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Ventricle assist device

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https://www.readbyqxmd.com/read/27873344/impact-of-residual-mitral-regurgitation-on-right-ventricular-systolic-function-after-left-ventricular-assist-device-implantation
#1
Serkan Ertugay, Hatice S Kemal, Umit Kahraman, Catagay Engin, Sanem Nalbantgil, Tahir Yagdi, Mustafa Ozbaran
Significant mitral regurgitation (MR) is thought to decrease after left ventricular assist device (LVAD) implantation, and therefore repair of mitral valve is not indicated in current practice. However, residual moderate and severe MR leads to pulmonary artery pressure increase, thereby resulting in right ventricular (RV) dysfunction during follow-up. We examined the impact of residual MR on systolic function of the right ventricle by echocardiography after LVAD implantation. This study included 90 patients (mean age: 51...
November 22, 2016: Artificial Organs
https://www.readbyqxmd.com/read/27855113/comparison-of-novel-physiological-load-adaptive-control-strategies-for-ventricular-assist-devices
#2
Moriz Habigt, Maike Ketelhut, Jonas Gesenhues, Frank Schrödel, Marc Hein, Mare Mechelinck, Thomas Schmitz-Rode, Dirk Abel, Rolf Rossaint
Terminal heart failure (HF) is the most prevalent cause of death in the Western world and the implantation of a left ventricular assist device (LVAD) has become the gold standard therapy today. Most of the actually implanted devices are driven at a constant speed (CS) regardless of the patient's physiological demand. A new physiological controller [power ratio (PR) controller], which keeps a constant ratio between LVAD power and left ventricular power, a previous concept [preload responsive speed (PRS) controller], which adds a variable LVAD power to reach a defined stroke work, and a CS controller were compared with an unimpaired ventricle in a full heart computer simulation model...
November 17, 2016: Biomedizinische Technik. Biomedical Engineering
https://www.readbyqxmd.com/read/27807535/rat-heterotopic-heart-transplantation-model-to-investigate-unloading-induced-myocardial-remodeling
#3
REVIEW
Xuebin Fu, Adrian Segiser, Thierry P Carrel, Hendrik T Tevaearai Stahel, Henriette Most
Unloading of the failing left ventricle in order to achieve myocardial reverse remodeling and improvement of contractile function has been developed as a strategy with the increasing frequency of implantation of left ventricular assist devices in clinical practice. But, reverse remodeling remains an elusive target, with high variability and exact mechanisms still largely unclear. The small animal model of heterotopic heart transplantation (hHTX) in rodents has been widely implemented to study the effects of complete and partial unloading on cardiac failing and non-failing tissue to better understand the structural and molecular changes that underlie myocardial recovery...
2016: Frontiers in Cardiovascular Medicine
https://www.readbyqxmd.com/read/27777298/management-of-systemic-right-ventricular-failure-in-patients-with-congenitally-corrected-transposition-of-the-great-arteries
#4
Aleksei A Filippov, Pedro J Del Nido, Nikolay V Vasilyev
In recent decades, significant progress has been made in the diagnosis and management of congenitally corrected transposition of the great arteries (ccTGA). Nevertheless, gradual dysfunction and failure of the right ventricle (RV) in the systemic circulation remain the main contributors to mortality and disability for patients with ccTGA, especially after adolescence. Anatomic repair of ccTGA effectively resolves the problem of failure of the systemic RV and has good early and midterm results. However, this strategy is applicable primarily in infants and children up to their teens and has associated risks and limitations, and new challenges can arise in the late postoperative period...
October 25, 2016: Circulation
https://www.readbyqxmd.com/read/27743468/a-monolithic-3d-0d-coupled-closed-loop-model-of-the-heart-and-the-vascular-system-experiment-based-parameter-estimation-for-patient-specific-cardiac-mechanics
#5
M Hirschvogel, M Bassilious, L Jagschies, S M Wildhirt, M W Gee
A model for patient-specific cardiac mechanics simulation is introduced, incorporating a 3-dimensional finite element model of the ventricular part of the heart which is coupled to a reduced-order 0-dimensional closed-loop vascular system, heart valve and atrial chamber model.The ventricles are modeled by a nonlinear orthotropic passive material law. The electrical activation is mimicked by a prescribed parametrized active stress acting along a generic muscle fiber orientation. Our activation function is constructed such that the start of ventricular contraction and relaxation as well as the active stress curve's slope are parameterized...
