Read by QxMD icon Read

Myocardial Oxygenation

Marty D Spranger, Jasdeep Kaur, Javier A Sala-Mercado, Abhinav C Krishnan, Rania Abu-Hamdah, Alberto Alvarez, Tiago M Machado, Robert A Augustyniak, Donal S O'Leary
Increases in myocardial oxygen consumption during exercise mainly occur via increases in coronary blood flow (CBF) as cardiac oxygen extraction is high even at rest. However, sympathetic coronary constrictor tone can limit increases in CBF. Increased sympathetic nerve activity (SNA) during exercise is, in part, a function of muscle metaboreflex activation (MMA). As SNA is heightened even at rest in subjects with hypertension (HTN), we tested whether HTN causes exaggerated coronary vasoconstriction during mild treadmill exercise with MMA (elicited by reducing hindlimb blood flow by ~60%) thereby limiting increases in CBF and ventricular performance...
October 21, 2016: American Journal of Physiology. Heart and Circulatory Physiology
Vanessa D Ortiz, Alexandre L de Castro, Cristina Campos, Rafael O Fernandes, Jéssica H P Bonetto, Rafaela Siqueira, Adriana Conzatti, Tânia R G Fernandes, Adriane Belló-Klein, Alex S R Araujo
Studies have shown a cardioprotective role of thyroid hormones (THs) in cardiac remodeling after acute myocardial infarction (MI). However, there is no data in the literature examining the influence of TH administration on the aortic tissue in an animal model of MI. This study aimed to evaluate the effects of thyroid hormones on the aorta after MI. Male Wistar rats were divided into a sham group (SHAM), infarcted group (AMI), sham+TH (SHAMT) and AMI+TH (AMIT). After MI, the animals received T3 and T4 (2 and 8μg/100g/day, respectively) by oral gavage for 12 days...
October 18, 2016: European Journal of Pharmacology
Cosmo Godino, Antonio Colombo, Alberto Margonato
Heart rate is an established prognostic marker for longevity and is an important contributor in the pathophysiology of various cardiovascular diseases, including ischemic heart disease and heart failure. Most ischemic episodes are triggered by an increase in heart rate, which causes an imbalance between myocardial oxygen delivery and consumption. In addition, increased heart rate is a modifiable risk factor for chronic heart failure. Ivabradine, an inhibitor of If ion channels, is an approved second-line anti-ischemic drug for the treatment of angina...
October 21, 2016: Clinical Drug Investigation
Wojciech Kosmala, Aleksandra Rojek, Monika Przewlocka-Kosmala, Leah Wright, Andrzej Mysiak, Thomas H Marwick
BACKGROUND: Impaired functional capacity is a hallmark of patients with heart failure with preserved ejection fraction (HFpEF). Despite the association of HFpEF with reduced myocardial compliance attributed to fibrosis, spironolactone has not been shown to alter outcomes-perhaps reflecting the heterogeneity of underlying pathological mechanisms. OBJECTIVES: The authors sought to identify improvement in exercise capacity with spironolactone in the subset of patients with HFpEF with exercise-induced increase in ratio between early mitral inflow velocity and mitral annular early diastolic velocity (E/e') reflecting elevation of left ventricular (LV) filling pressure...
October 25, 2016: Journal of the American College of Cardiology
Yang Li, Jian Li, Zhiwen Hou, Yang Yu, Bo Yu
The primary physiological function of Krüppel-like zinc-finger transcription factor (KLF5) is the regulation of cardiovascular remodeling. Vascular remodeling is closely related to the amelioration of various ischemic diseases. However, the underlying correlation of KLF5 and ischemia is not clear. In this study, we aim to investigate the role of KLF5 in myocardial ischemia reperfusion (IR) injury and the potential mechanisms involved. Cultured H9C2 cells were subjected to oxygen-glucose deprivation/reperfusion (OGD/Rep) to mimic myocardial IR injury in vivo...
October 17, 2016: Biomedicine & Pharmacotherapy, Biomédecine & Pharmacothérapie
Hani N Sabbah
Introduction Heart failure (HF) has reached epidemic proportions worldwide. Despite the availability of drugs that reduce mortality and afford good symptom relief, HF continues to exact a considerable clinical and economic burden. Current HF therapies elicit benefit by reducing cardiac workload by lowering heart rate and loading conditions, thereby reducing myocardial energy demands. Areas covered Recent recognition that the failing heart is "energy deprived" and its primary energy source, the mitochondria, is dysfunctional, has focused attention on mitochondria as a worthy therapeutic target...
