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cardiac output exercise

Domenico Acanfora, Pietro Scicchitano, Gerardo Casucci, Bernardo Lanzillo, Nicola Capuano, Giuseppe Furgi, Chiara Acanfora, Marialaura Longobardi, Raffaele Antonelli Incalzi, Giuseppe Piscosquito, Marco Matteo Ciccone
BACKGROUND: The aim of this study was to evaluate the effect of exercise training on cardiac function in heart failure (HF) patients recently suffering from acute decompensation. Radionuclide ambulatory ventricular function monitoring (VEST) was used to detect variations in cardiac hemodynamics during training period. METHODS: This was a monocentric, randomized, controlled trial. We enrolled 72 HF patients [left ventricle ejection fraction (LVEF) <40%] within two weeks after acute cardiogenic pulmonary edema: 40 in the elderly group, 32 in the middle-aged group...
October 11, 2016: International Journal of Cardiology
Martin J MacInnis, Martin J Gibala
Interval exercise typically involves repeated bouts of relatively intense exercise interspersed by short periods of recovery. A common classification scheme subdivides this method into high-intensity interval training (HIIT; 'near maximal' efforts) and sprint interval training (SIT; 'supramaximal' efforts). Both forms of interval training induce the classic physiological adaptations characteristic of moderate-intensity continuous training (MICT) such as increased aerobic capacity (VO2max ) and mitochondrial content...
October 17, 2016: Journal of Physiology
Marie Maagaard, Johan Heiberg
Patients with pectus excavatum (PE) often describe improvements in exercise stamina following corrective surgery. Studies have investigated the surgical effect on physiological parameters; still, no consensus has yet been reached. Therefore, the aim of this literature review was to describe the cardiac outcome after surgical correction, both at rest and during exercise. In February 2016, a detailed search of the databases PubMed, Medline, and EMBASE was performed. We assessed clinical studies that described cardiac outcomes both before and after surgical correction of PE...
September 2016: Annals of Cardiothoracic Surgery
Nathalie Thorin-Trescases, Doug Hayami, Carol Yu, Xiaoyan Luo, Albert Nguyen, Jean-François Larouche, Julie Lalongé, Christine Henri, André Arsenault, Mathieu Gayda, Martin Juneau, Jean Lambert, Eric Thorin, Anil Nigam
Pro-inflammatory angiopoietin-like 2 (angptl2) promotes endothelial dysfunction in mice and circulating angptl2 is higher in patients with cardiovascular diseases. We previously reported that a single bout of physical exercise was able to reduce angptl2 levels in coronary patients. We hypothesized that chronic exercise would reduce angptl2 in patients with post-acute coronary syndrome (ACS) and endothelial dysfunction. Post-ACS patients (n = 40, 10 women) were enrolled in a 3-month exercise-based prevention program...
2016: PloS One
Valérie Julian, David Thivel, Bruno Pereira, Frédéric Costes, Ruddy Richard, Martine Duclos
OBJECTIVE: The effects of a training program (TP) on muscle microvascularization during exercise remained to be explored in adolescents with obesity. We hypothesized that a TP would lead to better microvascular adaptations to exercise in skeletal muscle. METHODS: 15 inactive adolescents followed a 12-week TP where both peripheral (muscular microvascularization) and central (cardiac) adaptations to exercise (40 min exercise set at 70% V̇O2peak) were assessed before and after intervention...
October 4, 2016: Obesity Facts
P-M Leprêtre, M Ghannem, S Delanaud, T Porcher, A Barnabé, L Gaillard, N Jaunet, T Weissland
: Exercise prescription was generally based on the determination of ventilatory thresholds (VT1, VT2) during cardiopulmonary exercise testing (CPX). Changes in surface electromyographic activity (EMGth1, EMGth2) were also related to VT1 and VT2 in healthy subjects. OBJECTIVE: To observe the occurrence of EMGth1 and EMGth2 and whether these events accompany VT1 and VT2 during CPX in cardiac patients (CP). METHOD: Thirty-four CP (62.1±7.3years, 172...
September 30, 2016: Annales de Cardiologie et D'angéiologie
Stéphane Doutreleau, Irina Enache, Cristina Pistea, Fabrice Favret, Evelyne Lonsdorfer, Stéphane Dufour, Anne Charloux
We measured the effects of adding CO2 to an inhaled hypoxic gas mixture on cardio-respiratory parameters during maximal exercise. Eight young males performed four incremental maximal exercise tests on cycle under ambient air, hypoxia (FIO2 0.125), inhaled CO2 (FICO2 0.045), and combination of hypoxia and inhaled CO2. The highest ventilation (VE) and VE/CO2 output were recorded in CO2 inhalation and combined treatments. Arterial O2 partial pressure was higher in combined than in hypoxia treatment, but the difference between the treatments narrowed from rest to end-exercise, at least partly because the magnitude of the increase in VE (%) at exercise was smaller in combined treatment than in hypoxia...
