AF Class Research Articles

The abnormalities of free fatty acid metabolism in patients with hypertrophic cardiomyopathy, a single-center retrospective observational study

BackgroundPrevious studies have shown the importance of energy deficiency and malfunctioning mitochondria in the pathophysiology of hypertrophic cardiomyopathy (HCM). There has been a little research into the relationship between plasma free fatty acids (FFA), one of the heart’s main energy sources, and HCM. We evaluated its clinical importance in HCM to see if there was a link between plasma FFA metabolism and HCM.MethodsIn a single-center retrospective observational study, we investigated 420 HCM patients diagnosed at Beijing Anzhen Hospital between January 1, 2018, and December 31, 2022. Meanwhile, 1372 individuals without HCM (non-HCM) were recruited. 391 non-HCM patients were chosen as controls via a propensity score matching (PSM) study with a 1:1 ratio.ResultsFFA in HCM patients showed statistically significant correlations with creatinine (r = 0.115, p = 0.023), estimated GFR (r=-0.130, p = 0.010), BNP (r = 0.152, p = 0.007), LVEF (r=-0.227, p < 0.001), LVFS (r=-0.160, p = 0.002), and LAD (r = 0.112, p = 0.028). Higher FFA levels were found in HCM patients who had atrial fibrillation and NYHY functional classes III or IV (p = 0.015 and p = 0.022, respectively). In HCM patients, multiple linear regression analysis revealed that BNP and LVEF had independent relationships with increasing FFA (Standardized = 0.139, p = 0.013 and =-0.196, p < 0.001, respectively).ConclusionsAmong HCM patients, the plasma FFA concentration was lower, and those with AF and NYHY functional class III or IV had higher FFA levels, and LVEF and BNP were independently associated with increasing FFA. The findings of the study should help inspire future efforts to better understand how energy deficiency contributes to hypertrophic cardiomyopathy (HCM) development.

Asociación de ingesta alimentaria con riesgo de un trastorno alimentario, actividad física e índice de masa corporal en estudiantes universitarios mexicanos.

Abstract INTRODUCTION: During university life new routines and life-styles are adapted into conduct, which can associate to unfavorable changes in food consumption, alimentary-risk conducts (CAR) associated with alimentary-conduct disorders (TCA), sedentary life-style and restrained physical-activity (AF), which promote weight-gain and have repercussions on the body-mass index (IMC), enhancing the prevalence of overweight and obesity in such population. Objectives: The main objective for this study was to determine the association between the alimentary intake, CAR, AF, sedentary life-style and IMC in college students from Hidalgo state. MATERIALS AND METHODS: Transversal analytic study in a probabilistic sample of 378 students of both sexes, ranging from 18 to 30 years old in Hidalgo, México. The frequency of food consumption, TCA-risk, sedentary lifestyle, and AF were measured by the means of previously validated and standardized scales. The patient’s IMC was calculated from self-reports. RESULTS: TCA-risk was slightly higher in women (38.1%) than in men (29%), nonetheless the difference was not significant. The consumption of certain food-groups presented a significant difference by sex, TCA-risk and AF class. 31.7% of the sample registered a sedentary life-style, with men exerting more AF than women. The sampled population reached a total prevalence of 28% of overweight/obesity. CONCLUSION: Overweight/obesity increased 2.19 times the risk for developing a TCA in the overall population. In women, this condition increased 3.27 times the risk. It was observed that female sex is a protective factor (in 64% of the cases) to develop overweight/obesity (RM= 0.36, p&lt;0.01).

Priority switching scheduler

SummaryWe define a novel core network router scheduling architecture called priority switching scheduler (PSS), to carry and isolate time constrained and elastic traffic flows from best‐effort traffic. To date, one possible solution has been to implement a core DiffServ network with standard fair queuing and scheduling mechanisms as proposed in the well‐known “A Differentiated Services Code Point (DSCP) for Capacity‐Admitted Traffic” from RFC5865. This architecture is one of the most selected solutions by internet service provider for access networks (e.g., customer‐premises equipment) and deployed within several performance‐enhancing proxies (PEPs) over satellite communications (SATCOM) architectures. In this study, we argue that the proposed standard implementation does not allow to efficiently quantify the reserved capacity for the AF class. By using a novel credit‐based shaper mechanism called burst limiting shaper (BLS) to manage the AF class, we show that PSS can provide the same isolation for the time constrained EF class while better quantifying the part allocated to the AF class. PSS operates both when the output link capacity is fixed (e.g., wire links and terrestrial networks) or might vary due to system impairments or weather condition (e.g., wireless or satellite links). We demonstrate the capability of PSS through an emulated SATCOM scenario with variable capacity and show the AF output rate is less dependent on the EF traffic, which improves the quantification of the reserved capacity of AF, without impacting EF traffic.

