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https://www.readbyqxmd.com/read/28445779/the-acute-cardiorespiratory-effects-of-centrally-injected-arachidonic-acid-the-mediation-of-prostaglandin-e-d-and-f2%C3%AE
#1
Leman Gizem Erkan, Burcin Altinbas, Gokcen Guvenc, Begum Aydin, Nasir Niaz, Murat Yalcin
Arachidonic acid (AA), which is released from synaptic membrane phospholipid by neuroreceptor-initiated activation of phospholipase A2, is abundant in the brain and works as a neurotransmitter and/or neuromodulator in the central nervous system. Recently we reported that centrally injected AA generated pressor and hyperventilation effects by activating thromboxane A2 (TXA2) signaling pathway. The present study was designed to investigate the mediation of other metabolites of AA such as prostaglandin (PG) D, PGE and PGF2α alongside TXA2 in the AA-evoked cardiorespiratory effects in anaesthetized rats...
April 23, 2017: Respiratory Physiology & Neurobiology
https://www.readbyqxmd.com/read/28414673/purulent-pericarditis-due-to-an-infected-pacemaker-lead
#2
Teresa Backes
INTRODUCTION: Intravenous drug users have a substantially increased risk of infective endocarditis, especially in the setting of implanted cardiac devices. Purulent pericarditis is a rare occurrence that can occur iatrogenically or through direct or hematogenous spread. CASE DESCRIPTION: A 75 year old man with a past medical history significant for hepatitis C, IV drug abuse, and sick sinus syndrome status post pacemaker was brought in by EMS with a chief complaint of diaphoresis and chest pain...
March 2017: Journal of the Louisiana State Medical Society: Official Organ of the Louisiana State Medical Society
https://www.readbyqxmd.com/read/28331306/is-cardiac-autonomic-modulation-during-upper-limb-isometric-contraction-and-valsalva-maneuver-impaired-in-copd-patients
#3
Cássia da Luz Goulart, Ramona Cabiddu, Paloma de Borba Schneiders, Elisabete Antunes San Martin, Renata Trimer, Audrey Borghi-Silva, Andréa Lúcia Gonçalves da Silva
PURPOSE: To evaluate the heart rate variability (HRV) indices and heart rate (HR) responses during isometric contraction (IC) and Valsalva maneuver (VM) in COPD patients. METHODS: Twenty-two stable moderate to severe COPD patients were evaluated. R-R intervals were recorded (monitor Polar(®) S810i) during dominant upper limb IC (2 minutes). Stable signals were analyzed by Kubios HRV(®) software. Indices of HRV were computed in the time domain (mean HR; square root of the mean squared differences of successive RR intervals [RMSSD] and HRV triangular index [RR tri index]) and in the frequency domain (high frequency [HF]; low frequency [LF] and LF/HF ratio)...
2017: International Journal of Chronic Obstructive Pulmonary Disease
https://www.readbyqxmd.com/read/28331064/maternal-separation-diminishes-alpha-adrenergic-receptors-density-and-function-in-renal-vasculature-from-male-wistar-kyoto-rats
#4
Analia S Loria, Jeffrey L Osborn
Adult rats exposed to maternal separation (MatSep) are normotensive but display lower glomerular filtration rate and increased renal neuroadrenergic drive. The aim of this study was to determine the renal alpha-adrenergic receptor density and the renal vascular responsiveness to adrenergic stimulation in male rats exposed to MatSep. In addition, baroreflex sensitivity was assessed to determine a component of neural control of the vasculature. Using tissue collected from 4-month-old MatSep and control rats, alpha 1-adrenergic receptors (α1-ARs) were measured in renal cortex and isolated renal vasculature using receptor binding assay, and the α-AR subtype gene expression was determined by RT-PCR...
March 22, 2017: American Journal of Physiology. Renal Physiology
https://www.readbyqxmd.com/read/28323584/evidence-for-gz-adaptation-observed-with-wearable-biosensors-during-high-performance-jet-flight
#5
G Merrill Rice, Dallas Snider, Jeffrey L Moore, J Timothy Lavan, Rich Folga, Thomas B VanBrunt
INTRODUCTION: Few studies have evaluated physiological responses to high acceleration forces during actual flight and to our knowledge no normative data has been acquired by technologies such as wearable biosensors during high performance jet aircraft operations. METHODS: In-flight physiological data from an FDA cleared portable triaxial accelerometer and bio-sensor were observed from five active duty F-18 pilots of the Naval Flight Demonstration Squadron (Blue Angels)...