September 26, 2016: Respiratory Physiology & Neurobiology
Todd A Astorino, Ross M Edmunds, Amy Clark, Leesa King, Rachael M Gallant, Samantha Namm, Anthony Fischer, Kimi A Wood
: Increases in maximal oxygen uptake (VO2max) frequently occur with high-intensity interval training (HIIT), yet the specific adaptation explaining this result remains elusive. PURPOSE: This study examined changes in VO2max and cardiac output (CO) in response to periodized HIIT. METHODS: Thirty nine active men and women (mean age and VO2max = 22.9 ± 5.4 yr and 39.6 ± 5.6 mL/kg/min) performed HIIT and 32 men and women (age and VO2max = 25...
September 16, 2016: Medicine and Science in Sports and Exercise
Cornelia Volland, Sebastian Bremer, Kristian Hellenkamp, Nico Hartmann, Nataliya Dybkova, Sara Khadjeh, Anna Kutschenko, David Liebetanz, Stefan Wagner, Bernhard Unsöld, Michael Didié, Karl Toischer, Samuel Sossalla, Gerd Hasenfuß, Tim Seidler
TBC1D10C is a protein previously demonstrated to bind and inhibit Ras and Calcineurin. In cardiomyocytes, also CaMKII is inhibited and all three targeted enzymes are known to promote maladaptive cardiomyocyte hypertrophy. Here, in accordance with lack of Calcineurin inhibition in vivo, we did not observe a relevant anti-hypertrophic effect despite inhibition of Ras and CaMKII. However, cardiomyocyte-specific TBC1D10C overexpressing transgenic mice exhibited enhanced longevity. Ejection fraction and exercise capacity were enhanced in transgenic mice, but shortening of isolated cardiomyocytes was not increased...
September 26, 2016: Scientific Reports
Thibaut Guiraud, Marc Labrunée, Florent Besnier, Jean-Michel Sénard, Fabien Pillard, Daniel Rivière, Lisa Richard, Davy Laroche, Frédéric Sanguignol, Atul Pathak, Mathieu Gayda, Vincent Gremeaux
BACKGROUND: Isometric strengthening has been rarely studied in patients with coronary heart disease (CHD), mainly because of possible potential side effects and lack of appropriate and reliable devices. OBJECTIVE: We aimed to compare 2 different modes of resistance training, an isometric mode with the Huber Motion Lab (HML) and traditional strength training (TST), in CHD patients undergoing a cardiac rehabilitation program. DESIGN: We randomly assigned 50 patients to HML or TST...
September 16, 2016: Annals of Physical and Rehabilitation Medicine
Jasdeep Kaur, Alberto Alvarez, Hanna W Hanna, Abhinav C Krishnan, Danielle Senador, Tiago M Machado, Yasir H Altamimi, Abe T Lovelace, Maryetta D Dombrowski, Marty D Spranger, Donal O'Leary
The muscle metaboreflex and arterial baroreflex regulate arterial pressure through distinct mechanisms. During submaximal exercise muscle metaboreflex activation (MMA) elicits a pressor response virtually solely by increasing cardiac output (CO) while baroreceptor unloading increases mean arterial pressure (MAP) primarily through peripheral vasoconstriction. The interaction between the two reflexes when activated simultaneously has not been well established. We activated the muscle metaboreflex in chronically instrumented canines during dynamic exercise (via graded reductions in hindlimb blood flow; HLBF) followed by simultaneous baroreceptor unloading (via bilateral carotid occlusion; BCO)...
September 9, 2016: American Journal of Physiology. Heart and Circulatory Physiology
Michael R Pinsky
The primary role of the right ventricle (RV) is to deliver all the blood it receives per beat into the pulmonary circulation without causing right atrial pressure to rise. To the extent that it also does not impede left ventricular (LV) filling, cardiac output responsiveness to increased metabolic demand is optimized. Since cardiac output is a function of metabolic demand of the body, during stress and exercise states the flow to the RV can vary widely. Also, instantaneous venous return varies widely for a constant cardiac output as ventilatory efforts alter the dynamic pressure gradient for venous return...
September 10, 2016: Critical Care: the Official Journal of the Critical Care Forum
S Magder
Volume infusions are one of the commonest clinical interventions in critically ill patients yet the relationship of volume to cardiac output is not well understood. Blood volume has a stressed and unstressed component but only the stressed component determines flow. It is usually about 30 % of total volume. Stressed volume is relatively constant under steady state conditions. It creates an elastic recoil pressure that is an important factor in the generation of blood flow. The heart creates circulatory flow by lowering the right atrial pressure and allowing the recoil pressure in veins and venules to drain blood back to the heart...
