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233 result(s) for "Bicuspid Aortic Valve Disease - diagnostic imaging"
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Blood flow dynamics in the ascending aorta of patients with bicuspid aortic valve before and after transcatheter aortic valve replacement: a computational fluid dynamics study
Background Abnormal blood flow patterns are known to contribute to the ascending aortic dilation in patients with bicuspid aortic valve (BAV). The present study elucidated the blood flow characteristics in the dilated ascending aorta before and after transcatheter aortic valve replacement (TAVR) using computational fluid dynamics (CFD) analysis. Methods We performed CFD analysis in three BAV patients with ascending aortic dilation (maximum diameter ≥ 45 mm) who underwent TAVR. The blood flow streamline was visualized to evaluate the pre- and post-operative flow velocity, severity of vortex and helix, and wall shear stress (WSS) in the ascending aorta. Results Before the procedure, all three patients showed abnormal blood flow patterns, with vortex and helix in the ascending aorta. Regionally elevated WSS was also observed in the lateral or posterior ascending aortic wall (16.7 Pa, 12.2 Pa, and 14.5 Pa in patient 1, 2, and 3, respectively). After the procedure, the blood flow patterns significantly improved, and the maximum WSS also decreased (4.2 Pa, 1.1 Pa, and 3.2 Pa in patient 1, 2, and 3, respectively). Conclusion Abnormal blood flow patterns and WSS appeared to improve after TAVR in BAV patients with ascending aortic dilation. The impact on the long-term aortic growth rate and the incidence of aortic dissection requires further studies. Trial Registration Changes of Ascending Aortic Diameter in Patients Undergoing Transcatheter Aortic Valve Replacement. ClinicalTrial.gov number NCT05739253. Trial registration date 20,230,212.
Simulation study of transcatheter heart valve implantation in patients with stenotic bicuspid aortic valve
Bicuspid aortic valve (BAV) anatomy has routinely been considered an exclusion in the setting of transcatheter aortic valve implantation (TAVI) because of the large dimension of the aortic annulus having a more calcified, bulky, and irregular shape. The study aims to develop a patient-specific computational framework to virtually simulate TAVI in stenotic BAV patients using the Edwards SAPIEN 3 valve (S3) and its improved version SAPIEN 3 Ultra and quantify stent frame deformity as well as the severity of paravalvular leakage (PVL). Specifically, the aortic root anatomy of n.9 BAV patients who underwent TAVI was reconstructed from pre-operative CT imaging. Crimping and deployment of S3 frame were performed and then followed by fluid-solid interaction analysis to simulate valve leaflet dynamics throughout the entire cardiac cycle. Modeling revealed that the S3 stent frame expanded well on BAV anatomy with an elliptical shape at the aortic annulus. Comparison of predicted S3 deformity as assessed by eccentricity and expansion indices demonstrated a good agreement with the measurement obtained from CT imaging. Blood particle flow analysis demonstrated a backward blood jet during diastole, whereas the predicted PVL flows corresponded well with those determined by transesophageal echocardiography. This study represents a further step towards the use of personalized simulations to virtually plan TAVI, aiming at improving not only the efficacy of the implantation but also the exploration of “off-label” applications as the TAVI in the setting of BAV patients.
3D Characterization of the Aortic Valve and Aortic Arch in Bicuspid Aortic Valve Patients
Patients with bicuspid aortic valve (BAV) commonly have associated aortic stenosis and aortopathy. The geometry of the aortic arch and BAV is not well defined quantitatively, which makes clinical classifications subjective or reliant on limited 2D measurements. The goal of this study was to characterize the 3D geometry of the aortic arch and BAV using objective and quantitative techniques. Pre-TAVR computed tomography angiogram (CTA) in patients with BAV and aortic stenosis (AS) were analyzed (n = 59) by assessing valve commissural angle, presence of a fused region, percent of fusion, and calcium volume. The ascending aorta and aortic arch were reconstructed from patient-specific imaging segmentation to generate a centerline and calculate maximum curvature and maximum area change for the ascending aorta and the descending aorta. Aortic valve commissural angle signified a bimodal distribution suggesting tricuspid-like (≤ 150°, 52.5% of patients) and bicuspid-like (> 150°, 47.5%) morphologies. Tricuspid like was further classified by partial (10.2%) or full (42.4%) fusion, and bicuspid like was further classified into valves with fused region (27.1%) or no fused region (20.3%). Qualitatively, the aortic arch was found to have complex patient-specific variations in its 3D shape with some showing extreme diameter changes and kinks. Quantitatively, subgroups were established using maximum curvature threshold of 0.04 and maximum area change of 30% independently for the ascending and descending aorta. These findings provide insight into the geometric structure of the aortic valve and aortic arch in patients presenting with BAV and AS where 3D characterization allows for quantitative classification of these complex anatomic structures.
