超声心动图对急性心肌梗塞后左心室结构和功能的评价

目的 动脉观察急性心肌梗塞后左室结构和功能的变化,评价溶栓治疗对梗塞后心室重构的影响。方法 对２８例首发急性心肌梗塞患者于梗塞后第４周和第１２周进行超声心动图观察。所测参数有：左室舒张末期和收缩末期容积指数（ＬＶＥＤＶＩ,ＬＶＥＳＶＩ）及射血分数（ＥＦ）。结果 急性心肌梗塞患者ＬＶＥＤＶＩ,ＬＶＥＳＶＩ均明显增高;栓组ＬＶＥＤＶＩ,ＬＶＥＳＶＩ无明显变化,ＥＦ升高,未溶栓组ＬＶＥＤＶＩ,ＬＶＥＳＶ     

静脉溶栓治疗对急性心肌梗塞远期预后的影响

目的：观察静脉溶栓治疗对急性心肌梗塞（ＡＭＩ）患者远期预后的影响。方法：采用超声心动图、２４小时动态心电图、心电图运动试验及心室晚电位检查，对９４例接受溶栓治疗的ＡＭＩ患者进行６个月～３年的随访。结果：在６个月～３年的随访中，前壁再通组左房内径（ＬＡＤ）、左室舒张末内径（ＬＶＥＤ）和左室射血分数（ＬＶＥＦ）均明显短于前壁未通组（Ｐ均＜０．０５）；而下壁再通组与未通组ＬＡＤ、ＬＶＥＤ和ＬＶＥＦ无明显差别。再通组各种心律失常的发生率明显低于未通组，再通组的运动耐量明显高于未通组（Ｐ均＜０．０５）。结论：静脉溶栓对改善前壁心肌梗塞患者远期心功能疗效显著，对下壁心肌梗塞患者心功能改善不明显；但静脉溶栓对前壁或下壁心肌梗塞患者，在减少远期心律失常的发生，增强运动耐量和提高生活质量方面均有着重要意义。     

多普勒超声心动图对急性心肌梗塞患者溶栓治疗的评价

目的：探讨多普勒超声心动图对不同梗塞部位急性心肌梗塞（ＡＭＩ）溶栓治疗再通评价的意义。方法：对１６０例首次ＡＭＩ患者随机分成尿激酶溶栓治疗再通组和常规治疗对照组，采用彩色多普勒超声心动图测定左房内径（ＬＡＤ）、室间隔和左室后壁运动最小幅度（ＩＶＳＡ和ＬＶＰＷＡ）、左室射血分数（ＥＦ）、二尖瓣Ｅ点至室间隔距离（ＥＰＳＳ）和二尖瓣血流频谱Ａ峰最大速度与Ｅ峰最大速度比（Ａ／Ｅ）。结果：①溶栓治疗者再通率为５８．８２％（７０／１１９）。②急性前壁心肌梗塞（ＡＡＭＩ）患者的ＬＡＤ、ＥＰＳＳ和Ａ／Ｅ在溶栓组明显低于对照组（Ｐ＜０．０１，Ｐ＜０．０１，Ｐ＜０．０１）；溶栓再通组ＥＦ明显高于对照组（Ｐ＜０．０１）。③急性下壁心肌梗塞（ＡＩＭＩ）患者ＬＶＰＷＡ溶栓再通组高于对照组（Ｐ＜０．０５）；溶栓再通组Ａ／Ｅ明显低于对照组（Ｐ＜０．０１）。④ＡＡＭＩ＋ＡＩＭＩ患者ＥＦ在溶栓再通组明显高于对照组（Ｐ＜０．０１）；ＥＰＳＳ低于对照组（Ｐ＜０．０５）。结论：溶栓治疗可限制梗塞面积，挽救濒死心肌，改善左室功能。在梗塞部位上，前壁优于下壁，ＡＡＭＩ＋ＡＩＭＩ介于两者之间。     

急性心肌梗塞静脉溶栓后再通对左室重构的影响

目的：分析急性心肌梗塞（ＡＭＩ） 静脉溶栓再通对左室重构的影响。方法：把８２ 例ＡＭＩ静脉溶栓的病人分为再通组４８ 例,未通组３４ 例,在ＡＭＩ发病后（６±５．１） 月,用心脏彩超对不同部位室壁运动、室壁厚度、左室射血分数（ＬＶＥＦ）、左室舒张末内径（ＬＶＤＤ） 、左室收缩末内径（ＬＶＤＳ） 等观察。结果：前壁心肌梗塞两组间室壁运动幅度、梗塞区的室壁厚度有显著性差异（ Ｐ＜ ０．０１）, 而下壁心肌梗塞二组间无显著性差异（Ｐ＞０．０５）, 左室形态与功能差异显著（Ｐ＜ ０．０１）。结论：ＡＭＩ早期再灌注可改善左室重构     

