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Cardiac perfusion

Bhavisha Bakrania, Joey P Granger, Romain Harmancey
The mammalian heart is a major consumer of ATP and requires a constant supply of energy substrates for contraction. Not surprisingly, alterations of myocardial metabolism have been linked to the development of contractile dysfunction and heart failure. Therefore, unraveling the link between metabolism and contraction should shed light on some of the mechanisms governing cardiac adaptation or maladaptation in disease states. The isolated working rat heart preparation can be used to follow, simultaneously and in real time, cardiac contractile function and flux of energy providing substrates into oxidative metabolic pathways...
September 28, 2016: Journal of Visualized Experiments: JoVE
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
Hsing-Hua Tsai, Chin-Pu Lin, Yi-Hui Lin, Chih-Chin Hsu, Jong-Shyan Wang
PURPOSE: Exercise training improves endothelium-dependent vasodilation, whereas hypoxic stress causes vascular endothelial dysfunction. Monocyte-derived endothelial progenitor cells (Mon-EPCs) contribute to vascular repair process by differentiating into endothelial cells. This study investigates how high-intensity interval (HIT) and moderate-intensity continuous (MCT) exercise training affect circulating Mon-EPC levels and EPC functionality under hypoxic condition. METHODS: Sixty healthy sedentary males were randomized to engage in either HIT (3-min intervals at 40 and 80 % VO2max for five repetitions, n = 20) or MCT (sustained 60 % VO2max, n = 20) for 30 min/day, 5 days/week for 6 weeks, or to a control group (CTL) that did not received exercise intervention (n = 20)...
October 19, 2016: European Journal of Applied Physiology
Haleh Vaez, Moslem Najafi, Maryam Rameshrad, Negisa Seyed Toutounchi, Mehraveh Garjani, Jaleh Barar, Alireza Garjani
Toll like receptors (TLRs) are key players in the innate immune responses. The energy sensing enzyme, AMPK, has been implicated in the modulation of immunity. The present study investigated whether AMPK activation by metformin could contribute to the regulation of immune responses in the isolated heart via suppression of TLR4 activity, independent of circulatory immunity. Isolated Wistar rat hearts were perfused with Krebs-Henseleit buffer in the absence or presence of lipopolysaccharide (LPS; 0.2μM), LPS+metformin (10mM), and LPS+metformin+compound C (10μM)...
October 14, 2016: International Immunopharmacology
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
Sang-Geon Cho, Zeenat Jabin, Ki Seong Park, Jahae Kim, Sae-Ryung Kang, Seong Young Kwon, Geum-Cheol Jeong, Minchul Song, Jong Sang Kim, Jae Yeong Cho, Hyun Kuk Kim, Ho-Chun Song, Jung-Joon Min, Hee-Seung Bom
PURPOSE: The aim of this study was to evaluate the prognostic value of additional evaluation of left ventricular mechanical dyssynchrony (LVMD) by gated myocardial perfusion single-photon emission computed tomography (GMPS) in patients with acute myocardial infarction (MI) and multivessel disease. METHODS: One hundred and nine acute MI patients with >50 % stenosis in at least one non-culprit artery who underwent GMPS within 2 weeks were enrolled. All patients underwent successful revascularization of the culprit arteries...
October 18, 2016: European Journal of Nuclear Medicine and Molecular Imaging
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
Mark Doyle, Gerald M Pohost, C Noel Bairey Merz, Leslee J Shaw, George Sopko, William J Rogers, Barry L Sharaf, Carl J Pepine, Diane V Thompson, Geetha Rayarao, Lindsey Tauxe, Sheryl F Kelsey, Robert W W Biederman
BACKGROUND: We introduce an algorithmic approach to optimize diagnostic and prognostic value of gated cardiac single photon emission computed tomography (SPECT) and magnetic resonance (MR) myocardial perfusion imaging (MPI) modalities in women with suspected myocardial ischemia. The novel approach: bio-informatics assessment schema (BIAS) forms a mathematical model utilizing MPI data and cardiac metrics generated by one modality to predict the MPI status of another modality. The model identifies cardiac features that either enhance or mask the image-based evidence of ischemia...
October 2016: Cardiovascular Diagnosis and Therapy
Nicole Kurhanewicz, Rachel McIntosh-Kastrinsky, Haiyan Tong, Allen Ledbetter, Leon Walsh, Aimen Farraj, Mehdi Hazari
Short-term exposure to ambient air pollution is linked with adverse cardiovascular effects. While previous research focused primarily on particulate matter-induced responses, gaseous air pollutants also contribute to cause short-term cardiovascular effects. Mechanisms underlying such effects have not been adequately described, however the immediate nature of the response suggests involvement of irritant neural activation and downstream autonomic dysfunction. Thus, this study examines the role of TRPA1, an irritant sensory receptor found in the airways, in the cardiac response of mice to acrolein and ozone...
