Elastic properties of mitral valve

Mitral valve dynamics depend on force stability in the mitral leaflets, the mitral annulus, the chordae tendineae, and the papillary muscles. In chordal rupture conditions, the proper function of the valve disrupts, causing mitral regurgitation, the most prevalent valvular disease. In this study, Structural and FSI frameworks were employed to study valve dynamics in healthy, pathologic, and repaired states. Anisotropic, non-linear, hyper-elastic material properties applied to tissues of the valve while the first-order Ogden model reflected the best compatibility with the empirical data...

BACKGROUND AND AIM OF THE STUDY: Several techniques have been described for neo-chordal fixation to the papillary muscles without any reported clinical differences. The objective of this study is to compare in vitro the biomechanical properties of four of these common techniques. METHODS: We studied the biomechanical properties of expanded polytetrafluoroethylene neo-chordal fixation using four techniques: nonknotted simple stitch, nonknotted figure-of-eight stitch, knotted pledgeted mattress stitch, and knotted pledgeted stitch using commercially available prefabricated loops...

Cardiac volume overload from mitral regurgitation (MR) is a trigger for left ventricular dilatation, remodeling, and ultimate failure. While the functional and structural adaptations to this overload are known, the adaptation of myocardial mechanical properties remains unknown. Using a rodent model of MR, in this study, we discern changes in the passive material properties of the intact and decellularized myocardium. Eighty Sprague-Dawley rats (350-400 g) were assigned to two groups: (1) MR (n = 40) and (2) control (n = 40)...

Heart valve disease is a common manifestation of cardiovascular disease and is a significant cause of cardiovascular morbidity and mortality worldwide. The pulmonary valve (PV) is of primary concern because of its involvement in common congenital heart defects, and the PV is usually the site for prosthetic replacement following a Ross operation. Although effects of age on valve matrix components and mechanical properties for aortic and mitral valves have been studied, very little is known about the age-related alterations that occur in the PV...

The aim of this study was to assess whether the mechanical properties of mitral valve chordae tendineae are sensitive to being cross-linked under load. A total 64 chordae were extracted from eight porcine hearts. Two chordae (posterior basal) from each heart were subjected to uniaxial ramp testing and six chordae (two strut, two anterior basal and two posterior basal) were subjected to dynamic mechanical analysis over frequencies between 0.5 and 10 Hz. Chordae were either cross-linked in tension or cross-linked in the absence of loading...

AIMS : Chronic volume-overload can impair systolic and diastolic myocardial properties. We tested the hypothesis that Intrinsic Cardiac Elastography may detect alterations in passive myocardial elasticity in patients with chronic severe mitral regurgitation (MR) and predict worsening left ventricular (LV) function after mitral valve repair (MVr). METHODS AND RESULTS : Comprehensive transthoracic echocardiography and cardiac elastography were performed in 80 patients with primary MR (prolapse and/or flail leaflets) of varying severity and compared with 40 normal subjects...

Percutaneous edge-to-edge mitral valve (MV) repair using MitraClip has been recently established as a treatment option for patients with heart failure and functional mitral regurgitation (MR), which significantly expands the number of patients that can be treated with this device. This study aimed to quantify the morphologic, hemodynamic and structural changes, and evaluate the biomechanical interaction between the MitraClip and the left heart (LH) complex of a heart failure patient with functional MR using a fluid-structure interaction (FSI) modeling framework...

OBJECTIVE: To perform immunohistochemical typing of cells as a component of bioprosthetic (BP) heart valves explanted during reoperations for prosthetic valve endocarditis. MATERIAL AND METHODS: The authors investigated 8 models of KemCor and PeriCor artificial heart valves produced by NeoCor Company (Kemerovo, Russia), which were explanted from the mitral position due to infection of xenogeneic implanted material. The following markers: CD3 (T-lymphocytes), CD20 (B-lymphocytes), CD34 and VEGFR2 (endotheliocytes), CD68 (monocytes/macrophages), vimentin (fibroblasts), and α-smooth muscle actin (smooth muscle cells), were used for immunohistochemical typing of cells as a component of the analyzed samples...

The mitral valve is a highly heterogeneous tissue composed of two leaflets, anterior and posterior, whose unique composition and regional differences in material properties are essential to overall valve function. While mitral valve mechanics have been studied for many decades, traditional testing methods limit the spatial resolution of measurements and can be destructive. Optical coherence elastography (OCE) is an emerging method for measuring viscoelastic properties of tissues in a noninvasive, nondestructive manner...

The effects of the nitroxyl donor BMS-986231 on hemodynamics, left ventricular (LV) function, and pro-arrhythmic potential were assessed using canine heart failure models. BMS-986231 significantly (p < 0.05) increased LV end-systolic elastance, pre-load-recruitable stroke work, ejection fraction, stroke volume, cardiac output, ratio of early-to-late filling time integrals, and early mitral valve inflow velocity deceleration time. BMS-986231 significantly decreased LV filling pressures, end-diastolic stiffness, the time-constant of relaxation, end-diastolic wall stress, systemic vascular resistance, and myocardial oxygen consumption...

