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Cardiac physiology

C Manghani, A Gupta, V Tripathi, V Rani
Cardiomyopathy and associated heart failure continues to be one of the most severe complications that threaten a large population. Curcumin, one of the three curcuminoids of the spice turmeric, is very well known for a multitude of health benefits and functions. Norepinephrine (NE), a catecholamine and also a stress hormone may cause the cardiomyocytes to develop increased sensitivity to death with its increasing concentrations. In this study, we investigated the cardioprotective effect of curcumin in NE-induced cardiac apoptosis using several fluorescent and nonfluorescent microscopic techniques like DAPI, PI, Giemsa, PicroSirius and TUNEL...
October 25, 2016: Journal of Microscopy
W Gerald Rainer, David J Bailey, Harris W Hollis
Cardiac lipomas are rare and usually present as benign, encapsulated masses outside the heart; however, they can also be found within the atria. No single theory-including molecular genetic mutation-adequately explains why this occurs. Extensive career experience and broadened knowledge in embryology and cardiac physiology have helped us to develop a hypothesis based on invagination of extracardiac tumors. This report describes a vexing case of a giant right atrial lipoma, from 1985, in which the diagnosis was made incidentally during management of a patient's acute limb ischemia...
October 2016: Texas Heart Institute Journal
Colin F Royse, Leif Saager, Richard Whitlock, Jared Ou-Young, Alistair Royse, Jessica Vincent, P J Devereaux, Andrea Kurz, Ahmed Awais, Krit Panjasawatwong, Daniel I Sessler
BACKGROUND: Inflammation after cardiopulmonary bypass may contribute to postoperative delirium and cognitive dysfunction. The authors evaluated the effect of high-dose methylprednisolone to suppress inflammation on the incidence of delirium and postoperative quality of recovery after cardiac surgery. METHODS: Five hundred fifty-five adults from three hospitals enrolled in the randomized, double-blind Steroids in Cardiac Surgery trial were randomly allocated to placebo or 250 mg methylprednisolone at induction and 250 mg methylprednisolone before cardiopulmonary bypass...
October 24, 2016: Anesthesiology
Akshay Shekhar, Xianming Lin, Fang-Yu Liu, Jie Zhang, Huan Mo, Lisa Bastarache, Joshua C Denny, Nancy J Cox, Mario Delmar, Dan M Roden, Glenn I Fishman, David S Park
Rapid impulse propagation in the heart is a defining property of pectinated atrial myocardium (PAM) and the ventricular conduction system (VCS) and is essential for maintaining normal cardiac rhythm and optimal cardiac output. Conduction defects in these tissues produce a disproportionate burden of arrhythmic disease and are major predictors of mortality in heart failure patients. Despite the clinical importance, little is known about the gene regulatory network that dictates the fast conduction phenotype. Here, we have used signal transduction and transcriptional profiling screens to identify a genetic pathway that converges on the NRG1-responsive transcription factor ETV1 as a critical regulator of fast conduction physiology for PAM and VCS cardiomyocytes...
October 24, 2016: Journal of Clinical Investigation
Jeffrey M Pyne, Joseph I Constans, Mark D Wiederhold, Douglas P Gibson, Timothy Kimbrell, Teresa L Kramer, Jeffery A Pitcock, Xiaotong Han, D Keith Williams, Don Chartrand, Richard N Gevirtz, James Spira, Brenda K Wiederhold, Rollin McCraty, Thomas R McCune
Heart rate variability is a physiological measure associated with autonomic nervous system activity. This study hypothesized that lower pre-deployment HRV would be associated with higher post-deployment post-traumatic stress disorder (PTSD) symptoms. Three-hundred-forty-three Army National Guard soldiers enrolled in the Warriors Achieving Resilience (WAR) study were analyzed. The primary outcome was PTSD symptom severity using the PTSD Checklist - Military version (PCL) measured at baseline, 3- and 12-month post-deployment...
October 20, 2016: Biological Psychology
Lasse Skibsbye, Thomas Jespersen, Torsten Christ, Mary M Maleckar, Jonas van den Brink, Pasi Tavi, Jussi T Koivumäki
BACKGROUND: Refractoriness of cardiac cells limits maximum frequency of electrical activity and protects the heart from tonic contractions. Short refractory periods support major arrhythmogenic substrates and augmentation of refractoriness is therefore seen as a main mechanism of antiarrhythmic drugs. Cardiomyocyte excitability depends on availability of sodium channels, which involves both time- and voltage-dependent recovery from inactivation. This study therefore aims to characterise how sodium channel inactivation affects refractoriness in human atria...
