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Aortic stenosis is a condition which is fatal if left untreated. Novel quantitative imaging techniques which better characterise transvalvular pressure drops are being developed but require refinement and validation. A customisable and cost-effective workbench valve phantom circuit capable of replicating valve mechanics and pathology was created. The reproducibility and relationship of differing haemodynamic metrics were assessed from ground truth pressure data alongside imaging compatibility. The phantom met the requirements to capture ground truth pressure data alongside ultrasound and magnetic resonance image compatibility. The reproducibility was successfully tested. The robustness of three different pressure drop metrics was assessed: whilst the peak and net pressure drops provide a robust assessment of the stenotic burden in our phantom, the peak-to-peak pressure drop is a metric that is confounded by non-valvular factors such as wave reflection. The peak-to-peak pressure drop is a metric that should be reconsidered in clinical practice. Graphical abstract The left panel shows manufacture of low cost, functional valves. The central section demonstrates circuit layout, representative MRI and US images alongside gross valve morphologies. The right panel shows the different pressure drop metrics that were assessed for reproducibility

Background: We aim to explore the determinants of right ventricular wall tension (RV base-to-apex length multiplied by systolic pulmonary artery pressure [RV WT] and association with all-cause mortality in patients with moderate-to-severe tricuspid regurgitation. Materials & methods: Of total, 180 patients (71 ± 15 years, 54% females) were included. An increased RV WT was defined as >3300 mmHg x mm. Results: Patients with increased RV WT (n = 85, 47%) were more likely to be male and taller than patients with normal RV WT. In a multivariable-adjusted model, increased RV WT was associated with a 2.6-fold higher risk of all-cause mortality (HR: 2.59, 95% CI: 1.65–4.06). Conclusion: In patients with significant tricuspid regurgitation, an increased RV WT was common, and associated with a 2.6-fold higher risk of all-cause mortality. Male sex was the only independent determinant.

We describe the case of a 73-year-old woman presenting with heart failure, a degenerating bioprosthetic mitral valve, and severely dilated left atrium, and highlight the role of multimodality imaging in planning transseptal transcatheter mitral valve-in-valve implantation. (Level of Difficulty: Advanced.), Central Illustration

Heart failure is an inevitable end-stage consequence of significant valvular heart disease (VHD) that is left untreated and increasingly encountered in an ageing society. Recent advances in transcatheter procedures and improved outcomes after valve surgery mean that intervention can (and should) be considered in all patients - even the elderly and those with multiple comorbidities - at earlier stages of the natural history of primary VHD, before the onset of irreversible left ventricular dysfunction (and frequently before the onset of symptoms). All patients with known VHD should be monitored carefully in the setting of a heart valve clinic and those who meet guideline criteria for surgical or transcatheter intervention referred for intervention without delay. High quality evidence for the use of medical therapy in VHD is limited and achieving target doses in an elderly and comorbid population frequently challenging. Furthermore, determining whether the valve or ventricle is the principal disease driver is crucial (although the distinction is not always binary, and often unclear). Guideline-directed medical therapy remains the mainstay of treatment for secondary mitral regurgitation - although up to 50% of patients may fail to respond and should be considered for cardiac resynchronization, transcatheter or surgical valve intervention. Early and definitive management strategies are essential and should be overseen by a specialist Heart Team that includes a Heart Failure specialist. In this article, we provide an evidence-based summary of approaches to the medical treatment of VHD and clinical guidance for the best management of patients in situations where high quality evidence is lacking.

Uni-dimensional Doppler echocardiography data provide the mainstay of quantative assessment of aortic stenosis, with the transvalvular pressure drop a key indicator of haemodynamic burden. Sophisticated methods of obtaining velocity data, combined with improved computational analysis, are facilitating increasingly robust and reproducible measurement. Imaging modalities which permit acquisition of three-dimensional blood velocity vector fields enable angle-independent valve interrogation and calculation of enhanced measures of the transvalvular pressure drop. This manuscript clarifies the fundamental principles of physics that underpin the evaluation of aortic stenosis and explores modern techniques that may provide more accurate means to grade aortic stenosis and inform appropriate management.

