Left Ventricular Longitudinal Strain in Characterization and Outcome Assessment of Mixed Aortic Valve Disease Phenotypes

ObjectivesThe aims of this study were to characterize the interplay between mixed aortic valve disease (MAVD) phenotypes (defined by concomitant severities of aortic stenosis and aortic regurgitation) and left ventricular global longitudinal strain (LV-GLS), and to assess the prognostic utility of LV-GLS in MAVD.BackgroundLittle is known about the way LV-GLS separates MAVD phenotypes and if it is associated with their outcomes.MethodsThis observational cohort study evaluated 783 consecutive adult patients with left ventricular ejection fraction ≥50% and MAVD, which was defined as coexisting with at least moderate aortic stenosis and at least moderate aortic regurgitation. We measured the conventional echocardiographic variables and average LV-GLS from apical long, 2- and 4-chamber views. The primary endpoint was all-cause mortality.ResultsMean age of patients was 69 ± 15 years, and 58% were male. Mean LV-GLS was –14.7 ± 2.9%. In total, 458 patients (59%) underwent aortic valve replacement at a median period of 50 days (25th to 75th percentile range: 6 to 560 days). During a median follow-up period of 5.6 years (25th to 75th percentile range: 1.8 to 9.4 years), 391 patients (50%) died. When stratified patients into tertiles according to LV-GLS values, patients with worse LV-GLS had worse outcomes (p < 0.001). LV-GLS was independently associated with mortality (hazard ratio: 1.09; 95% confidential intervals: 1.04 to 1.14; p < 0.001), with the relationship between LV-GLS and mortality being linear.ConclusionsLV-GLS is associated with all-cause mortality. LV-GLS may be useful for risk stratification in patients with MAVD.     

Left atrial deformation analysis as a predictor of severity of coronary artery disease

Background

Two-dimensional (2D) speckle-tracking strain imaging is a novel method for assessment of regional myocardial deformation that uses tracking of acoustic speckles or kernels rather than Doppler myocardial velocities. It has been suggested that Left atrial (LA) strain as measured by 2D speckle tracking can be used to evaluate dynamic LA function.

Toilet plume aerosol generation rate and environmental contamination following bowl water inoculation with Clostridium difficile spores

Introduction

Clostridium difficile is the leading cause of health care–associated gastric illness. Environmental contamination with C difficile spores is a risk factor for contact transmission, and toilet flushing causes such contamination. This work explores toilet contamination persistence and environmental contamination produced over a series of flushes after contamination.

前壁心肌梗塞患者左室壁三维运动与左室流场变化相关性研究

目的应用血流向量成像技术（vector flow mapping,VFM）和三维斑点追踪技术（three-dimensional speckle tracking 3DT）,研究正常人和前壁心肌梗塞室壁节段性运动异常患者的心室腔内血流流场、流体力学状态与心肌机械力学状态间的关联关系.方法选取健康成人30例、前壁心肌梗塞患者30例,首先进行常规二维超声检查,之后分别进行实时全容积成像三维成像图像采集和VFM图像采集,在获取左心室全容积图像后分析图像,自动计算左心室旋转角度（rotation angle,RA）、各节段室壁运动峰值径向应变（Radial strain,RS）等参数,在VFM血流图像中分析心腔内血流速度向量、流线和漩涡等左心室流场参数.结果病例组与健康对照组相比,病例组LVEDV增大、LVEF减小（P〈0.05）;病例组在射血期左心室心腔内仍可见占据绝大部分左心室心腔的整体涡流;病例组的漩涡横径（Dx）、漩涡纵径（Dy）、涡流总持续时间均大于健康对照组,差异有统计学意义（P〈0.05）;病例组左心室旋转角度（rotation angle,RA）、旋转率（rotation rate,RR）、扭转角度（twist angle,TA）及扭转率（twistrate,TR）越小射血期左心室内涡流范围越大（漩涡横径Dx、漩涡纵径Dy增大）,持续时间越长,成显著负相关（r=-0.693,r=-0.751,r=-0.655,r=-0.672,P〈0.05）.结论左心室前间隔中间段、前壁中间段、心尖段RS、AS减低直接导致了本来在左心室内舒张期形成的涡流直接延续到了收缩期主动脉瓣开放之后,提示左心室重构以后心室形态改变,局部收缩功能减低导致了左心室内血流速度减低以及涡流持续时间延长,从而降低了左心室心腔内流体力学效率,使心脏搏出量减少.     

Evaluation of Ventricular-vascular Coupling in Patients with Type 2 Diabetes Mellitus Using 2-Dimensional Speckle Tracking Imaging

The elastic and functional coupling of heart and vessels makes the stroke work （SW） of the heart optimal. Speckle tracking imaging （STI） can evaluate the myocardial strain and function. We studied ventricular-vascular coupling in 80 diabetic patients with different systolic function using STI. The patients were divided into two groups according to ejection fraction （EF）： the diabetes mel- litus with normal EF （DMN） group and the diabetes mellitus with abnormal EF （DMA） group. Forty-two volunteers served as control group. The relative wall thickness （RWT）, left ventricular mass index （LVMI）, stroke volume （SV）, SW, rate-pressure product （RPP）, systemic vascular resis- tance index （SVRI）, left ventricular end-systolic elastance （Ees）, effective arterial elasticity （Ea） and ventricular-vascular coupling index （VVI） were measured and calculated by conventional echocardi- ography. The longitudinal strain （LS） at basement （LSBA）, papillary muscle （LSvM） and cardiac apex （LSAv） was assessed with STI. It was found： （A） compared with control group, in DMN and DMA groups, LSBA, LSvM and LSAp decreased, and they were lower in DMA group. （B） VVI, RPP and SVRI increased, and they were higher in DMN group; Ees decreased, and it was lower in DMA group. （C） LSBA, LSpM, and LSAv had negative correlation with VVI. LSAp, RWT, LVMI and SW were independent predictors for VVI. The area under the receiver operating characteristic （ROC） curves was used for identification of DMA and DMN with LSBA, LSpM, and LSAp, and the area under the ROC of LSAp was the largest. This study supports that myocardial LS could reflect the ventricu- lar-vascular coupling. Different segments had an order to “respond to” the state of the coupling, and the cardiac apex might be the earliest.     