12The effect of new NICE guidelines on cardiac device therapy

Introduction: The National Institute for Health and Care Excellence (NICE) published guidelines on implantable cardioverter defibrillators (ICD) in 2006 and cardiac resynchronisation therapy (CRT) in 2007. Since then, trials have shown benefit in additional populations including ICDs in non-ischaemic cardiomyopathy and CRT in patients with atrial fibrillation or less symptomatic heart failure, while echocardiography dyssynchrony has shown low correlation with clinical response. NICE's 2014 device therapy guidelines recognise these changes. We sought to explore the impact of these updated guidelines on our patient population, and their implications for future device implantation practice. Methods: The clinical and pacing notes of 223 patients receiving an ICD, CRT-P or CRT-D between April 2006 and December 2007 were reviewed to establish what device was recommended by contemporary NICE guidance at implantation. 2014 guidelines were then applied to the same population to determine their potential impact. Results: 170 patients received an ICD of whom 89 had records available for audit. 71 patients received CRT-P and 63 received CRT-D, all of whom were audited. Mean age was 64.5, 72.2 and 65.5 years and females accounted for 15%, 34% and 13% in the three groups respectively. Defibrillators were implanted for secondary prevention in 64/152 (42%) patients. The device implanted, the device indicated by the 2006/07 guidelines and that recommended by applying the 2014 guidelines are compared in figure 1. The device patients received did not always fulfil NICE guidance. Reasons included implantation of primary prevention ICDs in patients with non-ischaemic cardiomyopathy or chanelopathy (24), CRT in AF (23) or NYHA class 2 (15) not fulfilling certain investigative criteria such as echocardiographic dyssynchrony (16) or non-sustained and inducible VT (12), or patient choice, e.g. in declining a defibrillator when receiving CRT (2). The main effect of the 2014 guidance is a 51% increase number of CRT devices indicated - 85 in 2006/7 to 128 in 2014. Many investigations are now not required, including 25 dyssynchrony echos, 20 Holter monitors and 14 VT stimulation studies. Seventy-eight patients from the original cohort survived to generator replacement of whom five were upgraded to CRT-D, two were upgraded from single to dual chamber devices and 11 had device or lead revisions (predominantly due to lead advisories). One patient chose to have their device downgraded from CRT-D to CRT-P. Conclusions: New NICE guidance for device therapy increases the numbers of patients with both CRT and ICD indications. The most significant change is however, the increasing number of patients for whom CRT is recommended, highlighting the need for careful consideration of the patient's clinical condition and treatment preference, particularly as more patients now approach generator change. ![Graphic][1] [1]: /embed/inline-graphic-1.gif

Load-balanced differentiated services support switch

How to provide quality of service (QoS) guarantees in the routing and switching devices has become one of the key research topics in the areas of routing and switching technologies. Differentiated services architecture (DiffServ), which forwards packets based on their per-hop behaviours, is known as a promising way for supporting QoS in a high-speed backbone network scenario. Motivated by the load-balanced Birkhoff-von Neumann switch, which has received much attention recently because of its outstanding extensibility performance, in this study, the authors propose a new switch architecture called load-balanced DiffServ support switch (LBDS). LBDS consists of pipeline traffic bandwidth control, priority-based load balancing, and bandwidth-based priority scheduling to implement fast forwarding for expedited forwarding (EF) traffic and assured forwarding for AF classes of traffic. The authors evaluate LBDS by extensive theoretical analysis and comprehensive simulations. As expected, LBDS can provide bandwidth guarantees for both EF and AF traffic. We also show that under burst traffic arrivals, especially when the traffic arrival pattern is non-uniform and the load is above 0.6, LBDS performs much better delay performance than existing DiffServ support schemes.