September 10, 2016: Critical Care: the Official Journal of the Critical Care Forum
Edward P Snelling, Roger S Seymour, J E F Green, Leith C R Meyer, Andrea Fuller, Anna Haw, Duncan Mitchell, Anthony P Farrell, Mary-Ann Costello, Adian Izwan, Margaret Badenhorst, Shane K Maloney
This study presents a structure-function analysis of the mammalian left ventricle and examines the performance of the cardiac capillary network, mitochondria, and myofibrils at rest and during simulated heavy exercise. Left ventricular external mechanical work rate was calculated from cardiac output and systemic mean arterial blood pressure in resting sheep (Ovis aries; n = 4) and goats (Capra hircus; n = 4) under mild sedation, followed by perfusion-fixation of the left ventricle and quantification of the cardiac capillary-tissue geometry and cardiomyocyte ultrastructure...
October 1, 2016: Journal of Applied Physiology
Sigurdur S Stephensen, Katarina Steding-Ehrenborg, Ulf Thilén, Johan Holm, Peter Hochbergs, Hakan Arheden, Marcus Carlsson
BACKGROUND: The purpose of this study was to determine the effect of stress on left-to-right shunting in patients with atrial septal defect (ASD) and to investigate if the degree of shunting, cardiac output (CO), and right ventricular (RV) volumes are related to exercise capacity. METHODS: Twenty-six patients with a secundum ASD and 16 healthy volunteers were studied with rest/stress cardiac magnetic resonance using 20 µg/kg/min dobutamine and 0.25-0.75 mg atropine to quantify CO, pulmonary to systemic flow ratio (QP/QS), and left ventricular (LV) and RV volumes...
September 1, 2016: European Heart Journal Cardiovascular Imaging
Alessandro Piras, Giorgio Gatta
The aim of this investigation was to evaluate the recovery pattern of a whole body compression garment on hemodynamic parameters and on ANS activity following a swimming performance. Ten young male athletes were recruited and tested in two different days, with and without wearing the garment during the recovery phase. After a warm-up of 15 minutes, athletes were instructed to perform a maximal 400m freestyle swimming event, and then time series of beat-to-beat intervals for heart rate variability (HRV), baroreflex sensitivity (BRS), and hemodynamic parameters were recorded for 90 minutes of recovery...
August 19, 2016: Journal of Strength and Conditioning Research
Vadim N Dedov, Irina V Dedova
BACKGROUND: Sustained cardiac rehabilitation is the key intervention in the prevention and treatment of many human diseases. However, implementation of exercise programs can be challenging because of early fatigability in patients with chronic diseases, overweight individuals, and aged people. Current methods of fatigability assessment are based on subjective self-reporting such as rating of perceived exertion or require specialized laboratory conditions and sophisticated equipment. A practical approach allowing objective measurement of exercise-induced fatigue would be useful for the optimization of sustained delivery of cardiac rehabilitation to improve patient outcomes...
2016: JMIR Research Protocols
Hwang-Woon Moon, Sub Sunoo, Hun-Young Park, Dong-Jun Lee, Sang-Seok Nam
PURPOSE: Evaluation of metabolic parameters and cardiac function is important to determine the decrease in aerobic exercise capacity under hypoxic conditions. However, the variations in metabolic parameters and cardiac function and the reasons for the decrease in aerobic exercise capacity under hypoxic conditions have not been clearly explained. The purpose of this study was to compare the responses between sea level and various acute normobaric hypoxic conditions on metabolic parameters and cardiac function during exercise and recovery in order to evaluate aerobic exercise capacity...
2016: SpringerPlus
Sayuri Fuse, Ryotaro Kime, Takuya Osada, Norio Murase, Toshihito Katsumura
An increase in the incidence rate of cardiovascular disease is attributed to high daily sitting time, while a drop in risk of cardiovascular disease comes from a decrease in daily sitting time, rather than an increase in physical activity levels. Although short-duration passive exercise increases energy expenditure and blood flow, few studies have reported on the responses of cardiorespiratory dynamics to long-duration passive exercise. The purpose of this study was to consider the effect of long-duration passive exercise for 20 min on cardiorespiratory and muscle oxygen dynamics...
2016: Advances in Experimental Medicine and Biology
Ronald A Bronicki
OBJECTIVES: In this review, we discuss hemodynamic monitoring modalities, including their application, the interpretation of data, limitations, and impact on outcomes. DATA SOURCE: MEDLINE, PubMed. CONCLUSIONS: One of the tenets of critical care medicine is to ensure adequate tissue oxygenation. This assessment must be timely and accurate to optimize outcomes. The clinical assessment of cardiac function, cardiac output, and tissue oxygenation based on the physical examination and standard hemodynamic variables, although an indispensable part of this exercise, has significant limitations...
August 2016: Pediatric Critical Care Medicine
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