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Sustained physical exercise depends on delivery of oxygenated blood to exercising muscle. At least among healthy individuals, bulk transport of blood is tightly matched to metabolic demand, such that cardiac output increases by ∼6 L/min for every 1 L/min increase in oxygen uptake. Multiple factors contribute to the regulation of cardiac output, including central command, the exercise pressor reflex (EPR) and arterial baroreceptors. Pulmonary arterial and left ventricular pressures increase in proportion to the rise in cardiac output and exercise intensity. The right ventricle augments contractility to maintain ventricular-arterial (VA) coupling and lusitropy to facilitate venous return. Among patients with heart failure (HF), however, the ability to deliver blood to exercising muscle is compromised as a result of multiple abnormalities impacting EPR, ventricular contractility, haemodynamics and VA coupling. The purpose of this review is to provide an overview of the factors limiting exercise capacity and cardiac output among patients with HF compared to what is known about normal physiology among healthy individuals.
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http://dx.doi.org/10.1113/EP091505 | DOI Listing |
Clin Interv Aging
September 2025
Department of Nephrology, Huadong Hospital, Fudan University, Shanghai, People's Republic of China.
Objective: This study evaluates cardiac function in older adults with T2DM and preserved LVEF using two-dimensional speckle-tracking echocardiography to explore the risk factors associated with subclinical left ventricular systolic dysfunction (GLS <18%) in this population.
Methods: All patients (n = 87, aged 60 years and above) and controls (n = 20) underwent clinical assessment and echocardiography, including GLS assessment.
Results: Univariate analysis identified gender (OR 3.
Rev Cardiovasc Med
August 2025
Department of Neurosciences, Institute of Human Anatomy, University of Padova, 35121 Padova, Italy.
Harlequin syndrome, also known as differential hypoxia (DH) or North-South syndrome, is a serious complication of femoro-femoral venoarterial extracorporeal membrane oxygenation (V-A ECMO). Moreover, Harlequin syndrome is caused by competing flows between the retrograde oxygenated ECMO output and the anterograde ejection of poorly oxygenated blood from the native heart. In the setting of impaired pulmonary gas exchange, the addition of an Impella device (ECPELLA configuration), although beneficial for ventricular unloading and hemodynamic support, may further exacerbate this competition and precipitate DH.
View Article and Find Full Text PDFDrug Des Devel Ther
September 2025
Department of Anesthesiology, Women's Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang Province, People's Republic of China.
Purpose: Spinal anesthesia-induced hypotension can cause detrimental effects on both the mother and the fetus, and it remains a significant concern in obstetric anesthesia. The use of vasopressors is considered the most reliable and effective approach. Previous studies have shown that norepinephrine appears to be superior to phenylephrine in maintaining maternal heart rate and cardiac output.
View Article and Find Full Text PDFAnn Biomed Eng
September 2025
Department of Mechanical Engineering, Koc University, Rumeli Feneri Campus, Sarıyer, 34450, Istanbul, Turkey.
Purpose: The design and development of ventricular assist devices have heavily relied on computational tools, particularly computational fluid dynamics (CFD), since the early 2000s. However, traditional CFD-based optimization requires costly trial-and-error approaches involving multiple design cycles. This study aims to propose a more efficient VAD design and optimization framework that overcomes these limitations.
View Article and Find Full Text PDFPediatr Res
September 2025
Laboratory of Fetal Neuroprogramming, Institute of Health Sciences, University of O'Higgins, Rancagua, Chile.
Background: Fetal growth restriction (FGR) causes an adaptive redistribution of the cardiac output towards sustained cerebral vasodilation. However, the consequences of FGR and cerebral vasodilatation due to fetal hypoxia on the blood-brain barrier (BBB) are still poorly studied. This study assesses BBB permeability in the neonatal cortex of pups gestated under intrauterine hypobaric hypoxia.
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