从立体心电图的角度分析在体表心电图测量QTd的不合理性

目的　分析从体表心电图 (ECG)测量QT离散度 (QTd)的错误理由。方法　使用立体心电图仪对确诊的心肌梗死患者和正常对照组各 10 0例 ,进行 2 4导通道实时同步描记 12导联ECG、普通心电向量图 (VCG)、3导正交心电图 (O -ECG)、9导时间心向量图 (T -VCG)、变向时间心向量图 (DCT -VCG)检测。结果　①病例和对照组的QT间期、QTc在体表ECG、O -ECG、T -VCG三者之间的相关性良好 (r =0 879～ 0 993 ,P <0 0 1) ,而QTd、QTcd在体表ECG和T -VCG之间无明显相关 ;②两组所测QTd、QTcd值在体表ECG和O -ECG、体表ECG和T -VCG间均有显著性差异 (P <0 0 1) ,而QT、QTc无明显差异 ;③从两组间的比较来看 :病例组较对照组QT、QTc间期均在体表ECG、O -ECG和T -VCG上有明显延长 ,但QTd、QTcd仅在体表ECG上两组间的差异有显著性 (P <0 0 1) ,而在O -ECG、T -VCG上两组间无显著性差异。结论　同步 12导联的体表ECG ,在同一心动周期中只有 1个整体的QT间期。QT间期的测量最好采用SECG ,因从T -VCG的角度观察更准确。虽体表ECG上测量QTd在不同组间有差异 ,但在T -VCG上并无显著性差异     

倍他乐克对心绞痛患者QT间期离散度的影响

目的研究倍他乐克对冠心病劳力型心绞痛患者QT间期离散度(QTd)的影响。方法按照前瞻性研究设计,对162例入选患者进行随机、单盲试验研究,入选患者在治疗前做12导联同步心电图检查,测量心率、最大和最小QT间期,计算QTd、心率校正后QT间期离散度和QT间期离散度比,在治疗4周后重复上述心电图检查;治疗组服用倍他乐克50～100 mg/d,对照组服用安慰剂治疗,比较2组前后的QTd变化,用t检验进行统计学处理。结果倍他乐克可以明显缩短劳力性心绞痛患者的QTd和心率校正后QTd(QTcd),降低QT间期离散度比。比较两组治疗4周后的QTd、QTcd和QTd ratio数值,两组差异有统计学意义,QTd、QTcd和QT间期离散度比分别为(44.5±17.3)ms比(63.8±15.6)ms,P<0.01,(45.7±15.3)ms比(64.9±16.3)ms,P<0.01和4.94%±2.1%比8.08%±1.5%,P<0.001。结论倍他乐克在改善心肌缺血的同时可以明显的缩短QTd,降低QT间期离散度比;QT间期离散度比对预测冠心病患者发生恶性心律失常和猝死比QTd具有更重要的预后价值。     

QT离散度不能反映心肌复极的区域性差异

目的　探讨体表心电图上QT离散度 (QTd)是否可以反映区域性的心肌复极差异。方法　正常对照 (对照 )组和心肌梗死 (心梗 )组各有 12 0例 ,记录同步 12导联心电图 ,人工测量各导联QT间期 ,计算QTd。结果　与对照组相比 ,心梗组QTd明显增加 ,分别为 (5 6 3± 17 8)ms与 (10 0 9±5 4 3)ms,P <0 0 0 1;但两组之间存在很大交叉 ,无法确立参考值。最长QT和最短QT在两组的导联分布呈现一致趋势。心梗组全部 12导联QT间期均较对照组明显延长 ,平均QT间期分别为 (397 0± 4 6 8)ms与 (36 7 3± 2 2 8)ms ,P <0 0 0 1。不同梗死部位各亚组之间心电图各导联QT间期均值差异无显著性(P =0 6 36 ) ,未见到与梗死部位相关的区域性QT间期改变。结论　QTd增大常与QT间期延长同时出现 ,QTd增大从整体上反映了心肌复极异常 ,但是不能代表心肌复极的区域性差异。     

国内QT离散度的研究现状

QT离散度(QTd)是1990年由Day等提出的一个新概念,它的定义是指常规12导联心电图中最大QT间期与最小QT间期的差值。在实测导联不足12个时,QTd值应进行校正,即QTcd=QTmax-     