October 13, 2016: Toxicology and Applied Pharmacology
Rafel Ramos, Xavier Albert, Joan Sala, Maria Garcia-Gil, Roberto Elosua, Jaume Marrugat, Anna Ponjoan, María Grau, Manel Morales, Antoni Rubió, Pedro Ortuño, Lia Alves-Cabratosa, Ruth Martí-Lluch
BACKGROUND: Diagnosis of unrecognized myocardial infarction (UMI) remains an open question in epidemiological and clinical studies, inhibiting effective secondary prevention of myocardial infarction. We aimed to determine the prevalence and incidence of Q-wave UMI in asymptomatic individuals aged 35 to 74years, and to ascertain the positive predictive value (PPV) of asymptomatic Q-wave to diagnose UMI. METHODS: Two population-based cross-sectional studies were conducted, in 2000 (with 10-year follow-up) and in 2005...
October 5, 2016: International Journal of Cardiology
Jiahong Wang, Lan Zhao, Jiarui Wei, Shaoheng Zhang, Nannan Chen, Dongxing Ding, Qunlin Gong, Feng Su, Jian Yan, Pengxiang Zheng
BACKGROUND: Various therapies have been used to improve the symptoms and prognosis of patients with coronary artery disease. However, comparative studies showing more suitable choices for patients with ischaemic dilated cardiomyopathy (IDCM) and who smoke cigarettes are lacking. METHODS: A total of 338 patients were divided into four groups according to whether they received complete revascularisation (CR), and/or underwent smoking cessation (SC). They were followed prospectively for 12 months...
September 26, 2016: Heart, Lung & Circulation
Adam Ali Ghotbi, Andreas Kjaer, Lars Nepper-Christensen, Kiril Aleksov Ahtarovski, Jacob Thomsen Lønborg, Niels Vejlstrup, Kasper Kyhl, Thomas Emil Christensen, Thomas Engstrøm, Henning Kelbæk, Lene Holmvang, Lia E Bang, Rasmus Sejersten Ripa, Philip Hasbak
BACKGROUND: Determining infarct size and myocardial salvage in patients with ST-segment elevation myocardial infarction (STEMI) is important when assessing the efficacy of new reperfusion strategies. We investigated whether rest (82)Rb-PET myocardial perfusion imaging can estimate area at risk, final infarct size, and myocardial salvage index when compared to cardiac SPECT and magnetic resonance (CMR). METHODS: Twelve STEMI patients were injected with (99m)Tc-Sestamibi intravenously immediate prior to reperfusion...
October 14, 2016: Journal of Nuclear Cardiology: Official Publication of the American Society of Nuclear Cardiology
Guido Germano, Paul B Kavanagh, Terrence D Ruddy, R Glenn Wells, Yuan Xu, Daniel S Berman, Piotr J Slomka
OBJECTIVES: This paper investigates the ability of grouped quantification (an expression of the same-patient processing approach, or SPP) to improve repeatability of measurements in patients with multiple SPECT studies, and evaluates its performance compared to standard quantification in a population of 100 patients undergoing rest, stress, gated rest, and gated stress SPECT MPI. All acquisitions were performed twice, back-to-back, for a total of 800 image datasets (8 per patient). METHODS: Each dataset was automatically processed (a) independently, using standard quantitative software, and (b) as a group, together with the other 7 datasets belonging to the same patient, using an SPP-modified version of the software that registered the images to one another using a downhill simplex algorithm for the search of optimal translation, rotation, and scaling parameters...
October 14, 2016: Journal of Nuclear Cardiology: Official Publication of the American Society of Nuclear Cardiology
L Meng, N Matsuno, K Watanabe, M Furukori, H Obara, H Bochimoto, T Watanabe, H Fukukawa
BACKGROUND: The shortage of organ donors is a universal problem. Use of grafts from donors after cardiac death would greatly contribute to the expansion of the donor organ pool. The two major methods of preservation are cold storage and machine perfusion (MP) preservation, and each has its own advantages. Several studies have reported the relative merits of MP for the preservation for grafts from donors after cardiac death. In this study, we used scanning electron microscopy (SEM) to assess the damage to the liver between hypothermic and rewarming preservation conditions...