December 1, 2016: Aerospace Medicine and Human Performance
https://www.readbyqxmd.com/read/28306134/further-evidence-of-a-prolonged-hypotensive-and-a-bradycardic-effect-after-mandibular-extension-in-normal-volunteers
#6
C Del Seppia, S Ghione, Paola Foresi, E Fommei, D Lapi, A Colantuoni, R Scuri
We previously reported that in normotensive humans submaximal mouth opening (mandibular extension) obtained by an ad hoc dilator (spring device), associated with partial masticatory movements and prolonged for 10 minutes is followed by a long-lasting reduction of blood pressure (BP) and heart rate (HR). Similar results were obtained by us in anesthetized rats. A recent independent study failed to confirm the results in the normotensive human. We reassessed, in 25 normotensive volunteers, the effects on BP and HR of mandibular extension obtained by the spring device associated with partial masticatory movements compared to a control procedure, consisting in keeping a tongue depressor between the incisor teeth...
December 1, 2016: Archives Italiennes de Biologie
https://www.readbyqxmd.com/read/28304253/ventricular-parasystole-in-a-neonatal-rhesus-macaque-macaca-mulatta
#7
Dalis E Collins, Brandy L Dozier, Jeffrey J Stanton, Lois Ma Colgin, Rhonda MacAllister
A 6-d-old Indian-origin female rhesus macaque (Macaca mulatta) presented with bradycardia shortly after sedation with ketamine. No other cardiac abnormalities were apparent. Approximately 2 wk after the initial presentation, the macaque was again bradycardic and exhibited a regularly irregular arrhythmia on a prestudy examination. ECG, echocardiography, blood pressure measurement, SpO2 assessment, and a CBC analysis were performed. The echocardiogram and bloodwork were normal, but the infant was hypotensive at the time of echocardiogram...
December 1, 2016: Comparative Medicine
https://www.readbyqxmd.com/read/28257441/a-novel-approach-for-evaluating-the-effects-of-odor-stimulation-on-dynamic-cardiorespiratory-functions
#8
Eriko Kawai, Hidehiro Nakahara, Shin-Ya Ueda, Kou Manabe, Tadayoshi Miyamoto
We aimed to develop a novel method to quantitatively evaluate the effects of odor stimulation on cardiorespiratory functions over time, and to examine the potential usefulness of clinical aromatherapy. Eighteen subjects participated. Nine people were assigned to each of the two resting protocols. Protocol 1: After resting for 2 min in a sitting position breathing room air, the subject inhaled either air or air containing sweet marjoram essential oil from the Douglas bag for 6 min, Protocol 2: After resting for 5 min in a supine position, the subject inhaled the essential oil for 10 min, and then recovered for 10 min breathing room air...
2017: PloS One
https://www.readbyqxmd.com/read/28197279/a-sudden-change-of-heart-a-case-of-rapidly-reversed-stress-cardiomyopathy-in-a-critically-ill-patient
#9
Michael I Brener, Ali R Keramati, Marek A Mirski, Oscar H Cingolani
We report the case of a 79-year-old woman who presented to our hospital for elective removal of an infratentorial meningioma and suffered a periprocedural cardiac arrest. Shortly after uncomplicated induction of anesthesia prior to the surgery, the patient became hypotensive and bradycardic, culminating ultimately in a cardiac arrest with pulseless electrical activity. Return of spontaneous circulation occurred within 90 seconds of arrest, but the patient remained dependent on maximal doses of epinephrine and dopamine for hemodynamic support...
June 2016: Cardiology Research
https://www.readbyqxmd.com/read/28185059/severe-proarrhythmic-potential-of-the-antiemetic-agents-ondansetron-and-domperidone
#10
Gerrit Frommeyer, Christina Fischer, Christian Ellermann, Philipp S Lange, Dirk G Dechering, Simon Kochhäuser, Michael Fehr, Lars Eckardt
The potential of ondansetron and domperidone, both clinically established antiemetic agents, to increase the QT-interval has been described in several case reports. Therefore, the aim of the present study was to investigate whether these drugs may provoke polymorphic ventricular tachycardia in a sensitive experimental model of drug-induced proarrhythmia. In 10 female rabbits, ondansetron (1, 5 and 10 µM, n = 10) or domperidone (0.5, 1 and 2 µM, n = 8) was infused after obtaining baseline data. Eight endo- and epicardial monophasic action potentials and a simultaneously recorded 12-lead ECG reproduced the clinically observed QT-prolongation (ondansetron: 1 µM:+17 ms, 5 µM:+41 ms, 10 µM:+78 ms, p < 0...
February 9, 2017: Cardiovascular Toxicology
https://www.readbyqxmd.com/read/28122469/dexmedetomidine-for-refractory-intracranial-hypertension
#11
Kendra J Schomer, Christian M Sebat, Jason Y Adams, Jeremiah J Duby, Kiarash Shahlaie, Erin L Louie
Dexmedetomidine (DEX) is a selective α2 adrenergic agonist that is commonly used for sedation in the intensive care unit (ICU). The role of DEX for adjunctive treatment of refractory intracranial hypertension is poorly defined. The primary objective of this study was to determine the effect of DEX on the need for rescue therapy (ie, hyperosmolar boluses, extraventricular drain [EVD] drainages) for refractory intracranial hypertension. Secondary objectives included the number of intracranial pressure (ICP) excursions, bradycardic, hypotensive, and compromised cerebral perfusion pressure episodes...
