计算机波谱分析与喉动态镜观测在研究喉发声功能中的应用

应用IBM微机系统对31名正常人和31名喉疾病患者进行了声波、波谱描记,并与喉动态镜观察结果进行了比较,对声带的7种疾病的特异性进行了研究,认为二者结合可使喉发声功能的研究提高到新水平。     

健康人微伏级T波电交替渐量修正平均法检测分析

目的探讨渐量修正平均法检测健康人微伏级T波电交替(microvolt T wave alternans,MTWA)的正常范围。方法平板运动提升心率,渐量修正平均法检测120例健康志愿者各胸前导联T波交替电压(alternans voltage,Valt),分析其大小分布范围及与性别、年龄的关系。结果(1)各胸前导联T波交替电压数据均呈偏态分布;胸前导联Valt大小与年龄无关;V4、V5导联Valt男女性别间差异有统计学意义,女性高于男性。(2)各胸前导联T波交替电压有较大差别,第75百分位数分别为V1导联8.0μV;V2导联5.0μV;V3导联2.0μV;V4导联男性2.0μV,女性6.0μV;V5导联男性4.5μV,女性6.5μV;V6导联7.0μV;胸前导联T波交替电压最大值(Vmax)第75百分位数11.0μV。结论:渐量修正平均法检测健康人微伏级T波电交替不同胸前导联之间有较大差别;确定正常标准需要因导联而异。     

P波时限、P波离散度对特发性心房颤动的预测价值初探

Objective:To assess the sensitivity and the specifity of predicting idiopathic AF with P wave dura-tion and P wave dispersion. Methods: The maximum P wave duration and P wave dispersion in 36 patients with idio-pathic AF were measured and compared with those of sex-and age-matched healthy subjects. Results:The maxi-mum P wave duration and P wave dispersion were higher in patients with idiopathic Af than in control group. Themaximum P wave duration >110ms or P wave dispersion >40ms was used to differentiate patients from healthy     

Wave Intensity技术对高血压患者左心室收缩功能和颈动脉血管的研究

目的：探讨WI技术评价高血压患者左心室收缩功能和颈动脉血管的临床应用价值。方法：对56例高血压患者和50例健康志愿者采用高频线阵探头对颈动脉进行检测,应用echo—doppler系统测量颈动脉血流速度和直径变化,计算WI值（W1、W2和NA）、硬化参数（B）、弹性系数（Ep）、顺应性（AC）、增大指数（AI）和脉搏波传导速度（PWVβ、PWV-WI）,比较高血压组与对照组各参数值的差异。结果：高血压组与正常对照组相比较W1和W2增高,差异有统计学意义（P〈0．05）;高血压组β、Ep、PWVβ及PWV—WI较正常对照组增高,AC降低,且差异均有显著性意义（P〈0．05）。结论：WI技术能客观准确综合地反映高血压患者左心室收缩功能和血管弹性改变,高血压患者左心整体收缩功能高于健康成人。     

头针联合空气压力波治疗脑卒中后肩手综合征的疗效观察

目的将传统针刺疗法中的头皮针结合空气压力波治疗仪联合现代康复运动疗法与单纯采用现代康复运动疗法治疗脑卒中后肩手综合征的疗效进行对比研究。方法入选90例脑卒中并发肩手综合征患者,用随机数字法分为对照组与治疗组,每组45例;对照组:常规用药+康复训练;治疗组:在对照组的治疗基础上加用头皮针和空气压力波治疗仪的联合治疗,30 d为1个疗程,1个疗程后将两组的观察结果进行统计和对照分析;观察指标:(1)手功能试验(Carroll评分法);(2)疼痛分级指数(pain rating index,PRI评分);(3)手掌围度(使用软尺测量)。结果对照组45例脑卒中并发肩手综合征患者中,疗程结束后总有效28例,无效17例;治疗组45例脑卒中并发肩手综合征患者中,疗程结束后总有效39例,无效6例。两组疗效比较,治疗组中有效患者明显高于对照组,差异有统计学意义(P<0.01)。治疗组脑卒中并发肩手综合征患者手功能试验Carroll评分(57.71±34.34比较46.56±24.08)与疼痛分级指数PRI评分(8.09±3.56vs.17.31±6.08)显著高于对照组脑卒中并发肩手综合征患者,差异有统计学意义(P<0.05)。治疗组脑卒中并发肩手综合征患者手掌围度有效改善率91.1%明显高于对照组脑卒中并发肩手综合征患者57.8%,差异有统计学意义(P<0.01)。结论头针联合空气压力波结合康复训练是一种治疗脑卒中后肩手综合征行之有效的方法,尤其是在缓解肢体肿胀程度上较常规康复疗法显著。     