Rare case of aorto-left atrial tunnel with associated bicuspid aortic valve, large patent ductus arteriosus, and atrial septal defects
Aorto-cardiac tunnels represent uncommon cardiovascular anomalies connecting the ascending aorta to cardiac chambers and are typically characterized by extra-cardiac tubular channels. Among these, the involvement of the left atrium is exceptionally rare, with only a few cases reported in literature. Here, we describe a case of an aorto-left atrial tunnel in a 6-year-old boy with an associated bicuspid aortic valve, a large patent ductus arteriosus, and atrial septal defects. This case highlights the significance of multimodal imaging in the accurate identification and characterization of rare cardiovascular anomalies.
Unraveling aortic hemodynamics using fluid structure interaction: biomechanical insights into bicuspid aortic valve dynamics with multiple aortic lesions
Aortic lesions, exemplified by bicuspid aortic valves (BAVs), can complicate congenital heart defects, particularly in Turner syndrome patients. The combination of BAV, dilated ascending aorta, and an elongated aortic arch presents complex hemodynamics, requiring detailed analysis for tailored treatment strategies. While current clinical decision-making relies on imaging modalities offering limited biomechanical insights, integrating high-performance computing and fluid-structure interaction algorithms with patient data enables comprehensive evaluation of diseased anatomy and planned intervention. In this study, a patient-specific workflow was utilized to biomechanically assess a Turner syndrome patient's BAV, dilated ascending aorta, and elongated arch. Results showed significant improvements in valve function (effective orifice area, EOA increased approximately twofold) and reduction in valve stress (~ 1.8-fold) following virtual commissurotomy, leading to enhanced flow dynamics and decreased viscous dissipation (~ twofold) particularly in the ascending aorta. However, increased viscous dissipation in the distal transverse aortic arch offset its local reduction in the AAo post-intervention, emphasizing the elongated arch's role in aortic hemodynamics. Our findings highlight the importance of comprehensive biomechanical evaluation and integrating patient-specific modeling with conventional imaging techniques for improved disease assessment, risk stratification, and treatment planning, ultimately enhancing patient outcomes.
Patient-Specific Bicuspid Aortic Valve Biomechanics: A Magnetic Resonance Imaging Integrated Fluid–Structure Interaction Approach
Congenital bicuspid aortic valve (BAV) consists of two fused cusps and represents a major risk factor for calcific valvular stenosis. Herein, a fully coupled fluid–structure interaction (FSI) BAV model was developed from patient-specific magnetic resonance imaging (MRI) and compared against in vivo 4-dimensional flow MRI (4D Flow). FSI simulation compared well with 4D Flow, confirming direction and magnitude of the flow jet impinging onto the aortic wall as well as location and extension of secondary flows and vortices developing at systole: the systolic flow jet originating from an elliptical 1.6 cm2 orifice reached a peak velocity of 252.2 cm/s, 0.6% lower than 4D Flow, progressively impinging on the ascending aorta convexity. The FSI model predicted a peak flow rate of 22.4 L/min, 6.7% higher than 4D Flow, and provided BAV leaflets mechanical and flow-induced shear stresses, not directly attainable from MRI. At systole, the ventricular side of the non-fused leaflet revealed the highest wall shear stress (WSS) average magnitude, up to 14.6 Pa along the free margin, with WSS progressively decreasing towards the belly. During diastole, the aortic side of the fused leaflet exhibited the highest diastolic maximum principal stress, up to 322 kPa within the attachment region. Systematic comparison with ground-truth non-invasive MRI can improve the computational model ability to reproduce native BAV hemodynamics and biomechanical response more realistically, and shed light on their role in BAV patients’ risk for developing complications; this approach may further contribute to the validation of advanced FSI simulations designed to assess BAV biomechanics.
Sport PRactice and its Effects on aortic size and valve function in bicuspid Aortic valve Disease: a cross-sectional report from the SPREAD study
ObjectiveConcerns exist about the possible detrimental effects of exercise training on aortic size and valve function in individuals with bicuspid aortic valve (BAV). This multicentre international study aimed to determine the characteristics of aortic size and valve function in athletes versus non-athletes with BAV and athletes with tricuspid aortic valve (TAV).MethodsWe enrolled competitive athletes with BAV and age- and sex-matched athletes with TAV and non-athletes with BAV. We assessed valve function, aortic size and biventricular measures using echocardiography. Individuals with established moderate-severe AV stenosis, regurgitation or significant aortic dilation were excluded from the study.ResultsThe study population comprised 504 participants: 186 competitive athletes with BAV (84% males; age 30±11 years), 193 competitive athletes with TAV and 125 non-athletes with BAV. The aortic annulus was greater in athletes with BAV than athletes with TAV and non-athletes with BAV (p<0.001). Both athletic and non-athletic individuals with BAV had greater sinuses of Valsalva, sino-tubular junction and ascending aorta diameters than athletes with TAV (p<0.001). However, no significant differences were found between athletes and non-athletes with BAV. Left ventricular index volumes and mass were greater in athletes with BAV than in the other two groups (p<0.001). Individuals with BAV (athletes and non-athletes) had greater mean gradients than TAV athletes.ConclusionThis multicentre international study demonstrates no differences between athletes with BAV and non-athletes with BAV regarding aortic valve function or aortic dimensions. However, athletes with BAV have larger aortic diameters and a relatively worse valvular function than athletes with TAV.
