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Myocardial blood flow

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
Chris Amdisen, Anna K Keller, Rie Schultz Hansen, Rikke Nørregaard, Søren Palmelund Krag, Ulla Møldrup, Michael Pedersen, Bente Jespersen, Henrik Birn
INTRODUCTION: Ischemia/reperfusion injury (I/R-I) is a leading cause of acute kidney injury (AKI) and is associated with increased mortality. Danegaptide is a selective modifier of the gap junction protein connexion 43. It has cytoprotective as well as anti-arrhythmic properties and has been shown to reduce the size of myocardial infarct in pigs. The aim of this study was to investigate the ischemia-protective effect of Danegaptide in a porcine renal I/R-I model with two weeks follow up...
2016: PloS One
Junichiro Hashimoto
Arterial structure and function change progressively with advancing age. Owing to long-lasting repetitive stretch with intermittent cardiac contraction, elastic fibers in the tunica media of large arteries gradually degenerate and are replaced by collagenous fibers. Such medial degeneration causes elastic arteries to stiffen and dilate. However, the speed of the vascular aging varies considerably among individuals; a discrepancy often exists between the chronological age of an individual and the biological age of his or her arteries...
September 2016: Journal of Hypertension
Enrico Agabiti Rosei
Current Hypertension Guidelines emphasize the importance of assessing the presence of preclinical organ damage. In fact, an extensive evaluation of organ damage may increase the number of patients classified at high CV risk and therefore strongly influence the clinical management of patients. Hypertensive heart disease remains to date the form of organ damage for which there is the greatest amount of evidence of a strong independent prognostic significance. In the presence of a chronic pressure overload, a parallel addition of sarcomers takes place with an increase in myocyte width, which in turn increases left ventricular wall thickness; myocyte hypertrophy is also associated with apoptosis, collagen deposition and ventricular fibrosis with an impairment of coronary hemodynamics as well, thus profoundly influencing functional properties of the left (and right) ventricle...
September 2016: Journal of Hypertension
Sang-Chol Lee
Chronic hypertension can result in deleterious effects on various vascular organs including the heart and vessels. Cardiovascular magnetic resonance (CMR) has the unique advantage of the ability to assess ventricular volumes and function, valvular abnormalities, vascular pathology, myocardial perfusion and tissue characterization with high accuracy and reproducibility and also avoid the risk of radiation. As this is the case, CMR seems to be an ideal method for comprehensive assessment of patients with systemic hypertension...
September 2016: Journal of Hypertension
Puneet Kaur Randhawa, Amteshwar Singh Jaggi
Remote ischemic preconditioning (RIPC) treatment strategy is a breakthrough in the field of cardiovascular pharmacology as it has the potential to attenuate myocardial ischemia-reperfusion injury. However, the underlying intracellular pathways have not been widely explored. The present study intends to explore the possible role of TRPV1 channels in mediating remote hind limb preconditioning-induced cardioprotection. Remote hind limb preconditioning stimulus (4 cycles in succession) was delivered by tying the blood pressure cuff at the inguinal level of the rat...
October 17, 2016: Naunyn-Schmiedeberg's Archives of Pharmacology
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
Salim S Hayek, Yuri Klyachkin, Ahmed Asfour, Nima Ghasemzadeh, Mosaab Awad, Iraj Hesaroieh, Hina Ahmed, Brandon Gray, Jinhee Kim, Edmund K Waller, Arshed A Quyyumi, Ahmed K Abdel-Latif
: : Bone marrow-derived progenitor cells are mobilized into the peripheral blood after acute myocardial injury and in chronic ischemic heart disease. However, the mechanisms responsible for this mobilization are poorly understood. We examined the relationship between plasma levels of bioactive lipids and number of circulating progenitor cells (CPCs) in patients (N = 437) undergoing elective or emergent cardiac catheterization. Plasma levels of sphingosine-1 phosphate (S1P) and ceramide-1 phosphate (C1P) were quantified using mass spectrometry...
October 14, 2016: Stem Cells Translational Medicine
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
Francesco Giannini, Andrea Aurelio, Alaide Chieffo
Refractory angina is a chronic condition characterized by the presence of disabling symptoms due to severe obstructive coronary artery disease not improved by either optimal medical therapy and/or percutaneous or surgical revascularization. Mortality rates associated with this condition are quite low in clinically stable patients on optimal medical therapy. However, rehospitalization rates are high. In this subgroup of patients there is thus a clinical need for new therapies targeting an improvement of symptoms but taking into account the potential impact in terms of healthcare and costs...
