33 research outputs found

    Three dimensional echocardiography in valvular heart disease

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    Although cardiac structures exist in three dimensions, two dimensional (2-D) echocardiography only provides information in a single tomographic plane, the orientation of which is determined by the ultrasound window. Accordingly the use of geometric assumptions and/or mental integration of information from multiple 2-D images are needed to assess cardiac function and structure. Advances in ultrasound technology and image reconstruction have opened up the possibility of using three dimensional (3-D) techniques in both quantitative applications such as measurement of ventricular volumes and qualitative applications such as the assessment of valve stenosis or regurgitation. Further technical improvements in terms of real-time 3-D imaging and development of 3-D transoesophageal echo (TOE ) probes; have opened up further applications including intra-operative guidance of percutaneous valve interventions

    Left Atrial Function Is Associated with Earlier Need for Cardiac Surgery in Moderate to Severe Mitral Regurgitation: Usefulness in Targeting for Early Surgery

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    BACKGROUND: The aim of this study was to determine whether assessment of left atrial (LA) function helps identify patients at risk for early deterioration during follow-up with mitral valve prolapse and mitral regurgitation. METHODS: Patients with moderate to severe mitral regurgitation but no guideline-based indications for surgery were retrospectively identified from a dedicated clinical database. Maximal and minimal LA volumes were used to derive total LA emptying fraction ([maximal LA volume - minimal LA volume]/maximal L volume × 100%). Average values of peak contractile, conduit, and reservoir strain were obtained using two-dimensional speckle-tracking imaging. The study outcome was time to mitral surgery. RESULTS: One hundred seventeen patients were included; median follow-up was 18 months. Sixty-eight patients underwent surgery. Receiver operating characteristic curves were used to derive optimal cutoffs for TLAEF (>50.7%) and strain (reservoir, >28.5%; contractile, >12.5%). Using Cox analysis, TLAEF and contractile, reservoir, and conduit strain were univariate predictors of time to event. After multivariate analysis, TLAEF (hazard ratio, 2.59; P = .001), reservoir strain (hazard ratio, 3.06; P < .001), and contractile strain (hazard ratio, 2.01; P = .022) remained independently associated with events, but conduit strain did not. Using Kaplan-Meier curves, event-free survival was considerably improved in patients with values above the derived thresholds (TLAEF: 1-year survival, 78 ± 5% vs 28 ± 8%; 3-year survival, 68 ± 6% vs 13 ± 5%; P < .001 for both; reservoir strain: 1-year survival, 79 ± 5% vs 29 ± 7%; 3-year survival, 67 ± 6% vs 15 ± 6%; P < .001 for both; contractile strain: 1-year survival, 80 ± 5% vs 41 ± 7%; 3-year survival, 69 ± 6% vs 24 ± 6%; P < .001 for both). CONCLUSION: LA function is independently associated with surgery-free survival in patients with mitral valve prolapse and moderate to severe mitral regurgitation. Quantitative assessment of LA function may have clinical utility in guiding early surgical intervention in these patients

    Patent Foramen Ovale Closure in 2019

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    Patent foramen ovale (PFO) is a common abnormality affecting between 20% and 34% of the adult population. For most people it is a benign finding; however, in some the PFO can open widely, enabling a paradoxical embolus to transit from the venous to arterial circulation, which is associated with stroke and systemic embolisation. Percutaneous closure of PFO in patients with cryptogenic stroke has been undertaken for a number of years, and a number of purpose-specific septal occluders have been marketed. Recent randomised controlled trials have demonstrated that closure of PFO in patients with cryptogenic stroke is associated with reduced rates of recurrent stroke. After a brief overview of the anatomy of a PFO, this review considers the evidence for PFO closure in cryptogenic stroke. The review also addresses other potential indications for closure, including systemic embolisation, decompression sickness, platypnoea–orthodeoxia syndrome and migraine with aura. It lays out the pre-procedural investigations and preparation for the procedure. Finally, it gives an overview of the procedure itself, including discussion of closure devices

    Software for the frontiers of quantum chemistry:An overview of developments in the Q-Chem 5 package

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    This article summarizes technical advances contained in the fifth major release of the Q-Chem quantum chemistry program package, covering developments since 2015. A comprehensive library of exchange–correlation functionals, along with a suite of correlated many-body methods, continues to be a hallmark of the Q-Chem software. The many-body methods include novel variants of both coupled-cluster and configuration-interaction approaches along with methods based on the algebraic diagrammatic construction and variational reduced density-matrix methods. Methods highlighted in Q-Chem 5 include a suite of tools for modeling core-level spectroscopy, methods for describing metastable resonances, methods for computing vibronic spectra, the nuclear–electronic orbital method, and several different energy decomposition analysis techniques. High-performance capabilities including multithreaded parallelism and support for calculations on graphics processing units are described. Q-Chem boasts a community of well over 100 active academic developers, and the continuing evolution of the software is supported by an “open teamware” model and an increasingly modular design

    Echocardiographic Evaluation of Patent Foramen Ovale Prior to Device Closure

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    High-quality imaging of the atrial septum has never been so relevant to the adult cardiologist. This article focuses on the role of echocardiography in the evaluation of patent foramen ovale for closure. It provides a systematic and comprehensive approach to transesophageal echocardiographic study in such a patient. The salient information required for planning the device and equipment needed for the closure procedure are discussed

    Tricuspid regurgitation and the right ventricle in risk stratification and timing of intervention.

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    Tricuspid regurgitation natural history and treatment remains poorly understood. Right ventricular function is a key factor in determining prognosis, timing for intervention and longer-term outcome. The right ventricle is a thin walled chamber with a predominance of longitudinal fibres and a shared ventricular septum. In health, the low-pressure pulmonary circulation results in a highly compliant RV well equipped to respond to changes in preload but sensitive to even small alterations in afterload. In Part 1 of this article, discussion focuses on key principles of ventricular function assessment and the importance of right ventricular chamber size, volumes and ejection fraction, particularly in risk stratification in tricuspid regurgitation. Part 2 of this article provides an understanding of the causes of tricuspid regurgitation in the contemporary era, with emphasis on key patient groups and their management
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