Search results for "HEMODYNAMICS"

Role of Hemodynamic Forces in Unruptured Intracranial Aneurysms: An Overview of a Complex Scenario.

2017

Background An understanding of the natural history of unruptured intracranial aneurysms (IAs) has always played a critical role in presurgical or endovascular planning, to avoid possibly fatal events. Size, shape, morphology, and location are known risk factors for rupture of an aneurysm, but morphologic parameters alone may not be sufficient to perform proper rupture risk stratification. Methods We performed a systematic PubMed search and focused on hemodynamics forces that may influence aneurysmal initiation, growth, and rupture. Results We included 223 studies describing several hemodynamic parameters related to aneurysm natural history. In these studies, different modalities of aneurysm…

Noninvasive assessment of baroreflex sensitivity in post-MI patients by an open loop parametric model of RR-systolic pressure interactions

2003

Noninvasive evaluation of baroreflex sensitivity is considered an important goal for diagnosis and prognosis in post-MI patients. Methodological approach and physiological measure conditions may be the main causes for the differences found with respect to the standard Phenylephrine test. In this study, three linear parametric models, describing variability and mutual interactions of RR interval and systolic arterial pressure (SAP), were compared in relation to their ability to quantify baroreflex gain, using the Phenylephrine test index (Phe/sub BRS/) as reference. By monovariate autoregressive (AR) model, bivariate AR model and open loop ARXAR model, specific gain indexes (/spl alpha//sub …

[Compensation mechanisms of perioperative anemia].

2002

Neprilysin inhibition, endorphin dynamics, and early symptomatic improvement in heart failure: a pilot study

2020

Altres ajuts: This work was supported in part by Fundació La Marató de TV3 (201516-10, 201502-30), Societat Catalana de Cardiologia, "la Caixa" Banking Foundation. Altres ajuts: PERIS/SLT002-16-00234 Sacubitril/valsartan is a first-in-class angiotensin receptor-neprilysin inhibitor developed for the treatment of heart failure with reduced ejection fraction. Its benefits are achieved through the inhibition of neprilysin (NEP) and the specific blockade of the angiotensin receptor AT1. The many peptides metabolized by NEP suggest multifaceted potential consequences of its inhibition. We sought to evaluate the short-term changes in serum endorphin (EP) values and their relation with patients' p…

Coarctation of the Aorta: Quantitative Analysis by Transesophageal Echocardiography

1987

Summary Transesophageal echocardiography and standard two-dimensional echocardiography were performed in 15 patients with suspected coarctation of the aorta. Aortic diameters and crosssectional areas were determined by means of TEE and compared with clinical findings and catheterization data. The isthmus of the aorta could be imaged in all patients using TEE, but in only seven patients using standard suprasternal echocardiography. Compared with controls, aortic diameters were narrowed in 9 of 15 patients, and cross-sectional areas were reduced in 13 of 15. There was a satisfactory correlation between TEE data and angiographic and hemodynamic data. TEE is a promising method of a diagnosing a…

Computational fluid dynamics simulation to evaluate aortic coarctation gradient with contrast-enhanced CT

2014

Coarctation of aorta (CoA) is a narrowing of the aorta leading to a pressure gradient (Delta P) across the coarctation, increased afterload and reduced peripheral perfusion pressures. Indication to invasive treatment is based on values of maximal (systolic) trans-coarctation Delta P. A computational fluid dynamic (CFD) approach is herein presented for the non-invasive haemodynamic assessment of Delta P across CoA. Patient-specific CFD simulations were created from contrast-enhanced computed tomography (CT) and appropriate flow boundary conditions. Computed Delta P was validated with invasive intravascular trans-CoA pressure measurements. Haemodynamic indices, including pressure loss coeffic…

Epidemiología de la transfusión sanguínea en los Servicios de Medicina Intensiva en España: «Transfusion Day»

2022

Objective To describe the transfusion practice in the ICUs in Spain, according to national and international recommendations (guidelines).DesignProspective, cross-sectional, multi-centre study.ScopeData collection was carried out by means of a questionnaire sent electronically to the Heads of Service of 111 ICUs in Spain.Participants1,448 patients were included, aged 61.8 (SD 15.7) years, 66.2% male, with an SOFA of 4.7 ± 3.8 and average stay of 10.62 ± 17.49 days.VariablesDemographic and clinical variables of the patients were collected, as well as variables related to the transfusion act.ResultsOf the 1,448 patients, 9.9% received al least one transfusion of any blood product, 3.7% fresh …

Simulation of left ventricular outflow tract (LVOT) obstruction in transcatheter mitral valve-in-ring replacement.

2020

Left ventricular outflow tract (LVOT) obstruction is a feared complication of transcatheter mitral valve replacement (TMVR). This procedure leads to an elongation of LVOT in the left ventricle (namely, the neoLVOT), ultimately portending hemodynamic impairment and death. This study sought to understand the biomechanical implications of LVOT obstruction in two patients who underwent TMVR as an "off-label" application of the Edwards SAPIEN 3 (S3) Ultra transcatheter heart valve (THV). A computational framework of TMVR was developed to assess the neoLVOT area and quantify the sub-aortic flow structure. We observed that the annuloplasty ring serves as the key anchor zone of S3 Ultra THV. A good…

A Nonlinear Circulatory Model for Artificial Heart Studies

1983

Animals with total artificial heart replacement (TAH) have survived for up to 9 months with manually controlled driving systems. A certain physiological control is provided by the animals intact peripheral regulation resulting in pathological venous hemodynamics, expressing the needs for a technical automatic control system, replacing the natural sympathetic stimulation and Starlings Law of the heart. A nonlinear dynamic mathematical model of the human cardiovascular system (CVSM) containing the systemic and pulmonary components was outlined and verified, which is employable to analyse the hemodynamic behaviour under normal and abnormal states. By modifying this model, assuming that cardiac…

Standardized Hemorrhagic Shock Induction Guided by Cerebral Oximetry and Extended Hemodynamic Monitoring in Pigs.

2019

Hemorrhagic shock ranks among the main reasons for severe injury-related death. The loss of circulatory volume and oxygen carriers can lead to an insufficient oxygen supply and irreversible organ failure. The brain exerts only limited compensation capacities and is particularly at high risk of severe hypoxic damage.This article demonstrates the reproducible induction of life-threatening hemorrhagic shock in a porcine model by means of calculated blood withdrawal. We titrate shock induction guided by near-infrared spectroscopy and extended hemodynamic monitoring to display systemic circulatory failure, as well as cerebral microcirculatory oxygen depletion. In comparison to similar models tha…