乙肝并发小肝癌超声跟踪研究

目的：该研究主要就乙肝并发小肝癌患者的发展规律以及超声检查的临床应用价值展开分析讨论。方法选择该院2008年1月-2011年4月所收治的122例慢性乙肝患者作为研究对象,所有患者均是经过实验室检查,其结果显示患者的e抗原（HBeAg）、核心抗体（HBcAb）、表面抗原（HBsAg）均为阳性,所有患者在入院后均行二维超声检查以及三维图像重建,对其图像特点进行分析。并对患者肝内结节的二维以及三维超声检出率进行比较。结果在该研究的所有患者中,有34例患者出现了并发小肝癌的情况,对此类患者行三维超声检查可以对肝内的增生结节、小肝癌的形状及其与周边组织之间的关系进行清晰地显示,其检查出的小肝癌数量也明显多于二维超声的检出率,差异有统计学意义（Ρ＜0.05）。结论在对乙肝患者进行临床诊断时,超声动态观察可以尽早发现患者肝内结节性病变,三维超声多角度、多切面的检查可以在一定程度上提高小肝癌的诊断准确性,因此,在对乙肝患者进行临床诊断时,可以对超声诊断的方式进行大力推广并普及使用。     

时频识别技术在高压交联聚乙烯电缆局部放电检测中的应用

本文提出了一种基于 （等效带宽）— （等效时间长度）时频识别技术的局放检测方法,并通过现场应用论证了该方法的可行性和有效性：它能识别和分离放电源,准确提取局部放电信号,解决了长期以来干扰信号和局放信号无法区分的难点,为实现故障诊断和状态评估提供了可靠的判断依据。     

医院消毒供应中心信息化管理

从5省市106所医疗机构消毒供应中心信息追溯管理工作调研入手,对消毒供应中心信息追溯工作的现况进行了分析,阐述了存在的问题,简述了消毒供应中心信息管理系统基本功能,为规范消毒供应中心信息追溯管理提供依据。     

腰椎间盘退行性变的MR扩散张量成像初步研究

目的 运用DTI初步探讨无创评价活体椎间盘纤维环退变.方法 选择2010年9月至2011年3月腰椎门诊就诊行腰椎MR检查患者,排除脊柱畸形、肿瘤及相关手术患者,共纳入研究对象88例,年龄16 ～63岁,平均(37±13)岁.对研究对象进行快速自旋回波及平面回波成像.剔除磁敏感重的图像,共获得428个椎间盘,测量其平均扩散系数(MD)、各向异性分数(FA)并获得其纤维环成像图,根据纤维环示踪图(FT)图形态学改变,对纤维环进行分型并测量其MD和FA,并进行比较.数据资料为非正态分布,以四分位间距及中位数表示.采用SPSS11.0软件包,x2检验进行统计学分析.结果 运用纤维环示踪技术每个椎间盘均可得到纤维环成像图,且不同Pfirrmann级别其纤维环类型不同,纤维环分型与Pfirrmann分级密切相关:规则型FT图135个,其中PfirrmannⅡ级(92个)比例最高,占68.15％;杂乱型纤维环FT图195个,以PfirrmannⅢ(93个)、Ⅳ级(30个)为主,占63.07％;团块型纤维环FT因98个,以PfirrmannⅣ(39个)、Ⅴ级(43个)为主,占83.68％,差异具有统计学意义(Mantel-Haenszel x2检验,x2=183.90,P＜0.01).完整型FA值为0.32(0.29 ～0.35),MD值为12.40(11.50 ～13.20)×10-10 mm2/s;杂乱型FA值为0.35(0.33 ～0.38),MD值为11.10(9.92 ～ 12.00)×10 10mm2/s;团块型FA值为0.54(0.46～0.62),MD值为6.30(5.03～7.72)×10-10mm2/s.纤维环结构越杂乱,其MD值越低,FA值越高,差异具有统计学意义(Kruskal-Wallis秩和检验,x2值分别为219.74、243.88,P值均＜0.01).结论 DTI可无创性评估活体椎间盘结构变化,MD值及FA值有助于评价椎间盘退变程度.     

The surgical treatment of intra-abdominal sepsis

Intra-abdominal sepsis is frequently seen and dealt with by surgeons. It presents as a spectrum of conditions from uncomplicated localized infection through to complicated sepsis with generalized peritonitis. Complicated sepsis is frequently associated with a local and a systemic inflammatory response. The development of septic shock is associated with a high mortality. The management of this condition involves a multidisciplinary approach with either radiological or surgical procedures required to definitively deal with the source of the sepsis (source control). The range of surgical procedures includes open or laparoscopic techniques depending on the source and the extent of the sepsis. Adjuncts to source control are effective broad-spectrum antibiotic cover and effective fluid resuscitation.