October 20, 2016: Journal of Molecular and Cellular Cardiology
Michiko Nanao-Hamai, Bo-Kyung Son, Tsuyoshi Hashizume, Sumito Ogawa, Masahiro Akishita
Vascular calcification is one of the major complications of cardiovascular disease and is an independent risk factor for myocardial infarction and cardiac death. Postmenopausal women have a higher prevalence of vascular calcification compared with premenopausal women, suggesting protective effects of estrogen (E2). However, the underlying mechanisms of its beneficial effects remain unclear. In the present study, we examined the inhibitory effects of E2 on vascular smooth muscle cell (VSMC) calcification, and found that growth arrest-specific gene 6 (Gas6), a crucial molecule in vascular calcification, is transactivated by estrogen receptor α (ERα) in response to E2...
October 19, 2016: Biochemical and Biophysical Research Communications
Wilfried Dinh, Barbara Albrecht-Küpper, Mihai Gheorghiade, Adriaan A Voors, Michael van der Laan, Hani N Sabbah
Adenosine exerts a variety of physiological effects by binding to cell surface G-protein-coupled receptor subtypes, namely, A1, A2a, A2b, and A3. The central physiological role of adenosine is to preclude tissue injury and promote repair in response to stress. In the heart, adenosine acts as a cytoprotective modulator, linking cardiac function to metabolic demand predominantly via activation of adenosine A1 receptors (A1Rs), which leads to inhibition of adenylate cyclase activity, modulation of protein kinase C, and opening of ATP-sensitive potassium channels...
October 22, 2016: Handbook of Experimental Pharmacology
Magnolia Cardona-Morrell, Amanda Chapman, Robin M Turner, Ebony Lewis, Blanca Gallego-Luxan, Michael Parr, Ken Hillman
AIM: To investigate associations between clinical parameters - beyond the evident physiological deterioration and limitations of medical treatment - with in-hospital death for patients receiving Rapid Response System (RRS) attendances. METHODS: Retrospective case-control analysis of clinical parameters for 328 patients aged 60 years and above at their last RRS call during admission to a single teaching hospital in the 2012-2013 calendar years. Generalised estimating equation modelling was used to compare the deceased with a randomly selected sample of those who had RRS calls and survived admission (controls), matched by age group, sex, and hospital ward...
October 18, 2016: Resuscitation
Derek Nelson, Rachael M Heuer, Georgina K Cox, John D Stieglitz, Ronald Hoenig, Edward M Mager, Daniel D Benetti, Martin Grosell, Dane A Crossley
Exposure to polycyclic aromatic hydrocarbons (PAH) negatively impacts exercise performance in fish species but the physiological modifications that result in this phenotype are poorly understood. Prior studies have shown that embryonic and juvenile mahi-mahi (Coryphaeus hippurus) exposed to PAH exhibit morphological abnormalities, altered cardiac development and reduced swimming performance. It has been suggested that cardiovascular function inhibited by PAH exposure accounts for the compromised exercise performance in fish species...
October 14, 2016: Aquatic Toxicology
Riccardo Toninato, Silvia Scuri, Vincenzo Tarzia, Gino Gerosa, Francesca M Susin
PURPOSE: The gold standard therapy for patients with advanced heart failure is heart transplant. The gap between donors and patients in waiting lists promoted the development of circulatory support devices, such as the total artificial heart (TAH). Focusing on in vitro tests performed with CardioWest™ TAH (CW) driven by the SynCardia Freedom® portable driver (FD) the present study goals are: i) prove the reliability of a hydraulic circuit used as patient simulator to replicate a quasi-physiological scenario for various hydrodynamic conditions, ii) investigate the hydrodynamic performance of the CW FD, iii) help clinicians in possible interpretation of clinical cases outcomes...
October 15, 2016: International Journal of Artificial Organs
Walter H Reinhart
The hematocrit (Hct) determines the oxygen carrying capacity of blood, but also increases blood viscosity and thus flow resistance. From this dual role the concept of an optimum Hct for tissue oxygenation has been derived. Viscometric studies using the ratio Hct/blood viscosity at high shear rate showed an optimum Hct of 50-60% for red blood cell (RBC) suspensions in plasma. For the perfusion of an artificial microvascular network with 5-70μm channels the optimum Hct was 60-70% for high driving pressures. With lower shear rates or driving pressures the optimum Hct shifted towards lower values...
October 21, 2016: Clinical Hemorheology and Microcirculation
Lois Choy, Jie Ming Yeo, Vivian Tse, Shing Po Chan, Gary Tse
The mouse is the second mammalian species, after the human, in which substantial amount of the genomic information has been analyzed. With advances in transgenic technology, mutagenesis is now much easier to carry out in mice. Consequently, an increasing number of transgenic mouse systems have been generated for the study of cardiac arrhythmias in ion channelopathies and cardiomyopathies. Mouse hearts are also amenable to physical manipulation such as coronary artery ligation and transverse aortic constriction to induce heart failure, radiofrequency ablation of the AV node to model complete AV block and even implantation of a miniature pacemaker to induce cardiac dyssynchrony...