Valve-related heart disease affects 27 million patients worldwide and is associated with inflammation, fibrosis and calcification which progressively lead to organ structure change. Aortic stenosis is the most common valve pathology with controversies regarding its optimal management, such as the timing of valve replacement. Therefore, there is emerging demand for analysis and simulation of valves to help researchers and companies to test novel approaches. This paper describes how to build ultrasound- and MRI-compatible aortic valves compliant phantoms with a two-part mold technique using 3D printing. The choice of the molding material, PVA, was based on its material properties and experimentally tested dissolving time. Different diseased valves were then manufactured with ecoflex silicone, a commonly used tissue-mimicking material. The valves were mounted with an external support and tested in physiological flow conditions. Flow images were obtained with both ultrasound and MRI, showing physiologically plausible anatomy and function of the valves. The simplicity of the manufacturing process and low cost of materials should enable an easy adoption of proposed methodology. Future research will focus on the extension of the method to cover a larger anatomical area (e.g. aortic arch) and the use of this phantom to validate the non-invasive assessment of blood pressure differences.

Objective: Aortic stenosis (AS) is a prevalent valve condition with poor outcomes when left untreated. AS severity metrics are discordant in 30% of cases rendering clinical decision-making complex....

This paper presents collated results from the Delayed Enhancement MRI (DE-MRI) segmentation challenge at MICCAI 2012. DE-MRI Images from fifteen patients and fifteen pigs were randomly selected from two different imaging centres. Three independent sets of manual segmentations were obtained for each image and included in this study. A ground truth consensus segmentation based on all human rater segmentations was obtained using an Expectation-Maximization (EM) method (the STAPLE method). Automated segmentations from five groups contributed to this challenge.

Delayed-enhancement magnetic resonance imaging (DE-MRI) is an effective technique for imaging left ventricular (LV) infarct. Existing techniques for LV infarct segmentation are primarily threshold-based making them prone to high user variability. In this work, we propose a segmentation algorithm that can learn from training images and segment based on this training model. This is implemented as a Markov random field (MRF) based energy formulation solved using graph-cuts. A good agreement was found with the Full-Width-at-Half-Maximum (FWHM) technique.

Brief periods of ischaemia activate systemic mechanisms that induce whole-body tolerance to subsequent prolonged and injurious ischaemia. This phenomenon, remote ischaemic preconditioning (RIPC), is sufficiently acute to reduce ischaemia-reperfusion (IR) injury even when applied simultaneously with injurious ischaemia. This aspect of RIPC is termed remote postconditioning (RPostC). We have previously demonstrated a role for the autonomic nervous system in RIPC. Using an in vivo model of endothelial IR injury, we determined if RPostC is dependent on adrenergic autonomic mechanisms. Vascular ultrasound was used to assess endothelial function in healthy volunteers by measuring dilatation of the brachial artery in response to increased blood flow during reactive hyperaemia (flow-mediated dilatation; FMD). Endothelial IR injury was induced by 20 min of upper limb ischaemia (inflation of a blood pressure cuff to 200 mm Hg) followed by reperfusion. RPostC was induced by applying 2 cycles of 5 minutes ischaemia and 5 minutes reperfusion on the leg during arm ischaemia (via a second blood pressure cuff). In order to determine the dependence of RPostC on autonomic activation, we administered the alpha adrenoceptor blocker phentolamine (0.2– 0.7mg/min, intravenously) during the application of the RPostC stimulus. FMD was determined before ischaemia and at 20 minutes of reperfusion. FMD (percentage change from baseline diameter) was compared statistically by ANOVA. IR alone caused a significant reduction in FMD (5.9±0.7% pre- versus 2.2±0.4% post-IR, n=9, P0.05). Systemic phentolamine blocked the protective effects of RPostC (FMD 6.1±0.5% pre- versus 2.0±0.3% post-IR, n=7, P