Purpose The congenital heart defect Tetralogy of Fallot (ToF) affects 1 in 2500 newborns annually in the US and typically requires surgical repair of the right ventricular outflow tract (RVOT) early in life, with variations in surgical technique leading to large disparities in RVOT anatomy among patients. Subsequently, often in adolescence or early adulthood, patients usually require surgical placement

Purpose To show some preliminary results about the possibility to exploit a cardiovascular mathematical model—made patient-specific by noninvasive data routinely measured during ordinary clinical examinations—in order to obtain sufficiently accurate central blood pressure (BP) estimates. Methods A closed-loop multiscale (0D and 1D) model of the cardiovascular system is made patient-specific by using

Purpose Discrete subaortic stenosis (DSS) is a left-ventricular outflow tract (LVOT) obstruction caused by a membranous lesion. DSS is associated with steep aortoseptal angles (AoSAs) and is a risk factor for aortic regurgitation (AR). However, the etiology of AR secondary to DSS remains unknown. This study aimed at quantifying computationally the impact of AoSA steepening and DSS on aortic valve (AV)

Purpose To develop a novel model composed solely of Col I and Col III with the lower and upper limits set to include the ratios of Col I and Col III at 3:1 and 9:1 in which the structural and mechanical behavior of the resident CM can be studied. Further, the progression of fibrosis due to change in ratios of Col I:Col III was tested. Methods Collagen gels with varying Col I:Col III ratios to represent

Purpose Cellular therapy with mesenchymal stem cells (MSCs) shows promise for restoring function after myocardial infarction (MI). However, cellular therapy has yet to be clinically translated, in part because of difficulty in studying how MSCs interact with the post-MI scar microenvironment. This study aimed to design an in vitro model to study MSC behavior in the post-MI scar stiffness microenvironment

Purpose Variations in the vessel radius of segmented surfaces of intracranial aneurysms significantly influence the fluid velocities given by computer simulations. It is important to generate models that capture the effect of these variations in order to have a better interpretation of the numerically predicted hemodynamics. Also, it is highly relevant to develop methods that combine experimental observations

Purpose The initiation of thrombus formation in transcatheter aortic valves (TAVs) is not well understood. The foreign material components of a TAV may play a key role in TAV thrombogenesis. The goal of this study was to evaluate the thrombogenic potential of a TAV (entire valve) and its stent (with skirt). Methods Blood was collected from eight human donors with citrate anticoagulation and later reconstituted

Purpose In vitro patient-specific flexible vascular models are helpful for understanding the haemodynamic changes before and after endovascular treatment and for effective training of neuroendovascular interventionalists. However, it is difficult to fabricate models of overall unified or controllable thickness using existing manufacturing methods. In this study, we developed an improved and easily

Introduction Symptomatic mitral regurgitation (MR) is associated with high morbidity and mortality which can be ameliorated by surgical valve replacement or repair. Despite this, many patients are excluded from surgery. Transcatheter mitral repair and replacement has emerged as a promising therapeutic option for the treatment of severe MR. The majority of these procedures rely on high definition three

Objective In this study, a mechanical circulatory support simulation tool was used to investigate the application of a unique device with two centrifugal pumps and one motor for the biventricular assist device (BVAD) support application. Several conditions—including a range of combined left and right systolic heart failure severities, aortic and pulmonary valve regurgitation, and combinations of high

Purpose Previous studies have suggested improved recanalization efficiency by using cyclic aspiration as opposed to static aspiration for mechanical thrombectomy in the treatment of acute ischemic stroke (AIS). However, there has not been an investigation into which parameters optimize this theoretical approach. Therefore, this study was designed to investigate the application of static and cyclic

Purpose In previous studies we developed two mechanical prototypes of steerable catheters: the Sigma, which uses joysticks to actuate two steerable tip segments, and the Epsilon, which has a handle that is an enlarged version of the tip. In this study, we present a first performance evaluation of the prototypes in the cardiac environment. The evaluation was carried out by an expert user, an electrophysiologist

