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"Cardiac output"

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https://www.readbyqxmd.com/read/28921674/decline-in-effort-capacity-with-age-echocardiographic-stress-analysis-in-the-elderly
#1
Anat Milman, Gad Keren, Yan Topilsky
BACKGROUND: The present study was designed to assess the underlying mechanism of decline in effort capacity seen with aging. METHODS: We analyzed 250 healthy senior patients (≥65 years) with an ejection fraction ≥60% who underwent a stress echocardiogram test. The seniors (aged 65-94) were divided into 3 equal age groups (groups 1, 2, and 3), and their echo characteristics at rest and peak exercise (measured and calculated) were compared. RESULTS: Diastolic function at rest declined significantly (E lateral, E septal, E/E', A) with age, while other rest parameters were similar...
September 17, 2017: Echocardiography
https://www.readbyqxmd.com/read/28919891/moderate-intensity-exercise-affects-gut-microbiome-composition-and-influences-cardiac-function-in-myocardial-infarction-mice
#2
Zuheng Liu, Hai-Yue Liu, Haobin Zhou, Qiong Zhan, Wenyan Lai, Qingchun Zeng, Hao Ren, Dingli Xu
Physical exercise is commonly regarded as protective against cardiovascular disease (CVD). Recent studies have reported that exercise alters the gut microbiota and that modification of the gut microbiota can influence cardiac function. Here, we focused on the relationships among exercise, the gut microbiota and cardiac function after myocardial infarction (MI). Four-week-old C57BL/6J mice were exercised on a treadmill for 4 weeks before undergoing left coronary artery ligation. Cardiac function was assessed using echocardiography...
2017: Frontiers in Microbiology
https://www.readbyqxmd.com/read/28919370/with-age-a-lower-individual-breathing-reserve-is-associated-with-a-higher-maximal-heart-rate
#3
Martin Burtscher, Hannes Gatterer, Martin Faulhaber, Johannes Burtscher
INTRODUCTION: Maximal heart rate (HRmax) is linearly declining with increasing age. Regular exercise training is supposed to partly prevent this decline, whereas sex and habitual physical activity do not. High exercise capacity is associated with a high cardiac output (HR x stroke volume) and high ventilatory requirements. Due to the close cardiorespiratory coupling, we hypothesized that the individual ventilatory response to maximal exercise might be associated with the age-related HRmax...
September 14, 2017: Respiratory Physiology & Neurobiology
https://www.readbyqxmd.com/read/28916637/effect-of-increases-in-cardiac-contractility-on-cerebral-blood-flow-in-humans
#4
Shigehiko Ogoh, Gilbert Moralez, Takuro Washio, Satyam Sarma, Michinari Hieda, Steven A Romero, Matthew N Cramer, Manabu Shibasaki, Craig G Crandall
The effect of acute increases in cardiac contractility on cerebral blood flow (CBF) remains unknown. We hypothesized that the external carotid artery (ECA) downstream vasculature modifies the direct influence of acute increases in heart rate and cardiac function on CBF regulation. Twelve healthy subjects received two infusions of dobutamine (first a low dose; 5 μg/kg/min and then a high dose; 15 μg/kg/min) for 12 min each. Cardiac output, blood flow through the internal carotid artery (ICA) and ECA and echocardiographic measurements were performed during dobutamine infusions...
September 15, 2017: American Journal of Physiology. Heart and Circulatory Physiology
https://www.readbyqxmd.com/read/28915538/long-term-t3-and-t4-treatment-as-an-alternative-to-aerobic-exercise-training-in-improving-cardiac-function-post-myocardial-infarction
#5
Rayane Brinck Teixeira, Alexsandra Zimmer, Alexandre Luz de Castro, Bruna Gazzi de Lima-Seolin, Patrick Türck, Rafaela Siqueira, Adriane Belló-Klein, Pawan K Singal, Alex Sander da Rosa Araujo
Here we aimed to compare the beneficial effects of T3 and T4 hormone treatment to those provided by aerobic exercise training in Wistar rats post-myocardial infarction (MI). Rats in one group were SHAM-operated and in the other group were subjected to MI surgery. One week after surgery, the MI group animals either received T3 and T4 hormones by gavage or underwent a low intensity aerobic exercise training protocol on a treadmill, and both treatments lasted until 10 weeks after MI. Untreated SHAM-operated and MI groups were also followed for the same duration...