September 2016: IJC Heart & Vasculature
Débora Claësson, Tobias Wang, Hans Malte
Global warming results in increasing water temperature, which may represent a threat to aquatic ectotherms. The rising temperature affects ecology through physiology, by exerting a direct limiting effect on the individual. The mechanism controlling individual thermal tolerance is still elusive, but some evidence shows that the heart plays a central role, and that insufficient transport of oxygen to the respiring tissues may determine the thermal tolerance of animals. In this study, the influence of the heart in thermal limitation was investigated by measurements of aerobic scope in the European eel (Anguilla anguilla) together with measurements of cardiac output during rest and activity...
2016: Conservation Physiology
Pavol Sajgalik, Vaclav Kremen, Alex R Carlson, Vratislav Fabian, Chul-Ho Kim, Courtney M Wheatley, Vaclav Gerla, John A Schirger, Thomas P Olson, Bruce D Johnson
Cardiac output (CO) assessment as a basic hemodynamic parameter has been of interest in exercise physiology, cardiology and anesthesiology. Non-invasive techniques available are technically challenging, and thus difficult to use outside of the clinical or laboratory setting. We propose a novel method of non-invasive CO assessment using a single upper arm cuff. The method uses the arterial pressure pulse wave signal acquired from the brachial artery during 20 second intervals of suprasystolic occlusion. This method was evaluated on a cohort of 12 healthy individuals (age of 27...
October 20, 2016: Journal of Applied Physiology
Jakub Tomek, Rebecca A B Burton, Gil Bub
Cardiac arrhythmias are one of the most frequent causes of death worldwide. A popular biological model used to study arrhythmogenesis is the cultured cardiac cell monolayer, which provides a good trade-off between physiological relevance and experimental access. Excitation wave patterns are imaged using high-bandwidth detectors, producing large data sets that are typically analyzed manually. To make such analysis less time consuming and less subjective, we have designed and implemented a toolkit for segmentation and tracking of cardiac waves in optical mapping recordings...
October 18, 2016: Biophysical Journal
Sree Vamsee Chintapalli, Srinivas Jayanthi, Prema L Mallipeddi, Ravi Kumar Gundampati, Suresh Kumar Thallapuranam Krishnaswamy, Damian B van Rossum, Andriy Anishkin, Sean H Adams
Previous research has indicated that long-chain fatty acids can bind myoglobin (Mb) in an oxygen dependent manner. This suggests that Oxy-Mb may play an important role in fuel delivery in Mb-rich muscle fibers (e.g., type I fibers and cardiomyocytes), and raises the possibility that Mb also serves as an acylcarnitine binding protein. We report for the first time the putative interaction and affinity characteristics for different chain lengths of both fatty acids and acylcarnitines with Oxy-Mb using molecular dynamic simulations and isothermal titration calorimetry experiments...
October 7, 2016: Journal of Biological Chemistry
Giordano Tasca, Matteo Selmi, Emiliano Votta, Paola Redaelli, Francesco Sturla, Alberto Redaelli, Amando Gamba
BACKGROUND: Aortic root aneurysm can be treated with valve-sparing procedures. The David and Yacoub techniques have shown excellent long-term results but are technically demanding. Recently, a new and simpler procedure, the Sleeve technique, was proposed with encouraging results. We aimed to quantify the biomechanics of the initially aneurysmal aortic root (AR) after the Sleeve procedure to assess whether it induces abnormal stresses, potentially undermining its durability. METHODS: Two finite element (FE) models of the physiologic and aneurysmal AR were built, accounting for the anatomical asymmetry and the nonlinear and anisotropic mechanical properties of human AR tissues...
October 15, 2016: Annals of Thoracic Surgery
Attila Oláh, Dalma Kellermayer, Csaba Mátyás, Balázs Tamás Németh, Árpád Lux, Lilla Szabó, Marianna Török, Mihály Ruppert, Anna Meltzer, Alex Ali Sayour, Kálmán Benke, István Hartyánszky, Béla Merkely, Tamás Radovits
PURPOSE: Long-term exercise training is associated with characteristic cardiac adaptation, termed athlete's heart. Our research group previously characterized in vivo left ventricular (LV) function of exercise-induced cardiac hypertrophy in detail in a rat model, however the effect of detraining on LV function is still unclear. We aimed at evaluating the reversibility of functional alterations of athlete's heart after detraining. METHODS: Rats (n=16) were divided into detrained exercised (DEx) and detrained control (DCo) groups...
October 14, 2016: Medicine and Science in Sports and Exercise
Zhao Yang, Ma Ruixin, Yu Jing
OBJECTIVE: The role of the renin angiotensin aldosterone system (RAAS) and the gene variants of its components in hypertension have been investigated in various studies. A local tissue-specific renin-angiotensin system (local RAS) has considered as a regulator of cardiovascular physiology and homeostasis. However, no report has described the vagina protective efficacy of RAS inhibitors including ARB and ACEI. Therefore, we aim to investigate the effect of ARBs and ACEI on the vagina and cardiac expression of the local renin-angiotensin components...
September 2016: Journal of Hypertension
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