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Cardiac output measurement

Jonathan S Howard, Cherilyn N McLester, Thomas W Evans, John R McLester, Jimmy P Calloway
The PhysioFlow™ is a piece of equipment that uses bioimpedance cardiography to measure central hemodynamics. The purpose of this research was to explore the novel approach of monitoring central hemodynamics during free weight resistance exercise using bioimpedance cardiography throughout a 5 repetition maximum (5RM). Thirty participants ranging from beginner to advanced lifters (16 males and 14 females) completed a 5RM for back squat, seated push press, and bicep curl while connected to the PhysioFlow™ to assess the response of heart rate (HR), stroke volume (SV), cardiac output (Q), and ejection fraction (EF)...
2018: International Journal of Exercise Science
Rebecca R Vanderpool, Robert Naeije
The diagnosis and evaluation of severity of pulmonary vascular disease rests on the invasive determination of a pulmonary vascular resistance (PVR). It is often overlooked that PVR is linearly related to the viscosity of the blood, which in turn is curvilinearly related to hematocrit. We propose a correction diagram for patients with anemia or with polycythemia. Based on a distensibility model of the pulmonary circulation, we show that magnitude of hematocrit correction of PVR is increased in proportion to pulmonary artery wedge pressure (PAWP) and the measured levels of PVR or hematocrit, and decreased in case of preserved resistive vessel distensibility and absence of pulmonary hypertension...
March 14, 2018: American Journal of Respiratory and Critical Care Medicine
Mohamed Elgendi, Yongbo Liang, Rabab Ward
Photoplethysmogram (PPG) signals collected using a pulse oximeter are increasingly being used for screening and diagnosis purposes. Because of the non-invasive, cost-effective, and easy-to-use nature of the pulse oximeter, clinicians and biomedical engineers are investigating how PPG signals can help in the management of many medical conditions, especially for global health application. The study of PPG signal analysis is relatively new compared to research in electrocardiogram signals, for instance; however, we anticipate that in the near future blood pressure, cardiac output, and other clinical parameters will be measured from wearable devices that collect PPG signals, based on the signal's vast potential...
March 11, 2018: Diseases (Basel)
Devin B Phillips, Craig D Steinback, Sophie É Collins, Desi P Fuhr, Tracey L Bryan, Eric Y L Wong, Vincent Tedjasaputra, Mohit Bhutani, Michael K Stickland
COPD patients have increased central arterial stiffness and muscle sympathetic nervous activity (MSNA), both of which contribute to cardiovascular (CV) dysfunction and increased CV risk. Previous work suggests that COPD patients have elevated carotid chemoreceptor (CC) activity/sensitivity, which may contribute to the elevated MSNA and arterial stiffness. Accordingly, the effect of CC inhibition on central arterial stiffness, MSNA and CV function at rest in COPD patients was examined in a randomized placebo-controlled study...
March 12, 2018: Journal of Physiology
Cole S Bailey, Luke T Wooster, Mary Buswell, Sarvagna Patel, Paul P Pappagianopoulos, Kristian Bakken, Casey White, Melissa Tanguay, Jasmine B Blodgett, Aaron L Baggish, Rajeev Malhotra, Gregory D Lewis
OBJECTIVES: This study sought to characterize the functional and prognostic significance of oxygen uptake (VO2 ) kinetics following peak exercise in individuals with heart failure (HF). BACKGROUND: It is unknown to what extent patterns of VO2 recovery following exercise reflect circulatory response during exercise in HF with preserved ejection fraction (HFpEF) and HF with reduced ejection fraction (HFrEF). METHODS: We investigated patients (30 HFpEF, 20 HFrEF, and 22 control subjects) who underwent cardiopulmonary exercise testing with invasive hemodynamic monitoring and a second distinct HF cohort (n = 106) who underwent noninvasive cardiopulmonary exercise testing with assessment of long-term outcomes...
March 1, 2018: JACC. Heart Failure
Gabriel Altit, Shazia Bhombal, Krisa Van Meurs, Theresa A Tacy
INTRODUCTION: Newborns with congenital diaphragmatic hernia (CDH) have varying degrees of pulmonary hypoplasia and pulmonary hypertension (PH), and there is limited evidence that cardiac dysfunction is present. We sought to study early neonatal biventricular function and performance in these patients by reviewing early post-natal echocardiography (ECHO) measurements and comparing them to normal term newborns. METHODS: Retrospective case-control study reviewing clinical and ECHO data on term newborns with CDH and normal controls born between 2009 and 2016...
March 9, 2018: Pediatric Cardiology
Takanori Masuda, Takeshi Nakaura, Yoshinori Funama, Tomoyasu Sato, Toru Higaki, Masao Kiguchi, Yukari Yamashita, Naoyuki Imada, Kazuo Awai
Objective: To evaluate the effect of patient characteristics on popliteal aortic contrast enhancement at lower extremity CT angiography (LE-CTA) scanning. Materials and Methods: Prior informed consent to participate was obtained from all 158 patients. All were examined using a routine protocol; the scanning parameters were tube voltage 100 kVp, tube current 100 mA to 770 mA (noise index 12), 0.5-second rotation, 1.25-mm detector row width, 0.516 beam pitch, and 41...