October 15, 2016: International Journal for Numerical Methods in Biomedical Engineering
https://www.readbyqxmd.com/read/27692763/a-transapical-to-aorta-double-lumen-cannula-based-neonate-left-ventricular-assist-device-efficiently-unloads-the-left-ventricle-in-neonate-lambs
#6
Cheng Zhou, Dongfang Wang, Cherry Ballard-Croft, Guangfeng Zhao, Hassan K Reda, Stephen Topaz, Joseph Zwischenberger
OBJECTIVE: We are developing a transapical-to-aorta double lumen cannula (TAA DLC) for a less-invasive/more dependable neonatal left ventricular assist device. METHODS: The 18-Fr TAA DLC prototypes were bench tested and evaluated for 6 hours in neonate lambs (n = 6, 7.7-10 kg). The cardiac apex was exposed through a left anterolateral thoracotomy through the sixth intercostal space. The TAA DLC was inserted through a mattress stitch on apex, passing LV-aortic valve, into the ascending aorta with insertion/deployment guided by pressure waveform...
August 31, 2016: Journal of Thoracic and Cardiovascular Surgery
https://www.readbyqxmd.com/read/27660015/a-fully-integrated-electrochemical-biosensor-platform-fabrication-process-for-cytokines-detection
#7
Abdoullatif Baraket, Michael Lee, Nadia Zine, Monique Sigaud, Joan Bausells, Abdelhamid Errachid
Interleukin-1b (IL-1b) and interleukin-10 (IL-10) biomarkers are one of many antigens that are secreted in acute stages of inflammation after left ventricle assisted device (LVAD) implantation for patients suffering from heart failure (HF). In the present study, we have developed a fully integrated electrochemical biosensor platform for cytokine detection at minute concentrations. Using eight gold working microelectrodes (WEs) the design will increase the sensitivity of detection, decrease the time of measurements, and allow a simultaneous detection of varying cytokine biomarkers...
September 9, 2016: Biosensors & Bioelectronics
https://www.readbyqxmd.com/read/27605222/evaluation-of-the-heartware-ventricular-assist-device-lavare-cycle-in-a-particle-image-velocimetry-model-and-in-clinical-practice
#8
Daniel Zimpfer, Martin Strueber, Philipp Aigner, Jan D Schmitto, Arnt E Fiane, Robert Larbalestier, Steven Tsui, Paul Jansz, Andre Simon, Stephan Schueler, Francesco Moscato, Heinrich Schima
OBJECTIVES: Ventricular blood stasis is a concern for continuous flow mechanical support devices and might contribute to the formation of thromboembolic events. The HeartWare® Ventricular Assist System (HVAD®) is equipped with the Lavare™ cycle that is a periodic speed modulation feature designed to alter flow patterns within the left ventricle and reduce areas of potential blood stasis. Here, we report in vitro and clinical findings on the effects of the Lavare cycle. METHODS: The effect of pump speed changes on the intraventricular flow field was examined with an in vitro particle image velocimetry model...
November 2016: European Journal of Cardio-thoracic Surgery
https://www.readbyqxmd.com/read/27586549/b-type-natriuretic-peptide-powerful-predictor-of-end-stage-chronic-heart-failure-in-individuals-with-systolic-dysfunction-of-the-systemic-right-ventricle
#9
Marketa Hegarova, Jaroslav Brotanek, Milos Kubanek, Radka Kockova, Janka Franekova, Vera Lanska, Ivan Netuka, Vojtech Melenovsky, Ivan Malek, Josef Kautzner
AIM: To assess whether B-type natriuretic peptide (BNP) can serve as a predictor of end-stage chronic heart failure (CHF) in patients with severe systolic dysfunction of the systemic right ventricle (SRV). METHODS: We performed a retrospective analysis in 28 patients with severe systolic dysfunction of the SRV (ejection fraction 23 ± 6%) who were evaluated as heart transplant (HTx) candidates between May 2007 and October 2014. The primary endpoints of the study (end-stage CHF) were progressive CHF, urgent HTx, and ventricular assist device (VAD) implantation...
August 31, 2016: Croatian Medical Journal
https://www.readbyqxmd.com/read/27570334/percutaneous-double-lumen-cannula-for-right-ventricle-assist-device-system-a-computational-fluid-dynamics-study
#10
Francesca Condemi, Dongfang Wang, Gionata Fragomeni, Fuqian Yang, Guangfeng Zhao, Cameron Jones, Cherry Ballard-Croft, Joseph B Zwischenberger
OBJECTIVES: Our goal is to develop a double lumen cannula (DLC) for a percutaneous right ventricular assist device (pRVAD) in order to eliminate two open chest surgeries for RVAD installation and removal. The objective of this study was to evaluate the performance, flow pattern, blood hemolysis, and thrombosis potential of the pRVAD DLC. METHODS: Computational fluid dynamics (CFD), using the finite volume method, was performed on the pRVAD DLC. For Reynolds numbers <4000, the laminar model was used to describe the blood flow behavior, while shear-stress transport k-ω model was used for Reynolds numbers >4000...
