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mechanical aortic valve

Per Martin Arvidsson, Johannes Töger, Marcus Carlsson, Katarina Steding-Ehrenborg, Gianni Pedrizzetti, Einar Heiberg, Hakan Arheden
Intracardiac blood flow is driven by hemodynamic forces that are exchanged between the blood and myocardium. Previous studies have been limited to 2D measurements or investigated only LV forces. Right ventricular forces and their mechanistic contribution to asymmetric redirection of flow in the RV have not been measured. We therefore aimed to quantify three-dimensional hemodynamic forces in both ventricles in a cohort of healthy subjects, using magnetic resonance imaging 4D flow measurements. 25 controls,14 elite endurance athletes, and two patients with left ventricular dyssynchrony were included...
October 21, 2016: American Journal of Physiology. Heart and Circulatory Physiology
Maral Ouzounian, Vivek Rao, Cedric Manlhiot, Nachum Abraham, Carolyn David, Christopher M Feindel, Tirone E David
BACKGROUND: Although aortic valve-sparing (AVS) operations are established alternatives to composite valve graft (CVG) procedures for patients with aortic root aneurysms, comparative long-term outcomes are lacking. OBJECTIVES: This study sought to compare the results of patients undergoing AVS procedures with those undergoing CVG operations. METHODS: From 1990 to 2010, a total of 616 patients age <70 years and without aortic stenosis underwent elective aortic root surgery (AVS, n = 253; CVG with a bioprosthesis [bio-CVG], n = 180; CVG with a mechanical prosthesis [m-CVG], n = 183)...
October 25, 2016: Journal of the American College of Cardiology
Marina Pieri, Alessandro Belletti, Fabrizio Monaco, Antonio Pisano, Mario Musu, Veronica Dalessandro, Giacomo Monti, Gabriele Finco, Alberto Zangrillo, Giovanni Landoni
BACKGROUND: In patients undergoing cardiac surgery, a reduced preoperative left ventricular ejection fraction (LVEF) is common and is associated with a worse outcome. Available outcome data for these patients address specific surgical procedures, mainly coronary artery bypass graft (CABG). Aim of our study was to investigate perioperative outcome of surgery on patients with low pre-operative LVEF undergoing a broad range of cardiac surgical procedures. METHODS: Data from patients with pre-operative LVEF ≤40 % undergoing cardiac surgery at a university hospital were reviewed and analyzed...
October 18, 2016: BMC Anesthesiology
Lindsey J Anstine, Chris Bobba, Samir Ghadiali, Joy Lincoln
Risk factors of heart valve disease are well defined and prolonged exposure throughout life leads to degeneration and dysfunction in up to 33% of the population. While aortic valve replacement remains the most common need for cardiovascular surgery particularly in those aged over 65, the underlying mechanisms of progressive deterioration are unknown. In other cardiovascular systems, a decline in endothelial cell integrity and function play a major role in promoting pathological changes, and while similar mechanisms have been speculated in the valves, studies to support this are lacking...
October 15, 2016: Journal of Molecular and Cellular Cardiology
Giordano Tasca, Matteo Selmi, Emiliano Votta, Paola Redaelli, Francesco Sturla, Alberto Redaelli, Amando Gamba
BACKGROUND: Aortic root aneurysm can be treated with valve-sparing procedures. The David and Yacoub techniques have shown excellent long-term results but are technically demanding. Recently, a new and simpler procedure, the Sleeve technique, was proposed with encouraging results. We aimed to quantify the biomechanics of the initially aneurysmal aortic root (AR) after the Sleeve procedure to assess whether it induces abnormal stresses, potentially undermining its durability. METHODS: Two finite element (FE) models of the physiologic and aneurysmal AR were built, accounting for the anatomical asymmetry and the nonlinear and anisotropic mechanical properties of human AR tissues...
October 15, 2016: Annals of Thoracic Surgery
Linfeng Qian, Junnan Zheng, Hongfei Xu, Liping Shi, Lanjuan Li
BACKGROUND: Patients with respiratory failure caused by H7N9 may benefit from veno-venous, veno-arterial, and veno-veno-arterial extracorporeal membrane oxygenation (ECMO) support. CASE SUMMARY: A 55-year-old male patient was suffering from H7N9-caused acute respiratory distress syndrome (ARDS). He had a mechanical mitral and aortic valve replacement surgery and was using warfarin for anticoagulation. After prolonged mechanical ventilation, oxygen saturation was not improved...
October 2016: Medicine (Baltimore)
Sang Min Park, Haemin Jeong, Kyung-Soon Hong, Christopher Kim
BACKGROUND: In a patient underwent aortic valve replacement (AVR) due to bicuspid aortic valve (BAV) insufficiency without marked dilation of ascending aorta, the development of delayed-typed aneurysmal complication of ascending aorta has been often reported because the dilated aorta tends to grow insidiously with age. CASE SUMMARY: A 58-year-old man who underwent AVR with mechanical valve due to severe aortic regurgitation secondary to BAV 7 years previously presented with exertional chest discomfort for 1 year...
