Elucidating the mechanisms underlying left ventricular function recovery in patients with ischemic heart failure undergoing surgical remodeling: A 3-dimensional ultrasound analysis.

Objective: The study objective was to elucidate the mechanisms of left ventricle functional recovery in terms of endocardial contractility and synchronicity after surgical ventricular reconstruction.

Methods: Real-time 3-dimensional transthoracic echocardiography was performed on 20 patients with anterior left ventricle remodeling and ischemic heart failure before surgical ventricular reconstruction and at 6-month follow-up, and on 15 healthy controls matched by age and body surface area. Real-time 3-dimensional transthoracic echocardiography datasets were analyzed through TomTec software (4D LV-Analysis; TomTec Imaging Systems GmbH, Unterschleissheim, Germany): Left ventricle volumes, ejection fraction, and global longitudinal strain were computed; the time-dependent endocardial surface yielded by 3-dimensional speckle-tracking echocardiography was postprocessed through in-house software to quantify local systolic minimum principal strain as a measure of fiber shortening and mechanical dispersion as a measure of fiber synchronicity.

4D MDCT in the assessment of the tricuspid valve and its spatial relationship with the right coronary artery: A customized tool based on computed tomography for the planning of percutaneous procedures.

Multidetector computed tomography (MDCT) is currently the imaging technique of choice for the assessment of tricuspid valve (TV) annulus geometry and relationship with the right coronary artery (RCA). However, standardized protocols with a full 3D analysis are still lacking to plan percutaneous procedures for functional tricuspid regurgitation (FTR). A novel customized 4-dimensional tool based on MDCT data was developed and provided accurate information on TV annulus morphology (3D-perimeter, 2D-Area, maximum and minimum diameters, eccentricity index), function and distance to the RCA, crucial for patient selection of percutaneous TV procedures.

Myocardial reconstruction in ischaemic cardiomyopathy.

An increase in left ventricular volume after a myocardial infarction is a key component of the adverse remodelling process leading to chamber dysfunction, heart failure and an unfavourable outcome. Hence, the therapeutic strategies have been designed to reverse the remodelling process by medical therapy, devices or surgical strategies. Surgical ventricular reconstruction primarily combined with myocardial revascularization has been introduced as an optional intervention aimed to reduce the left ventricle through resection of the scar tissue and is recommended in selected patients with predominant heart failure symptoms, and with myocardial scarring and moderate left ventricular remodelling.

A microscale biomimetic platform for generation and electro-mechanical stimulation of 3D cardiac microtissues.

Organs-on-chip technology has recently emerged as a promising tool to generate advanced cardiac tissue models, by recapitulating key physiological cues of the native myocardium. Biochemical, mechanical, and electrical stimuli have been investigated and demonstrated to enhance the maturation of cardiac constructs. However, the combined application of such stimulations on 3D organized constructs within a microfluidic platform was not yet achieved.

Dynamic and quantitative evaluation of degenerative mitral valve disease: a dedicated framework based on cardiac magnetic resonance imaging.

Background: Accurate quantification of mitral valve (MV) morphology and dynamic behavior over the cardiac cycle is crucial to understand the mechanisms of degenerative MV dysfunction and to guide the surgical intervention. Cardiac magnetic resonance (CMR) imaging has progressively been adopted to evaluate MV pathophysiology, although a dedicated framework is required to perform a quantitative assessment of the functional MV anatomy.

Methods: We investigated MV dynamic behavior in subjects with normal MV anatomy (n=10) and patients referred to surgery due to degenerative MV prolapse, classified as fibro-elastic deficiency (FED, n=9) and Barlow's disease (BD, n=10).

In vitro and in silico approaches to quantify the effects of the Mitraclip system on mitral valve function.

Mitraclip implantation is widely used as a valid alternative to conventional open-chest surgery in high-risk patients with severe mitral valve (MV) regurgitation. Although effective in reducing mitral regurgitation (MR) in the majority of cases, the clip implantation produces a double-orifice area that can result in altered MV biomechanics, particularly in term of hemodynamics and mechanical stress distribution on the leaflets. In this scenario, we combined the consistency of in vitro experimental platforms with the versatility of numerical simulations to investigate clip impact on MV functioning.

Biomechanical drawbacks of different techniques of mitral neochordal implantation: When an apparently optimal repair can fail.

Objectives: Intraoperative assessment of the proper neochordal length during mitral plasty may be complex sometimes. Patient-specific finite element models were used to elucidate the biomechanical drawbacks underlying an apparently correct mitral repair for isolated posterior prolapse.

Methods: Preoperative patient-specific models were derived from cardiac magnetic resonance images; integrated with intraoperative surgical details to assess the location and extent of the prolapsing region, including the number and type of diseased chordae; and complemented by the biomechanical properties of mitral leaflets, chordae tendineae, and artificial neochordae.