October 2016: Giornale Italiano di Cardiologia
Asim Rizvi, Bríain Ó Hartaigh, Paul Knaapen, Jonathon Leipsic, Leslee J Shaw, Daniele Andreini, Gianluca Pontone, Subha Raman, Muhammad Akram Khan, Michael Ridner, Faisal Nabi, Alessia Gimelli, James Jang, Jason Cole, Ryo Nakazato, Christopher Zarins, Donghee Han, Ji Hyun Lee, Jackie Szymonifika, Millie J Gomez, Quynh A Truong, Hyuk-Jae Chang, Fay Y Lin, James K Min
BACKGROUND: Coronary computed tomography angiography (CCTA) allows for non-invasive assessment of obstructive coronary artery disease (CAD) beyond measures of stenosis severity alone. This assessment includes atherosclerotic plaque characteristics (APCs) and calculation of fractional flow reserve (FFR) from CCTA (FFRCT). Similarly, stress imaging by myocardial perfusion scintigraphy (MPS) provides vital information. To date, the diagnostic performance of integrated CCTA assessment versus integrated MPS assessment for diagnosis of vessel-specific ischemia remains underexplored...
October 6, 2016: BMC Cardiovascular Disorders
Claire E Raphael, Robert Cooper, Kim H Parker, Julian Collinson, Vassilis Vassiliou, Dudley J Pennell, Ranil de Silva, Li Yueh Hsu, Anders M Greve, Sukh Nijjer, Chris Broyd, Aamir Ali, Jennifer Keegan, Darrel P Francis, Justin E Davies, Alun D Hughes, Andrew Arai, Michael Frenneaux, Rod H Stables, Carlo Di Mario, Sanjay K Prasad
BACKGROUND: Angina is common in hypertrophic cardiomyopathy (HCM) and is associated with abnormal myocardial perfusion. Wave intensity analysis improves the understanding of the mechanics of myocardial ischemia. OBJECTIVES: Wave intensity analysis was used to describe the mechanisms underlying perfusion abnormalities in patients with HCM. METHODS: Simultaneous pressure and flow were measured in the proximal left anterior descending artery in 33 patients with HCM and 20 control patients at rest and during hyperemia, allowing calculation of wave intensity...
October 11, 2016: Journal of the American College of Cardiology
Z Zhang, Z Xu, Y Dai, Y Chen
Homocysteine is an amino acid that is produced from the metabolic demethylation of dietary methionine. It has gained arising attention for its association with increased risk of myocardial infarction, stroke and venous thromboembolism. Erectile dysfunction (ED), especially for vasculogenic ED, is a vascular disorder of cavernosal vascular bed. In this prospective pilot case-control study, we investigated plasma homocysteine levels in 32 ED patients and 20 healthy control men. Related patients characteristics including age, weight, height, marital status, smoking and drinking status, level of education were collected and analysed as well as penile colour Doppler ultrasound parameters...
October 6, 2016: Andrologia
Adriaan Coenen, Marisa M Lubbers, Akira Kurata, Atsushi Kono, Admir Dedic, Raluca G Chelu, Marcel L Dijkshoorn, Alexia Rossi, Robert-Jan M van Geuns, Koen Nieman
OBJECTIVES: To investigate the additional value of transmural perfusion ratio (TPR) in dynamic CT myocardial perfusion imaging for detection of haemodynamically significant coronary artery disease compared with fractional flow reserve (FFR). METHODS: Subjects with suspected or known coronary artery disease were prospectively included and underwent a CT-MPI examination. From the CT-MPI time-point data absolute myocardial blood flow (MBF) values were temporally resolved using a hybrid deconvolution model...
October 4, 2016: European Radiology
Michael B Stokes, Nitesh Nerlekar, Stuart Moir, Karen S Teo
BACKGROUND: Imaging of the heart is important in the diagnosis and follow-up of a broad range of cardiac pathology. The authors discuss the growing role of cardiac magnetic resonance imaging (CMR) in cardiology practice and its relevance to primary healthcare. OBJECTIVE: In this article we discuss the advantages of CMR over other imaging modalities, and give a brief description of the common CMR techniques and cardiac pathologies where CMR is especially useful. DISCUSSION: CMR provides specific advantages over other cardiac imaging modalities when evaluating pathology in congenital heart disease, cardiac masses, cardiomyopathies, and in some aspects of ischaemic and valvular heart diseases...