Circulating Matrix Metalloproteinases for Prediction of Aortic Dilatation in Children with Bicuspid Aortic Valve: A Single-Center, Observational Study
Circulating biomarkers have been proposed for early identification of aortic dilatation progression associated with bicuspid aortic valve (BAV), but matrix metalloproteinases (MMPs) are distinguished as signatures of increased extracellular matrix degradation, a landmark of aneurysm formation. The current study aims to identify the role of MMP-1, MMP-2, MMP-9, and the MMP inhibitor, TIMP-1, in identifying aortic dilation in children with BAV. We conducted a study on 73 children divided into two study groups, depending on the presence of aortic dilatation (group 1–43 BAV controls and group 2–30 children with BAV and aortic dilatation). Each patient underwent a cardiac ultrasound and, in each case, serum MMP-1, MMP-2, MMP-9, and TIMP-1 were quantified using xMAP technology. Comparison of the MMPs between the two study groups revealed significantly higher values only in the case of TIMP-1, among BAV controls. Moreover, the same TIMP-1 inversely correlated with aortic annulus absolute size and z score, as well as with ascending aorta z score. No particular correlation between the aortic phenotype and the presence of aortic dilatation was found. Future longitudinal research starting at pediatric ages could show the significance of MMPs screening in BAV individuals as predictors of aortic aneurysm formation.
A novel NOTCH1 nonsense variant in a bicuspid aortic valve family with intrafamilial clinical heterogeneity
Background Bicuspid aortic valve (BAV) represents a prevalent form of congenital heart disease. The NOTCH1 gene is implicated in the pathogenesis of BAV, and congenital valve anomalies caused by variants in this gene are classified as Aortic Valve Disease 1 (AOVD1), which is inherited in an autosomal dominant pattern. Methods Echocardiographic data and peripheral blood samples were collected from a Chinese family manifesting a clinical phenotype characterized by various cardiovascular abnormalities, including BAV. Exome sequencing target enrichment technology was performed to identify candidate genes and variants. This was followed by family segregation analysis using Sanger sequencing. Results A novel nonsense variant, c.2266G > T (p.Glu756Ter), was identified in the NOTCH1 gene (NM_017617.5) within this family. Individuals harboring the p.Glu756Ter pathogenic variant (III4, II7, II9, and I2) exhibited BAV – associated phenotypes. Conversely, the proband carrying p.Glu756Ter pathogenic variant (IV1) presented with distinct clinical phenotypes, including a persistent left superior vena cava (PLSVC) and a widened coronary sinus. Family members without the p.Glu756Ter pathogenic variant showed no cardiovascular abnormalities. This variant is located in exon 14 of the NOTCH1 gene, resulting in a premature stop codon. Bioinformatics analysis predicted that p.Glu756Ter induces nonsense-mediated mRNA decay or produces a truncated protein, impairing NOTCH1 receptor function. Conclusions The NOTCH1 variant is a prevalent genetic factor in BAV etiology, exhibiting both interfamilial and intrafamilial phenotypic variability with incomplete penetrance. PLSVC and a widened coronary sinus represent common anatomical variations within the general population. Nevertheless, the potential role of NOTCH1 variants in the development of these vascular anomalies should be considered.
Is Bicuspid Aortic Valve Morphology Genetically Determined? A Family-Based Study
Bicuspid aortic valve (BAV) is a common congenital heart disease, with a 10-fold higher prevalence in first-degree relatives. BAV has different phenotypes based on the morphology of cusp fusion. These phenotypes are associated with different clinical courses and prognoses. Currently, the determinants of the valve phenotype are unknown. In this study we evaluated the role of genetics using familial cohorts. Patients with BAV and their first-degree relatives were evaluated by echocardiography. The concordance in BAV phenotype between pairs of family members was calculated and compared with the concordance expected by chance. We then performed a systematic literature review to identify additional reports and calculated the overall concordance rate. During the study period, 70 cases from 31 families and 327 sporadic cases were identified. BAV was diagnosed in 14% of the screened relatives. The proportions of the morphologies identified was: 12.3% for type 0, 66.2% for type 1-LR, 15.4% for type 1-RN, 4.6% for type 1-NL, and 1.5% for type 2. For the assessment of morphologic concordance, we included 120 pairs of first-degree relatives with BAV from our original cohort and the literature review. Concordance was found only in 62% of the pairs which was not significantly higher than expected by chance. In conclusion, our finding demonstrates intrafamilial variability in BAV morphology, suggesting that morphology is determined by factors other than Mendelian genetics. As prognosis differs by morphology, our findings may suggest that clinical outcomes may vary even between first-degree relatives. [Display omitted]