March 2018: Korean Journal of Radiology: Official Journal of the Korean Radiological Society
Satyanarayan T Shanbhag, Bernard Choong, Maxim Petrov, Brett Delahunt, John A Windsor, Anthony R J Phillips
BACKGROUND: Critical illness including severe acute pancreatitis is associated with the multiple organ dysfunction syndrome. The "gut-lymph" hypothesis states that multiple organ dysfunction syndrome is due to release of toxic factors from the intestine into the mesenteric lymph. The aims of this study were to determine the effect of normotensive acute pancreatitis conditioned mesenteric lymph on cardiac function and whether external drainage of mesenteric lymph would protect the heart...
March 5, 2018: Surgery
Ineke Nederend, Eco J C de Geus, Lucia J M Kroft, Jos J M Westenberg, Nico A Blom, Arend D J Ten Harkel
BACKGROUND: Coarctation of the aorta (CoA) is one of the most common congenital heart defects. Due to improved surgical techniques, most patients live into adulthood. However, late complications including hypertension, recoarctation and arrhythmias are common. The autonomic nervous system (ANS) might play a role in the pathology. The aim of this study was to evaluate cardiac ANS activity and cardiac function in children after CoA repair and investigate the relationship between the two...
March 5, 2018: Annals of Thoracic Surgery
Olga Frlic, Alenka Seliškar, Aleksandra Domanjko Petrič, Rok Blagus, George Heigenhauser, Modest Vengust
General anesthesia (GA) can cause abnormal lung fluid redistribution. Pulmonary circulation transvascular fluid fluxes ( J VA ) are attributed to changes in hydrostatic forces and erythrocyte volume (EV) regulation. Despite the very low hydraulic conductance of pulmonary microvasculature it is possible that GA may affect hydrostatic forces through changes in pulmonary vascular resistance (PVR), and EV through alteration of erythrocyte transmembrane ion fluxes ( ion J VA ). Furosemide (Fur) was also used because of its potential to affect pulmonary hydrostatic forces and ion J VA ...
2018: Frontiers in Physiology
Farid Froghi, Rahul Koti, Kurinchi Gurusamy, Susan Mallett, Douglas Thorburn, Linda Selves, Sarah James, Jeshika Singh, Manuel Pinto, Christine Eastgate, Margaret McNeil, Helder Filipe, Fatima Jichi, Nick Schofield, Daniel Martin, Brian Davidson
BACKGROUND: Patients with liver cirrhosis undergoing liver transplantation have a hyperdynamic circulation which persists into the early postoperative period making accurate assessment of fluid requirements challenging. Goal-directed fluid therapy (GDFT) has been shown to reduce morbidity and mortality in a number of surgery settings. The impact of GDFT in patients undergoing liver transplantation is unknown. A feasibility trial was designed to determine patient and clinician support for recruitment into a randomised controlled trial of GDFT following liver transplantation, adherence to a GDFT protocol, participant withdrawal, and to determine appropriate endpoints for a subsequent larger trial to evaluate the efficacy of GDFT in patients undergoing liver transplantation...
March 7, 2018: Trials
Mare Mechelinck, Marc Hein, Sven Bellen, Rolf Rossaint, Anna B Roehl
The extent of right ventricular compensation compared to the left ventricle is restricted and varies among individuals, which makes it difficult to define. While establishing a model of acute pulmonary hypertension in pigs we observed two different kinds of compensation in our animals. Looking deeper into the hemodynamic data we tried to delineate why some animals could compensate and others could not. Pulmonary hypertension (mean pressure 45 mmHg) was induced gradually by infusion of a stable thromboxane A2 analogue U46619 in a porcine model (n = 22)...
March 2018: Physiological Reports
Angela Briganti, Flavia Evangelista, Paola Centonze, Annaliso Rizzo, Francesco Bentivegna, Antonio Crovace, Francesco Staffieri
BACKGROUND: Haemodynamic variations normally occur in anaesthetized animals, in relation to the animal status, administered drugs, sympathetic and parasympathetic tone, fluid therapy and surgical stimulus. The possibility to measure some cardiovascular parameters, such as cardiac output (CO), during anaesthesia would be beneficial for both the anaesthesia management and its outcome. New techniques for the monitoring of CO are aimed at finding methods which are non invasive, accurate and with good trending ability, which can be used in a clinical setting...