October 2016: Medicine (Baltimore)
Katsutoshi Miura, Hideki Katoh
The aim of this study was to reveal the pathogenesis of aortic stenosis (AS) and regurgitation (AR) by comparing differences in mechanical and biochemical alterations. We applied scanning acoustic microscopy (SAM) to measure the speed of sound (SOS) through valves to estimate the elasticity and monitor sensitivity to protease treatment, as the SOS is correlated with the stiffness of materials, which is reduced after digestion by proteases. The fibrosa of both the AS and AR groups were stiffer than the fibrosa of the normal group...
2016: BioMed Research International
Pedram Hanafizadeh, Nima Mirkhani, Mohammad Reza Davoudi, Mahtab Masouminia, Keyvan Sadeghy
Coronary arteries, which are branched from the sinuses, have tangible effects on the hemodynamic performance of the bileaflet mechanical heart valve (BMHV), especially in the diastolic phase. To better understand this issue, a computer model of ascending aorta including realistic sinus shapes and coronary arteries has been generated in this study in order to investigate the BMHV performance during diastole. Three-dimensional transient numerical analysis is conducted to simulate the diastolic blood flow through the hinges and in coronary arteries under the assumption of non-Newtonian behavior...
October 2016: Artificial Organs
Noman Ahmed Jang Khan, Masroor A Khan, Guillermo Juan Morell Chardon
End stage renal disease has a list of consequences, cardiovascular being the most common. Inefficient dialysis can cause significant deposition of calcium all over the body, including heart valves making heart function impaired. We illustrate a case of 38-year-old female with end stage renal disease on peritoneal dialysis. The patient had been complaining of pain and swelling of the right hand for the last few months and had been seen by hand surgeon and was admitted electively for the biopsy of hand lesions...
2016: Case Reports in Cardiology
Kuk Hui Son, Chang-Hyu Choi, Jae-Ik Lee, Kun Woo Kim, Ji Sung Kim, So Young Lee, Kook Yang Park, Chul Hyun Park
BACKGROUND: Guidelines for esophagogastroduodenoscopy (EGD) in the West allow the continued use of warfarin under therapeutic international normalized ratio (INR) level. In Korea, no guidelines have been issued regarding warfarin treatment before EGD. The authors surveyed Korean cardiac surgeons about how Korean cardiac surgeons handle warfarin therapy before EGD using a questionnaire. Participants were requested to make decisions regarding the continuation of warfarin therapy in two hypothetical cases...
October 2016: Korean Journal of Thoracic and Cardiovascular Surgery
Tania A Pawade, Timothy R G Cartlidge, William S A Jenkins, Philip D Adamson, Phillip Robson, Christophe Lucatelli, Edwin J R Van Beek, Bernard Prendergast, Alan R Denison, Laura Forsyth, James H F Rudd, Zahi A Fayad, Alison Fletcher, Sharon Tuck, David E Newby, Marc R Dweck
BACKGROUND: 18F-Fluoride positron emission tomography (PET) and computed tomography (CT) can measure disease activity and progression in aortic stenosis. Our objectives were to optimize the methodology, analysis, and scan-rescan reproducibility of aortic valve 18F-fluoride PET-CT imaging. METHODS AND RESULTS: Fifteen patients with aortic stenosis underwent repeated 18F-fluoride PET-CT. We compared nongated PET and noncontrast CT, with a modified approach that incorporated contrast CT and ECG-gated PET...
October 2016: Circulation. Cardiovascular Imaging
Oliver J Harrison, Narain Moorjani, Christopher Torrens, Sunil K Ohri, Felino R Cagampang
Bicuspid aortic valve (BAV) disease is the most common congenital cardiac abnormality and predisposes patients to life-threatening aortic complications including aortic aneurysm. Quantitative real-time reverse transcription PCR (qRT-PCR) is one of the most commonly used methods to investigate underlying molecular mechanisms involved in aortopathy. The accuracy of the gene expression data is dependent on normalization by appropriate housekeeping (HK) genes, whose expression should remain constant regardless of aortic valve morphology, aortic diameter and other factors associated with aortopathy...
2016: PloS One
Jeremy Ben-Shoshan, Arie Steinvil, Yaron Arbel, Yan Topilsky, Leehee Barak, Michal Entin-Meer, Ran Levy, Arie Lorin Schwartz, Gad Keren, Ariel Finkelstein, Shmuel Banai
BACKGROUND: Transcatheter aortic valve replacement (TAVR) exposes the systemic vasculature to increased mechanical forces. Endothelial adaptation to mechanical stimuli is associated with angiogenic activation through various growth factors. We studied the potential angiogenic shift evoked by TAVR. METHODS: From a cohort of 69 consecutive patients undergoing TAVR, we excluded patients with conditions known to affect angiogenic factors, and serum vascular endothelial growth factor (VEGF) and angiopoietin (Ang)-1 and Ang-2 were assessed by ELISA...
