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https://www.readbyqxmd.com/read/29302122/rvad-support-in-the-setting-of-submassive-pulmonary-embolism
#1
Antonio Salsano, Elena Sportelli, Guido Maria Olivieri, Nicola Di Lorenzo, Silvia Borile, Francesco Santini
Patients with submassive pulmonary embolism (PE), although normotensive, are characterized by right ventricular (RV) dysfunction and elevated levels of biomarkers of cardiac damage. The best treatment option in these cases is still a subject of debate and the use of thrombolysis in submassive PE remains controversial. A 57-year-old Caucasian male with unprovoked PE, normal blood pressure, and elevated troponin I values was referred to the cardiovascular department. In view of the presence of a right atrium thrombus, the patient underwent surgical embolectomy under extracorporeal circulation, with the extraction of a huge thrombus together with fragmented thrombi from both pulmonary arteries...
December 2017: Journal of Extra-corporeal Technology
https://www.readbyqxmd.com/read/29298692/an-in-vivo-comparison-of-stimulated-echo-and-motion-compensated-spin-echo-sequences-for-3%C3%A2-t-diffusion-tensor-cardiovascular-magnetic-resonance-at-multiple-cardiac-phases
#2
Andrew D Scott, Sonia Nielles-Vallespin, Pedro F Ferreira, Zohya Khalique, Peter D Gatehouse, Philip Kilner, Dudley J Pennell, David N Firmin
BACKGROUND: Stimulated-echo (STEAM) and, more recently, motion-compensated spin-echo (M2-SE) techniques have been used for in-vivo diffusion tensor cardiovascular magnetic resonance (DT-CMR) assessment of cardiac microstructure. The two techniques differ in the length scales of diffusion interrogated, their signal-to-noise ratio efficiency and sensitivity to both motion and strain. Previous comparisons of the techniques have used high performance gradients at 1.5 T in a single cardiac phase...
January 3, 2018: Journal of Cardiovascular Magnetic Resonance
https://www.readbyqxmd.com/read/29228952/association-between-left-ventricular-mechanics-and-diffuse-myocardial-fibrosis-in-patients-with-repaired-tetralogy-of-fallot-a-cross-sectional-study
#3
Christopher M Haggerty, Jonathan D Suever, Arichanah Pulenthiran, Abba Mejia-Spiegeler, Gregory J Wehner, Linyuan Jing, Richard J Charnigo, Brandon K Fornwalt, Mark A Fogel
BACKGROUND: Patients with repaired tetralogy of Fallot (TOF) have progressive, adverse biventricular remodeling, leading to abnormal contractile mechanics. Defining the mechanisms underlying this dysfunction, such as diffuse myocardial fibrosis, may provide insights into poor long-term outcomes. We hypothesized that left ventricular (LV) diffuse fibrosis is related to impaired LV mechanics. METHODS: Patients with TOF were evaluated with cardiac magnetic resonance in which modified Look-Locker (MOLLI) T1-mapping and spiral cine Displacement encoding (DENSE) sequences were acquired at three LV short-axis positions...
December 11, 2017: Journal of Cardiovascular Magnetic Resonance
https://www.readbyqxmd.com/read/29216239/effects-of-early-afterdepolarizations-on-excitation-patterns-in-an-accurate-model-of-the-human-ventricles
#4
Enid Van Nieuwenhuyse, Gunnar Seemann, Alexander V Panfilov, Nele Vandersickel
Early Afterdepolarizations, EADs, are defined as the reversal of the action potential before completion of the repolarization phase, which can result in ectopic beats. However, the series of mechanisms of EADs leading to these ectopic beats and related cardiac arrhythmias are not well understood. Therefore, we aimed to investigate the influence of this single cell behavior on the whole heart level. For this study we used a modified version of the Ten Tusscher-Panfilov model of human ventricular cells (TP06) which we implemented in a 3D ventricle model including realistic fiber orientations...
2017: PloS One
https://www.readbyqxmd.com/read/29136124/what-is-the-clinical-significance-of-ventricular-mural-antagonism
#5
Paul P Lunkenheimer, Peter Niederer, Robert S Stephenson, Klaus Redmann, Randas V Batista, Morten Smerup, Robert H Anderson
Recent morphological studies provide evidence that the ventricular walls are arranged as a 3D meshwork of aggregated cardiomyocyte chains, exhibiting marked local structural variations. In contrary to previous findings, up to two-fifths of the chains are found to have a partially transmural alignment, thus deviating from the prevailing tangential orientation. Upon contraction, they produce, in addition to a tangential force, a radial force component that counteracts ventricular constriction and aids widening of the ventricular cavity...