Purpose The paper present findings from an in vitro experimental study of a stentless human aortic bioprosthesis (HAB) made of bacterial cellulose (BC). Three variants of the basic model were designed and tested to identify the valve prosthesis with the best performance parameters. The modified models were made of BC, and the basic model of pericardium. Methods Each model (named V1, V2 and V3) was

Purpose Patch reconstruction of the posterior mitral leaflet using small intestinal submucosa extracellular matrix has been successfully performed in a porcine study. The patch reconstruction, however, resulted in non-physiological systolic widening of the mitral annulus, suggesting the need for an annuloplasty ring. The objective was to characterize the impact on annular dynamics and leaflet geometry

Purpose We accelerate a pathline-based cardiovascular model building method by training machine learning models to directly predict vessel lumen surface points from computed tomography (CT) and magnetic resonance (MR) medical image data. Methods We formulate vessel lumen detection as a regression task using a polar coordiantes representation. Results Neural networks trained with our regression formulation

Purpose Existing hemodynamic studies on aortic dissection after thoracic endovascular aortic repair (TEVAR) apply geometric simplifications. This study aims to evaluate the necessity of more accurate geometries at the proximal landing zone in computational fluid dynamic (CFD) studies. Methods Three patient-specific 3D aortic dissection models with different geometric accuracies at the proximal landing

Background Preservation and improvement of heart and vessel health is the primary motivation behind cardiovascular disease (CVD) research. Development of advanced imaging techniques can improve our understanding of disease physiology and serve as a monitor for disease progression. Various image processing approaches have been proposed to extract parameters of cardiac shape and function from different

Purpose The therapeutic drug-loaded nanoparticles (NPs, 20–100 nm) have been widely used to treat brain disorders. To improve systemic brain delivery efficacy of these NPs, it is necessary to quantify their transport parameters across the blood–brain barrier (BBB) and understand the underlying transport mechanism. Methods Permeability of an in vitro BBB, bEnd3 (mouse brain microvascular endothelial

Purpose Our previous studies have confirmed the safety and efficacy of the novel fully bioresorbable PLLA scaffold (PowerScaffold®) at 12 months implantation. In the present study, the scaffold absorption and coronary vessel remodeling at 4 years were evaluated. Methods After PowerScaffold® were implanted into 13 coronary arteries of 6 miniature pigs, quantitative coronary angiography (QCA) was performed

Purpose This study aims to quantify the patient-specific hemodynamics of complex conduit routing configurations of coronary artery bypass grafting (CABG) operation which are specifically suitable for off-pump surgeries. Coronary perfusion efficacy and local hemodynamics of multiple left internal mammary artery (LIMA) with sequential and end-to-side anastomosis are investigated. Using a full anatomical

Purpose Interventional cardiology devices and especially stents are constantly evolving. A good radiopacity is essential to properly position the stent and to reduce the risk of complications during percutaneous coronary intervention (PCI). We wanted to assess the radiopacity of coronary stents. Methods 9 stents were evaluated. Stents were deployed in a silicon bifurcation model and several pulsed

Purpose Preeclampsia (PE) is a pregnancy complication of abnormally elevated blood pressure and organ damage where endothelial function is impaired. Wall shear stress (WSS) strongly effects endothelial cell morphology and function but in PE the WSS values are unknown. WSS calculations from ultrasound inaccurately assume cylindrical arteries and patient specific computational fluid dynamics (CFD) typically

Purpose Acute increases in hydrostatic pressure activate endothelial signaling pathways that modulate barrier function and vascular permeability. We investigated the role the glycocalyx and established mechanotransduction pathways in pressure-induced albumin transport across rat lung microvascular endothelial cells. Methods Rat lung microvascular endothelial cells (RLMEC) were cultured on Costar Snapwell

Purpose Mitral regurgitation (MR) is the second most common valve disease in industrialized countries. Despite its high prevalence, little is known about its impact on the flow dynamics in the left ventricle (LV). Because of the interdependence between valvular function and hemodynamics in the heart chambers, an exploration of the dynamics in the LV could lead to a diagnosis of MR. This in vitro study

