Old and new intravenous inotropic agents in the treatment of advanced heart failure

Inotropic agents are administered to improve cardiac output and peripheral perfusion in patients with systolic dysfunction and low cardiac output. However, there is evidence of increased mortality and adverse effects associated with current inotropic agents. These adverse outcomes may be ascribed to patient selection, increased myocardial energy expenditure and oxygen consumption, or to specific mechanisms of action. Both sympathomimetic amines and type III phosphodiesterase inhibitors act through an increase in intracellular cyclic adenosine monophoshate and free calcium concentrations, mechanisms that increase oxygen consumption and favor arrhythmias. Concomitant peripheral vasodilation with some agents (phosphodiesterase inhibitors and levosimendan) may also lower coronary perfusion pressure and favor myocardial damage. New agents with different mechanisms of action might have a better benefit to risk ratio and allow an improvement in tissue and end-organ perfusion with less untoward effects. We have summarized the characteristics of the main inotropic agents for heart failure treatment, the data from randomized controlled trials, and future perspectives for this class of drugs.     

2型糖尿病对左室功能的影响

目的:探讨2型糖尿病(DM)对心脏左室功能的影响。方法:选取行冠状动脉造影及左室造影中冠状动脉造影阴性患者193例作为研究对象,按是否患2型DM分为DM组(93例)和对照组(100例)。对比2组左室造影所测左室射血分数(LVEF)、左室舒张末容积指数(LVEDVI)、左室舒张末压(LVEDP)及心脏彩超测得心脏各参数间的差异,并进行统计学分析。结果:2组间LVEF、LVEDVI、左室直径、右房直径、右室直径差异无统计学意义(P>0.05),而DM组LVEDP高于对照组[(9.4±2.6)∶(7.9±2.0)mmHg(1 mmHg=0.133kPa)],P<0.01;DM组左房直径较对照组增大[(37.1±6.3)∶(34.6±0.6)mm],P<0.01;E/A比值较对照组降低(1.0±0.3∶1.1±0.3),P<0.05。结论:2型DM可降低患者的左室舒张功能。     

高效液相色谱法测定蒙药复方述达格-4有效部位中山奈素和高良姜素的含量

目的：建立同时测定蒙药复方述达格-4有效部位中高良姜素、山奈素的高效液相色谱含量测定方法。方法：采用反相高效液相色谱法,色谱柱为Diamosil C18（4.6mm×250mm,5μm）,以乙腈（A）-0.5%磷酸水溶液为流动相,梯度洗脱（0～20min,34%A→37%A;20～60min,37%A）,流速1.0mL/min检测波长为286nm,柱温30℃,进样量20μL。结果：高良姜素、山奈素的线性范围分别为0.04～0.4μg（r=0.9999）,0.01656～0.1656μg（r=0.9999）;平均加样回收率（n=6）分别为99.92%、98.92%;RSD为2.09、2.33。结论：本法准确、简便,具有良好的重复性,可为蒙药复方述达格-4质量控制提供依据。     

左心室射血分数正常心力衰竭患者临床分析

目的：探讨心力衰竭(CHF)患者左心室射血分数(LVEF)≥40％与＜40％的临床比较差异,并评价相关影响因素。方法：选择心功能不全临床体征符合NYHA分级Ⅱ～Ⅳ级的患者100例,LVEF≥40％为观察组,LVEF＜40％为对照组,比较两组差异。结果：与对照组相比,观察组谷丙转氨酶(ALT)、既往高血压的患病率、左心室...     

新型无创心输出量监测仪在充血性心力衰竭患者中的应用研究

目的 应用无创心输出量监测仪(NICOM)对充血性心力衰竭(CHF)患者进行研究,探讨其在CHF患者中的应用价值.方法 对81例诊断为CHF的患者及200名正常人进行超声心动图检查和NICOM检查,对检查结果进行分析.结果 CHF组每博输出量(SV)分别为(52.15±15.90)ml,(47.75 4±15.39)m...     

Power-efficient simulation of detailed cortical microcircuits on SpiNNaker

Numerous brain structures are composed of distinct layers and such stratification has a profound effect on extracellular diffusion transport in these structures. We have derived a more general form of diffusion equation incorporating inhomogeneities in both the extracellular volume fraction (α) and diffusion permeability (θ). A numerical solution of this equation for a special case of layered environment was employed to analyze diffusion in the CA1 region of hippocampus where stratum pyramidale occupied by the bodies of principal neurons is flanked by stratum radiatum and stratum oriens. Extracellular diffusion in the CA1 region was measured in vitro by real-time iontophoretic and real-time pressure methods, and numerical analysis found that stratum pyramidale had a significantly smaller extracellular volume fraction (α = 0.127) and lower diffusion permeability (θ = 0.327) than the other two layers (α = 0.218, θ = 0.447). Stratum pyramidale thus functioned as a diffusion barrier for molecules attempting to cross it. We also demonstrate that unless the detailed properties of all layers are taken into account when diffusion experiments are interpreted, the extracted apparent parameters of the extracellular space lose their physical meaning and capacity to describe any individual layer. Such apparent parameters depend on diffusion distance and direction, giving a false impression of microscopic anisotropy and non-Gaussian behavior. This finding has implications for all diffusion mediated physiological processes as well as for other diffusion methods including integrative optical imaging and diffusion-weighted magnetic resonance imaging.     