November 9, 2017: European Journal of Cardio-thoracic Surgery
https://www.readbyqxmd.com/read/29127361/reentry-via-high-frequency-pacing-in-a-mathematical-model-for-human-ventricular-cardiac-tissue-with-a-localized-fibrotic-region
#6
Soling Zimik, Rahul Pandit
Localized heterogeneities, caused by the regional proliferation of fibroblasts, occur in mammalian hearts because of diseases like myocardial infarction. Such fibroblast clumps can become sources of pathological reentrant activities, e.g., spiral or scroll waves of electrical activation in cardiac tissue. The occurrence of reentry in cardiac tissue with heterogeneities, such as fibroblast clumps, can depend on the frequency at which the medium is paced. Therefore, it is important to study the reentry-initiating potential of such fibroblast clumps at different frequencies of pacing...
November 10, 2017: Scientific Reports
https://www.readbyqxmd.com/read/29105899/left-ventricular-geometry-as-a-major-determinant-of-left-ventricular-ejection-fraction-physiological-considerations-and-clinical-implications
#7
REVIEW
Filippos Triposkiadis, Gregory Giamouzis, Konstantinos Dean Boudoulas, Georgios Karagiannis, John Skoularigis, Harisios Boudoulas, John Parissis
The limited myocardial fibre thickening and shortening alone cannot explain the marked left ventricular (LV) volume reduction during LV ejection. This can only be achieved with LV helical (spiral) orientation of myocardial fibres, which is determined by the non-contractile LV myocardial components (intrasarcomeric and extrasarcomeric cytoskeleton, extracellular matrix). Preservation of LV ejection fraction (LVEF) in heart failure (HF) is due to the presence of normal ellipsoid LV configuration and spiral myocardial fibre orientation...
November 6, 2017: European Journal of Heart Failure
https://www.readbyqxmd.com/read/29046645/computational-cardiac-modeling-reveals-mechanisms-of-ventricular-arrhythmogenesis-in-long-qt-syndrome-type-8-cacna1c-r858h-mutation-linked-to-ventricular-fibrillation
#8
Jieyun Bai, Kuanquan Wang, Yashu Liu, Yacong Li, Cuiping Liang, Gongning Luo, Suyu Dong, Yongfeng Yuan, Henggui Zhang
Functional analysis of the L-type calcium channel has shown that the CACNA1C R858H mutation associated with severe QT interval prolongation may lead to ventricular fibrillation (VF). This study investigated multiple potential mechanisms by which the CACNA1C R858H mutation facilitates and perpetuates VF. The Ten Tusscher-Panfilov (TP06) human ventricular cell models incorporating the experimental data on the kinetic properties of L-type calcium channels were integrated into one-dimensional (1D) fiber, 2D sheet, and 3D ventricular models to investigate the pro-arrhythmic effects of CACNA1C mutations by quantifying changes in intracellular calcium handling, action potential profiles, action potential duration restitution (APDR) curves, dispersion of repolarization (DOR), QT interval and spiral wave dynamics...
2017: Frontiers in Physiology
https://www.readbyqxmd.com/read/29040438/geometric-predictors-of-left-ventricular-outflow-tract-obstruction-in-patients-with-hypertrophic-cardiomyopathy-a-3d-computed-tomography-analysis
#9
Yunsun Song, Dong Hyun Yang, Bríain Ó Hartaigh, Se Jin Cho, Joon-Won Kang, Young-Hak Kim, Joon Bum Kim, Dae-Hee Kim, Jong-Min Song, Duk-Hyun Kang, Jae-Kwan Song, Tae-Hwan Lim
Aims: To establish geometric predictors of left ventricular outflow tract obstruction (LVOTO) in hypertrophic cardiomyopathy (HCM) patients by use of cardiac computed tomography (CT). Methods and results: A total of 141 consecutive patients with HCM who underwent cardiac CT comprised the analytic sample. The degree, pattern, and extent of left ventricular (LV) hypertrophy were evaluated using 3D CT. Abnormality of papillary muscle (PM), mitral valve, and aorto-mitral angle were evaluated quantitatively...
October 11, 2017: European Heart Journal Cardiovascular Imaging
https://www.readbyqxmd.com/read/28974283/is-mesocardia-with-left-sided-caval-vein-draining-to-coronary-sinus-a-contraindication-for-a-percutaneous-pulmonary-valve-implantation-a-case-description
#10
Marinos Kantzis, Christoph M Happel, Nikolaus A Haas
Introduction Although the right jugular vein approach for percutaneous pulmonary valve implantation is well described, there are no reports that describe a percutaneous pulmonary valve implantation through a left superior caval vein to coronary sinus pathway. Case A 14-year-old female with tetralogy of Fallot, mesocardia, left superior caval vein draining into the coronary sinus, and hemiazygos continuation of the inferior caval vein underwent ventricular septal defect closure, with homograft insertion from the right ventricle to the pulmonary artery, patch augmentation of the left pulmonary artery, and creation of an atrial communication...