March 6, 2018: BMC Veterinary Research
Sebastian Voicu, Georgios Sideris, Jean-Guillaume Dillinger, Demetris Yannopoulos, Nicolas Deye, Chantal Kang, Michel Bonneau, Jason Bartos, Antoni Kedra, Sophie Bailliart, Adrien Pasteur-Rousseau, Guy Amah, Philippe Bonnin, Jacques Callebert, Patrick Henry, Bruno Megarbane
Circulatory failure following cardiac arrest (CA) requires catecholamine support and occasionally veno-arterial extracorporeal membrane oxygenation (vaECMO). VaECMO-generated blood flow is continuous and retrograde, increasing ventricular stroke work. Our aim was to assess the benefit of a device generating a pulsatile vaECMO flow synchronized with the heart rhythm lowering systolic vaECMO output on the left ventricular ejection fraction (LVEF) and pulmonary capillary pressure (Pcap) after CA. This experimental randomized study in pigs compared standard nonpulsatile vaECMO (control) with pulsatile synchronized vaECMO (study) group using a pulsatility-generating device...
March 6, 2018: Artificial Organs
Marshall M Mrocki, Vivian B Nguyen, Paul Lombardo, Megan R Sutherland, Jonathan G Bensley, Ilias Nitsos, Beth J Allison, Richard Harding, Robert De Matteo, Michal Schneider, Graeme R Polglase, M Jane Black
Preterm birth prematurely exposes the immature heart to the haemodynamic transition at birth, which has the potential to induce abnormal cardiac remodelling. Magnetic resonance imaging studies in young adults born preterm have shown abnormalities in the gross structure of the ventricles (particularly the right ventricle; RV), but the cellular basis of these alterations is unknown. The aim of this study, conducted in sheep, was to determine the effect of moderate preterm birth on RV cellular structure and function in early adulthood...
March 6, 2018: Journal of Physiology
Christoffer Göransson, Niels Vejlstrup, Thomas Scheike, Jørn Carlsen
BACKGROUND: Normally, morbidity precedes mortality in pulmonary arterial hypertension (PAH) and is assessed with recognized surrogate measures of survival. Cardiovascular magnetic resonance (CMR) can assess right ventricular (RV) structure and function which is directly related to survival in PAH. This study describes CMR-assessed weekly cardiac variability in PAH, allowing calculation of sample sizes for trials comparing PAH targeted treatment effects and optimal methods for individual monitoring...
April 15, 2018: International Journal of Cardiology
Nathan Cho, Shadi E Razipour, Megan L McCain
Cardiac fibroblasts and their activated derivatives, myofibroblasts, play a critical role in wound healing after myocardial injury and often contribute to long-term pathological outcomes, such as excessive fibrosis. Thus, defining the microenvironmental factors that regulate the phenotype of cardiac fibroblasts and myofibroblasts could lead to new therapeutic strategies. Both chemical and biomechanical cues have previously been shown to induce myofibroblast differentiation in many organs and species. For example, transforming growth factor beta 1, a cytokine secreted by neutrophils, and rigid extracellular matrix environments have both been shown to promote differentiation...
January 1, 2018: Experimental Biology and Medicine
Martin Kluckow
Assessment and treatment of the VLBW infant with cardiovascular impairment requires understanding of the underlying physiology of the infant in transition. The situation is dynamic with changes occurring in systemic blood pressure, pulmonary pressures, myocardial function, and ductal shunt in the first postnatal days. New insights into the role of umbilical cord clamping in the transitional circulation have been provided by large clinical trials of early versus later cord clamping and a series of basic science reports describing the physiology in an animal model...
2018: Frontiers in Pediatrics
Stéphane Doutreleau, Irina Enache, Cristina Pistea, Bernard Geny, Anne Charloux
In this study, we hypothesized that adding CO2 to an inhaled hypoxic gas mixture will limit the rise of pulmonary artery pressure (PAP) induced by a moderate exercise. Eight 20-year-old males performed four constant-load exercise tests on cycle at 40% of maximal oxygen consumption in four conditions: ambient air, normobaric hypoxia (12.5% O2 ), inhaled CO2 (4.5% CO2 ), and combination of hypoxia and inhaled CO2 . Doppler echocardiography was used to measure systolic (s)PAP, cardiac output (CO). Total pulmonary resistance (TPR) was calculated...
March 3, 2018: Pflügers Archiv: European Journal of Physiology
Torsten Birkholz, Christian Leuthold, Joachim Schmidt, Harald Ihmsen, Jürgen Schüttler, Christian Jeleazcov
BACKGROUND: Sufentanil is used for general anesthesia and analgesia. The study aim was to determine the effect of pharmacologically induced changes in cardiac output on the pharmacokinetics of sufentanil in anesthetized pigs. METHODS: Twenty-four pigs were randomly assigned to low, high, and control cardiac output groups. Cardiac output was decreased or increased from baseline by at least 40%, or maintained within ± 10% of baseline, respectively. Sufentanil was administered as a bolus followed by a continuous infusion for 120 min...
March 1, 2018: Anesthesiology
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