366 research outputs found
Echocardiographic assessment of congenital mitral stenosis.
To assess the severity and precise anatomy of congenital mitral stenosis (MS), 17 patients with congenital left ventricular inflow obstruction were studied by M-mode and two-dimensional echocardiography (2DE) and by cardiac catheterization. In six patients MS was an isolated lesion and in 11 it was combined with other cardiovascular malformations. The diagnosis was confirmed at operation or autopsy in 15 patients. Twenty normal subjects of the same age and sex were selected as controls. M-mode amplitude and speed of diastolic closure (E-F slope) of the anterior mitral valve leaflet were determined in all patients. Mitral valve areas were traced after careful short-axis 2DE scans in 15 patients. Supravalvar, valvar, or subvalvar obstruction was evaluated in patients with surgical or autopsy documentation. Analysis of M-mode echocardiograms showed a reduction of E-F slope in all patients compared to normal control subjects but a poor correlation between E-F slope and hemodynamic data (mitral valve areas or pressure gradients). Diastolic fluttering of either or both mitral valve leaflets was found in 12 patients. It is concluded that M-mode echocardiography may be useful for qualitative assessment of congenital MS, even in the presence of associated heart defects, but less useful in evaluating its severity. Analysis of 2DE revealed good correlation between mitral valve areas as calculated with 2DE and with the Gorlin formula at cardiac catheterization, despite the complexity of the congenital mitral lesion. Anatomic varieties of congenital left ventricular inflow obstruction, such as stenosing supravalvar mitral ring or parachute deformity of the mitral valve, were recognized at 2DE.(ABSTRACT TRUNCATED AT 250 WORDS
Implantable devices for heart failure monitoring: the CardioMEMS™ system.
Several devices have been developed for heart failure (HF) treatment and monitoring. Among device-based monitoring tools, CardioMEMS™ has received growing research attention. This document reflects the key points of an ESC consensus meeting on implantable devices for monitoring in HF, with a particular focus on CardioMEMS™
Design and commissioning of a thermal stability test-rig for mixtures as working fluids for ORC applications
Abstract A novel test-rig for studying the thermal stability of mixtures as working fluids for ORC applications was designed and commissioned at the Laboratory of Compressible-fluid dynamics for Renewable Energy Applications (CREA) of Politecnico di Milano, in collaboration with the University of Brescia. The set-up is a standard one, in which a vessel containing the fluid under scrutiny is placed in a vertical oven for ~ 100 hours at a constant temperature T = Tstress. During the test, the pressure P is monitored to detect thermal decomposition of the fluid. After the test, the vessel is placed in a controlled thermal bath, where the pressure is measured at different value of the temperature T, with
Design and commissioning of a thermal stability test-rig for mixtures as working fluids for ORC applications
A novel test-rig for studying the thermal stability of mixtures as working fluids for ORC applications was designed and commissioned at the Laboratory of Compressible-fluid dynamics for Renewable Energy Applications (CREA) of Politecnico di Milano, in collaboration with the University of Brescia. The set-up is a standard one, in which a vessel containing the fluid under scrutiny is placed in a vertical oven for ~ 100 hours at a constant temperature T = Tstress. During the test, the pressure P is monitored to detect thermal decomposition of the fluid. After the test, the vessel is placed in a controlled thermal bath, where the pressure is measured at different value of the temperature T, with T < Tstress and T < Tc (Tc critical temperature). The resulting isochoric pressure-temperature dependence is compared to that obtained before the fluid underwent thermal stress. If departure from the initial fluid behavior is observed, significant thermal decomposition occurred and a chemical analysis of the decomposition products is carried out using gas chromatography and mass spectroscopy. The novelty of the set-up is the possibility of taking samples of both liquid and vapor phases of the fluid, a capability that was introduced to study thermal decomposition of mixtures, whose composition depends on the pressure and temperature, as well as to capture the more volatile products of thermal decomposition of pure fluids and mixtures. Preliminary experimental results are reported for the pure siloxane fluid MDM (Octamethyltrisiloxane, C8H24O2Si3)
Favorable Trend of Implantable Cardioverter-Defibrillator Service Life in a Large Single-Nation Population: Insights From 10-Year Analysis of the Italian Implantable Cardioverter-Defibrillator Registry
Background: Implantable cardioverter-defibrillators (ICDs) are widely employed for the prevention of sudden cardiac death. Despite technological improvements, patients often need to undergo generator replacement, which entails the risk of periprocedural complications. Our aim was to estimate the service life of ICDs over a 10-year interval and to assess the main causes of replacement on the basis of data from the National ICD Registry of the Italian Society of Arrhythmology and Cardiac Pacing (AIAC). Methods and Results: The registry includes data from over 400 hospitals in Italy. We included all patients who underwent device replacement from calendar years 2007 to 2016. The median service life of the ICDs and its trend over the years was estimated across the 3 types of devices (single-chamber, dual-chamber, cardiac resynchronization therapy defibrillator) and the indication to implantation. The causes of replacement were also analyzed. We included 29 158 records from 27 676 patients (80.9% men; mean age at device replacement 65.8±12.0 years). The median service life was 57.3 months (interquartile range 27.8 months). Over the years, service life showed an increasing trend. The majority of patients underwent elective replacement because of battery end of life, and over the years there was a significant reduction of replacement for recalls, erosion/infections, and cardiac resynchronization therapy upgrading. Conclusions: Our data from a large single-nation population showed that the trend of ICD service life, independently from ICD type, indication, and settings, significantly improved over time. Moreover, there was a striking reduction of interventions for upgrading and infection/erosion. This favorable trend has important clinical, organizational, and financial implications