Purpose The endothelial glycocalyx (GCX) plays a critical role in the health of the vascular system. Degradation of the GCX has been implicated in the onset of diseases like atherosclerosis and cancer because it disrupts endothelial cell (EC) function that is meant to protect from atherosclerosis and cancer. Examples of such EC function include interendothelial cell communication via gap junctions

Purpose In 2007 the two senior authors wrote a review on the structure and function of the endothelial glycocalyx layer (Weinbaum in Annu Rev Biomed Eng 9:121–167, 2007). Since then there has been an explosion of interest in this hydrated gel-like structure that coats the luminal surface of endothelial cells that line our vasculature due to its important functions in (A) basic vascular physiology and

Purpose Anisodamine hydrobromide (Ani HBr) has been used to improve the microcirculation during cardiovascular disorders and sepsis. Glycocalyx plays an important role in preserving the endothelial cell (EC) barrier permeability and nitric oxide (NO) production. We aimed to test the hypothesis that Ani HBr could protect the EC against permeability and NO production via preventing glycocalyx shedding

Purpose Mechanical heart valves (MHVs) are widely used to replace diseased heart valves, but it may suffer from cavitation due to the rapid closing velocity of the leaflets, resulting in the damage of red blood cells and platelets. The aim of this study is to apply computational fluid dynamics (CFD) method to investigate the cavitation in bileaflets mechanical heart valves (BMHVs) and discuss the effects

Purpose Transport of water and solutes across vascular endothelium is important in normal physiology and critical in the development of various diseases, including atherosclerosis. However, there is debate about the routes for such transport. We recently showed that an albumin-sized tracer crossed endothelium at bicellular and tricellular junctions, a tracer having the size of high density lipoprotein

Background Current design strategies for small diameter vascular grafts (< 6 mm internal diameter; ID) are focused on mimicking native vascular tissue because the commercially available grafts still fail at small diameters, notably due to development of intimal hyperplasia and thrombosis. To overcome these challenges, various design approaches, material selection, and surface modification strategies

Purpose The quantitative analysis of contrast-enhanced Computed Tomography Angiography (CTA) is essential to assess aortic anatomy, identify pathologies, and perform preoperative planning in vascular surgery. To overcome the limitations given by manual and semi-automatic segmentation tools, we apply a deep learning-based pipeline to automatically segment the CTA scans of the aortic lumen, from the

Purpose Computational models of cardiovascular structures rely on their accurate mechanical characterization. A validated method able to infer the material properties of patient-specific large vessels is currently lacking. The aim of the present study is to present a technique starting from the flow-area (QA) method to retrieve basic material properties from magnetic resonance (MR) imaging. Methods

Introduction Tricuspid regurgitation (TR) affects approximately 1.6 million Americans and is associated with just a 63.9% 1-year survival rate in its moderate to severe forms due to its asymptomatic nature and late diagnosis and surgical referral. As a result, industrial fervor has begun to broach this topic, with several percutaneous treatment devices currently under development. As much remains unknown

Purpose The objective of this study was to reprogram human adipogenic mesenchymal stem cells (hADMSCs) to form Purkinje cells and to use the reprogrammed Purkinje cells to bioprint Purkinje networks. Methods hADMSCs were reprogrammed to form Purkinje cells using a multi-step process using transcription factors ETS2 and MESP1 to first form cardiac progenitor stem cells followed by SHOX2 and TBX3 to

Purpose Atherosclerosis preferentially occurs near the junction of branching vessels, where blood recirculation tends to occur (Malek et al. in J Am Med Assoc 282(21):2035–2042, 1999, https://doi.org/10.1001/jama.282.21.2035). For decades, CFD has been used to predict flow patterns such as separation and recirculation zones in hemodynamic models, but those predictions have rarely been validated with