October 2016: Australian Family Physician
Giuseppe Muscogiuri, Wolfgang G Rehwald, U Joseph Schoepf, Pal Suranyi, Sheldon E Litwin, Carlo N De Cecco, Julian L Wichmann, Stefanie Mangold, Damiano Caruso, Stephen R Fuller, Richard R Bayer 2nd, Akos Varga-Szemes
PURPOSE: To evaluate a new dark-blood late gadolinium enhancement (LGE) technique called "T(Rho) And Magnetization transfer and INvErsion Recovery" (TRAMINER) for the ability to detect myocardial LGE versus standard "bright-blood" inversion recovery (SIR) imaging. MATERIALS AND METHODS: This Institutional Review Board (IRB)-approved, Health Insurance Portability and Accountability Act (HIPAA)-compliant prospective study included 40 patients (62 ± 14 years [mean ± standard deviation (SD)], 29 males) with suspected myocardial infarction (MI) referred for the assessment of myocardial viability...
September 30, 2016: Journal of Magnetic Resonance Imaging: JMRI
Ursula Reiter, Gert Reiter, Martin Manninger, Gabriel Adelsmayr, Julia Schipke, Alessio Alogna, Alexandra Rajces, Aurelien F Stalder, Andreas Greiser, Christian Mühlfeld, Daniel Scherr, Heiner Post, Burkert Pieske, Michael Fuchsjäger
BACKGROUND: The hypertensive deoxy-corticosterone acetate (DOCA)-salt-treated pig (hereafter, DOCA pig) was recently introduced as large animal model for early-stage heart failure with preserved ejection fraction (HFpEF). The aim of the present study was to evaluate cardiovascular magnetic resonance (CMR) of DOCA pigs and weight-matched control pigs to characterize ventricular, atrial and myocardial structure and function of this phenotype model. METHODS: Five anesthetized DOCA and seven control pigs underwent 3 T CMR at rest and during dobutamine stress...
September 30, 2016: Journal of Cardiovascular Magnetic Resonance
Sebastiaan T Roos, François T Yu, Otto Kamp, Xucai Chen, Flordeliza S Villanueva, John J Pacella
Coronary intervention for myocardial infarction often results in microvascular embolization of thrombus. Sonoreperfusion therapy (SRP) using ultrasound and microbubbles restored perfusion in our in vitro flow model of microvascular obstruction. In this study, we assessed SRP efficacy using whole blood as the perfusate with and without tissue plasminogen activator (tPA). In a phantom vessel bearing a 40-μm-pore mesh to simulate the microvasculature, microthrombi were injected to cause microvascular obstruction and were treated using SRP...
September 26, 2016: Ultrasound in Medicine & Biology
Cher-Rin Chong, Gao J Ong, John D Horowitz
Angina pectoris, or symptomatic myocardial ischaemia, reflects an impairment of coronary blood flow, and usually a deficiency of available myocardial energetics. Treatment options vary with the precise cause, which may vary with regards to the roles of increased myocardial oxygen demand versus reduced supply. Traditionally, organic nitrates, β-adrenoceptor antagonists, and non-dihydropyridine calcium antagonists were the only commonly used prophylactic anti-anginal agents. However, many patients failed to respond adequately to such therapy, and/or were unsuitable for their use...
October 6, 2016: Expert Opinion on Emerging Drugs
Ljubica Mandic, Denise Traxler, Alfred Gugerell, Katrin Zlabinger, Dominika Lukovic, Noemi Pavo, Georg Goliasch, Andreas Spannbauer, Johannes Winkler, Mariann Gyöngyösi
PURPOSE OF REVIEW: Myocardial infarction (MI) leading to heart failure displays an important cause of death worldwide. Adequate restoration of blood flow to prevent this transition is a crucial factor to improve long-term morbidity and mortality. Novel regenerative therapies have been thoroughly investigated within the past decades. RECENT FINDINGS: Increased angiogenesis in infarcted myocardium has shown beneficial effects on the prognosis of MI; therefore, the proangiogenic capacity of currently tested treatments is of specific interest...
2016: Current Cardiovascular Imaging Reports
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