BACKGROUND/OBJECTIVE: Takayasu arteritis (TA) is characterized by extensive aortic, large and midsize arterial wall inflammation. The aim of this study was to assess the morphological and elastic properties of the aorta and large arteries and the impact on left ventricular (LV) mechanics in children with TA. METHODS: Seven pediatric TA patients (6 female patients, 13.8 ± 3.2 years) were assessed with magnetic resonance imaging, vascular ultrasound, applanation tonometry, and echocardiography from February 2015 until July 2017 and compared with 7 age- and sex-matched controls...

OBJECTIVE: As the use of minimally invasive surgery in cardiothoracic surgery increases, so does the need for simulation and training. We developed a heart model for simulation and training of minimally invasive cardiac surgery, particularly minimally invasive mitral valve repair using our new three-dimensional printing system. METHODS: Digital imaging and communication in medicine data from patient computed tomography, three-dimensional computer-aided design, and three-dimensional printing helped create replicas of the heart and thoracic cavity...

BACKGROUND: Left ventricular (LV) filling following atrial contraction generates LV myocardial stretch that propagates from base to apex with a speed proportional to myocardial elasticity. The aim of this study was to test the hypothesis that intrinsic velocity propagation of myocardial stretch (iVP) would be altered in patients with valvular disease and chronic LV pressure overload or volume overload, which may adversely affect mechanical properties of the LV tissue. A second aim was to compare iVP with flow propagation velocity in the chamber...

BACKGROUND: Heart valves which exist naturally in an extreme-pressure system must have evolved in a way to resist the stresses of high pressure. Giraffes are interesting as they naturally have a blood pressure twice that of humans. Thus, knowledge regarding giraffe heart valves may aid in developing techniques to design improved pressure-resistant biological heart valves. METHODS: Heart valves from 12 giraffes and 10 calves were explanted and subjected to either biomechanical or morphological examinations...

OBJECTIVE: To assess the profile of changes in airway and respiratory tissue mechanics within a follow-up study performed in children with mitral valve disease, before and after surgical valve repair. DESIGN: Perioperative measurements in a prospective, consecutive cross-sectional study. SETTING: University hospital, tertiary care teaching hospital PARTICIPANTS: The study comprised 24 children with congenital or post-rheumatic mitral valve insufficiency...

The mitral valve (MV) is a highly complex cardiac valve consisting of an annulus, anterior and posterior leaflets, chordae tendineae (chords) and two papillary muscles. The chordae tendineae mechanics play a pivotal role in proper MV function: the chords help maintain proper leaflet coaptation and rupture of the chordae tendineae due to disease or aging can lead to mitral valve insufficiency. Therefore, the aim of this study was to characterize the mechanical properties of aged human and ovine mitral chordae tendineae...

Chordae tendineae are essential for maintaining mitral valve function. Chordae replacement is one of the valve repair procedures commonly used to treat mitral valve regurgitation. But current chordae alternatives (polytetrafluoroethylene, ePTFE) do not have the elastic and self-regenerative properties. Moreover, the ePTFE sutures sometimes fail due to degeneration, calcification and rupture. Tissue-engineered chordae tendineae may overcome these problems. The utility of xenogeneic chordae for tissue-engineered chordae tendineae has not yet been adequately explored...

BACKGROUND: α1-Antitrypsin (AAT) deficiency (AATD) is a genetic condition associated with early-onset panacinar emphysema and, less often, vascular disease. Recently, abnormal elastic properties of ascending aortic wall were described in ZZ genotype AATD subjects who incidentally showed an increased left ventricular mass. MATERIALS AND METHODS: To evaluate biventricular dimensions, valvular apparatus, systolic and diastolic function, 33 AATD subjects with ZZ genotype and 33 healthy subjects matched for age and sex underwent a complete echocardiographic assessment...

AIM: The aim of this study was to evaluate the effects of percutaneous mitral balloon valvuloplasty (PMBV) on short- and intermediate-term aortic stiffness in patients with mitral stenosis. MATERIALS AND METHODS: This prospective study included 56 patients with critical mitral stenosis in normal sinus rhythm (68% female; mean age: 42 ± 11 years) and 37 healthy controls. Aortic stiffness was measured using transthoracic echocardiography before PMBV, and 24-48 hours and 1 year post procedure...

BACKGROUND AND AIM OF THE STUDY: Although mitral stenosis has profound effects on the circulation and hemodynamics, few data exist regarding its impact on aortic elastic properties. The study aim was to determine the association between mitral stenosis and aortic elastic properties by using strain and distensibility as a surrogate. METHODS: Sixty-six patients with echocardiographic documentation of rheumatic mitral stenosis, and 25 age- and gender-matched healthy control subjects were enrolled in the study...