September 11, 2017: Biomedicine & Pharmacotherapy, Biomédecine & Pharmacothérapie
https://www.readbyqxmd.com/read/28915226/pulmonary-vascular-function-and-aerobic-exercise-capacity-at-moderate-altitude
#6
Vitalie Faoro, Gael Deboeck, Marco Vicenzi, Anne-Fleur Gaston, Bamodi Simaga, Grégory Doucende, Ilona Hapkova, Emma Roca, Enric Subirats, Fabienne Durand, Robert Naeije
PURPOSE: There has been suggestion that a greater "pulmonary vascular reserve" defined by a low pulmonary vascular resistance (PVR) and a high lung diffusing capacity (DL) allow for a superior aerobic exercise capacity. How pulmonary vascular reserve might affect exercise capacity at moderate altitude is not known. METHODS: Thirty-eight healthy subjects underwent an exercise stress echocardiography of the pulmonary circulation, combined with measurements of DL for nitric oxide (NO) and carbon monoxide (CO) and a cardiopulmonary exercise test at sea level and at an altitude of 2250 m...
October 2017: Medicine and Science in Sports and Exercise
https://www.readbyqxmd.com/read/28913740/temporary-mechanical-circulatory-support-for-cardiogenic-shock
#7
REVIEW
Jean Touchan, Maya Guglin
Cardiogenic shock is a life-threatening presentation of severe heart failure with high morbidity and mortality. Given the modest increased in cardiac output and neutral/negative survival benefits with today's available inotropes (namely, dobutamine and milrinone), the use of mechanical circulatory support (MCS) has increased dramatically over the past 2 decades. In this review article, we discuss the physiologic concept, clinical evidence of benefit, and current use and indications/potential complications of the four most commonly used devices for MCS: intra-aortic balloon pump, Impella percutaneous ventricular assist device, TandemHeart, and extracorporeal membrane oxygenation (ECMO)...
September 14, 2017: Current Treatment Options in Cardiovascular Medicine
https://www.readbyqxmd.com/read/28912726/cardiovascular-and-muscular-consequences-of-work-matched-interval-type-of-concentric-and-eccentric-pedaling-exercise-on-a-soft-robot
#8
Martin Flück, Rebekka Bosshard, Max Lungarella
Eccentric types of endurance exercise are an acknowledged alternative to conventional concentric types of exercise rehabilitation for the cardiac patient, because they reduce cardiorespiratory strain due to a lower metabolic cost of producing an equivalent mechanical output. The former contention has not been tested in a power- and work-matched situation of interval-type exercise under identical conditions because concentric and eccentric types of exercise pose specific demands on the exercise machinery, which are not fulfilled in current practice...
2017: Frontiers in Physiology
https://www.readbyqxmd.com/read/28912258/frank-starling-mechanism-and-short-term-adjustment-of-cardiac-flow
#9
José Guilherme Chaui-Berlinck, Luiz Henrique Alves Monteiro
The Frank-Starling Law of the heart is a filling-force mechanism (FFm), a positive relationship between the distension of a ventricular chamber and its force of ejection, and such a mechanism is found across all the studied vertebrate lineages. The functioning of the cardiovascular system is usually described by means of the cardiac and vascular functions, the former related to the contractility of the heart and the latter related to the after-load imposed to the ventricle. The crossing of these functions is the so-called operation point, and the FFm is supposed to play a stabilizing role for the short-term variations in the working of the system...
September 14, 2017: Journal of Experimental Biology
https://www.readbyqxmd.com/read/28912128/aging-modifies-the-effect-of-cardiac-output-on-middle-cerebral-artery-blood-flow-velocity
#10
Anne-Sophie G T Bronzwaer, Jasper Verbree, Wim J Stok, Mat J A P Daemen, Mark A van Buchem, Matthias J P van Osch, Johannes J van Lieshout
An association between cerebral blood flow (CBF) and cardiac output (CO) has been established in young healthy subjects. As of yet it is unclear how this association evolves over the life span. To that purpose, we continuously recorded mean arterial pressure (MAP; finger plethysmography), CO (pulse contour; CO-trek), mean blood flow velocity in the middle cerebral artery (MCAV; transcranial Doppler ultrasonography), and end-tidal CO2 partial pressure (PetCO2) in healthy young (19-27 years), middle-aged (51-61 years), and elderly subjects (70-79 years)...
