Search results for "Ventricular Function"
showing 10 items of 237 documents
Assessment of the cardiostimulant action of propionyl-L-carnitine on chronically volume-overloaded rat hearts.
1993
Chronic volume overload was induced in young rats of Wistar strain by surgical opening of the aorto-caval fistula. Three months later, during in vitro perfusion with exogenous palmitate, left ventricular function and energy turnover (QO2) of hypertrophied hearts were severely depressed. This seemed to be related to impaired long-chain fatty acid utilization, as reflected by decreased 14CO2 production from U-14C-palmitate and decreased tissue levels of L-carnitine. Another group of rats exposed to chronic volume overload was pretreated for 2 weeks before sacrifice with propionyl-L-carnitine (250 mg/kg/day), and the hearts were perfused with 1.2 mM palmitate and 10 mM propionyl-L-carnitine. I…
Prospective Comparison on Cardiac Iron and Liver Iron by MR In Thalassemia Major Patients Treated with Combination Deferipron–Desferrioxamine Versus …
2010
Abstract Abstract 5164 Introduction: Using T2* MR a randomised placebo controlled study from Sardinia demonstrated combination therapy with deferiprone and desferrioxamine (DFP+DFO) significantly more effective than DFO in improving myocardial iron. One non-randomised study from Sardinia and one observational study from Greece seem to confirm for DFP+DFO therapy the most rapid clearance of cardiac iron. No data are available in literature about prospective comparisons on cardiac iron and function and liver iron in TM patients treated with DFP+DFO versus DFP and DFO in monotherapy. The aim of this multi-centre study was to assess prospectively in a large clinical setting the efficacy of the …
Cardiovascular imaging in the diagnosis and monitoring of cardiotoxicity: cardiovascular magnetic resonance and nuclear cardiology
2016
Chemotherapy-induced cardiotoxicity (CTX) is a determining factor for the quality of life and mortality of patients administered potentially cardiotoxic drugs and in long-term cancer survivors. Therefore, prevention and early detection of CTX are highly desirable, as is the exploration of alternative therapeutic strategies and/or the proposal of potentially cardioprotective treatments. In recent years, cardiovascular imaging has acquired a pivotal role in this setting. Although echocardiography remains the diagnostic method most used to monitor cancer patients, the need for more reliable, reproducible and accurate detection of early chemotherapy-induced CTX has encouraged the introduction o…
Heart failure with preserved ejection fraction infrequently evolves toward a reduced phenotype in long-term survivors: a long-term prospective longit…
2019
Background: Long-term trajectories of left ventricular ejection fraction (LVEF) in heart failure (HF) patients with preserved EF (HFpEF) remain unclear. Our objective was to assess long-term longitudinal trajectories in consecutive HFpEF patients and the prognostic impact of LVEF dynamic changes over time. Methods and Results: Consecutive ambulatory HFpEF patients admitted to a multidisciplinary HF Unit were prospectively evaluated by 2-dimensional echocardiography at baseline and at 1, 3, 5, 7, 9, and 11 years of follow-up. Exclusion criteria were patients having a previous known LVEF <50%, patients undergoing only 1 echocardiogram study, and those with a diagnosis of dilated, noncompa…
Reliability and Accuracy of Echocardiography for Follow-up Studies after Intervention
1987
By two-dimensional echocardiography limitations of M-mode echocardiography have been eliminated. As a direct and noninvasive method two-dimensional echocardiography seems to be an ideal method for analysis of left ventricular function in follow-up studies. In relation to other methods there are no limitations concerning x-ray exposure, physicians and patients safety. Before different studies can be discussed, reliability and accuracy of two-dimensional echocardiography have to be evaluated. Beat-to-beat, day-to-day, intra- and interobserver variability will be discussed, followed by description of follow-up studies after intervention.
Physical therapy in heart failure with preserved ejection fraction: A systematic review.
2014
About 50% of patients with heart failure (HF) have preserved ejection fraction (HFpEF) which is especially common in elderly people with highly prevalent co-morbid conditions. HFpEF is usually defined as an ejection fraction equal to or greater than 50%, although some studies have used a limit as low as 40%. The prevalence of this syndrome is expected to increase over the next decades. The associated impact on mortality and hospital readmissions has made of this entity a major public health issue. Despite the fact that mortality and re-hospitalisation rates of HFpEF are similar to the syndrome of HF with reduced ejection fraction (HFrEF), currently there is no available evidence-based thera…
[Effect of flecainide on longitudinal and transverse conduction velocities in ventricular myocardium. An experimental study].
2007
It is known that the effect of flecainide on longitudinal and transverse ventricular conduction velocities depends on the coupling interval. If this is so, whether the longitudinal or transverse direction is predominantly affected could depend on the magnitude of the coupling interval. In order to investigate this hypothesis, we studied the effect of flecainide, 1 micromol/L, on conduction velocities in excised heart preparations from 11 rabbits using a basal cycle length of 250 ms and inserting two extrastimuli at a decreasing coupling interval. Flecainide significantly reduced both conduction velocities. However, the effect increased as the coupling interval decreased for only the longitu…
Tetrodotoxin slightly shortens action potential duration in ventricular but not in atrial heart muscle.
1988
Tetrodotoxin (TTX), at concentrations significantly decreasing maximal upstroke velocity (dV/dtmax) of the action potential, exerted variable effects on action potential duration (APD) in different myocardial preparations. APD was virtually unchanged by tetrodotoxin in the guinea pig atrium, but slightly shortened in the guinea pig ventricle at maximally effective concentrations. In the human ventricle, both dV/dtmax and APD were reduced in the same concentration range of TTX. These results suggest that a TTX-sensitive sodium current significantly contributes to the repolarization phase of the action potential in ventricular but not in atrial heart muscle.
Serum uric acid and outcomes in patients with chronic heart failure through the whole spectrum of ejection fraction phenotypes: Analysis of the ESC-E…
2021
Background: Retrospective analyses of clinical trials indicate that elevated serum uric acid (sUA) predicts poor outcome in heart failure (HF). Uric acid can contribute to inflammation and microvascular dysfunction, which may differently affect different left ventricular ejection fraction (LVEF) phenotypes. However, role of sUA across LVEF phenotypes is unknown. Objectives: We investigated sUA association with outcome in a prospective cohort of HF patients stratified according to LVEF. Methods: Through the Heart Failure Long-Term Registry of the European Society of Cardiology (ESC-EORP-HFLT), 4,438 outpatients were identified and classified into: reduced (= 50% HFpEF) LVEF. Endpoints were t…
Quantification of myocardial blood flow and blood flow reserve in the presence of arterial dispersion: A simulation study
2002
Myocardial blood flow (MBF) can be quantified using dynamic T1-weighted MRI of diffusible tracers and a mathematical model of underlying vasculature. Quantification of MBF by means of T1- weighted MRI requires knowledge of the arterial input function (AIF). The AIF can be estimated from the left ventricular (LV) cavity. However, dispersion may occur between the LV and the tissue of interest because of the laminar blood flow profiles, branching of venules, and because of stenosis. To evaluate the influence of dispersion on the results of MBF quantification, a simulation study was performed. The dispersion was described as a convolution of the AIF with an exponential residue function. Synthet…