Search results for "Ventricle"

Rheumatoid arthritis affects left ventricular mass: Systematic review and meta-analysis.

2015

Abstract Background Cardiovascular disease represents one of the most important extra-articular causes of morbidity and mortality in patients with rheumatoid arthritis (RA). Evidences showed that several cardiac structures can be affected during the course of the disease as well as abnormalities of left ventricular diastolic filling. Contrasting data are available about left ventricular mass (LVM) involvement in patients asymptomatic for cardiovascular disease. The purpose of this systematic review and meta-analysis is to summarize the effects of RA on LVM in rheumatoid arthritis patients without cardiovascular disease. Methods A systematic research of the current case–control studies was c…

Left ventricular noncompaction presenting like a double-chambered left ventricle

2015

Echocardiography in assessing acute pulmonary hypertension due to pulmonary embolism.

1980

Eighteen patients with acute pulmonary embolism were studied with right heart catheterization and M mode echocardiography. No patient had evidence of preexisting cardiopulmonary disease; pulmonary embolism was documented with pulmonary angiography. The mean pulmonary arterial pressure correlated with the angiographic severity index of embolic obstruction (r = 0.61, p 2 , p 2 ) and in 5 patients with acute pulmonary embolism and a mean normal pulmonary arterial pressure (10.9 ± 0.4 mm/m 2 ). For all measurements the index size of the right pulmonary artery correlated with the mean pulmonary arterial pressure (r = 0.84, p

Quantitative contrast-enhanced myocardial perfusion magnetic resonance imaging: Simulation of bolus dispersion in constricted vessels

2009

Quantification of myocardial blood flow (MBF) by means of T 1 -weighted first-pass magnetic resonance imaging(MRI) requires knowledge of the arterial input function (AIF), which is usually estimated from the left ventricle (LV). Dispersion of the contrast agent bolus may occur between the LV and the tissue of interest, which leads to systematic underestimation of the MBF. The aim of this study was to simulate the dispersion along a simplified coronary artery with different stenoses. To analyze the dispersion in vessels with typical dimensions of coronary arteries, simulations were performed using the computational fluid dynamics approach. Simulations were accomplished on straight vessels wi…

RELEASE OF CATECHOLAMINES FROM THE HEART

1966

Publisher Summary This chapter discusses the release of catecholamines from the heart. The isolated heart of the rabbit with the sympathetic nervous supply from the right stellate ganglion intact was set up according to Hukovio and Muscholl. The ganglion was stimulated for 30 s at supramaximal voltage with rectangular impulses of 3–5 ms duration a frequency of 10 shocks/s. Each stimulation period was followed by a resting period of 30 s. In the rabbit, four doses of 50 mg/kg l-α-methyldopa decreased the noradrenaline concentration in auricles, right, and left ventricles by 38–60%. An equimolar amount of α-methyl noradrenaline was detected in the tissues. Reserpine and guanethidine in doses,…

Endo-neuro-sonography: anatomic aspects of the ventricles.

1997

To evaluate the usefulness of transendoscopic sonography, we have studied the use of a new sonographic probe of 6 F diameter in 11 fresh specimens. We achieved a precise imaging of well known anatomic structures and, moreover, obtained an additional dimension in endoscopy, since the sonographic probe adds a transverse scan to the endoscopic view, like a mini-CT at the tip of the probe. In this way, we also examined the guiding characteristics of this imaging technique, both in real time and on-line. Our results promise further interesting aspects of this technique in minimally invasive neurosurgery and suggest that further development and clinical experience seem to be justified.

Tetralogy of Fallot as a Model to Study Cardiac Progenitor Cell Migration and Differentiation During Heart Development

2009

Tetralogy of Fallot (ToF) has long been considered a congenital disorder that occurs due to environmental alterations during gestation. Recently, several mutated genes have been discovered that are thought to be responsible for the malformations observed in ToF. These genetic mutations, which are microdeletions, are sporadic and are frequently also present in trisomy 21 patients. The ToF malformations can be lethal, but for the last 50 years, surgical repairs that place an artificial patch to repair the four features of ToF have improved the survival of patients with ToF. However, 0.5% to 6% of patients who survive after surgical repair of ToF die of sudden cardiac death caused by ventricul…

Role of cardiac dyssynchrony and resynchronization therapy in functional mitral regurgitation

2016

Functional mitral regurgitation (FMR) is a common complication of left ventricle (LV) dysfunction and remodelling. Recently, it has been recognized as an independent prognostic factor in both ischaemic and non-ischaemic LV dysfunctions. In this review article, we discuss the mechanisms through which cardiac dyssynchrony is involved in FMR pathophysiologic cascade and how cardiac resynchronization therapy (CRT) can have therapeutic effects on FMR by reverting specific dyssynchrony pathways. We analyse recent clinical trials focusing on CRT impact on FMR in 'real-world' patients, the limits and future perspectives that could eventually generate new predictors of CRT response in terms of FMR r…

Focus on right ventricular outflow tract septal pacing

2013

SummaryExperimental and clinical studies have shown that right ventricular apical pacing may result in long-term deleterious effects on account of its negative impact on left ventricular remodeling through desynchronization. This risk appears more pronounced in patients with even moderate left ventricular dysfunction and generally occurs after at least 1 year of pacing. As right ventricular apical pacing may be associated with the development of organic mitral insufficiency, other sites that allow for more physiological stimulation, such as right ventricular outflow tract septal pacing, have been developed, with good feasibility and reproducibility. However, the prospective randomized studi…

Impact of Aortic Stenosis on Myofiber Stress: Translational Application of Left Ventricle-Aortic Coupling Simulation

2020

The severity of aortic stenosis (AS) has traditionally been graded by measuring hemodynamic parameters of transvalvular pressure gradient, ejection jet velocity, or estimating valve orifice area. Recent research has highlighted limitations of these criteria at effectively grading AS in presence of left ventricle (LV) dysfunction. We hypothesized that simulations coupling the aorta and LV could provide meaningful insight into myocardial biomechanical derangements that accompany AS. A realistic finite element model of the human heart with a coupled lumped-parameter circulatory system was used to simulate AS. Finite element analysis was performed with Abaqus FEA. An anisotropic hyperelastic mo…