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https://www.readbyqxmd.com/read/28935040/cardiopulmonary-exercise-testing-what-is-its-value
#1
REVIEW
Marco Guazzi, Francesco Bandera, Cemal Ozemek, David Systrom, Ross Arena
Compared with traditional exercise tests, cardiopulmonary exercise testing (CPET) provides a thorough assessment of exercise integrative physiology involving the pulmonary, cardiovascular, muscular, and cellular oxidative systems. Due to the prognostic ability of key variables, CPET applications in cardiology have grown impressively to include all forms of exercise intolerance, with a predominant focus on heart failure with reduced or with preserved ejection fraction. As impaired cardiac output and peripheral oxygen diffusion are the main determinants of the abnormal functional response in cardiac patients, invasive CPET has gained new popularity, especially for diagnosing early heart failure with preserved ejection fraction and exercise-induced pulmonary hypertension...
September 26, 2017: Journal of the American College of Cardiology
https://www.readbyqxmd.com/read/28921674/decline-in-effort-capacity-with-age-echocardiographic-stress-analysis-in-the-elderly
#2
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
#3
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
#4
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/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/28912726/cardiovascular-and-muscular-consequences-of-work-matched-interval-type-of-concentric-and-eccentric-pedaling-exercise-on-a-soft-robot
#7
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/28912128/aging-modifies-the-effect-of-cardiac-output-on-middle-cerebral-artery-blood-flow-velocity
#8
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/28906053/the-effects-of-menstrual-cycle-phase-on-the-incidence-of-plateau-at-v%C3%AB-o2max-and-associated-cardiorespiratory-dynamics
#9
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/28892884/effect-of-metaboreflex-on-cardiovascular-system-in-subjects-of-metabolic-syndrome
#10
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/28878952/pathophysiology-of-exercise-intolerance-in-chronic-diseases-the-role-of-diminished-cardiac-performance-in-mitochondrial-and-heart-failure-patients
#11
Jodi McCoy, Matthew Bates, Christopher Eggett, Mario Siervo, Sophie Cassidy, Jane Newman, Sarah A Moore, Grainne Gorman, Michael I Trenell, Lazar Velicki, Petar M Seferovic, John G F Cleland, Guy A MacGowan, Doug M Turnbull, Djordje G Jakovljevic
OBJECTIVE: Exercise intolerance is a clinical hallmark of chronic conditions. The present study determined pathophysiological mechanisms of exercise intolerance in cardiovascular, neuromuscular, and metabolic disorders. METHODS: In a prospective cross-sectional observational study 152 patients (heart failure reduced ejection fraction, n=32; stroke, n=34; mitochondrial disease, n=28; type two diabetes, n=28; and healthy controls, n=30) performed cardiopulmonary exercise testing with metabolic and haemodynamic measurements...
2017: Open Heart
https://www.readbyqxmd.com/read/28877974/exertional-dyspnoea-in-pulmonary-arterial-hypertension
#12
Daniel Dumitrescu, Olivier Sitbon, Jason Weatherald, Luke S Howard
Dyspnoea is a principal presenting symptom in pulmonary arterial hypertension (PAH), and often the most distressing. The pathophysiology of PAH is relatively well understood, with the primary abnormality of pulmonary vascular disease resulting in a combination of impaired cardiac output on exercise and abnormal gas exchange, both contributing to increased ventilatory drive. However, increased ventilatory drive is not the sole explanation for the complex neurophysiological and neuropsychological symptom of dyspnoea, with other significant contributions from skeletal muscle reflexes, respiratory muscle function, and psychological and emotional status...
September 30, 2017: European Respiratory Review: An Official Journal of the European Respiratory Society
https://www.readbyqxmd.com/read/28864438/measuring-stroke-volume-impedance-cardiography-vs-phase-contrast-magnetic-resonance-imaging
#13
Matthew Borzage, Kimia Heidari, Thomas Chavez, Istvan Seri, John C Wood, Stefan Blüml
BACKGROUND: Determination of cardiac output requires measurement of both heart rate and stroke volume. Techniques for measuring heart rate are widespread, and 1 technique for bedside monitoring of stroke volume is electrical impedance cardiography. OBJECTIVES: To determine the accuracy and precision of stroke volume measured via impedance cardiography and whether the technique can be used to detect trends. METHODS: Eleven healthy research participants (22-52 years old) were examined with simultaneous impedance cardiography and phase-contrast magnetic resonance imaging at rest and during exercise...
September 2017: American Journal of Critical Care: An Official Publication, American Association of Critical-Care Nurses
https://www.readbyqxmd.com/read/28863039/extracorporeal-membrane-oxygenation-for-end-stage-interstitial-lung-disease-with-secondary-pulmonary-hypertension-at-rest-and-exercise-insights-from-simulation-modeling
#14
Scott Chicotka, Daniel Burkhoff, Marc L Dickstein, Matthew Bacchetta
Interstitial lung disease (ILD) represents a collection of lung disorders with a lethal trajectory with few therapeutic options with the exception of lung transplantation. Various extracorporeal membrane oxygenation (ECMO) configurations have been used for bridge to transplant (BTT), yet no optimal configuration has been clearly demonstrated. Using a cardiopulmonary simulation, we assessed different ECMO configurations for patients with end-stage ILD to assess the physiologic deficits and help guide the development of new long-term pulmonary support devices...
