Left Ventricular Pacing In Patients With Congestive Heart Failure

Cardiac resynchronisation therapy (CRT) using biventricular (BIV) pacing has proved its effectiveness to correct myocardial asynchrony and improve clinical status of patients with severe congestive heart failure (CHF) and widened QRS. Despite a different effect on left ventricular electrical dispersion, left univentricular (LV) pacing is able to achieve the same mechanical synchronisation as BIV pacing in experimental studies and in humans. This results in clinical benefits of LV pacing at mid-term follow-up, with significant improvement in functional class, quality of life and exercise tolerance at the same extent as those observed with BIV stimulation in non randomised studies. Furthermore these benefits are obtained at lesser costs and with conventional dual-chamber devices. However, LV pacing has to be compared to BIV pacing in randomised trials before being definitely considered as a cost-effective alternative to BIV pacing

Asymptotic behavior of the local score of independent and identically distributed random sequences

AbstractLet (Xn)n⩾1 be a sequence of real random variables. The local score is Hn=max1⩽i<j⩽n(Xi+⋯+Xj). If (Xn)n⩾1 is a “good” Markov chain under its invariant measure, the Xi are centered, we prove that Hn/n converges in distribution to B1∗ when n→+∞, where B1∗=max0⩽u⩽1|Bu| and (Bu,u⩾0) is a standard Brownian motion, B0=0. If (Xn)n⩾1 a sequence of i.i.d. random variables, E(X1)=δ/n and Var(X1)=σ2>0, we prove the convergence of Hn/n to σξδ/σ where ξγ=max0⩽u⩽1{(B(u)+γu)−min0⩽s⩽u(B(s)+γs)}. We approximate the probability distribution function of ξγ and we determine the asymptotic behavior of P(ξγ⩾a),a→+∞

The Use of Epicardial Electrogram as a Simple Guide to Select the Optimal Site of Left Ventricular Pacing in Cardiac Resynchronization Therapy

Cardiac resynchronization therapy (CRT) has been demonstrated to improve symptoms and survival in patients with left ventricular (LV) systolic dysfunction and dyssynchrony. To achieve this goal, the LV lead should be positioned in a region of delayed contraction. We hypothesized that pacing at the site of late electrical activation was also associated with long-term response to CRT. We conducted a retrospective study on 72 CRT patients. For each patient, we determined the electrical delay (ED) from the onset of QRS to the epicardial EGM and the ratio of ED to QRS duration (ED/QRS duration). After a followup of 30 ± 20 months, 47 patients responded to CRT. Responders had a significantly longer ED and greater ratio of ED/QRS duration than nonresponders. An ED/QRS duration ≥0.38 predicted a response to CRT with 89% specificity and 53% sensitivity

Peroxide grafted PDMS: hydrosilylation reaction study and thiol-ene chemistry as an alternative pathway

International audiencePeroxide containing PDMS were synthesized according to a new pathway. Although hydrosilylation is one of the main reaction carried out in silicone chemistry, the catalysts used are very sensitive to the chemical nature of the reactants and remained inefficient to graft allylic peroxide. Radical catalyzed thiol-ene chemistry was involved for the first time to yield an initiator group containing polymer. Peroxide grafted polysiloxane structure and decomposition were characterized using 1H, 13C and 29Si NMR, FT-IR and RAMAN spectroscopies, SEC and DSC. These macroinitiators can be used to obtain polysiloxane able to undergo cross-linking

Documentation of baseline and policy scenarios for Test Case 1

Environmental Economics and Policy,

Vegetable oil hybrid films cross-linked at the air-water interface: formation kinetics and physical characterization