October 4, 2017: Cardiology in the Young
https://www.readbyqxmd.com/read/28840949/hidden-in-the-heart-a-peculiar-type-of-left-ventricular-remodeling-after-acute-myocardial-infarction
#11
Marianna Cicenia, Francesco Fedele, Valentina Petronilli, Carlotta De Carlo, Federica Moscucci, Mauro Schina, Susanna Sciomer
We reported an unusual case of left ventricular pouch, in a 72-year-old man who had an acute coronary syndrome treated with percutaneous revascularization. The echocardiogram showed a sort of pouch, delimited by epicardium and endocardium, confirmed by 3D echo. This finding appeared as an echo free area, with a really slight color flow inside. We consequently supposed it would be a dissecting hematoma, a rare complication of the ischemic disease, due to the rupture of the intramyocardial vessels among the spiral myocardial fibers...
August 25, 2017: Echocardiography
https://www.readbyqxmd.com/read/28790973/malignant-cerebellar-edema-subsequent-to-accidental-prescription-opioid-intoxication-in-children
#12
Daniel Duran, Robert D Messina, Lauren A Beslow, Julio D Montejo, Jason K Karimy, Charuta Gavankar Furey, Alison D Sheridan, Gordon Sze, Yanki Yarman, Michael L DiLuna, Kristopher T Kahle
We present two recent cases of toddlers who developed malignant cerebellar edema subsequent to accidental ingestion of prescription opioids. Both children presented acute neurological decline, hydrocephalus, and tonsillar herniation requiring emergent ventricular drain placement, suboccipital craniectomy, and partial cerebellectomy. Together with several other reports, these cases suggest the existence of an uncommon yet severe syndrome of acute opioid-induced malignant cerebellar edema. We hypothesize that the condition results from a combination of primary opioid receptor-mediated changes in neuronal metabolism that are exacerbated by secondary hypoxic insult...
2017: Frontiers in Neurology
https://www.readbyqxmd.com/read/28636811/performance-evaluation-of-gpu-parallelization-space-time-adaptive-algorithms-and-their-combination-for-simulating-cardiac-electrophysiology
#13
Rafael S Oliveira, Bernardo M Rocha, Denise Burgarelli, Wagner Meira, Christakis Constantinides, Rodrigo Weber Dos Santos
The use of computer models as a tool for the study and understanding of the complex phenomena of cardiac electrophysiology has attained increased importance nowadays. At the same time, the increased complexity of the biophysical processes translates into complex computational and mathematical models. In order to speed up cardiac simulations and to allow more precise and realistic uses, two different techniques have been traditionally exploited: parallel computing and sophisticated numerical methods. In this work, we combine a modern parallel computing technique based on multicore and graphics processing units (GPUs), and a sophisticated numerical method based on a new space-time adaptive algorithm...
June 21, 2017: International Journal for Numerical Methods in Biomedical Engineering
https://www.readbyqxmd.com/read/28550650/single-breath-hold-3-d-cine-imaging-of-the-left-ventricle-using-cartesian-sampling
#14
Jens Wetzl, Michaela Schmidt, François Pontana, Benjamin Longère, Felix Lugauer, Andreas Maier, Joachim Hornegger, Christoph Forman
OBJECTIVES: Our objectives were to evaluate a single-breath-hold approach for Cartesian 3-D CINE imaging of the left ventricle with a nearly isotropic resolution of [Formula: see text] and a breath-hold duration of [Formula: see text]19 s against a standard stack of 2-D CINE slices acquired in multiple breath-holds. Validation is performed with data sets from ten healthy volunteers. MATERIALS AND METHODS: A Cartesian sampling pattern based on the spiral phyllotaxis and a compressed sensing reconstruction method are proposed to allow 3-D CINE imaging with high acceleration factors...
May 26, 2017: Magma
https://www.readbyqxmd.com/read/28536896/helical-distribution-of-hypertrophy-in-patients-with-hypertrophic-cardiomyopathy-prevalence-and-clinical-implications
#15
Dafne Viliani, Eduardo Pozo, Norma Aguirre, Alberto Cecconi, María J Olivera, Paloma Caballero, Luis J Jiménez-Borreguero, Fernando Alfonso
Recently a novel pattern of helical distribution of hypertrophy has been described in patients with hypertrophic cardiomyopathy (HCM). Our aim was to determine its prevalence and potential implications in an unselected cohort. One-hundred- and eight consecutive patients diagnosed with HCM by cardiac magnetic resonance (CMR) were included (median clinical follow up of 1718 days). All clinical and complementary test information was prospectively collected. The presence of a helical pattern was assessed by a simple measurement of the maximal left ventricle (LV) wall thickness (LVWT) for each of the 17 classical LV segments and it was classified in one of three types according to its extension...