Color‐aware power and rate adaptation in IP‐based CDMA radio access networks

AbstractWith IP technology being in the epicenter of future wireless networks, IP‐centric resource management is currently receiving an increasing research attention. In this paper, a power and rate adaptation semantic is proposed that integrates quality of service (QoS) information from the IP layer of the differentiated services (DiffServ) architecture together with lower layer criteria in order to optimize packet transmission over the wireless interface. An optimization problem is formulated based on the output of a time sliding window three color marker (TSWtcm) of the ingress DiffServ node in the radio access network (RAN), where color aware power and rate control are performed. The critical impetus of the proposed approach besides minimization of the transmitted power is mainly twofold. Firstly, to achieve the required per‐class aggregate data rate, while prioritizing and ensuring QoS of in‐profile packets and secondly, to increase aggregate power gains by penalizing out‐of‐profile packets. The seminal aspect of the proposed scheme is that tangible power gains can be achieved by differentiating transmission of conformant and non‐conformant packets while at the same time the power gains within each AF classes can be utilized to enhance the performance of in‐profile traffic. To buttress the case, both theoretical and simulation results are meticulously presented that depict architectural and performance related aspects of the proposed scheme. Copyright © 2005 John Wiley &amp; Sons, Ltd.

The two markers system for TCP and UDP flows in a differentiated services network

There are two cruxes of issues identified in differentiated services (Diffserv) networks: one is TCP dynamics, and the other is the interaction of TCP and UDP flows for assured forwarding per hop behaviour (PHB). The saw-tooth like behaviours of TCP prevent each flow from realising its target rate, and congestion insensitive flows such as UDP penalise for TCP flows when both are given same AF class. Therefore, we argue the use of TCP-friendly building blocks and fairness modules in the Diffserv architecture regarding these issues, and propose two markers system (TMS) that is able to properly mark packets and fairly share the bandwidth to each flow for their targeted sending rates. TMS has two marking modules that are placed on the source and the edge of a Diffserv network, respectively. For sources of the network, TCP-source making module plays important roles of reducing TCP impacts in the assured services and adequately marking packets. Next, in the edge of the network, the edge-embedded marking module conducts new fairness policy based on the marking rate of flows from sources, so-called ‘marking rate-based fairness’. Finally, we present simulation results to illustrate the effectiveness of TMS scheme over several parameters. That is, TMS alleviates TCP impacts over assured service and the issue of unfair distribution of excess bandwidth in an over-provisioned networks as well as unfair degradation in an under-provisioned network for TCP and UDP flows.

인터넷에서 Assured Forwarding 패킷을 위한 사이클링 패킷 폐기 메커니즘

본 논문에서 제안한 사이클링 패킷 폐기 메커니즘은 사이클 사이의 트래픽 변화를 예측하여 패킷 폐기를 적응적으로 처리할 수 있다. 따라서 제안된 메커니즘은 RIO 메커니즘의 단순 폐기율 적용에 대한 단점을 보완하고, 동적 엄격 패킷 폐기 메커니즘의 예측 가능한 오류율을 최소화하였다. 시뮬레이션을 수행하여, 망 트래픽의 상태에 따라 동적으로 변하는 전송가능 폐기순위에 따른 처리율과 패킷 폐기율을 분석하였다. 시뮬레이션을 분석한 결과 제안된 메커니즘은 트래픽의 양에 상관없이 각 AF 클래스의 폐기순위를 엄격하게 적용하고 폐기순위에 따른 패킷 전송능력이 개선하였음을 증명하였다. Cycling Packet Dropping mechanism we proposed in this paper adaptively drops packets, as predicting traffic pattern between each cycle. Therfore the proposed mechanism makes up for the drawback of RIO mechanism and minimizes errors being capable of predicting in Dynamic and Strict Packet Dropping mechanism. And we executed a simulation and analyzed the throughput and packet drop rate based on the Sending Drop Precedence changing dynamically depending on the network traffic. The results show that the proposed mechanism provides better performance on drop precedence levels and stricter drop precedence policy for AF class.