June 25, 2016: Canadian Journal of Cardiology
Laura Mourino-Alvarez, Montserrat Baldan-Martin, Laura Gonzalez-Calero, Carlos Martinez-Laborde, Tamara Sastre-Oliva, Rafael Moreno-Luna, Luis F Lopez-Almodovar, Pedro L Sanchez, Francisco Fernandez-Aviles, Fernando Vivanco, Luis R Padial, Finn Akerstrom, Gloria Alvarez-Llamas, Fernando de la Cuesta, María G Barderas
BACKGROUND: The most common valve diseases are calcific aortic stenosis (AS) and aortic regurgitation (AR). The former is characterized by thickening of valve leaflets followed by progressive calcification, which produces progressive aortic valve (AV) narrowing, increased pressure afterload on the left ventricle (LV) and subsequent LV hypertrophy. On the other hand, AR is due to malcoaptation of the valve leaflets with resultant diastolic reflux of blood from aorta back to the LV producing volume and pressure overload and progressive LV dilatation...
September 26, 2016: International Journal of Cardiology
Carmen Rueda-Martínez, M Carmen Fernández, María Teresa Soto-Navarrete, Manuel Jiménez-Navarro, Ana Carmen Durán, Borja Fernández
Bicuspid aortic valve (BAV) is the most frequent congenital cardiac malformation in humans, and appears frequently associated with dilatation of the ascending aorta. This association is likely the result of a common aetiology. Currently, a Syrian hamster strain with a relatively high (∼40%) incidence of BAV constitutes the only spontaneous animal model of BAV disease. The characterization of molecular alterations in the aorta of hamsters with BAV may serve to identify pathophysiological mechanisms and molecular markers of disease in humans...
2016: PloS One
Jack B Keenan, Rajesh Janardhanan, Brandon T Larsen, Zain Khalpey
A 24-year-old man with systemic lupus erythematosus and antiphospholipid syndrome complicated by lupus nephritis presented with acute limb ischaemia secondary to an embolus. Following embolectomy, the patient underwent a transthoracic echocardiogram which revealed a large vegetation on all three cusps of the aortic valve. The patient was taken for an urgent aortic valve replacement with a mechanical valve. Cultures of one cusp remained sterile. Histopathological examination of the remaining two cusps revealed sterile fibrin-rich thrombotic vegetations characteristic of non-bacterial thrombotic endocarditis...
October 4, 2016: BMJ Case Reports
Taylor Suess, Joseph Anderson, Andrea Sherman, Tyler Remund, Kathryn Pohlson, Gopinath Mani, Stephen Gent, Patrick Kelly
OBJECTIVE: This study proposes to establish a simulation-based technique for evaluating shear accumulation in stent grafts and to use the technique to assess the performance of a novel branched stent graft system. METHODS: Computational fluid dynamics models, with transient boundary conditions, particle injection, and rigid walls, simplifying assumptions were developed and used to evaluate the shear accumulation in various stent graft configurations with a healthy aorta as comparison...
September 29, 2016: Journal of Vascular Surgery
Heather N Hutson, Taylor Marohl, Matthew Anderson, Kevin Eliceiri, Paul Campagnola, Kristyn S Masters
Disorganization of the valve extracellular matrix (ECM) is a hallmark of calcific aortic valve disease (CAVD). However, while microarchitectural features of the ECM can strongly influence the biological and mechanical behavior of tissues, little is known about the ECM microarchitecture in CAVD. In this work, we apply advanced imaging techniques to quantify spatially heterogeneous changes in collagen microarchitecture in CAVD. Human aortic valves were obtained from individuals between 50 and 75 years old with no evidence of valvular disease (healthy) and individuals who underwent valve replacement surgery due to severe stenosis (diseased)...
2016: PloS One
Silje Ekroll Jahren, Bernhard Michael Winkler, Paul Philipp Heinisch, Jessica Wirz, Thierry Carrel, Dominik Obrist
OBJECTIVES: In this study, the influence of aortic root distensibility on the haemodynamic parameters and valve kinematics of a bioprosthetic aortic valve was investigated in a controlled in vitro experiment. METHODS: An Edwards INTUITY Elite 21 mm sutureless aortic valve (Edwards Lifesciences, Irvine, CA, USA) was inserted in three transparent aortic root phantoms with different wall thicknesses (0.55, 0.85 and 1.50 mm) mimicking different physiological distensibilities...
September 28, 2016: Interactive Cardiovascular and Thoracic Surgery
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