体表心电标测测定急性心肌梗死患者QT离散度的探讨

目的 探讨有更大体表取样范围的体表心电标测(BSPM)中反映的QT间期离散度及分布.方法 (1)记录1998年3月至1999年12月间68例急性心肌梗死患者(平均年龄59岁)的96导联体表心电标测图及12导联心电图,分别测定QT间期及QT离散度,并与58名正常对照(平均年龄50岁)进行对比分析.结果 (1)正常人及急性心肌梗死患者BSPM法测得的QT离散度、QT最大值均大于12导心电图值,QT最小值小于12导心电图;(2)正常人BSPM法测得的QTd为(50.6±17.1)ms.最大值多位于左侧胸及偏后部、胸骨上部和右锁骨区,最小值位于胸部偏右下部.急性心肌梗死患者BSPM法测得的QTd为(83.3±28.7)ms,较正常对照组高.QT间期分布发生明显变化,QT间期最大值移至覆盖于心肌梗死部位的体表区域;(3)BSPM法测得QTd的变异系数低于12导心电图.BSPM法区分急性心肌梗死患者与正常人QTd的灵敏度高于12导心电图(分别为81%,58%);特异性分别为91%和90%.结论 12导心电图及BSPM方法均表明急性心肌梗死患者QT离散度增加,BSPM方法较12导心电图能更有效地发现体表QT间期最大、最小值及心室复极的离散,尤其可展示QT间期的空间分布.     

高血压左心室肥厚患者心电图QT离散度改变

目的　探讨原发性高血压左心室肥厚患者心电图QT离散度 (简称QTd)变化。　方法　用美国超九 ATL(XO16 3)彩色多谱勒诊断仪二维超声测量其舒张期左心室室间隔厚度和左心室后壁厚度 ,以≥ 1 2cm作为左心室肥厚诊断标准 ,对高血压左心室肥厚组 (n =36 ,男 女 =2 0 16例 ,平均年龄 6 0岁± 12岁 )、高血压左心室非肥厚组(n =5 0 ,男 女 =30 2 0例 ,平均年龄 6 2岁± 12岁 )进行测量 ,再用心电图ECG 8110P( 0 180 8A3)描记其常规 12导联心电图 ,手工测量其最大QT间期 (QTmax)、最小QT间期 (QTmin)和心动周期RR间期 ,计算QTd和心率校正的QTcd ,并随机匹配正常人群组 (n =4 0 ,男 女 =2 4 16例 ,平均年龄 5 8岁± 13岁 )。　结果　高血压左心室肥厚组QTd为6 0ms± 17ms ,QTcd为 6 8ms± 2 4ms,高血压左心室非肥厚组QTd为 4 1ms± 13ms,QTcd为 4 3ms± 17ms ,正常人群组QTd为 4 3ms± 11ms ,QTcd为 4 4ms± 16ms,前两组比较有显著性差异 ,P <0 0 1,后两组比较无显著性差异 ,P >0 0 5。　结论　原发性高血压左心室肥厚患者QT间期离散度增大。     

QT离散度在心血管疾病中应用的现况

QT离散度(QT dispersion，QTd)是心电图各导联间QT时限变异的程度。通常测量的方法是应用体表常规12导联心电图上最大的QT间期（QTmax)减去最小的QT间期（QTmin)所得的时限差值为QTd。1985年Campbell等首先发现不同导联间QT间期的差异有其规律性，是由于心肌复极不一致所引起，并     

健康老年人QT间期离散度的检测及其相关因素分析探讨

目的建立健康老年人12导联同步心电图QT间期离散度平均值及其相关因素分析。方法对1028例65～95(69.4±17.3)岁健康老年人,用SR-1000A心电综合自动分析仪采集12导联同步体表心电图数据,并录入软盘,专人在显示器上进行回放分析。增益放大1mV=20～40mm,纸速放大50～100mm/s。测量QTmax、QTmin,按Bazett公式校正QTcmax、QTcmin,计算QTd(QTmax-QTmin)及QTcd(QTcmax-QTcmin)。微机数理统计。结果QTmax、QTmin、QTcmax、QTcmin、QTd及QTcd平均值随增龄呈增大趋势,但在年龄组间及男女间差别无统计学意义。65～95岁QTmax平均值为399.39±32.93ms,QTmin为364.99±31.06ms,QTcmax为445.87±28.21ms,QTcmin为406.60±29.84ms,QTd为33.97±11.15ms,QTcd为38.14±12.84ms。结论健康老年人各年龄QTd为12～50ms,QTcd为13～60ms。QTd与心率、年龄及性别无明显相关性。     