October 19, 2016: Expert Review of Cardiovascular Therapy
Yang Sun, Dajun Zhao, Yang Yang, Chao Gao, Xing Zhang, Zhiqiang Ma, Shuai Jiang, Lin Zhao, Wenhao Chen, Kai Ren, Wei Yi, Feng Gao
The underlying mechanisms of cardioprotection of adiponectin (APN) against ischemia/reperfusion (I/R) injury remain largely unknown. The present study aimed to investigate whether calreticulin (CRT) mediated APN's cardioprotection against I/R injury. We inhibited mice cardiac CRT expression via intra-myocardial injection of CRT SiRNA, performed transient LAD ligation, measured the cardiac function, apoptosis and oxidative stress to identify CRT's effects on cardioprotective actions of APN against I/R injury in vivo...
October 18, 2016: Apoptosis: An International Journal on Programmed Cell Death
Agathe Gerwina Elena Pollmann, Marianne Frederiksen, Eva Prescott
PURPOSE: Evidence of the effect of cardiac rehabilitation (CR) after heart valve surgery is scarce, but nevertheless CR is recommended for this group of patients. Therefore, this study assessed the effect of CR on exercise capacity, cardiovascular risk factors, and long-term mortality and morbidity, as well as predictors for enrolment in or failing to complete CR. METHODS: A review of medical records identified 250 patients who underwent heart valve surgery between January 2009 and August 2013...
October 14, 2016: Journal of Cardiopulmonary Rehabilitation and Prevention
Martino Deidda, Rosalinda Madonna, Ruggiero Mango, Pasquale Pagliaro, Pier P Bassareo, Lucia Cugusi, Silvio Romano, Maria Penco, Francesco Romeo, Giuseppe Mercuro
Despite advances in supportive and protective therapy for myocardial function, heart failure caused by various clinical conditions, including cardiomyopathy due to antineoplastic therapy, remains a major cause of morbidity and mortality. Because of the limitations associated with current therapies, investigators have been searching for alternative treatments that can effectively repair the damaged heart and permanently restore its function. Damage to the heart can result from both traditional chemotherapeutic agents, such as anthracyclines, and new targeted therapies, such as trastuzumab...
May 2016: Journal of Cardiovascular Medicine
Kyoung Im Cho, Min Gu Chon
OBJECTIVE: Inhaled ilroprost can improve clinical status and symptoms in Eisenmenger syndrome (ES). Right ventricular (RV) function is important prognostic factor of pulmonary arterial hypertension. But there has been insufficient data in echocardiographic parameters related to RV function after long term iloprost therapy. So we evaluated effect of long term iloprost treatment on RV function and other parameters measured by echocardiography in this study. DESIGN AND METHOD: Eleven consecutive patients with ES associated with congenital heart disease underwent echocardiographic measurements at baseline and 48 weeks after iloprost therapy...
September 2016: Journal of Hypertension
Muhammad Oneeb Rehman Mian, Julie Demeulemeester, Jean-Luc Bigras, Mariane Bertagnolli, Li Feng Xie, Katryn Paquette, Rong Wu, Anik Cloutier, Thuy Mai Luu, Anne-Monique Nuyt
OBJECTIVE: Studies support a direct causal association between preterm birth and increased risk of cardiovascular diseases. Increased left and right ventricular mass, and impaired systolic and diastolic function were observed in young adults born preterm. Deleterious neonatal conditions, as in preterm birth, could significantly impact on myocardial tissue. We investigated how left ventricle (LV) echocardiographic parameters in young adults born preterm correlated with neonatal health parameters and interventions data...
September 2016: Journal of Hypertension
Jason J Rose, Ling Wang, Qinzi Xu, Charles F McTiernan, Sruti Shiva, Jesus Tejero, Mark T Gladwin
Carbon monoxide (CO) poisoning affects 50,000 people a year in the United States. The clinical presentation runs a spectrum, ranging from headache and dizziness to coma and death, with a mortality rate ranging from 1-3%. A significant number of patients who survive CO poisoning suffer from long term neurologic and affective sequelae. The neurologic deficits do not necessarily correlate with blood CO levels, but likely result from the pleiotropic effects of CO on cellular mitochondrial respiration, cellular energy utilization, inflammation and free radical generation, especially in the brain and heart...
October 18, 2016: American Journal of Respiratory and Critical Care Medicine
Maude St-Onge, Kurt Anseeuw, Frank Lee Cantrell, Ian C Gilchrist, Philippe Hantson, Benoit Bailey, Valéry Lavergne, Sophie Gosselin, William Kerns, Martin Laliberté, Eric J Lavonas, David N Juurlink, John Muscedere, Chen-Chang Yang, Tasnim Sinuff, Michael Rieder, Bruno Mégarbane
OBJECTIVE: To provide a management approach for adults with calcium channel blocker poisoning. DATA SOURCES, STUDY SELECTION, AND DATA EXTRACTION: Following the Appraisal of Guidelines for Research & Evaluation II instrument, initial voting statements were constructed based on summaries outlining the evidence, risks, and benefits. DATA SYNTHESIS: We recommend 1) for asymptomatic patients, observation and consideration of decontamination following a potentially toxic calcium channel blocker ingestion (1D); 2) as first-line therapies (prioritized based on desired effect), IV calcium (1D), high-dose insulin therapy (1D-2D), and norepinephrine and/or epinephrine (1D)...