缺血性心肌病左室重构变化的超声研究

目的 应用二维多普勒超声心动图（２ＤＤＥ）评价缺血性心肌病（ＩＣＭ）患者左室重构（ＬＶＲ）的病理生理改变。方法 用２ＤＤＥ对５６例ＩＣＭ患者ＬＶＲ的病理生理改变引进了研究,另有５０例正常对照者。指标包括左室舒张末期直径（ＬＶＤＤ）、左室舒张末期容积（ＬＶＥＤＶ）、左室收缩末期容积（ＬＶＥＳＶ）、左室收缩末期室壁应力（ＥＳＳ）、左室射血分数（ＥＦ）、左室峰值充盈率（ＰＦＲ）、峰值流速Ａ（ＰＶＡ）、峰     

二维多普勒超声对缺血性心肌病左室重构变化的研究

目的对缺血性心肌病（ＩＣＭ）患者的左室重构（ＬＶＲ）病理生理变化进行分析研究。方法应用ＨＰ ７７０２０ＡＣ型彩色多普勒血流显像仪（探头频率３．５ＭＨｚ）分别对５６例ＩＣＭ患者和５０例正常对照组进行分析评价。结果显示ＩＣＭ组的各项指标与正常组比较有显著性差异（Ｐ＜０．０１～０．００１）。ＩＣＭ组的ＬＶＥＤｄ、ＥＤＶ、ＥＳＶ、ＥＳＳ、ＰＶＡ、ＬＡＴ、ＬＡＦ显著增大，ＥＦ、ＣＯ、ＬＶＳＣＩ、ＭＶＣＦ、ＰＶＥ、ＰＦＲ及ＰＶＡ／ＰＶＥ显著降低（Ｐ＜０．０１～０．００１）。结论认为ＩＣＭ病人ＬＶＲ的主要病因与心肌缺血引起的梗塞区膨展、左室扩张、容量负荷及室壁应力的增加有关，而ＥＳＶ、ＥＤＶ及ＥＦ可作为了解ＩＣＭ远期预后的最佳指标     

溶栓对急性心肌梗塞患者左心功能的影响

目的： 评价溶栓治疗对急性心肌梗塞（ＡＭＩ）患者左心功能的影响。方法：经静脉溶栓治疗的９６ 例患者ＡＭＩ后１ 个月进行锝９９ 心肌扫描,计算各项心功能指标。结果：５９ 例再通者的ＥＦ％ 、ＰＥＲ和ＰＦＲ均明显优于３７ 例未通者（Ｐ均＜ ０．０１）。左室扩张者的各类指标与ＬＶＥＤｄ 呈负相关（ｒ＝ － ０．４１～－ ０．８０, Ｐ＜ ０．０１）。结论： ＡＭＩ的溶栓治疗能明显地改善心功能     

高血压病左室心肌重量指数与室性心律失常的关系

探讨高血压病左室心肌重量指数与室性心律失常的关系。方法采用彩超及２４ｈ动态心电监测技术，对９８例高血压病（ＥＨ）患者左室心肌重量指数（ＬＶＭＩ）及室性心律失常（ＶＡ）的发生情况进行检测。结果ＥＨ患者左室心肌肥厚（ＬＶＨ）组ＶＡ发生率明显高于非心肌肥厚组（Ｐ＜０．０１）。且重度ＬＶＨ组较轻度ＬＶＨ组ＶＡ发生率高（Ｐ＜０．００１）。结论ＬＶＨ可导致ＶＡ的发生，ＶＡ的发生可能是ＬＶＨ出现心脏性猝死的直接原因。     

钙拮抗剂与转换酶抑制剂对老年高血压左室肥厚的影响

目的：观察ＡＣＥＩ和ＣａＡ治疗后对高血压左室肥厚的影响。方法：随机分为两组，分别用ＡＣＥＩ和ＣａＡ治疗６个月，观察对血压，左室肥厚（ＬＶＨ）和左心功能的影响。结果：（１）两类药物均有明显的降压作用（Ｐ均〈０．０１）；（２）治疗后３个月ＩＶＳＴ，ＰＷＴ，ＬＶＭＩ即有减少。６个月上述指标减少更明显，且ＡＣＥＩ下降幅度大于ＣａＡ（Ｐ〈０．０５），ＡＣＥＩ还能使ＬＶＤｄ逐渐缩小；（３）Ｅ／Ａ比例明显升高（     

急性心肌梗死早期二尖瓣血流减速时间预测左室扩大的价值

目的 探讨急性心肌梗死（ＡＭＩ）患者早期二尖瓣血流减束时间预测左室扩大的价值。方法 行直接经皮冠状动脉腔内球囊成形（ＰＴＣＡ）的ＡＭＩ患者３４例,于梗死后第７、３０、６０、９０ｄ行二维和多普勒超声心动图检查,以左室容积增大２０％以上为左室扩大,按Ｅ峰减速时间（ＤＴ）长短分为两组,ＤＴ≤１３０ｍｓ的１３例为Ａ组,ＤＴ〉１３０ｍｓ的２１例为Ｂ组。结果 ＡＭＩ后９０ｄ,左室舒张末期容积指数（ＬＶＥＤＶＩ     

Determination of creatine kinase isoenzyme MB activity in serum using immunological inhibition of creatine kinase M subunit activity. Activity kinetics and diagnostic significance in myocardial infarction.