Vegetable oil based hybrid films were developed thanks to a novel solvent- and heating- free method at the air-water interface using silylated castor oil cross-linked via a sol-gel reaction. To understand the mechanism of the hybrid film formation, the reaction kinetics was studied in detail by using complementary techniques: rheology, thermogravimetric analysis, and infrared spectroscopy. The mechanical properties of the final films were investigated by nano-indentation, whereas their structure was studied using a combination of wide-angle X-ray scattering, electron diffraction, and atomic force microscopy. We found that solid and transparent films form in 24 hours and, by changing the silica precursor to castor oil ratio, their mechanical properties are tunable in the MPa-range by about a factor of twenty. In addition to that, a possible optimization of the cross-linking reaction with different catalysts was explored and finally, cytotoxicity tests were performed on fibroblasts proving the absence of film toxicity. The results of this work pave the way to a straightforward synthesis of castor-oil films with tunable mechanical properties: hybrid films cross-linked at the air-water interface combine an easy and cheap spreading protocol with the features of their thermal history optimized for possible future micro/nano drug loading, thus representing excellent candidates for the replacement of non-environment friendly petroleum-based materials

Photodynamic therapy as a treatment for digestive cancers

Introduction: Photodynamic Therapy or PDT has been used and validated in the endoscopic treatment of superficial esophagus lesions such as high grade dysplasia (HGD) and/or intramucosal carcinoma. PDT is also currently used as a palliative treatment of non resectable cholangiocarcinomas.Introduction : La PDT est une thérapeutique endoscopique à visée curative validée pour les lésions superficielles de l' sophage type dysplasies de haut grade (DHG) et/ou carcinome intra-muqueux (CIM). Elle est maintenant régulièrement utilisée à visée palliative en association avec les prothèses biliaires dans le traitement des cholangiocarcinomes non résécables

Imaging in the Land of 1000 Hills: Rwanda Radiology Country Report

Rwanda is an equatorial country in central Africa (Figure 1), and part of the East African Community of Burundi, Kenya, Uganda and Tanzania. It is a small country, just over 10,000 square miles. Its population of nearly 12,000,000 makes it the most densely populated state in continental Africa. Rwanda’s capital, Kigali, is a mile-high city. Its elevation makes the climate much cooler and more comfortable than a typical equatorial climate. The average annual temperature is 20.5 degrees Celsius with a narrow range – April, the coldest month has an average temperature of 20 degrees, whereas August, the warmest month has an average temperature of 21.5 degrees. Economically, Rwanda functions as a subsistence agricultural country but has been actively striving to emerge as a middle-income country. Its primary exports are coffee and tea. In 1994, the majority Hutu population carried out mass genocide of the ethnic Tutsi minority In a coordinated slaughter committed by neighbors against each other, and with low-technology weapons like machetes, nearly 1,000,000 people were killed in 100 days (1). The country was devastated. Immediately post-genocide, Rwanda was one of the poorest countries in the world with nearly 70% of the population living below the poverty line (2). Until 1997, Rwanda had the lowest life expectancy of any country in the world (3). The physician work force was depleted due to the direct and indirect consequences of the Rwandan Genocide. Since this time there has been a steady economic recovery (4), along with remarkable medical recovery. Average life expectancy nationwide, only 27 years in the early 1990s, has now reached 63 years (3). Since the 2012 publication (5) highlighting its advances, radiology in Rwanda has benefitted from the capital infusion that has helped to propel the overall growth in the economic and health sectors. As of 2012, there are five national referral hospitals, 41 district hospitals, one military hospital and 451 health centers (6). The health centers are staffed primarily by nurses, while the district hospitals are staffed by general practitioners (graduates of medical school without a post-graduate education). Of the 625 total physicians in the country in 2011, 150 had completed residency (3)

Embracing the Unreliability of Memory Devices for Neuromorphic Computing

The emergence of resistive non-volatile memories opens the way to highly energy-efficient computation near- or in-memory. However, this type of computation is not compatible with conventional ECC, and has to deal with device unreliability. Inspired by the architecture of animal brains, we present a manufactured differential hybrid CMOS/RRAM memory architecture suitable for neural network implementation that functions without formal ECC. We also show that using low-energy but error-prone programming conditions only slightly reduces network accuracy