Pseudo-Oversensing of the T Wave by an Implantable Cardioverter Defibrillator: A Nonclinical Problem

Two patients are described who had pseudo-oversensing of T waves during follow-up testing of the Medtronic PCD. Each patient exhibited appropriate T wave sensing following closely coupled spontaneous QRS complexes to subthreshold stimuli without having T wave sensing following sensed or paced complexes. One patient also revealed T wave sensing following fusion beats. The occurrence of T wave sensing in these unique clinical situations was due to the auto-adjusting sensitivity threshold function used by the PCD. Recognition of this normal sensing function will prevent inappropriate reprogramming of the sensitivity or postpace refractory period, interventions that could potentially lead to ventricular tachyarrhythmia undersensing.     

体外震波对骨和骨疾病的作用及其机制

体外震波（extracorporeal shock wave，ESW）于20世纪80年代中期开始用于骨科领域，目前，它作为一种非侵入性治疗方法用于治疗多种骨相关疾病。为指导其进一步用于临床治疗并提高疗效，了解它对正常骨组织的影响和对骨疾病的治疗作用及其机制非常重要。现已有不少学者对这些方面进行了相关的基础与临床研究，取得了明显进展。本文就体外震波对骨和骨疾病的作用及其机制综述如下。     

枣花丹合剂对失眠症夜间慢波睡眠影响的研究

目的:观察枣花丹合剂对失眠症夜间慢波睡眠的影响。方法:选择无器质性病变,每天睡眠少于240~300min为主症者64例患者随机分为两组。枣花丹合剂组在08:00和19:00时分别服用枣花丹合剂200mL。对照组在08:00和19:00时服同量红糖水,连服4周。睡眠监测的数据包括记录时间、非快动眼睡眠期、快动眼睡眠期、睡眠时间、觉醒时间、睡眠比、觉醒比。结果:枣花丹合剂组与对照组相比,夜间睡眠Ⅰ、Ⅱ期减少,Ⅲ、Ⅳ期增加;夜间觉醒次数减少,总睡眠时间明显增加;SWS睡眠结构比改变,SWS睡眠的连续性好、周期性显著,明显优于对照组改变,差异有统计学意义(P<0.05)。结论:枣花丹合剂可以增加失眠症夜间慢波睡眠,是治疗失眠症的一种有效和较好治疗方法。     

黄芪对ESWL致兔肾损伤后缺氧诱导因子-1α表达的影响

目的探讨缺氧诱导因子-1α（HIF-1α）在ESWL致肾脏损伤中的作用及黄芪是否通过调节HIF-1α的表达而发挥对肾脏的保护作用。方法45只家兔随机分为对照组、ESWL损伤组和黄芪治疗组,每组15只,除对照组外,所有动物接受ESWL处理（18kV,1 500次）。黄芪治疗组家兔于冲击前3d至后2d,每天注射黄芪注射液2.0g/kg。2周后处死家兔,取肾脏HE染色观察肾组织形态学改变,免疫组织化学染色观察HIF-1α在肾脏中的表达。结果ESWL处理后肾小管上皮细胞肿胀、脱落,小管内可见大量管型,肾间质大量炎细胞浸润;黄芪治疗组以上病变显著减轻。ESWL损伤组HIF-1α显著表达于肾小管上皮细胞及间质,黄芪能够明显抑制HIF-1α的表达。结论HIF-1α参与了ESWL对肾脏的损伤,黄芪可能通过抑制HIF-1α的表达发挥对肾脏的保护作用。     

急性心肌梗死患者J波的临床研究

目的　研究心电图有 J波的急性心肌梗死 ( AMI)患者的临床情况。方法　选择住院的急性心肌梗死患者 10 2例 ,心电图有 J波者 5 0例为研究组 ,心电图无 J波者 5 2例为对照组 ,比较两组临床情况。结果　心电图有 J波组比心电图无 J波组发生胸闷 ( 3 0 /5 0∶ 2 0 /5 2 ,P<0 .0 5 )、前壁心肌梗死 ( 2 8/5 0∶ 18/5 2 ,P<0 .0 5 )、合并糖尿病 ( 14/5 0∶ 4/5 2 ,P<0 .0 5 )、超声心动图检查发生舒张功能减低 ( 2 4/5 0∶ 14/5 2 ,P<0 .0 5 )、心电图检查发现室性心动过速 ( 11/5 0∶ 1/5 1,P<0 .0 5 )者多。结论　心电图有 J波者比心电图无 J波者临床情况差 ,易于发生严重心律失常     