不同类型室性心律失常患者QTd与QTcd变化及其临床意义

<正> QT间期离散度(QTd)是指12导联心电图各导联间QT间期存在的差异.1985年由Campbell等报道QTd是心室复极时间的局部差异在体表心电图上的反映而非记录技术伪差所致.1990年由Day等首先证实QTd具有重要的临床价值.本文分析100例定性心律失常患者QTd与校正QT间期离散度(QTcd)值,旨在探讨其对恶性室性心律失常的预测价值.     

QT离散度与高血压合并Ⅱ型糖尿病的关系探讨

目的　探讨QT离散度 (QTd)与高血压 (EH)合并Ⅱ型糖尿病 (NIDDM)的关系。方法　测量 5 2例EH合并NIDDM(A组 )和 5 2例EH无并发症患者 (B组 )以及 5 0例正常人 (C组 )的同步 12导联心电图及其最大Q -T间期 (QTmax) ,最小Q -T间期 (QTmin) ,QTd =QTmax -QTmin。用Bazett公式计算校正的QTd(QTcd) ,进行比较分析。结果　QTd、QTcd :A组分别为 (5 5 8± 13 2 )ms和 (63 8± 13 6)ms;B组分别为 (40 6± 8 4)ms和 (46 1± 10 0 )ms;C组分别为 (40 0± 9 7)ms和 (44 1± 10 9)ms。A组与B组、A组与C组比较有非常显著的统计学意义 (P <0 0 1)。结论　QTd、QTcd与高血压合并Ⅱ型糖尿病密切相关 ,可作为预测其心血管受损程度的敏感指标     

Research and Evaluation of the Influence of the Construction of the Gate and the Influence of the Piston Velocity on the Distribution of Gases into the Volume of the Casting

Distribution of gasses to the cast volume and volume of pores can be maintained within the acceptable limits by means of correct setting of technological parameters of casting and by selection of suitable structure and gating system arrangement. The main idea of this paper solves the issue of suitability of die casting adjustment—i.e., change of technological parameters or change of structural solution of the gating system—with regards to inner soundness of casts produced in die casting process. Parameters which were compared included height of a gate and velocity of a piston. The melt velocity in the gate was used as a correlating factor between the gate height and piston velocity. The evaluated parameter was gas entrapment in the cast at the end of the filling phase of die casting cycle and at the same time percentage of porosity in the samples taken from the main runner. On the basis of the performed experiments it was proved that the change of technological parameters, particularly of pressing velocity of the piston, directly influences distribution of gasses to the cast volume.     

Weighing the QT Intervals with the Slope or the Amplitude of the T Wave

Objective: The reproducibility of QT interval measurements is low, even for the mean QT interval based on the standard ECG. In this study we analyzed whether the reproducibility of the mean weighed QT interval was better than the simple mean QT interval. The weighing was based on the amplitude of the T wave or the slope of the steepest tangent on the terminal part of the T wave. Material and methods: 12‐lead ECGs of 130 postmyocardial infarction patients were obtained. The QT intervals were measured by the tangent‐method on two occasions by the same observer Mismatch QT intervals were defined as QT intervals that were measured at only one occasion. Sixteen ECGs were rejected. The data were split into 34 and 80 ECGs for optimization and validation of the weighing, respectively. The weighed QT dispersion was calculated as the weighed mean of the three longest minus the weighed mean of the three shortest QT intervals. Results: Weighing with the slope increased the reproducibility by 41% (P = 3 10^‐6), but weighing with the amplitude reduced it by 20% (P = 0.02). However, if measurements with errors above 75 ms were rejected, weighing with the slope or the amplitude increased the reproducibility with 26% and 20% (P = 0.02), respectively. Weighing did not change the reproducibility of the weighed QT dispersion. Conclusion: Weighing with the slope improved the reproducibility of the mean weighed QT interval. However, if measurements with errors above 75 ms were rejected, weighing with the amplitude also increased the reproducibility. Weighing did not change the reproducibility of the weighed QT dispersion. Weighing is particularly efficient at reducing the negative impact of mismatch QT intervals on the reproducibility. A.N.E. 2002;7(1):4–9     