November 2017: International Journal of Cardiovascular Imaging
https://www.readbyqxmd.com/read/28465995/asymptomatic-left-ventricular-dissection
#16
Andras Nagy, Zafar Iqbal Khan, Saeed Yahya Al Sayari, Abdelaziz Sabry Aboushaeshae, Rathibala Natarajan
Intramyocardial dissection is an uncommon complication of myocardial infarction, chest trauma, and percutaneous intervention. It is usually caused by a hemorrhagic dissection among the spiral myocardial fibers. Carries high mortality and there is still uncertainty regarding invasive or conservative management. We present a case of the left ventricular dissection discovered incidentally.
April 2017: Journal of Cardiovascular Echography
https://www.readbyqxmd.com/read/28444501/validation-of-numerical-simulation-methods-in-aortic-arch-using-4d-flow-mri
#17
Shohei Miyazaki, Keiichi Itatani, Toyoki Furusawa, Teruyasu Nishino, Masataka Sugiyama, Yasuo Takehara, Satoshi Yasukochi
Computational fluid dynamics (CFD) are the gold standard in studying blood flow dynamics. However, CFD results are dependent on the boundary conditions and the computation model. The purpose of this study was to validate CFD methods using comparison with actual measurements of the blood flow vector obtained with four-dimensional (4D) flow magnetic resonance imaging (MRI). 4D Flow MRI was performed on a healthy adult and a child with double-aortic arch. The aortic lumen was segmented to visualize the blood flow...
August 2017: Heart and Vessels
https://www.readbyqxmd.com/read/28297843/spiral-wave-dynamics-in-a-mathematical-model-of-human-ventricular-tissue-with-myocytes-and-purkinje-fibers
#18
Alok Ranjan Nayak, A V Panfilov, Rahul Pandit
We present systematic numerical studies of the possible effects of the coupling of human endocardial and Purkinje cells at cellular and two-dimensional tissue levels. We find that the autorhythmic-activity frequency of the Purkinje cell in a composite decreases with an increase in the coupling strength; this can even eliminate the autorhythmicity. We observe a delay between the beginning of the action potentials of endocardial and Purkinje cells in a composite; such a delay increases as we decrease the diffusive coupling, and eventually a failure of transmission occurs...
February 2017: Physical Review. E
https://www.readbyqxmd.com/read/28213506/role-of-apamin-sensitive-calcium-activated-small-conductance-potassium-currents-on-the-mechanisms-of-ventricular-fibrillation-in-pacing-induced-failing-rabbit-hearts
#19
Dechun Yin, Yu-Cheng Hsieh, Wei-Chung Tsai, Adonis Zhi-Yang Wu, Zhaolei Jiang, Yi-Hsin Chan, Dongzhu Xu, Na Yang, Changyu Shen, Zhenhui Chen, Shien-Fong Lin, Peng-Sheng Chen, Thomas H Everett
BACKGROUND: Ventricular fibrillation (VF) during heart failure is characterized by stable reentrant spiral waves (rotors). Apamin-sensitive small-conductance calcium-activated potassium currents (IKAS) are heterogeneously upregulated in failing hearts. We hypothesized that IKAS influences the location and stability of rotors during VF. METHODS AND RESULTS: Optical mapping was performed on 9 rabbit hearts with pacing-induced heart failure. The epicardial right ventricular and left ventricular surfaces were simultaneously mapped in a Langendorff preparation...
February 2017: Circulation. Arrhythmia and Electrophysiology
https://www.readbyqxmd.com/read/28129401/impact-of-bounded-noise-and-rewiring-on-the-formation-and-instability-of-spiral-waves-in-a-small-world-network-of-hodgkin-huxley-neurons
#20
Yuangen Yao, Haiyou Deng, Chengzhang Ma, Ming Yi, Jun Ma
Spiral waves are observed in the chemical, physical and biological systems, and the emergence of spiral waves in cardiac tissue is linked to some diseases such as heart ventricular fibrillation and epilepsy; thus it has importance in theoretical studies and potential medical applications. Noise is inevitable in neuronal systems and can change the electrical activities of neuron in different ways. Many previous theoretical studies about the impacts of noise on spiral waves focus an unbounded Gaussian noise and even colored noise...
2017: PloS One
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