2016: Biocybernetics and Biomedical Engineering
https://www.readbyqxmd.com/read/27562439/outflow-monitoring-of-a-pneumatic-ventricular-assist-device-using-external-pressure-sensors
#11
Seong Min Kang, Keun Her, Seong Wook Choi
BACKGROUND: In this study, a new algorithm was developed for estimating the pump outflow of a pneumatic ventricular assist device (p-VAD). The pump outflow estimation algorithm was derived from the ideal gas equation and determined the change in blood-sac volume of a p-VAD using two external pressure sensors. OBJECTIVES: Based on in vitro experiments, the algorithm was revised to consider the effects of structural compliance caused by volume changes in an implanted unit, an air driveline, and the pressure difference between the sensors and the implanted unit...
2016: Biomedical Engineering Online
https://www.readbyqxmd.com/read/27521176/heartware-ventricular-assist-device-as-a-bridge-to-heart-transplantation-in-a-patient-with-congenitally-corrected-transposition-of-the-great-arteries-and-dextrocardia
#12
Muhammad A Soofi, Andrew P Ignaszewski, Anson W Cheung, Jamil G Bashir
Congenitally corrected transposition of the great arteries (ccTGA) is a rare condition with prevalence of <0.5%. Dextrocardia is reported among 20% of them. Among patients with ccTGA, heart failure is a common presentation, especially in the fourth or fifth decade of life and survival is dismal without heart transplantation. A left ventricular assist device (LVAD) is considered for bridge to transplantation if early heart transplantation is not available or as destination therapy for patients ineligible for heart transplant...
August 11, 2016: Interactive Cardiovascular and Thoracic Surgery
https://www.readbyqxmd.com/read/27510470/preoperative-echocardiography-examination-of-right-ventricle-function-in-patients-scheduled-for-lvad-implantation-correlates-with-postoperative-hemodynamic-examinations
#13
Paweł Nadziakiewicz, Tomasz Niklewski, Bożena Szyguła-Jurkiewicz, Jerzy Pacholewicz, Michał Zakliczyński, Jarosław Borkowski, Tomasz Hrapkowicz, Marian Zembala
BACKGROUND Left ventricular assist devices (LVAD) are used to treat heart failure. Preoperative prediction of RV function after LVAD implantation is crucial. Correlations were found between preoperative echo and RV function after LVAD implantation. MATERIAL AND METHODS We retrospectively reviewed 23 male patients (8 ischemic, 15 nonischemic cardiomyopathy) with LVAD implantation (17 HeartWare, 6 HeartMate II) at the Silesian Center for Heart Diseases from 1 January 2013 to 28 October 2014. Preoperative TTE data of RV function included RVFAC (fractional area change), TAPSE (tricuspid annulus plane systolic excursion), RV diameter (RV4), and RV/LV (right/left ventricle) ratio...
August 11, 2016: Annals of Transplantation: Quarterly of the Polish Transplantation Society
https://www.readbyqxmd.com/read/27496492/right-ventricular-function-in-patients-with-left-ventricular-assist-device-support-by-pulsatile-polvad-mev-and-continuous-flow-pumps-heartware-and-heartmate-ii
#14
P Nadziakiewicz, J Borkowski, B Szygula-Jurkiewicz, T Niklewski, J Pacholewicz, M Zakliczynski, T Hrapkowicz, M Zembala
BACKGROUND: Left ventricular assist device (LVAD) support is increasingly used in patients with heart failure. The right ventricle (RV) plays a main role in LVAD support. Little is known about the effects of pulsatile Polvad MEV devices or continuouseconds flow pumps on RV function. We compared hemodynamic parameters of RV in patients after implantation of Polvad MEV (PM) and Heartware (HW) or Heartmate II (HMII) LVADs. METHODS: Forty-four patients were retrospectively reviewed after implantation of PM (group P; n = 24 [21 M, 3 F]) or HW or HMII (group C; n = 20 [20 M, 0 F]) LVADs from April 2007 to February 2014...
June 2016: Transplantation Proceedings
https://www.readbyqxmd.com/read/27487837/minimally-invasive-approach-for-percutaneous-centrimag-right-ventricular-assist-device-support-using-a-single-protekduo-cannula
#15
Toshinobu Kazui, Phat L Tran, Angela Echeverria, Catherine F Jerman, Jessika Iwanski, Samuel S Kim, Richard G Smith, Zain I Khalpey
BACKGROUND: Right ventricular failure is a serious complication after left ventricular assist device placement. CASE PRESENTATION: A 70-year-old male in decompensated heart failure with right ventricular failure after the placement of a left ventricular assist device. A single dual-lumen PROTEKDuo cannula was inserted percutaneously via the internal jugular vein to draw blood from the right atrium and return into the pulmonary artery using the CentriMag system, by passing the failing ventricle...
