Search results for "reserve"

Bestimmung der myokardialen Perfusionsreserve bei KHK-Patienten mit der kontrastmittelverstärkten MRT: Ein Vergleich zwischen semiquantitativer und q…

2002

OBJECTIVE Comparison between two semiquantitative methods and a quantitative evaluation of myocardial blood flow (MBF) for assessment of myocardial perfusion reserve (MPR) in patients with CAD. MATERIAL AND METHODS 9 patients with coronary stenoses > 50 % were examined with an ECG-gated Saturation Recovery Turbo FLASH sequence by using Gd-DTPA as contrast agent (CA). The entive measurements were performed both during rest and hyperemia induced by adenosine. The up-slopes of the signal-time S(t) curves in the myocardium and left ventricular (LV) cavity were evaluated by a linear fit. MPR was calculated from the original up-slopes of the myocardial S(t) curves and from the up-slopes, which we…

Empagliflozin in heart failure with preserved ejection fraction: decoding its molecular mechanism of action using artificial intelligence

2021

Abstract   Rationale The use of sodium-glucose co-transporter 2 inhibitors (SGLT2i) to treat heart failure with preserved ejection fraction (HFpEF) is under investigation in ongoing clinical trials, but the exact mechanism of action is unclear. Here we aimed to use artificial intelligence (AI) to characterize the mechanism of action of empagliflozin in HFpEF at the molecular level. Methods We retrieved information regarding HFpEF pathophysiological motifs and differentially expressed genes/proteins, together with empagliflozin target information and bioflags, from specialized publicly available databases. Artificial neural networks and deep learning AI were used to model the molecular effec…

The Association Between Quantitative Flow Ratio and Intravascular Imaging-defined Vulnerable Plaque Characteristics in Patients With Stable Angina an…

2021

Background: This study aimed to examine whether quantitative flow ratio (QFR), an angiography-based computation of fractional flow reserve, was associated with intravascular imaging-defined vulnerable plaque features, such as thin cap fibroatheroma (TCFA) in patients with stable angina, and non-ST-segment elevation acute coronary syndrome.Methods: Patients undergoing optical coherence tomography (OCT) or intravascular ultrasound (IVUS) examinations were identified from two prospective studies and their interrogated vessels were assessed with QFR. Lesions in the OCT cohort were classified into tertiles: QFR-T1 (QFR ≤ 0.85), QFR-T2 (0.85 < QFR ≤ 0.93), and QFR-T3 (QFR > 0.93). L…

Prognostic impact of systolic blood pressure in acute heart failure with preserved ejection fraction in older patients

2021

Abstract Aims Recent guidelines recommend a systolic blood pressure (SBP) target below 130 mmHg in heart failure patients with preserved ejection fraction (HFpEF), whatever their age. We investigated whether this intensive SBP control was associated with better survival in very old adults hospitalized for acute HFpEF. Methods and results We conducted an observational study in an acute geriatric unit: all consecutive patients discharged from hospital for acute heart failure from 1 March 2019 to 29 February 2020 with a diagnosis of HFpEF were included. Re‐hospitalization and all‐cause mortality at 1 year were compared according to the mean SBP at discharge (patients with a mean SBP < 130 mmHg…

Myocardial blood flow quantification for evaluation of coronary artery disease by computed tomography

2017

During the last decade coronary computed tomography angiography (CTA) has become the preeminent non-invasive imaging modality to detect coronary artery disease (CAD) with high accuracy. However, CTA has a limited value in assessing the hemodynamic significance of a given stenosis due to a modest specificity and positive predictive value. In recent years, different CT techniques for detecting myocardial ischemia have emerged, such as CT-derived fractional flow reserve (FFR-CT), transluminal attenuation gradient (TAG), and myocardial CT perfusion (CTP) imaging. Myocardial CTP imaging can be performed with a single static scan during first pass of the contrast agent, with monoenergetic or dual…

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 &lt;50%, patients undergoing only 1 echocardiogram study, and those with a diagnosis of dilated, noncompa…

Clinical utility of cardiopulmonary exercise testing in patients with heart failure with preserved ejection fraction

2017

Left ventricular non-compaction cardiomyopathy in children: Is segmental fibrosis the cause of tissue Doppler alterations and of EF reduction?

2009

Noncompaction of the ventricular myocardium (LVNC) is a rare congenital cardiomyopathy resulting from an arrest in normal endomyocardial embryogenesis. In 2002 Jenni et al. [Jenni R, Wyss CA, Oechslin EN, Kaufmann PA. Isolated ventricular noncompaction is associated with coronary microcirculatory dysfunction. J Am Coll Cardiol 2002; 39:450-454.] reported a microvascular dysfunction in 12 patients affected by non compaction: areas of restricted myocardial perfusion have been documented by scintigraphy, suggesting a reduction of Coronary flow reserve. McMahon et al reported in a recent article a reduction of TD velocities in children with noncompaction of the left ventricle, compared with nor…

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…

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…