This is a new method for the determination of creatine kinase isoenzyme MB activity in serum. The method uses direct activity measurement of creatine kinase B subunit activity after blocking of CK-M subunit activity by inhibiting antibodies. The test takes no longer than 15 min. The method yields an intra-serial C.V. of 2.0-12.9%, and a C.V. from day to day of 5.5%. The detection limit is 3.4 U/l creatine kinase MB. In the 95 cases with proven myocardial infarction several types of creatine kinase MB activity kinetics could be determined. The percentage of creatine kinase MB of peak CK-total is 6-25%, with a mean of 11.1%. The amount of creatine kinase MB with respect to total CK activity after reinfarction is higher than the amount after initial infarction.     

Dissociable correlates of two classes of retrieval processing in prefrontal cortex

Although substantial evidence suggests that the prefrontal cortex (PFC) implements processes that are critical for accurate episodic memory judgments, the specific roles of different PFC subregions remain unclear. Here, we used event-related functional magnetic resonance imaging to distinguish between prefrontal activity related to operations that (1) influence processing of retrieval cues based on current task demands, or (2) are involved in monitoring the outputs of retrieval. Fourteen participants studied auditory words spoken by a male or female speaker and completed memory tests in which the stimuli were unstudied foil words and studied words spoken by either the same speaker at study, or the alternate speaker. On "general" test trials, participants were to determine whether each word was studied, regardless of the voice of the speaker, whereas on "specific" test trials, participants were to additionally distinguish between studied words that were spoken in the same voice or a different voice at study. Thus, on specific test trials, participants were explicitly required to attend to voice information in order to evaluate each test item. Anterior (right BA 10), dorsolateral prefrontal (right BA 46), and inferior frontal (bilateral BA 47/12) regions were more active during specific than during general trials. Activation in anterior and dorsolateral PFC was enhanced during specific test trials even in response to unstudied items, suggesting that activation in these regions was related to the differential processing of retrieval cues in the two tasks. In contrast, differences between specific and general test trials in inferior frontal regions (bilateral BA 47/12) were seen only for studied items, suggesting a role for these regions in post-retrieval monitoring processes. Results from this study are consistent with the idea that different PFC subregions implement distinct, but complementary processes that collectively support accurate episodic memory judgments.     

俯卧位通气对高海拔地区肺复张治疗无效急性呼吸窘迫综合征患者氧合的影响

目的 探讨俯卧位通气对高海拔地区肺复张术(RM)治疗无效急性呼吸窘迫综合征(ARDS)患者的治疗作用.方法 从海拔2260m的地区医院筛选RM治疗无效的41例ARDS患者[平均氧合指数( PaO2/FiO2)较RM前升高＜20％视为RM无效],依不同病因分为肺内源性ARDS组(ARDSp组)和肺外源性ARDS组(ARDSexp组),每组再按信封法随机分为俯卧位组和仰卧位组,即ARDSp俯卧位组(11例)、ARDSp仰卧位组(9例)、ARDSexp俯卧位组(10例)、ARDSexp仰卧位组(11例).在通气前及通气1、2、3、4h监测动脉血氧分压( PaO2)、PaO2/FiO2、静态顺应性(Cst)、气道阻力(Raw)的变化.结果 通气lh时,ARDSexp俯卧位组PaO2/FiO2( mm Hg,l mm Hg=0.133 kPa)即较通气前显著升高(157.4±40.6比129.3±48.7,P＜0.05),并随通气时间延长呈持续增高趋势,4h达峰值(219.1 ±41.1);且ARDSexp俯卧位组通气3h内PaO2/FiO2较其他3组显著增高,另3组间则差异无统计学意义.ARDSp俯卧位组、ARDSexp俯卧位组通气4h时PaO2/FiO2均较相应仰卧位组显著增高(208.8±39.7比127.4±47.1,219.1±41.1比124.9±50.8,均P＜0.05).4组通气前后Cst无显著改变,各组间差异也无统计学意义.ARDSp俯卧位组通气4h时Raw(cmH2O·L-1·s-1)较通气前显著降低(6.8±1.7比10.7±1.8,P＜0.05),且明显低于其他3组;其他3组各时间点Raw组内及组间比较差异均无统计学意义.结论 俯卧位通气作为ARDS机械通气重要策略之一,可以改善RM无效高原ARDS患者的氧合,为抢救患者赢得宝贵的时间.     