January 1, 2017: Journal of Intensive Care Medicine
https://www.readbyqxmd.com/read/28091703/bolus-application-of-landiolol-and-esmolol-comparison-of-the-pharmacokinetic-and-pharmacodynamic-profiles-in-a-healthy-caucasian-group
#12
RANDOMIZED CONTROLLED TRIAL
Günther Krumpl, Ivan Ulc, Michaela Trebs, Pavla Kadlecová, Juri Hodisch
PURPOSE: The aim of this prospective study was to compare in non-Asian subjects the pharmacokinetics (PK), pharmacodynamics (PD), safety, and tolerability of two short-acting cardioselective β1-adrenergic antagonists, landiolol and esmolol, after administration of three different bolus dosages. MATERIALS AND METHODS: We conducted a single-center, prospective, double-blinded, randomized study in three cross-over periods with 12 healthy subjects (7 women and 5 men, mean age of 24...
April 2017: European Journal of Clinical Pharmacology
https://www.readbyqxmd.com/read/28089877/permanent-pacemaker-implantation-in-octogenarians-with-unexplained-syncope-and-positive-electrophysiologic-testing
#13
Georgios Giannopoulos, Charalampos Kossyvakis, Vasiliki Panagopoulou, Dimitrios Tsiachris, Konstantinos Doudoumis, Maria Mavri, Dimitrios Vrachatis, Konstantinos Letsas, Michael Efremidis, Apostolos Katsivas, John Lekakis, Spyridon Deftereos
BACKGROUND: Syncope is a common problem in the elderly, and a permanent pacemaker is a therapeutic option when a bradycardic etiology is revealed. However, the benefit of pacing when no association of symptoms to bradycardia has been shown is not clear, especially in the elderly. OBJECTIVE: The aim of this study was to evaluate the effect of pacing on syncope-free mortality in patients aged 80 years or older with unexplained syncope and "positive" invasive electrophysiologic testing (EPT)...
May 2017: Heart Rhythm: the Official Journal of the Heart Rhythm Society
https://www.readbyqxmd.com/read/28011835/comparing-maximum-rate-and-sustainability-of-pacing-by-mechanical-vs-electrical-stimulation-in-the-langendorff-perfused-rabbit-heart
#14
T Alexander Quinn, Peter Kohl
AIMS: Mechanical stimulation (MS) represents a readily available, non-invasive means of pacing the asystolic or bradycardic heart in patients, but benefits of MS at higher heart rates are unclear. Our aim was to assess the maximum rate and sustainability of excitation by MS vs. electrical stimulation (ES) in the isolated heart under normal physiological conditions. METHODS AND RESULTS: Trains of local MS or ES at rates exceeding intrinsic sinus rhythm (overdrive pacing; lowest pacing rates 2...
December 2016: Europace: European Pacing, Arrhythmias, and Cardiac Electrophysiology
https://www.readbyqxmd.com/read/27871603/prophylactic-phenylephrine-infusion-for-the-prevention-of-hypotension-after-spinal-anesthesia-in-the-elderly-a-randomized-controlled-clinical-trial
#15
Fabrice Ferré, Philippe Marty, Laura Bruneteau, Virgine Merlet, Benoît Bataille, Anne Ferrier, Claude Gris, Matt Kurrek, Olivier Fourcade, Vincent Minville, Agnes Sommet
STUDY OBJECTIVE: Hypotension frequently occurs during spinal anesthesia (SA), especially in the elderly. Phenylephrine is effective to prevent SA-induced hypotension during cesarean delivery. The objective of this study was to evaluate the efficacy and safety of prophylactic infusion of phenylephrine after SA for orthopedic surgery in the elderly. DESIGN: This prospective, randomized, double-blind, and placebo-controlled study included 54 patients older than 60 years undergoing elective lower limb surgery under SA (injection of 10 mg of isobaric bupivacaine with 5 μg of sufentanyl)...
