RFPH) defined as pulmonaryvascular resistance (PVR) > 2.5 Wood units (WU), transpulmonary gradient (TPG) > 12 mmHg or ≤2.5 WUwith systolic arterial pressure ≤85 mmHg during vasoreactivity test, following sildenafil therapy.Material and methods:Between2007and20181136patientswereevaluatedatourdepartmentascandidatesforHTx. Thirty-five of them, who presented with systolic HF and were not eligible for HTx due to RFPH, wereincluded in the study (31 men aged 55.1 ± 7.4 years). In all the patients sildenafil wa…
Effects of Fenoldopam on Intracranial Pressure and Hemodynamic Variables at Normal and Elevated Intracranial Pressure in Anesthetized Pigs
1994
Fenoldopam (FE), a dopamine DA1-receptor agonist, has been introduced for treatment of arterial hypertension and heart failure and for preservation of renal function. Vasodilators are generally assumed to affect all vascular beds including the cerebral circulation. We have evaluated effects of FE-induced (4 micrograms.kg-1.min-1) arterial hypotension on intracranial pressure (ICP) and intraocular pressure (IOP) under conditions of normal and increased intracranial elastance. ICP and IOP responses to hypertension were tested by infusion of angiotensin II (15 micrograms.kg-1.min-1), and the response to hypercapnia was tested by elimination and reintegration of soda lime canisters in the breat…
A model of stepwise isovolaemic blood exchange in anaesthetised, spontaneously breathing rats to evaluate the oxygen transport efficiency of artifici…
2000
Our research pursues the production of hypo-oncotic artificial oxygen carriers, based on artificial covalently cross-linked hyperpolymeric mammalian haemoglobins. To evaluate their in vivo efficiency in oxygen delivery to the tissue we developed a small animal model of stepwise isovolaemic blood exchange in anaesthetised, spontaneously breathing rats. With the aid of a two-way respiratory micro valve for small animals the overall oxygen uptake by the tissue of the animal can be determined. Measurements of oxygen contents in arterial and mixed venous blood and of some further blood parameters together with known oxygen-binding characteristics of artificial and native oxygen carriers, permits…
No improvement in perfusion and oxygenation of experimental tumors upon application of vasodilator drugs
2001
The oxygen deficiency seen in solid tumors is predominantly caused by an insufficient O2 supply as a result of inadequate tumor perfusion. The aim of this study was to analyze whether a number of vasodilator drugs might be suitable to increase tumor perfusion and consequently improve the oxygenation status of experimental tumors. Rats with s.c. DS-sarcomas were treated with either Na+-nitroprusside (7-25 microg x min(-1) x kg(-1) BW) or nifedipine (10 microg x min(-1) x kg(-1) BW). Red blood cell (RBC) flux was assessed continuously using laser-Doppler flowmetry and mean tumor pO2 was measured polarographically using O2-sensitive catheter electrodes. Systemic application of the vasodilator …
Inhaled Prostacyclin, Nitric Oxide, and Nitroprusside in Pulmonary Hypertension After Mitral Valve Replacement
2005
Abstract Objective: Pulmonary hypertension increases morbidity and mortality in patients undergoing heart surgery. Mitral valve stenosis is frequently associated with an increase in pulmonary vascular resistance (PVR). Cardiopulmonary bypass exacerbates pulmonary hypertension in patients undergoing cardiac surgery. The aim of this study was to compare the hemodynamic effects of inhaled prostacyclin and nitric oxide and the administration of i.v. nitroprusside during cardiac surgery with a clinical, pharmacodynamic dose-response, prospective, randomized, and double-blind study (Group A: inhaled prostacyclin; Group B: inhaled nitric oxide; Group C: nitroprusside). Materials and Methods: Fifty…
Ceramide inhibits Kv currents and contributes to TP-receptor-induced vasoconstriction in rat and human pulmonary arteries
2011
et al.
Color Doppler Hemodynamics of Giant Cell Arteritis
1994
Objectives: To determine quantitative and qualitative hemodynamic alterations within the ophthalmic, central retinal, and short posterior ciliary arteries in patients with giant cell arteritis (GCA) proved by biopsy specimen. Design, Patients, and Setting: A consecutive case series of patients with GCA referred to an urban eye hospital who were evaluated with color Doppler imaging that was used to analyze orbital blood flow velocities and vascular resistance in 22 consecutive patients with GCA compared with age and sex-matched controls. Results: Patients with GCA all demonstrated significantly reduced central retinal and short posterior ciliary arterial mean flow velocities as well as signi…
Effects of inhaled glaucine on pulmonary responses to antigen in sensitized guinea pigs.
2000
The alkaloid (S)-(+)-1,2,9,10-tetramethoxyaporphine (glaucine) is a phosphodiesterase 4 inhibitor with bronchodilator and anti-inflammatory activity in vitro. In this study, we examined the in vivo effects of glaucine on an animal model of asthma. In ovalbumin sensitized guinea pigs, inhaled glaucine (10 mg ml(-1), 3 min) inhibited the acute bronchoconstriction produced by aerosol antigen (antigen response was 256+/-42 and 95+/-14 cm H(2)O l(-1) s(-1) in control and glaucine-treated animals, respectively; P<0.05). Pretreatment with glaucine (10 mg ml(-1), 10 min inhalation, 30 min pre- and 3 h post-antigen exposure) markedly reduced airway hyperreactivity to histamine, eosinophil lung accum…
Relationship between kidney findings and systemic vascular damage in elderly hypertensive patients without overt cardiovascular disease
2017
Few studies have investigated the influence of age on the relationships between systemic vascular damage, kidney dysfunction, and intrarenal hemodynamic changes in patients with hypertension without overt cardiovascular disease. The authors enrolled 126 elderly patients with hypertension (aged ≥65 years) and 350 nonelderly patients with hypertension (aged <65 years). Carotid intima‐media thickness, renal resistive index, and aortic pulse wave velocity were performed in all patients. Elderly patients with hypertension had lower estimated glomerular filtration rates and higher albuminuria, renal resistive index, carotid intima‐media thickness, and aortic pulse wave velocity compared with none…
Prognostic Value of Pulmonary Vascular Resistance by Magnetic Resonance in Systolic Heart Failure
2016
Abstract Background: Pulmonary hypertension is associated with poor prognosis in heart failure. However, non-invasive diagnosis is still challenging in clinical practice. Objective: We sought to assess the prognostic utility of non-invasive estimation of pulmonary vascular resistances (PVR) by cardiovascular magnetic resonance to predict adverse cardiovascular outcomes in heart failure with reduced ejection fraction (HFrEF). Methods: Prospective registry of patients with left ventricular ejection fraction (LVEF) < 40% and recently admitted for decompensated heart failure during three years. PVRwere calculated based on right ventricular ejection fraction and average velocity of the pulmonary…