September 2016: Transplantation Proceedings
J Hunter Mehaffey, Eric J Charles, Ashish K Sharma, Dustin T Money, Yunge Zhao, Mark H Stoler, Christine L Lau, Curtis G Tribble, Victor E Laubach, Mark E Roeser, Irving L Kron
OBJECTIVE: Critical organ shortages have resulted in ex vivo lung perfusion gaining clinical acceptance for lung evaluation and rehabilitation to expand the use of donation after circulatory death organs for lung transplantation. We hypothesized that an innovative use of airway pressure release ventilation during ex vivo lung perfusion improves lung function after transplantation. METHODS: Two groups (n = 4 animals/group) of porcine donation after circulatory death donor lungs were procured after hypoxic cardiac arrest and a 2-hour period of warm ischemia, followed by a 4-hour period of ex vivo lung perfusion rehabilitation with standard conventional volume-based ventilation or pressure-based airway pressure release ventilation...
September 22, 2016: Journal of Thoracic and Cardiovascular Surgery
Anu K Kaskinen, Laura Martelius, Turkka Kirjavainen, Paula Rautiainen, Sture Andersson, Olli M Pitkänen
BACKGROUND: Lung ultrasounds show vertical artifacts known as B-lines in the presence of increased extravascular lung water (EVLW). We aimed to investigate whether lung ultrasound could estimate EVLW after congenital cardiac surgery. METHODS: This prospective observational study comprised 61 children (age range 3 days to 7.4 years) undergoing congenital cardiac surgery. We compared postoperative B-line scores from lung ultrasounds, early postoperative ultrasound as our primary interest, with corresponding postoperative chest radiography (CXR) lung edema scores, with static lung compliance, and with short-term clinical outcome interpreted as time on mechanical ventilation and length of pediatric intensive care unit (PICU) stay...
October 14, 2016: Pediatric Pulmonology
Tobias Opthof, Carol Ann Remme, Esther Jorge, Francisco Noriega, Rob F Wiegerinck, Arlin Tasiam, Leander Beekman, Jesus Alvarez-Garcia, Cristian Munoz-Guijosa, Ruben Coronel, Juan Cinca
BACKGROUND: The repolarization pattern of the human heart is unknown. OBJECTIVE: We performed a multisite analysis of the activation-repolarization patterns and mRNA expression patterns of ion channel subunits in isolated human hearts. METHODS: Hearts from three donors without reported cardiac disease were Langendorff perfused with the patient's own blood. A standard ECG was obtained prior to explantation. Up to 92 unipolar electrograms from 24 transmural needles were obtained during right atrial pacing...
October 10, 2016: Heart Rhythm: the Official Journal of the Heart Rhythm Society
Kyoko Hijiya, Toyofumi F Chen-Yoshikawa, Takeshi Kondo, Hideki Motoyama, Akihiro Ohsumi, Daisuke Nakajima, Jin Sakamoto, Keiji Ohata, Mamoru Takahashi, Satona Tanaka, Ei Miyamoto, Akihiro Aoyama, Hiroshi Date
BACKGROUND: We hypothesized that an injured lung graft from donation after cardiac death donors could be reconditioned before transplantation using an ex vivo lung perfusion (EVLP) system and ventilation with high-dose short-acting β2-adrenergic receptor agonists. METHODS: Cardiac arrest was induced in a canine model by intravenous potassium chloride injection. Lungs were randomly assigned to two groups after 150 minutes of warm ischemia: inhalation of 1,400 μg of procaterol (BETA group, n = 5) or control group receiving solvent (CON group, n = 5) during EVLP...
October 10, 2016: Annals of Thoracic Surgery
Charles L Francoeur, Stephan A Mayer
For patients who survive the initial bleeding event of a ruptured brain aneurysm, delayed cerebral ischemia (DCI) is one of the most important causes of mortality and poor neurological outcome. New insights in the last decade have led to an important paradigm shift in the understanding of DCI pathogenesis. Large-vessel cerebral vasospasm has been challenged as the sole causal mechanism; new hypotheses now focus on the early brain injury, microcirculatory dysfunction, impaired autoregulation, and spreading depolarization...
October 14, 2016: Critical Care: the Official Journal of the Critical Care Forum
Mohamed Ghalayini, Pierre-Yves Brun, Pascal Augustin, Elise Guivarch, Marie Pierre Dilly, Sophie Provenchere, Pierre Mordant, Yves Castier, Philippe Montravers, Dan Longrois
Competitive flows syndrome result in severe regional hypoxemia when the deoxygenated flow from the native left ventricle (LV) competes with oxygenated flow from extracorporeal life support (ECLS) pump with potentially severe consequences for the cerebral and coronary circulations. Fast correction of hypoxemia could be obtained by decreasing native LV flow by infusion of a short-acting beta-blocker (esmolol). Our purpose was to retrospectively review the efficacy of esmolol in this situation and hypothesize on the potential mechanisms of action and the associated risks...
September 2016: Journal of Extra-corporeal Technology
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