December 2016: Journal of Clinical Anesthesia
https://www.readbyqxmd.com/read/27844147/acute-ivabradine-treatment-reduces-heart-rate-without-increasing-atrial-fibrillation-inducibility-irrespective-of-underlying-vagal-activity-in-dogs
#16
Kazunori Uemura, Masashi Inagaki, Can Zheng, Toru Kawada, Meihua Li, Masafumi Fukumitsu, Masaru Sugimachi
Ivabradine, a bradycardic agent, has been shown to stably reduce patient's heart rate (HR) in the setting of acute cardiac care. However, an association between atrial fibrillation (AF) risk and acute ivabradine treatment remains a controversial clinical issue, and has not been thoroughly investigated. Bradycardia and abnormal atrial refractoriness induced by ivabradine treatment may enhance vulnerability to AF induction, especially when vagal nerve is concurrently activated. We aimed to experimentally investigate the effects of acute ivabradine treatment with/without concurrent vagal activation on AF inducibility...
November 14, 2016: Heart and Vessels
https://www.readbyqxmd.com/read/27816306/intravenous-electrical-vagal-nerve-stimulation-prior-to-coronary-reperfusion-in-a-canine-ischemia-reperfusion-model-markedly-reduces-infarct-size-and-prevents-subsequent-heart-failure
#17
Takahiro Arimura, Keita Saku, Takamori Kakino, Takuya Nishikawa, Takeshi Tohyama, Takafumi Sakamoto, Kazuo Sakamoto, Takuya Kishi, Tomomi Ide, Kenji Sunagawa
BACKGROUND: Reducing myocardial damage is a prerequisite to prevent chronic heart failure after acute myocardial infarction (AMI). Although vagal nerve stimulation (VNS) has been repeatedly demonstrated to have potent anti-infarct effect, technical difficulties have precluded its clinical application. We developed a novel therapeutic strategy of intravenous VNS (iVNS) and examined whether iVNS administered prior to coronary reperfusion in a canine AMI model reduces infarct size and prevents heart failure...
January 15, 2017: International Journal of Cardiology
https://www.readbyqxmd.com/read/27794538/methyl-cpg-binding-protein-2-function-in-cholinergic-neurons-mediates-cardiac-arrhythmogenesis
#18
José A Herrera, Christopher S Ward, Xander H T Wehrens, Jeffrey L Neul
Sudden unexpected death occurs in one quarter of deaths in Rett Syndrome (RTT), a neurodevelopmental disorder caused by mutations in Methyl-CpG-binding protein 2 (MECP2). People with RTT show a variety of autonomic nervous system (ANS) abnormalities and mouse models show similar problems including QTc interval prolongation and hypothermia. To explore the role of cardiac problems in sudden death in RTT, we characterized cardiac rhythm in mice lacking Mecp2 function. Male and female mutant mice exhibited spontaneous cardiac rhythm abnormalities including bradycardic events, sinus pauses, atrioventricular block, premature ventricular contractions, non-sustained ventricular arrhythmias, and increased heart rate variability...
October 18, 2016: Human Molecular Genetics
https://www.readbyqxmd.com/read/27776979/chronic-kidney-disease-impairs-renal-nerve-and-haemodynamic-reflex-responses-to-vagal-afferent-input-through-a-central-mechanism
#19
REVIEW
Ibrahim M Salman, Cara M Hildreth, Jacqueline K Phillips
We investigated age- and sex-related changes in reflex renal sympathetic nerve activity (RSNA) and haemodynamic responses to vagal afferent stimulation in a rodent model of chronic kidney disease (CKD). Using anaesthetised juvenile (7-8weeks) and adult (12-13weeks) Lewis Polycystic Kidney (LPK) and Lewis control rats of either sex (n=63 total), reflex changes in RSNA, heart rate (HR) and mean arterial pressure (MAP) to vagal afferent stimulation (5-s train, 4.0V, 2.0-ms pulses, 1-16Hz) were measured. In all groups, stimulation of the vagal afferents below 16Hz produced frequency-dependent reductions in RSNA, HR and MAP, while a 16Hz stimulus produced an initial sympathoinhibition followed by sympathoexcitation...
October 11, 2016: Autonomic Neuroscience: Basic & Clinical
https://www.readbyqxmd.com/read/27763697/changes-in-cardiovascular-responses-to-chemoreflex-activation-of-rats-recovered-from-protein-restriction-are-not-related-to-at1-receptors
#20
Renato Willian Martins Sá, Andrea Siqueira Haibara, Paula Magalhães Gomes, Giovana Lopes Aguiar, Rafael Souza Leopoldino Nascimento, Maria Lucia Pedrosa, Andréia Carvalho Alzamora, Lisandra Brandino de Oliveira, Leonardo Máximo Cardoso
What is the central question of this study? In this study, we sought to investigate whether cardiovascular responses to peripheral chemoreflex activation of rats recovered from protein restriction are related to activation of AT1 receptors. What is the main finding and its importance? This study highlights the fact that angiotensinergic mechanisms activated by AT1 receptors do not support increased responses to peripheral chemoreflex activation by KCN in rats recovered from protein restriction. Also, we found that protein restriction led to increased resting ventilation in adult rats, even after recovery...
January 1, 2017: Experimental Physiology
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