October 3, 2016: Critical Care Medicine
Wangde Dai, Elissa Cheung, Rick J Alleman, Justin B Perry, Mitchell E Allen, David A Brown, Robert A Kloner
PURPOSE: Dysfunctional mitochondria are considered to be the major source of intracellular reactive oxygen species and play a central role in the pathophysiology of myocardial ischemia/reperfusion. This study sought to determine effects of mitochondria-targeted cytoprotective peptide SBT-20 on myocardial infarct size in two different models of ischemia/reperfusion. METHODS: For in vivo studies, anesthetized Sprague Dawley rats were subjected to 30 min of coronary artery occlusion followed by 3 h of reperfusion...
October 17, 2016: Cardiovascular Drugs and Therapy
Jennifer Gile, Tobias Eckle
Cardiovascular disease is the number one cause of death worldwide. A powerful strategy for cardioprotection would be to identify specific molecules or targets that mimic ischemic preconditioning (IP), where short non-lethal episodes of ischemia and reperfusion prior to myocardial infarction result in dramatic reduction of infarct sizes. Since 1960 researchers believed that adenosine has a strong cardio-protective potential. In fact, with the discovery of cardiac IP in 1986 by Murry et al., adenosine was the first identified molecule that was used in studying the underlying mechanism of IP...
2016: Journal of Nature and Science
Nicolas Persico, Jeremy Bourenne, Antoine Roch
No abstract text is available yet for this article.
September 2016: Journal of Thoracic Disease
María S Brea, Romina G Díaz, Daiana S Escudero, Claudia I Caldiz, Enrique L Portiansky, Patricio E Morgan, Néstor G Pérez
BACKGROUND: Myocardial stretch increases force biphasically: the Frank-Starling mechanism followed by the slow force response (SFR). Based on pharmacological strategies, we proposed that epidermal growth factor (EGF) receptor (EGFR or ErbB1) activation is crucial for SFR development. Pharmacological inhibitors could block ErbB4, a member of the ErbB family present in the adult heart. We aimed to specifically test the role of EGFR activation after stretch, with an interference RNA incorporated into a lentiviral vector (small hairpin RNA [shRNA]-EGFR)...
October 15, 2016: Journal of the American Heart Association
Andreia Noites, Carla Patrícia Freitas, Joana Pinto, Cristina Melo, Ágata Vieira, Aníbal Albuquerque, Madalena Teixeira, Fernando Ribeiro, José Mesquita Bastos
BACKGROUND: Cardiovascular diseases are the leading cause of death globally and sedentary lifestyle is one of the main risk factors. Home-based cardiac rehabilitation (CR) programs appear to be effective to improve exercise tolerance. The aim of the study, therefore, was to evaluate the effects of a phase IV (maintenance) home-based CR program on cardiorespiratory fitness and daily physical activity of patients recovering from an acute myocardial infarction. METHODS: This pilot study, with a sub-group randomised controlled trial, included 32 individuals recovering from a myocardial infarction, randomly divided into the experimental group (EG, n=16) and the control group (CG, n=16)...
September 13, 2016: Heart, Lung & Circulation
German Cediel, Maribel Gonzalez-Del-Hoyo, Anna Carrasquer, Rafael Sanchez, Carme Boqué, Alfredo Bardají
OBJECTIVE: To identify patients with type 2 myocardial infarction (MI) and patients with non-ischaemic myocardial injury (NIMI) and to compare their prognosis with those of patients with type 1 MI. METHODS: A retrospective observational study was performed in 1010 patients admitted to the emergency department of a university hospital with at least one troponin I test between 2012 and 2013. Participants were identified using laboratory records and divided into three groups: type 1 MI (rupture of atheromatous plaque), type 2 MI (imbalance between myocardial oxygen supply and/or demand) and NIMI (patients who did not meet diagnostic criteria for type 1 or type 2 MI)...
October 14, 2016: Heart: Official Journal of the British Cardiac Society
Kady Fischer, Dominik P Guensch, Nancy Shie, Julie Lebel, Matthias G Friedrich
BACKGROUND: Breathing maneuvers can elicit a similar vascular response as vasodilatory agents like adenosine; yet, their potential diagnostic utility in the presence of coronary artery stenosis is unknown. The objective of the study is to investigate if breathing maneuvers can non-invasively detect inducible ischemia in an experimental animal model when the myocardium is imaged with oxygenation-sensitive cardiovascular magnetic resonance (OS-CMR). METHODS AND FINDINGS: In 11 anesthetised swine with experimentally induced significant stenosis (fractional flow reserve <0...
2016: PloS One
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"