Genetic Variants of the Renin-Angiotensin-Aldosterone System and Reverse Remodeling After Cardiac Resynchronization Therapy
Background: Reverse remodeling (RR) after cardiac resynchronization therapy (CRT) is associated with favorable clinical outcomes in heart failure (HF). The renin-angiotensin-aldosterone system (RAAS) is involved in the remodeling process. Methods and Results: We assessed the association between RR and 8 common RAAS gene variants, which were determined by TaqMan assays, in 156 outpatients with chronic HF. RR was defined as a O15% decrease in left ventricular end systolic volume (LVESV) at 9 (interquartile range 7e12) months after CRT. We matched 76 patients who did not show RR (RR) to 80 RR? control subjects by age, sex, HF etiology, New York Heart Association (NYHA) functional class and left ventricular ejection fraction (LVEF). The frequency of the minor allele of the NR3C2 gene (rs5522 C/T), encoding the mineralocorticoid receptor, was higher in RR than in RR (24/126 vs 10/150; P value after false discovery rate correction: <.0193). Conversely, LVESV decreased significantly less after CRT in carriers of the NR3C2 minor C allele (P 5 .02). After adjustment for age, sex, NYHA functional class, previous myocardial infarction, atrial fibrillation, and LVEF, RR remained independently associated with NR3C2 C allele carriage (odds ratio 3.093, 95% confidence interval 1.253e7.632). Conclusions: The association of RR after CRT with a common polymorphism in the mineralocorticoid receptor gene involved in aldosterone signaling suggests a possible role for variants in RAAS genes in progressive LV function decline, despite apparently effective CRT
Treatment of atrial fibrillation with a dual defibrillator in heart failure patients (TRADE HF): protocol for a randomized clinical trial.
Background: Heart failure(HF) and atrial fibrillation(AF) frequently coexist in the same patient and are associated with increased mortality and frequent hospitalizations. As the concomitance of AF and HF is often associated with a poor prognosis, the prompt treatment of AF in HF patients may significantly improve outcome.Methods/design: Recent implantable cardiac resynchronization (CRT) devices allow electrical therapies to treat AF automatically. TRADE-HF (trial registration: NCT00345592; http://www.clinicaltrials.gov) is a prospective, randomized, double arm study aimed at demonstrating the efficacy of an automatic, device-based therapy for treatment of atrial tachycardia and fibrillation(AT/AF) in patients indicated for CRT. The study compares automatic electrical therapy to a traditional more usual treatment of AT/AF: the goal is to demonstrate a reduction in a combined endpoint of unplanned hospitalizations for cardiac reasons, death from cardiovascular causes or permanent AF when using automatic atrial therapy as compared to the traditional approach involving hospitalization for symptoms and in-hospital treatment of AT/AF.Discussion: CRT pacemaker with the additional ability to convert AF as well as ventricular arrhythmias may play a simultaneous role in rhythm control and HF treatment. The value of the systematic implantation of CRT ICDs with the capacity to deliver atrial therapy in HF patients at risk of AF has not yet been explored. The TRADE-HF study will assess in CRT patients whether a strategy based on automatic management of atrial arrhythmias might be a valuable option to reduce the number of hospital admission and to reduce the progression the arrhythmia to a permanent for
The increased risk of stroke/transient ischemic attack in women with a cardiac implantable electronic device is not associated with a higher atrial fibrillation burden
To evaluate if the increased thromboembolic risk in female patients may be related to a higher burden of atrial fibrillation (AF)
1091-223 The implantable defibrillator and the long QT syndrome: An overview of current use and outcome
Activation of Siglec-7 Results in Inhibition of in Vitro and in Vivo Growth of Human Mast Cell Leukemia Cells
Advanced systemic mastocytosis is a rare and still untreatable disease. Blocking antibodies against inhibitory receptors, also known as 'immune checkpoints', have revolutionized anti-cancer treatment. Inhibitory receptors are expressed not only on normal immune cells, including mast cells but also on neoplastic cells. Whether activation of inhibitory receptors through monoclonal antibodies can lead to tumor growth inhibition remains mostly unknown. Here we show that the inhibitory receptor Siglec-7 is expressed by primary neoplastic mast cells in patients with systemic mastocytosis and by mast cell leukemia cell lines. Activation of Siglec-7 by anti-Siglec-7 monoclonal antibody caused phosphorylation of Src homology region 2 domain-containing phosphatase-1 (SHP-1), reduced phosphorylation of KIT and induced growth inhibition in mast cell lines. In SCID-beige mice injected with either the human mast cell line HMC-1.1 and HMC-1.2 or with Siglec-7 transduced B cell lymphoma cells, anti-Siglec-7 monoclonal antibody reduced tumor growth by a mechanism involving Siglec-7 cytoplasmic domains in 'preventive' and 'treatment' settings. These data demonstrate that activation of Siglec-7 on mast cell lines can inhibit their growth in vitro and in vivo. This might pave the way to additional treatment strategies for mastocytosis
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