August 31, 2017: ASAIO Journal: a Peer-reviewed Journal of the American Society for Artificial Internal Organs
https://www.readbyqxmd.com/read/28862962/inspiratory-muscle-training-is-associated-with-improved-inspiratory-muscle-strength-resting-cardiac-output-and-the-ventilatory-efficiency-of-exercise-in-patients-with-a-fontan-circulation
#15
Karina Laohachai, David Winlaw, Hiran Selvadurai, Ganesh Kumar Gnanappa, Yves d'Udekem, David Celermajer, Julian Ayer
BACKGROUND: Patients with a Fontan circulation have reduced exercise capacity and respiratory muscle strength. Inspiratory muscle training (IMT) improves exercise capacity and quality of life in adults with heart failure. We assessed whether 6 weeks of a home-based program of IMT improves inspiratory muscle strength and the ventilatory efficiency of exercise in adolescent patients with a Fontan circulation. METHODS AND RESULTS: Twenty-three adolescent participants (aged 16±2 years) with a Fontan circulation underwent 6 weeks of IMT for 30 minutes daily...
August 21, 2017: Journal of the American Heart Association
https://www.readbyqxmd.com/read/28862384/atrial-septostomy-with-a-predefined-diameter-using-a-novel-occlutech-atrial-flow-regulator-improves-symptoms-and-cardiac-index-in-patients-with-severe-pulmonary-arterial-hypertension
#16
Ramasamy Rajeshkumar, Sreeja Pavithran, Kothandam Sivakumar, Joseph J Vettukattil
OBJECTIVES: A novel Occlutech atrial flow regulator (AFR) implantation gives an atrial septal predefined predictable fenestration. BACKGROUND: Atrial septostomy relieves syncope in pulmonary arterial hypertension (PAH) by improving left heart filling, cardiac output and systemic oxygen transport despite hypoxia. Symptoms recur when small fenestrations close spontaneously. METHODS: AFR was implanted after informed consent in patients with severe PAH presenting with syncope and right heart failure...
September 1, 2017: Catheterization and Cardiovascular Interventions
https://www.readbyqxmd.com/read/28860965/resetting-of-the-baroreflex-control-of-sympathetic-vasomotor-activity-during-natural-behaviors-description-and-conceptual-model-of-central-mechanisms
#17
REVIEW
Roger A L Dampney
The baroreceptor reflex controls arterial pressure primarily via reflex changes in vascular resistance, rather than cardiac output. The vascular resistance in turn is dependent upon the activity of sympathetic vasomotor nerves innervating arterioles in different vascular beds. In this review, the major theme is that the baroreflex control of sympathetic vasomotor activity is not constant, but varies according to the behavioral state of the animal. In contrast to the view that was generally accepted up until the 1980s, I argue that the baroreflex control of sympathetic vasomotor activity is not inhibited or overridden during behaviors such as mental stress or exercise, but instead is reset under those conditions so that it continues to be highly effective in regulating sympathetic activity and arterial blood pressure at levels that are appropriate for the particular ongoing behavior...
2017: Frontiers in Neuroscience
https://www.readbyqxmd.com/read/28820609/cardio-pulmonary-interactions-physiologic-basis-and-clinical-applications
#18
Michael R Pinsky
The hemodynamic effects of ventilation can be grouped into three concepts: 1) spontaneous ventilation is exercise; 2) changes in lung volume alter autonomic tone, pulmonary vascular resistance, and can compress the heart in the cardiac fossa; 3) spontaneous inspiratory efforts decrease intrathoracic pressure (ITP) increasing venous return and impeding left ventricular (LV) ejection; whereas positive pressure ventilation decreases venous return and unloads LV ejection. Spontaneous inspiratory efforts may induce acute LV failure and cardiogenic pulmonary edema...
August 18, 2017: Annals of the American Thoracic Society
https://www.readbyqxmd.com/read/28819094/atrioventricular-conduction-delay-predicts-impaired-exercise-capacity-in-patients-with-heart-failure-with-reduced-ejection-fraction
#19
Jakub Stępniewski, Grzegorz Kopeć, Wojciech Magoń, Piotr Podolec
BACKGROUND Atrioventricular conduction delay (AVCD) impairs left ventricular (LV) filling and consequently leads to a reduction of cardiac output. We hypothesized that in patients with severely depressed LV function and coexisting intraventricular conduction disturbances (IVCD), AVCD can affect exercise performance. Therefore, we evaluated the association of AVCD and exercise capacity in patients with heart failure (HFREF) and coexisting IVCD. MATERIAL AND METHODS We included patients with stable, chronic HFREF, LVEF <35%, sinus rhythm, and QRS ≥120 ms...
August 18, 2017: Medical Science Monitor: International Medical Journal of Experimental and Clinical Research
https://www.readbyqxmd.com/read/28818484/the-physiology-of-submaximal-exercise-the-steady-state-concept
#20
REVIEW
Guido Ferretti, Nazzareno Fagoni, Anna Taboni, Paolo Bruseghini, Giovanni Vinetti
The steady state concept implies that the oxygen flow is invariant and equal at each level along the respiratory system. The same is the case with the carbon dioxide flow. This condition has several physiological consequences, which are analysed. First, we briefly discuss the mechanical efficiency of exercise and the energy cost of human locomotion, as well as the roles played by aerodynamic work and frictional work. Then we analyse the equations describing the oxygen flow in lungs and in blood, the effects of ventilation and of the ventilation - perfusion inequality, and the interaction between diffusion and perfusion in the lungs...
August 15, 2017: Respiratory Physiology & Neurobiology
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