县级以下综合医疗机构医务人员对现代结控知识的认识现状调查

目的本文旨在了解医务人员现代结控知识掌握的现状及培训效果?方法于培训前后进行问卷调查,内容包括:病例发现?结核病诊断及化疗?结果培训前疫情报告和转诊,回答正确者占75.2%?71.7%;对临床表现?查痰和诊断依据,回答正确者占83.5%?42.5%?40.8%;抗痨药物?用药方法?化疗原则?短化方案?短化疗程?治愈标准六项,回答正确者占58%?14.4%?20.8%?9.2%?17%?24.3%?培训后再次调查发现,90%以上医务人员对现代结控基本知识已掌握?结论各级医务人员现代结控知识是很贫乏的,因此,对其进行系统培训是极为必要的,此项工作省时?省力?投入少,可收到事半功倍的效果。     

大骨节病病区水,粮实验对动物的骨和软骨中化学元素组成的影响

用质子激发 X 线荧光分析方法(PIXE)测定了大骨节病病区和非病区的水、粮以及用该水粮喂养的大白鼠的肋软骨和硬骨中22种化学元素的含量。结果发现水粮中存在差异的元素反应在用该水粮喂养的大白鼠的骨、软骨中也存在差异,含量都低的元素有 P、Mn、Cu、As、Zn。都高的有铅。其中锌低在水、粮、硬骨和软骨中都完全一致呈非常显著性差异(p<0.01)。提示病区水、粮中化学元素对骨质的影响不是单一元素缺乏或过多所致,而是多种元素的复合因素。     

Assessment of the Soft-Tissue Seal at the Interface between the Base of the Fixed Denture Pontic and the Oral Mucosa

Fixed dentures (bridges) are often selected as a treatment option for a defective prosthesis. In this study, we assess the contact condition between the base of the pontic and oral mucosa, and examine the effect of prosthetic preparation and material biocompatibility. The molars were removed and replaced with experimental implants with a free-end type bridge superstructure after one week. In Experiment 1, we assessed different types of prosthetic pre-treatment: (1) the untreated control group (Con: mucosa recovering from the tooth extraction); (2) the laser irradiation group (Las: mucosa recovering after the damage caused by a CO₂ laser); and (3) the tooth extraction group (Ext: mucosa recovering immediately after the teeth extraction). In Experiment 2, five materials (titanium, zirconia, porcelain, gold-platinum alloy, and self-curing resin) were placed at the base of the bridge pontic. Four weeks after the placement of the bridge, the mucosa adjacent to the pontic base was histologically analyzed. In Experiment 1, the Con and Las groups exhibited no formation of an epithelial sealing structure on the pontic base. In the Ext group, adherent epithelium was observed. In Experiment 2, the sealing properties at the pontic interface were superior for titanium and the zirconia compared with those made of porcelain or gold-platinum alloy. In the resin group, a clear delay in epithelial healing was observed.     

高胆红素血症对肿瘤标志物测定的影响探讨

目的探讨高胆红素血症对Ca19-9、Ca24-2和CEA检测的影响.方法对320例胆管、胆囊良恶性疾病病人,15例胆囊炎病人的胆汁和血清以及10例肝硬化、10例黄疸肝炎病人进行Ca19-9、Ca24-2和CEA检测.结果在良性胆管、胆囊疾病中,Ca19-9的假阳性最高;在胆红素增高的良性疾病中,Ca19-9假阳性率达46.7%;15例胆汁和血清以及10例肝硬化和10例黄疸肝炎病人中,Ca19-9的假阳性率分别为93%、20%、80%和80%.结论高胆红素血症对Ca19-9检测影响最明显,胆囊、胆管良恶性疾病鉴别时,以Ca24-2和CEA检测为佳.