B型利钠肽检测在慢性心力衰竭不同分级中的应用

目的探讨B型利钠肽(BNP)在慢性心力衰竭患者不同分级中的应用。方法选取慢性心衰患者246例,健康对照组30例,慢性心衰患者按美国纽约心脏病协会(NYHA)分级方案将心功能分为Ⅰ～Ⅳ级,分别测定各级患者和健康对照组BNP浓度,对受试者进行BNP工作特征曲线(ROC)分析,通过超声心动图检查计算各级患者左心室射血分数(LEVF%),并比较Ⅲ级、Ⅳ级心力衰竭患者治疗数周前后BNP浓度。结果 BNP诊断心力衰竭的诊断界值(cut off)为98.5pg/mL,诊断灵敏度为84.6%,特异性为94.5%;不同分级衰竭组BNP水平均明显高于健康对照组,差异有统计学意义(P<0.05);246例慢性心力衰竭患者BNP水平与左室射血分数LVEF%呈负相关,相关系数为-0.733(P<0.01);Ⅲ级、Ⅳ级患者治疗数周后BNP水平都有所下降,下降幅度接近30%。结论 BNP是诊断心力衰竭的最佳心肌标志物,可以作为评价心脏功能分级的一个客观指标,帮助指导临床治疗和预后判断都有重要价值。     

脑利钠肽、肌钙蛋白T和I监测对重症脓毒症和脓毒症休克预后的意义

目的 比较重症脓毒症和脓毒症休克时脑利钠肽(BNP)、肌钙蛋白T(TnT)及肌钙蛋白I (TnI)水平的差异,探索重症脓毒症及脓毒症休克时心脏损害的程度及检测BNP、TnT及TnI的意义.方法 回顾性分析2005年至2010年在北京首都医科大学附属北京友谊医院住院诊断为重症脓毒症和脓毒症休克的患者共98例,住院期间行超声心动图检查,住院第1、3、7天检测BNP,TnT及TnI.其中重症脓毒症患者57例,脓毒症休克患者41例.重症脓毒症组(S)分为心功能正常组(Sn)、心功能异常组(Sa)、死亡组(Sd)和存活组(Ss)四个亚组,脓毒症休克组(SS)分为心功能正常组(SSn)、心功能异常组(SSa)、死亡组(SSd)及存活组(SSs)四个亚组.x2检验判断各组病死率的是否存在统计学差异,SNK-q比较各组间血浆BNP、TnT、TnI水平是否具有统计学差异,以直线相关判断上述指标与EF值的相关性,受试者工作曲线(ROC)评估上述指标与预后的关系.结果 (1)S组和SS组的BNP和TnI水平差异无统计学意义,但SS组的TnT水平明显高于S组(P=0.001);(2) Sa组BNP、TnT及TnI显著高于Sn组,Sd组BNP明显高于Ss组(P=0.001); (3) SSa组BNP、TnT及TnI明显高于SSn组,SSd组BNP明显高于SSs组(第1天P=0.001,第3天P＝0.001,第7天P=0.016);(4) SSn组的TnT、TnI显著高于Sn组,且SSn组第1、3、7天的BNP均明显高于Sn组(第1天P=0.006,第3天P=0.006,第1天P=0.001); (5) Sd及SSd组的BNP均明显高于Ss组和SSs组;(6)S组与SS组中心功能异常组的病死率更高,差异具有统计学意义(Sa与Sn组比较,P＜0.05,SSa与SSn组比较,P＜0.05);(7) Sd和SSd患者入院时的EF值和BNP水平呈负相关(r=-0.603,P＜0.01),入院72 h内BNP水平＞0.39 ng/ml可作为预测死亡的临界点,其敏感度92.9％,特异性80.8％.结论 血浆BNP、TnT及TnI水平可在一定程度上反应患者心脏损伤的严重程度,BNP、TnT及TnI水平明显升高者预后较差;BNP可作为预测脓毒症心脏损伤患者预后的指标.     

Cardiac resynchronization therapy reverses severe dyspnea associated with acceleration‐dependent left bundle branch block in a patient with structurally normal heart

A 55‐year‐old woman presented with severe dyspnea during acceleration‐dependent left bundle branch block (LBBB). Metoprolol initially ameliorated symptoms by preventing the heart rate at which LBBB occurred. Over time LBBB presented at slower heart rates and the patient developed recurrent dyspnea during an activity that correlated with the development of LBBB on event monitors and exercise stress testing. A biventricular pacemaker was implanted, and the patient's symptoms remain resolved after a follow‐up of over 4 years. More research is needed to define the use of cardiac resynchronization therapy in patients with normal heart function.     

Myocardial Contraction Fraction Predicts Cardiovascular Events in Patients With Hypertrophic Cardiomyopathy and Normal Ejection Fraction

BackgroundMyocardial contraction fraction (MCF), the ratio of left ventricular stroke volume to myocardial volume, is a novel parameter that can distinguish between pathologic and physiologic hypertrophy. However, its prognostic value in hypertrophic cardiomyopathy (HCM) has never been examined. The objective was to determine if MCF is associated with functional capacity and predicts adverse cardiovascular outcomes in patients with HCM and normal left ventricular ejection fraction (LVEF).Methods and ResultsWe conducted a prospective cohort study of 137 patients with HCM and LVEF ≥55%. Patients were followed for 2.7 ± 2.5 years. We examined association of MCF with New York Heart Association (NYHA) functional class and a composite outcome of embolic stroke, heart transplantation, and cardiac death. We performed time-to-event analysis with the use of Cox proportional hazards modeling and stepwise elimination. The average age was 52 ± 18 years. The average MCF was 26 ± 11%. MCF was inversely correlated with NYHA functional class (P = .001). A total of 20 subjects experienced an outcome event with an event rate of 5.6% per patient-year. MCF independently predicted the outcome (adjusted hazard ratio 0.50 per 10% increase, 95% confidence interval 0.28–0.90, adjusted P = .02).ConclusionsIn patients with HCM and normal LVEF, MCF is associated with functional capacity and independently predicts adverse cardiovascular outcomes.