September 2017: Physiological Reports
https://www.readbyqxmd.com/read/28911286/the-effect-of-a-surgery-specific-cardiac-output-guided-haemodynamic-algorithm-on-outcomes-in-patients-undergoing-pancreaticoduodenectomy-in-a-high-volume-centre-a-retrospective-comparative-study
#11
L Weinberg, J Banting, L Churilov, R L McLeod, K Fernandes, I Chao, T Ho, D Ianno, V Liang, V Muralidharan, C Christophi, M Nikfarjam
In this retrospective observational study performed in a high-volume hepatobiliary-pancreatic unit, we evaluated the effect of a surgery-specific goal-directed therapy (GDT) physiologic algorithm on complications and length of hospital stay. We compared patients who underwent pancreaticoduodenectomy with either a standardised Enhanced Recovery After Surgery program (usual care group), or a standardised Enhanced Recovery After Surgery program in combination with a surgery-specific cardiac output-guided algorithm (GDT group)...
September 2017: Anaesthesia and Intensive Care
https://www.readbyqxmd.com/read/28906053/the-effects-of-menstrual-cycle-phase-on-the-incidence-of-plateau-at-v%C3%AB-o2max-and-associated-cardiorespiratory-dynamics
#12
Dan Gordon, Adrian Scruton, Richard Barnes, James Baker, Luciano Prado, Viviane Merzbach
The purpose of this study was to examine the effect of menstrual cycle phase on maximal oxygen uptake (V˙O2max) and associated cardiodynamic responses. A total of 16 active females volunteered of which n = 10 formed the non-oral contraceptive pill group (n-OCP), displaying a regular menstrual cycle of 28·4 ± 2·2 days (age 20·6 ± 1·6 years, height 169·9 ± 6·4 cm, mass 68·7 ± 7·9 kg) and n = 6 formed the oral contraceptive pill group (OCP) (monophasic pill) (age 21·7 years ± 2·16, height 168·1 cm ± 6·8 cm, mass 61·6 ± 6·8 kg)...
September 14, 2017: Clinical Physiology and Functional Imaging
https://www.readbyqxmd.com/read/28902662/circadian-hemodynamics-in-men-and-women-with-high-blood-pressure-dipper-vs-nondipper-and-racial-differences
#13
Andrew Sherwood, LaBarron K Hill, James A Blumenthal, Alan L Hinderliter
OBJECTIVE: The 'nondipping' pattern of circadian blood pressure (BP) variation is an established independent predictor of adverse cardiovascular outcomes. Although this phenomenon has been widely studied, its underlying circadian hemodynamics of cardiac output and systemic vascular resistance (SVR) have not been well characterized. We evaluated the hypothesis that BP nondipping would be associated with a blunted night-time reduction in SVR in a biracial sample of 140 (63 African-American and 77 white) men and women with elevated clinic BP (130-159/85-99 mmHg)...
September 11, 2017: Journal of Hypertension
https://www.readbyqxmd.com/read/28902380/-organ-interactions-heart-and-kidney
#14
Daniel Salleck, Stefan John
The interactions between heart and kidney are various and of clinical relevance. Worsening of one organ often influences the function of the other. With NYHA and KDIGO we have classification systems for heart and kidney failure and those should be used for cardiorenal systems as well. Furthermore there is a useful classification system for cardiorenal syndromes itself. Cardiorenal syndrome is a complex illness which should be treated by interdisciplinary medical teams. A key roll in pathophysiology is the renin-angiotensin-aldosteron-system (RAAS)...
September 2017: Deutsche Medizinische Wochenschrift
https://www.readbyqxmd.com/read/28900614/echocardiographic-evaluation-of-pulmonary-pressures-and-right-ventricular-function-after-pediatric-cardiac-surgery-a-simple-approach-for-the-intensivist
#15
REVIEW
Maurice Beghetti
Pulmonary hypertension (PH) is diagnosed using cardiac catheterization and is defined as an elevation of mean pulmonary artery pressure (PAP) greater than 25 mmHg. Although invasive hemodynamics remains the gold standard and is mandatory for disease confirmation, transthoracic echocardiography (TTE) is an extremely useful non-invasive and widely available tool that allows for screening and follow-up, in particular, in the acute setting. TTE may be a valuable alternative, allowing for direct measurement and/or indirect assessment of PAP...