Purpose Multiple studies have shown that spectral analysis of tissue autofluorescence can be used as a live indicator for various pathophysiological states of cardiac tissue, including ischemia, ablation-induced damage, or scar formation. Yet today there are no percutaneous devices that can detect autofluorescence signals from inside a beating heart. Our aim was to develop a prototype catheter to demonstrate

PurposeRecent studies have noted a degree of variance between the geometries segmented by different groups from 3D medical images that are used in computational fluid dynamics (CFD) simulations of patient-specific cardiovascular systems. The aim of this study was to determine if the applied sequence of magnetic resonance imaging (MRI) also introduced observable variance in CFD results. MethodsUsing

PurposeThe lack of long-term patency of synthetic vascular grafts currently available on the market has directed research towards improving the performance of small diameter grafts. Improved radial compliance matching and tissue ingrowth into the graft scaffold are amongst the main goals for an ideal vascular graft. MethodsBiostable polyurethane scaffolds were manufactured by electrospinning and implanted

PurposeCrosslinked poly(vinyl alcohol) (PVA) is a biomaterial that can be used for multiple cardiovascular applications. The success of implanted biomaterials is contingent on the properties of the material. A crucial consideration for blood-contacting devices is their potential to incite thrombus formation, which is dependent on the material surface properties. The goal of this study was to quantify

PurposeTo investigate the anatomical and functional effects of complete surgical reconstruction of the posterior mitral leaflet and associated chordae tendineae with a patch made of 2-ply small intestinal submucosal extracellular matrix in vitro. MethodsSeven explanted mitral valves with intact subvalvular apparatus from 80-kg pigs were evaluated in a left heart simulator and served as their own controls

PurposeThe left atrium and left ventricle are the primary inflow cannulation sites for heart failure patients supported by rotary blood pumps (RBPs). Haemodynamic differences exist between inflow cannulation sites and have been well characterized at rest, yet the effect during exercise with the same centrifugal RBP has not been previously well established. The purpose of this study was to investigate

PurposeAs the promoter of the stent expansion, the balloon plays a very important role, offering a strong influence on the deployment process. Balloon-artery interaction is pointed as a probable cause of restenosis, stressing the relevance of balloon modeling when simulating the stenting procedure. In this work, an in-silico study of the balloon modeling strategies is performed. MethodsUltrasonic-microcasting

PurposeResidual stress tensor has an essential influence on the mechanical behaviour of soft tissues and can be particularly useful in evaluating growth and remodelling of the heart and arteries. It is currently unclear if one single radial cut using the opening angle method can accurately estimate the residual stress. In many previous models, it has been assumed that a single radial cut can release

PurposeBicuspid aortic valve (BAV) is a congenital heart malformation with phenotypic heterogeneity. There is no prior computational study that assesses the haemodynamic and valve mechanics associated with BAV type 2 against a healthy tricuspid aortic valve (TAV) and other BAV categories. MethodsA proof-of-concept study incorporating three-dimensional fluid-structure interaction (FSI) models with idealised

PurposeThrombosis within an occluded coronary arterial fistula (CAF) may cause angina and myocardial infarction. This study aims to estimate how the occlusion position of CAFs with terminal aneurysm affects the risk stratification of thrombosis in the fistula in terms of hemodynamics. MethodsTwelve CAF models were reconstructed based on patient-specific computed tomography angiogram (CTA) images. They

PurposeThe main purpose is to compare the characteristics and performance of a centrifugal blood pump with and without center post. Furthermore, to propose a center post design guide for the development of centrifugal blood pumps: finding the appropriate height and diameter of the center post. MethodsA centrifugal blood pump with different center post configurations is investigated using Computational

PurposeAtrial fibrillation (AF) is the most common heart rhythm disorder in the world. Radiofrequency catheter ablation (RFCA) has become the preferred method of treatment for drug-refractory AF. One of the rare (< 0.2%) but deadly (≈ 80%) complications of RFCA is Atrioesophageal fistula (AEF). Although the exact pathophysiological events in developing AEF are not fully understood, one hypothesis is