Digital imaging among medical facilities

The Department of Veterans Affairs (VA) in the USA operates a network of 172 medical centres which all utilize a hospital information system (HIS) which has been developed and is currently maintained by the VA. During the past several years, an image management and communication module has been developed, installed and clinically utilized at the Washington DC and Maryland VA Medical Centres. This image management and communication system, referred to as the decentralized hospital computer program (DHCP) imaging system, is fully integrated with a commercial picture archiving and communication system (PACS). The system is utilized to capture, archive, and display all images generated within the hospital including radiology, nuclear medicine, pathology, endoscopy, bronchoscopy, and dermatology, intraoperative photographs, ECG data, and a limited number of paper documents. The ultimate goal of the project is to have all patient text and image data available at any clinical workstation to any authorized user anywhere within the network of medical centres. Clinical requirements for an imaging workstation include ease of use, rapid and reliable access to the complete set of patient information, and images which are of acceptable quality to meet the requirements of the user and the subspecialty. Patient confidentiality and data security must be safeguarded at all times. Integration of the images with the remainder of the patient's database was found to be critical to the success of the project. The experience at the Washington and Maryland facilities suggests that an imaging system that is successfully integrated with a hospital information system can provide substantial clinical and economic benefits both within and among medical centres. Clinical acceptance and utilization of the system has been excellent, particularly in diagnostic radiology where DHCP Imaging has been interfaced to a commercial PAC system. Based upon this initial experience, the VA has begun to deploy the system throughout its large network of medical centres.     

Myocardial elastography at both high temporal and spatial resolution for the detection of infarcts

Myocardial elastography is a novel method for noninvasively assessing regional myocardial function, with the advantages of high spatial and temporal resolution and high signal-to-noise ratio (SNR). In this paper, in-vivo experiments were performed in anesthetized normal and infarcted mice (one day after left anterior descending coronary artery [LAD] ligation) using a high-resolution (30 MHz) ultrasound system (Vevo 770, VisualSonics Inc., Toronto, ON, Canada). Radiofrequency (RF) signals of the left ventricle (LV) in longitudinal (long-axis) view and the associated electrocardiogram (ECG) were simultaneously acquired. Using a retrospective ECG gating technique, 2-D full field-of-view RF frames were acquired at an extremely high frame rate (8 kHz) that resulted in high-quality incremental displacement and strain estimation of the myocardium. The incremental results were further accumulated to obtain the cumulative displacements and strains. Two-dimensional and M-mode displacement images and strain images (elastograms), as well as displacement and strain profiles as a function of time, were compared between normal and infarcted mice. Incremental results clearly depicted cardiac events including LV contraction, LV relaxation and isovolumetric phases in both normal and infarcted mice, and also evidently indicated reduced motion and deformation in the infarcted myocardium. The elastograms indicated that the infarcted regions underwent thinning during systole rather than thickening, as in the normal case. The cumulative elastograms were found to have higher elastographic SNR (SNR(e)) than the incremental elastograms (e.g., 10.6 vs. 4.7 in a normal myocardium, and 6.0 vs. 2.4 in an infarcted myocardium). Finally, preliminary statistical results from nine normal (m = 9) and seven infarcted (n = 7) mice indicated the capability of the cumulative strain in differentiating infracted from normal myocardia. In conclusion, myocardial elastography could provide regional strain information at simultaneously high temporal (>/=0.125 ms) and spatial ( approximately 55 microm) resolution as well as high precision ( approximately 0.05 microm displacement). This technique was thus capable of accurately characterizing normal myocardial function throughout an entire cardiac cycle, at the same high resolution, and detecting and localizing myocardial infarction in vivo.     

Clinical Pharmacokinetics of Morphine

Morphine, the most widely used mu-opioid analgesic for acute and chronic pain, is the standard against which new analgesics are measured. A thorough understanding of the pharmacokinetics of morphine is required in order to safely and effectively use this analgesic in a wide variety of patients with different levels of organ function. A MEDLINE search was conducted to identify literature published between 1966 and January 2002 relevant to the pharmacokinetics of morphine. These publications were reviewed and the literature summarized regarding unique and clinically important elements of morphine disposition relative to its parenteral administration (including intravenous, intramuscular, subcutaneous, epidural and intrathecal administration), absorption profile (immediate release, controlled release, and sublingual/buccal, and rectal administration), distribution, and its metabolism/ excretion. Special populations, including infants, elderly, and those with renal/liver failure, have a unique morphine pharmacokinetic profile that must be taken into account in order to maximize analgesic efficacy and reduce the risk of adverse events.