生活方式干预对糖耐量异常者动脉内膜厚度及弹性的影响

目的探讨饮食、运动等生活方式干预对糖耐量异常者颈动脉内膜中膜厚度与臂踝脉搏波传导速度的影响。方法收集糖耐量异常者162例,随机分为78例对照组,84例干预组;对照组给予每3个月1次的糖尿病健康知识宣教(电话),干预组在此基础上进行为期24个月的生活方式干预,并每月随访1次。每例均采用超声及全自动动脉硬化仪测定颈动脉内膜中膜厚度与臂踝脉搏波传导速度。各组均进行前后自身对照和组间对照,并评价干预效果。结果经过24个月生活方式干预,干预组糖尿病累计发病率较对照组显著下降;干预组较干预前甘油三酯、口服糖耐量试验2 h血糖显著降低(P<0.05),其余指标经对比后差异无统计学意义;干预组与对照组比较,两组颈动脉内膜中膜厚度有显著性差异(P<0.05),除臂踝脉搏波传导速度、体质指数、高密度脂蛋白外,其余各项指标均有显著改善(P<0.05或P<0.01)。结论生活方式干预能有效改善糖耐量异常患者的代谢状态,降低糖尿病发病率,并能延缓其血管病变的发展;强化生活方式干预应在糖耐量异常人群中大力推行。     

New echocardiographic applications for assessing global left ventricular diastolic function

A number of promising and highly technological echocardiographic imaging tools have recently been introduced to assess left ventricular diastolic function (i.e., the capacity of the ventricle to relax and fill). They permit quantification of distinct features of intraventricular blood flow velocity and pressure fields and myocardial tissue velocities. However, accurate interpretation of the new images and clinical indices is still cumbersome, as basic knowledge about intraventricular hemodynamics and ventricular wall mechanics is often insufficient. This review article provides a comprehensive and original overview of the hemodynamical and mechanical events that occur during diastole and discusses how this new information can be used in the clinical and research setting to evaluate diastolic function in the healthy and the diseased heart. It furthermore aims to explain the underpinnings of the techniques in such a way that the underlying biomechanical concepts (fluid dynamics and wall mechanics) become less obscure to cardiologists and echocardiographers and such that the biomedical engineers are given some insights into the avalanche of diastolic performance indices that currently exist.     

Increased augmentation of central blood pressure is associated with increases in carotid intima–media thickness in type 2 diabetic patients