F wave studies after intrathecal methotrexate administration

Electrophysiological examinations were done on 20 patients aged 40–71 years with recently diagnosed high grade non-Hodgkin's lymphomas. General chemotherapy and intrathecal chemotherapy in order to prevent central nervous system (CNS) involvement were begun. On the first day of chemotherapeutic cycle patients received intrathecally methotrexate (ITMTX) and prednisolone. Electrophysiological study was carried out twice in each subject: before ITMTX injection and a day after injection. The study procedure included: a conventional nerve conduction examination (peripheral conduction velocity and compound muscle action potential amplitude), the F wave latency and amplitude measurement and F ratio (F-M-1/2M) calculation for peroneal and tibial nerve bilaterally. Results of the first and the second examinations were statistically compared by t-Student's test. No significant differences between values of estimated parameters were found. The study revealed no recent alterations in proximal, paraspinal motor conduction and motor neuron excitability due to antidromical activation after single ITMTX administration.     

超声显像诊断下肢深静脉血栓的临床应用

目的：探讨超声诊断下肢深静脉血栓的临床价值。方法：应用ＨＰ８５００多功能彩超仪，７．５ＭＨｚ线阵探头，外周血管软件检查临床疑下肢深静脉血栓３２例，另取１２例正常人２４条下肢深静脉作对照。２ＤＵＳ显示形态学改变，ＣＶＩ及ＰＷ模式观察血流状态。结果：超声检出下肢深静脉血栓形成２５例，除外血栓形成７例。２ＤＵＳ显示血栓形成部位血管内径明显增大，与患者健侧同水平深静脉内径进行配对ｔ检验，ｔ＝１３．８２，Ｐ     

Validity of Electrode Placement at Fpz to Detect Alpha Wave

Abstract: The possibility on placing electrodes at Fpz-A₂ instead of C₃-A₂ was investigated to obtain a more stable configuration avoiding obstruction by the hair. Our original system of alpha wave detection by a microcomputer was used, and a total of 22 all-night hypnograms of five healthy young students waa recorded. Pearson's moment correlation coefficients of alpha wave % between the two positions were 0.780–0.948. Except for one subject, alpha wave % taken at Fpz-A₂ tended to be 3–5% lower than that at C₃-A₂. The above analysis indicates that using EEG electrode position of Fpz-A₂ is valid and useful as a stable electrode configuration for a long-time monitoring.     

血流频谱分析在乳腺肿块鉴别诊断中的价值

目的：检验血流频谱分析在鉴别乳腺原发性肿块良恶性方面的价值并确立最佳的数值标准。方法：使用彩色多普勒血流显像和能量多普勒显像分别引导脉冲多普勒频谱分析，检查了１０４例乳腺原发性包块（良性５５例６３个病灶，恶性４９例６４个病灶），测量指标包括肿块周边与内部血流收缩期峰速、搏动指数及阻力指数，并分别绘制受试者工作曲线确定各自的最佳阈值。结果，以ＣＤＦＩ状态取频谱，乳癌病灶周边及内部血流的平均ＰＳＶ，Ｐ     

In vitro evaluation of ablation parameters of normal and fibrous aorta using smooth excimer laser coronary angioplasty

A modified exeimer laser energy delivery system was used to irradiate 100 segments of normal and fibrous aorta in vitro. The laser beam was scanned into 8 fiber bundles consisting of 50 fibers each resulting in a reduction of the applied pulse energy. The total repetition rate was increased to 150 Hz in order to keep the repetition rate per fiber bundle close to 20 Hz and to minimize thermal injury. The results demonstrate that effective ablation (etch rate per 8 pulses > 2.0 μm) occurred at an energy fluency of 50 mJ/mm² in both normal and fibrous aorta. Tissue damage (carbonization, tissue separation, fissures, cracks, and vacuolization) was in a range of 100 ± 28 to 152 ± 30 μm for normal aorta and in a range of 57 ± 35 to 110 ± 39 μm for fibrous aorta. We conclude that effective ablation of normal and fibrous human aorta can be achieved by the application of smooth excimer laser coronary angioplasty. This improvement of excimer laser technology may result in a reduction of shock wave- and cavitation-induced damage leading to a reduction of tissue injury. However, this awaits further in vitro and in vivo confirmation. © 1993 Wiley-Liss, Inc.