PurposeCurrently used cannulae for extracorporeal carbon dioxide removal (ECCO2R) are associated with complications such as thrombosis and distal limb ischemia, especially for long-term use. We hypothesize that the risk of these complications is reducible by attaching hemodynamically optimized grafts to the patient’s vessels. In this study, as a first step towards a long-term stable ECCO2R connection

PurposeFibrocalcific aortic valve disease (CAVD) is caused by the deposition of calcific nodules in the aortic valve leaflets, resulting in progressive loss of function that ultimately requires surgical intervention. This process is actively mediated by the resident valvular interstitial cells (VICs), which, in response to oxidized lipids, transition from a quiescent to an osteoblast-like state. The

PurposeOptimal assessment of cardiovascular performance requires simultaneous measurement of load independent left ventricular (LV) contractility, arterial function and LV/arterial coupling. We aimed to demonstrate feasibility of non-invasive ventricular pressure–volume and aortic pressure-flow-impedance measurements using simultaneous arterial tonometry (AT) and cardiovascular magnetic resonance imaging

PurposeModeling of hemolysis due to fluid stresses faces significant methodological challenges, particularly in geometries with turbulence or complex flow patterns. It is currently unclear how existing phenomenological blood-damage models based on laminar viscous stresses can be implemented into turbulent computational fluid dynamics simulations. The aim of this work is to generalize the existing laminar

The emergence of transcatheter aortic valve replacement (TAVR) has segued the development of transcatheter mitral valve (MV) repair devices. Transcatheter mitral valve repair has become a well-established alternative for patients with severe primary and secondary mitral regurgitation (MR) and with a perceived surgical risk. Transcatheter mitral valve replacement (TMVR) could become a more complete

PurposeAdditional pulmonary blood flow (APBF) can provide better pulsating blood flow and systemic arterial oxygen saturation, while low blood pulsation and low oxygen saturation are defects of the Fontan and Glenn procedure. Studying the hemodynamic effect of APBF is beneficial for clinical decisions. This study aimed to explore the effect on particle washout, as well as the differences among the

PurposeA treatment device without a stent is needed for peripheral stenotic artery treatment. We have proposed short-term heating balloon angioplasty, photo-thermo dynamic balloon angioplasty (PTDBA). Though smooth muscle cells (SMCs) after PTDBA are fixed in a stretched formation in a porcine model, influences of this stimulus on SMCs have not been investigated. SMC migration after vascular dilatation

ObjectiveArterial stiffness and endothelial function are two established surrogate markers of subclinical atherosclerosis and are quantified by three arterial parameters: elasticity, viscosity and radius of the arterial wall. Yet, the current methods for their assessment are unsuitable for routine use. Post-exercise response of the cardiovascular (CV) system serves as a more sensitive detection of

PurposeMetabolic alterations underlie many pathophysiological conditions, and their understanding is critical for the development of novel therapies. Although the assessment of metabolic changes in vivo has been historically challenging, recent developments in molecular imaging have allowed us to study novel metabolic research concepts directly in the living subject, bringing us closer to patients

IntroductionLeft ventricular (LV) remodeling is a critical process underlying heart failure (HF) development and progression. While LV global longitudinal strain determined by speckle-tracking echocardiography (STE) provides a promising basis to monitor LV remodeling, reported strain measures are limited by the masking of regional differences and a dependency on hemodynamic load. ObjectivesOur goal

PurposeCarotid artery corrected flow time (cFT) derived from Doppler USG is a known predictor of volume responsiveness. However, it can’t be obtained continuously, and is operator dependent. In this prospective study, correlation between Doppler derived carotid artery cFT and pressure transducer derived radial artery cFT was evaluated in adult patients undergoing surgery under general anaesthesia.

PurposeRecent studies have demonstrated that miRNAs play a vital role in regulating myocardial ischemia/reperfusion injury (MIRI). MiR-217 has been proven to be implicated in cardiac diseases such as chronic heart failure and cardiac myxoma. However, the role of miR-217 in MIRI is not clear. MethodsA mouse MIRI model was established and the myocardial infarct size was evaluated by TTC staining. The