2016: Journal of Cardiothoracic Surgery
https://www.readbyqxmd.com/read/27474972/echocardiographic-assessment-of-the-right-ventricle-impact-of-the-distinctly-load-dependency-of-its-size-geometry-and-performance
#16
REVIEW
Michael Dandel, Roland Hetzer
Right ventricular (RV) size, shape and function are distinctly load-dependent and pulmonary load is an important determinant of RV function in patients with congestive heart failure (CHF) due to primary impaired left ventricular function and in those with pre-capillary pulmonary hypertension (PH). In a pressure overloaded RV, not only dilation and aggravation of tricuspid regurgitation, but also systolic dysfunction leading to RV failure (RVF) can occur already before the development of irreversible alterations in RV myocardial contractility...
October 15, 2016: International Journal of Cardiology
https://www.readbyqxmd.com/read/27442862/ex-vivo-assessment-of-a-parabolic-tip-inflow-cannula-for-pediatric-continuous-flow-vads
#17
Michael T Griffin, Matthew F Grzywinski, Hannah J Voorhees, Marina V Kameneva, Salim E Olia
To address the challenge of unloading the left ventricle during pediatric mechanical circulatory support using next-generation rotary blood pumps, a novel inflow cannula was developed. This unique inflow cannula for pediatric, continuous-flow, left ventricular assist devices (VADs) with a parabolic-shaped inlet entrance was evaluated alongside a bevel-tip and fenestrated-tip cannula via an ex vivo, isolated-heart experimental setup. Performance was characterized using two clinical scenarios of over-pumping and hypovolemia, created by varying pump speed and filling preload pressure, respectively, at ideal and off-axis cannula placement to assess ventricular unloading and positional sensitivity...
September 2016: ASAIO Journal: a Peer-reviewed Journal of the American Society for Artificial Internal Organs
https://www.readbyqxmd.com/read/27441034/enhancement-of-arterial-pressure-pulsatility-by-controlling-continuous-flow-left-ventricular-assist-device-flow-rate-in-mock-circulatory-system
#18
Selim Bozkurt, Frans N van de Vosse, Marcel C M Rutten
Continuous-flow left ventricular assist devices (CF-LVADs) generally operate at a constant speed, which reduces pulsatility in the arteries and may lead to complications such as functional changes in the vascular system, gastrointestinal bleeding, or both. The purpose of this study is to increase the arterial pulse pressure and pulsatility by controlling the CF-LVAD flow rate. A MicroMed DeBakey pump was used as the CF-LVAD. A model simulating the flow rate through the aortic valve was used as a reference model to drive the pump...
2016: Journal of Medical and Biological Engineering
https://www.readbyqxmd.com/read/27424467/mechanical-circulatory-support-as-bridge-to-transplantation-for-the-failing-single-ventricle
#19
George J Arnaoutakis, David Blitzer, Stephanie Fuller, Aaron W Eckhauser, Lisa M Montenegro, Joseph W Rossano, J William Gaynor
BACKGROUND: Circulatory failure necessitating cardiac transplantation will ultimately develop in many patients with functional single-ventricle physiology. Interest in the use of mechanical circulatory support (MCS) in this population is growing. METHODS: This was a retrospective case series of patients with functional single-ventricle physiology who underwent MCS with a ventricular assist device or a total artificial heart as a bridge to cardiac transplantation between January 2006 and December 2014...
July 14, 2016: Annals of Thoracic Surgery
https://www.readbyqxmd.com/read/27403189/acute-fulminant-myocarditis-successfully-bridged-to-recovery-with-left-ventricular-assist-device-and-complicated-by-flail-mitral-valve
#20
Pınar Türker Duyuler, Serkan Duyuler, Ekrem Şahan, Şeref Alp Küçüker
Acute fulminant myocarditis is a life-threatening inflammatory disease of the myocardium characterized by the rapid deterioration of the hemodynamic status of the affected individual. With prompt recognition and appropriate management, complete recovery of ventricular function is likely within a few weeks. We introduce a 28-year-old man with acute fulminant myocarditis, who experienced circulatory collapse following acute angina and dyspnea. The patient had high troponin levels with low ejection fraction and normal coronary arteries...
January 13, 2016: Journal of Tehran Heart Center
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