A Method to Quantify Tensile Biaxial Properties of Mouse Aortic Valve Leaflets

2020 ◽  
Vol 142 (10) ◽  
Author(s):  
Daniel Chaparro ◽  
Valentina Dargam ◽  
Paulina Alvarez ◽  
Jay Yeung ◽  
Ilyas Saytashev ◽  
...  

Abstract Understanding aortic valve (AV) mechanics is crucial in elucidating both the mechanisms that drive the manifestation of valvular diseases as well as the development of treatment modalities that target these processes. Genetically modified mouse models have become the gold standard in assessing biological mechanistic influences of AV development and disease. However, very little is known about mouse aortic valve leaflet (MAVL) tensile properties due to their microscopic size (∼500 μm long and 45 μm thick) and the lack of proper mechanical testing modalities to assess uniaxial and biaxial tensile properties of the tissue. We developed a method in which the biaxial tensile properties of MAVL tissues can be assessed by adhering the tissues to a silicone rubber membrane utilizing dopamine as an adhesive. Applying equiaxial tensile loads on the tissue–membrane composite and tracking the engineering strains on the surface of the tissue resulted in the characteristic orthotropic response of AV tissues seen in human and porcine tissues. Our data suggest that the circumferential direction is stiffer than the radial direction (n = 6, P = 0.0006) in MAVL tissues. This method can be implemented in future studies involving longitudinal mechanical stimulation of genetically modified MAVL tissues bridging the gap between cellular biological mechanisms and valve mechanics in popular mouse models of valve disease.

2019 ◽  
Vol 2019 ◽  
pp. 1-5
Author(s):  
Kanksha Peddi ◽  
Alexander L. Hsu ◽  
Tomas H. Ayala

ST-elevation myocardial infarction (STEMI) is a rare and potentially fatal complication of infective endocarditis. We report the ninth case of embolic native aortic valve infective endocarditis causing STEMI and the first case to describe consecutive embolisms leading to infarctions of separate coronary territories. Through examination of this case in the context of the previous eight similar documented cases in the past, we find that infective endocarditis of the aortic valve can and frequently affect more than a single myocardial territory and can occur consecutively. Further, current treatment modalities for embolic infective endocarditis causing acute myocardial infarction are limited and unproven. This index case illustrates the potential severity of complications and the challenges in developing standardized management for such patients.


2006 ◽  
Vol 252 (1-2) ◽  
pp. 126-135 ◽  
Author(s):  
Ilpo Huhtaniemi ◽  
Petteri Ahtiainen ◽  
Tomi Pakarainen ◽  
Susana B. Rulli ◽  
Fu-Ping Zhang ◽  
...  

Author(s):  
Yasser Shaban Mubarak ◽  
MD; Muhammad Hussian Abdel Wahaab, MD

- Percutaneous Coronary Intervention (PCI) is widely recognized as an effective treatment for Acute Coronary Syndrome (ACS). Inspite of advances in equipment and experience of interventional cardiologist, still there are rare complications occurred [1]. Iatrogenic injury of the aortic valve leaflet is a rare. Aortic insufficiency (AI) after a PCI suggests an iatrogenic valve injury. Aortic leaflet injury is not common but possible complication of PCI. Because of the serious consequences, it should be mentioned in the informed consent. Aortic repair of iatrogenic injury is possible, and it can be performed with excellent clinical and functional midterm results. So, Aortic valve replacement (AVR) is the last option [2].


2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 817-818
Author(s):  
B. Hugues ◽  
B. Emsen ◽  
J. Ternacle ◽  
R. Huguet ◽  
A. Fiore ◽  
...  

Background:Five to eleven percent of infective endocarditis (IE) are associated with a musculoskeletal infection. Thanks to its good sensitivity, the use of PET-CT in this pathology makes it possible to confirm the diagnosis by seeking valvular hypermetabolism but also by mapping distant septic foci.Objectives:The main objective of our study was to assess the prevalence of osteoarticular fixation (OAF) with PET-CT, symptomatic or not, in patients with IE. The secondary objectives were to determine predictive factors for osteoarticular infections such as the type of valve damage (native or prosthetic) and germ.Methods:This study was carried out on the basis of a prospective cohort of patients admitted in the department of cardiology in Henri Mondor Hospital for IE suspicion between August 2015 and July 2019. Demographic, clinical, bacteriological, imaging and therapeutic data have been collected. Patients matching Duke’s modified criteria according to ESC 2015 (Duke + IE) and / or a cardiac fixation according to standard whole-body PET-CT were included in the analysis. All of the PET-CT scans were reviewed by a nuclear medicine specialist to confirm whether or not there was a heart condition and to look for septic-looking OAF.Results:From this cohort, we included 90 IE Duke + patients and 42 patients with cardiac PET-CT fixation (including 31 IE Duke +). In the IE Duke + group, we found OAF in 18 patients (20%), 39% of whom were asymptomatic. There were 9 spondylodiscitis (4 on the cervical level, 7 on the thoracic level, and 2 on the lumbar level), 5 glenohumeral arthritis, 2 coxofemoral arthritis, 1 sternoclavicular arthritis and 1 sacroiliac arthritis. The IE affected the aortic valve in 50% of the cases and the mitral valve in 22%. In other cases, the infection involved the internal automatic defibrillator (ICD) or the pacemaker. The valves were prosthetic in 73% of the cases. The bacterial ecology was mainly represented by Enterococcus faecalis (39%) then staphylococcus aureus (17%) against 14% and 13% respectively in the entire IE Duke + group. In the group with cardiac PET-CT fixation, OAF was found in 10 patients (40%), 70% of whom were asymptomatic. Among them, there were 5 spondylodiscitis (2 cervico- thoracic and 3 exclusively thoracic), 2 glenohumeral arthritis (20%), 2 coxofemoral arthritis and 1 sternoclavicular arthritis. The IE affected the aortic valve in 60% of the cases, mitral in 30% of the cases and it was an infection on ICD in 10% of the cases. The main germs found were Enterococcus faecalis (30% of cases) and Staphylococcus epidermidis (20% of cases).Conclusion:In patients with IE, PET-CT seems to be interesting in detection of osteoarticular infections, and consequently, could impact the diagnosis and the treatment modalities. In our cohort, 1 patient in 5 had an OAF and nearly 40% of them were asymptomatic. The overrepresentation of enterococcus is consistent with recent data in the literatureReferences:[1]Dahl A, Iversen K, Tonder N, Hoest N, Arpi M, Dalsgaard M, et al. Prevalence of Infective Endocarditis in Enterococcus faecalis Bacteremia. J Am Coll Cardiol. 16 juill 2019;74(2):193‑201.Disclosure of Interests:Benjamin HUGUES: None declared, Bérivan EMSEN: None declared, Julien TERNACLE: None declared, Raphaëlle HUGUET: None declared, Antonio FIORE: None declared, Raphaëlle LEPEULE: None declared, Xavier Chevalier: None declared, Mukedaisi ABULIZI: None declared, Florent Eymard Consultant of: Regenlab


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