2017: Frontiers in Pediatrics
https://www.readbyqxmd.com/read/28899910/human-hypoxic-pulmonary-vasoconstriction-is-unaltered-by-8%C3%A2-h-of-preceding-isocapnic-hyperoxia
#16
Hung-Yuan Cheng, Quentin P P Croft, Matthew C Frise, Nick P Talbot, Nayia Petousi, Peter A Robbins, Keith L Dorrington
Exposure to sustained hypoxia of 8 h duration increases the sensitivity of the pulmonary vasculature to acute hypoxia, but it is not known whether exposure to sustained hyperoxia affects human pulmonary vascular control. We hypothesized that exposure to 8 h of hyperoxia would diminish the hypoxic pulmonary vasoconstriction (HPV) that occurs in response to a brief exposure to hypoxia. Eleven healthy volunteers were studied in a crossover protocol with randomization of order. Each volunteer was exposed to acute isocapnic hypoxia (end-tidal PO2 = 50 mmHg for 10 min) before and after 8 h of hyperoxia (end-tidal PO2 = 420 mmHg) or euoxia (end-tidal PO2 = 100 mmHg)...
September 2017: Physiological Reports
https://www.readbyqxmd.com/read/28899642/evaluation-of-myocardial-function-according-to-early-diastolic-intraventricular-pressure-difference-in-fetuses
#17
Yuka Yamamoto, Ken Takahashi, Yo Takemoto, Maki Kobayashi, Keiichi Itatani, Toshiaki Shimizu, Atsuo Itakura, Satoru Takeda
BACKGROUND: Intraventricular pressure difference (IVPD), the diastolic suction during early diastole, is known as a useful marker of myocardial diastolic function in adults with different heart diseases, but there are no studies of fetal IVPD. The aim of this study was to determine whether IVPD exists and changes prenatally and whether IVPD correlates with preexisting parameters to evaluate fetal cardiac diastolic function and ventricular dominance. METHODS: Cross-sectional study data (stroke volume, fetal cardiac output, E/A ratio, and myocardial performance index) from 117 healthy fetuses at 17 to 36 weeks of gestation were retrospectively evaluated...
September 9, 2017: Journal of the American Society of Echocardiography
https://www.readbyqxmd.com/read/28895094/fluid-loading-and-norepinephrine-infusion-mask-the-left-ventricular-preload-decrease-induced-by-pleural-effusion
#18
Kristian Borup Wemmelund, Viktor Kromann Ringgård, Simon Tilma Vistisen, Janus Adler Hyldebrandt, Erik Sloth, Peter Juhl-Olsen
BACKGROUND: Pleural effusion (PLE) may lead to low blood pressure and reduced cardiac output. Low blood pressure and reduced cardiac output are often treated with fluid loading and vasopressors. This study aimed to determine the impact of fluid loading and norepinephrine infusion on physiologic determinants of cardiac function obtained by ultrasonography during PLE. METHODS: In this randomised, blinded, controlled laboratory study, 30 piglets (21.9 ± 1.3 kg) had bilateral PLE (75 mL/kg) induced...
September 11, 2017: Intensive Care Medicine Experimental
https://www.readbyqxmd.com/read/28892884/effect-of-metaboreflex-on-cardiovascular-system-in-subjects-of-metabolic-syndrome
#19
Pramita Dubey, Sunita Tiwari, Manish Bajpai, Kalpana Singh, Praveen Jha
INTRODUCTION: Metaboreflex is a reflex in which muscle receptors send signals regarding metabolic (metabolites accumulation like lactic acid, potassium, adenosine) conditions of the muscles to nucleus tractus solitarius via afferent III and IV fibres to cause haemodynamic adjustments in order to regulate blood flow on the basis of the status of contracting muscle. Dysregulation in its mechanism in metabolic syndrome is demonstrated. AIM: To study the effect of metaboreflex by both isometric and rhythmic handgrip exercise on CVS parameters {Blood Pressure (BP), Cardiac Output (CO) and Systemic Vascular Resistance (SVR)} in subjects of metabolic syndrome...
July 2017: Journal of Clinical and Diagnostic Research: JCDR
https://www.readbyqxmd.com/read/28891509/role-of-the-medullary-lateral-tegmental-field-in-sympathetic-control
#20
Michael George Zaki Ghali
The sympathetic nervous system maintains and regulates arterial pressure and tissue perfusion, via control of cardiac output and vasomotor tone. Sympatho-vascular-mediated increases in blood pressure are effected by arterioloconstriction, which causes an increase in afterload, and/or venoconstriction, which increases venous return, left ventricular preload, and consequently, the force of cardiac contraction via Frank-Starling mechanisms; withdrawal of sympathetic drive elicits reciprocal effects. Spinalization reduces mammalian arterial pressure to 40-50 mm Hg consequent to the elimination of descending medullary pre-sympathetic bulbospinal drive to preganglionic sympathetic fibers in the intermediolateral cell column of the spinal cord...
2017: Journal of Integrative Neuroscience
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