Aims/hypothesis Type 2 diabetes is associated with a two- to seven-fold increase in cardiovascular morbidity and mortality. The aim of this study was to determine the relationships between intima–media thickness (IMT), an established marker of atherosclerosis, large artery function and other determinants of cardiovascular risk in type 2 diabetic patients.Methods We studied 228 type 2 diabetic patients (75 women, aged 62±2 years [mean±SEM]). Carotid IMT was bilaterally measured using ultrasound technology. Applanation tonometry and pulse wave analysis were used to measure aortic systolic and diastolic blood pressures, central pressure augmentation (AG) and the augmentation index (AIx), a measure of systemic arterial stiffness. Conventional cardiovascular risk factors (lipids, HbA₁c, smoking and diabetes duration) were also assessed.Results Women had higher AG and AIx (p<0.0001), despite comparable systolic BP and heart rate in women and men. In women, AG (r=0.39, p<0.001), age (r=0.32, p<0.01), brachial systolic BP (r=0.34, p<0.01) and aortic systolic BP (r=0.34, p<0.01) correlated with IMT. In men, age (r=0.41, p<0.001), diabetes duration (r=0.25, p<0.01), AG (r=0.22, p<0.01), aortic systolic BP (r=0.21, p<0.01), brachial systolic BP (r=0.21, p<0.01) and body weight (r=0.16, p<0.05) correlated with IMT. In multiple linear regression analyses, AG and aortic systolic BP, but not brachial systolic BP, were age-independent determinants of IMT in men and women. In all patients, increased AG (adjusted for sex, age and heart rate) correlated with longer duration of diabetes, urinary albumin excretion and IMT.Conclusions/interpretation Measures of central systolic pressure correlate with carotid IMT, independently of age and other risk markers.     

Reservoir and excess pressures predict cardiovascular events in high-risk patients

Background

Analysis of the arterial pressure curve plays an increasing role in cardiovascular risk stratification. Measures of wave reflection and aortic stiffness have been identified as independent predictors of risk. Their determination is usually based on wave propagation models of the circulation. Another modeling approach relies on modified Windkessel models, where pressure curves can be divided into reservoir and excess pressure. Little is known of their prognostic value.

Methods and results

The aim of this study is to evaluate the predictive value of parameters gained from reservoir theory applied to aortic pressure curves in a cohort of high-risk patients. Furthermore the relation of these parameters to those from wave separation analysis is investigated.Central pressure curves from 674 patients with preserved ejection fraction, measured by radial tonometry and a validated transfer function, were analyzed. A high correlation between the amplitudes of backward traveling pressure waves and reservoir pressures was found (R = 0.97). Various parameters calculated from the reservoir and excess pressure waveforms predicted cardiovascular events in univariate Cox proportional hazards modeling. In a multivariate model including several other risk factors such as brachial blood pressure, the amplitude of reservoir pressure remained a significant predictor (HR = 1.37 per SD, p = 0.016).

Conclusions

Based on very different models, parameters from reservoir theory and wave separation analysis are closely related and can predict cardiovascular events to a similar extent. Although Windkessel models cannot describe all of the physiological properties of the arterial system, they can be useful to analyze its behavior and to predict cardiovascular events.     

Alterations in Carotid Parameters in ApoE–/– Mice Treated with a High-Fat Diet: A Micro-ultrasound Analysis

Information on the common carotid artery and cerebral microcirculation can be obtained by micro-ultrasound (µUS). The aim of the study described here was to investigate high-fat diet-induced alterations in vascular parameters in ApoE–/– mice. Twenty-two ApoE–/– male mice were examined by µUS and divided into the standard diet (ApoE–/–_SD) and high-fat diet (ApoE–/–_HF) groups. The µUS examination was repeated after 4 mo (T₁). Carotid stiffness, reflection magnitude and reflection index were measured; the amplitudes of the first (W₁) and second (W₂) local maxima, the local minimum (W_b) and the reflection index (RI_WIA?=?W_b/W₁) were assessed with wave intensity analysis. At T₁, ApoE–/–_HF mice had increased carotid stiffness (1.48 [0.36] vs. 1.88 [0.51]) and reflection magnitude (0.89 [0.07] vs. 0.94 [0.07]) values. Longitudinal comparisons highlighted increases in carotid stiffness for ApoE–/–_HF mice (from 1.37 [0.25] to 1.88 [0.51] m/s) but not for ApoE–/–_SD mice (from 1.40 [0.62] to 1.48 [0.36] m/s). ApoE–/–_HF mice exhibited carotid artery stiffening and increased wave reflections.