心电图Ⅲ导联ST段偏移在急性前壁心肌梗死中的意义

目的　旨在明确常规体表心电图ST段偏移对急性前壁心肌梗死患者左冠状动脉前降支 (LAD)堵塞部位的预测价值。方法　根据病损部位在LAD第一对角支或第一间隔支的近端抑或远端 ,87例急性前壁心肌梗死患者被分为近端组和远端组 ,并比较两组患者的心电图改变。结果　①近端组Ⅰ、aVL导联ST段抬高≥ 1mm的发生率高于远端组患者 (I:5 0 %vs 35 % ,aVL :6 1%vs4 2 % ,P <0 0 1) ;②近端组患者下壁导联Ⅱ、Ⅲ和aVF的ST段压低≥ 1mm的发生率明显高于远端组患者(Ⅱ :79%vs 2 9% ,Ⅲ :86 %vs 19% ,aVF :75 %vs 4 5 % ,P <0 0 1) ;③作为LAD近端病损的预测指标 ,Ⅲ导联ST段压低≥ 1mm的敏感性和特异性高于aVL导联ST段抬高≥ 1mm的敏感性和特异性 (86 %vs 6 1% ,81%vs 5 8% ,P <0 0 1)。结论　常规体表心电图Ⅲ导联ST段明显压低是判断前壁心肌梗死患者LAD近端堵塞的良好指标     

急性下壁心肌梗死累及右心室或侧后壁时对心电图胸前导联ST段影响的研究

目的 :探讨急性下壁心肌梗死累及右心室或侧后壁时 ,对心电图胸前导联 ST段改变的影响及其临床意义。方法 :对 1 1 8例首次急性下壁心肌梗死患者的心电图进行比较分析。结果 :急性下壁心肌梗死时心电图下壁导联 ST段抬高幅度与胸前导联 ST段改变均呈负相关 (P均 <0 .0 1 )。在 1 6例同时合并右室梗死的患者中 ,胸前导联 ST段改变幅度〔V2 导联为 (0 .6 3± 1 .82 ) mm〕及与下壁导联 ST段抬高的比值 (V2 / a VF为0 .84± 1 .6 1 )均高于单纯下壁梗死组〔V2 导联为 (0 .35± 1 .6 5 ) m m,V2 / a VF为 0 .2 9± 1 .2 8〕;而 38例同时合并侧后壁梗死的患者胸前导联 ST段压低的幅度〔V2 导联为 (- 1 .2 0± 1 .5 2 ) mm〕及与下壁导联 ST段抬高的比值 (V2 / a VF为 - 0 .33± 1 .1 5 )均低于单纯下壁梗死组 ,且差异具有显著性意义 (P<0 .0 1或 P<0 .0 5 )。如去掉累及右室梗死和侧后壁梗死的病例 ,可使急性下壁心肌梗死心电图下壁导联与胸前导联 ST段的相关性显著提高 (r=- 0 .797,P<0 .0 1 )。结论 :急性下壁心肌梗死患者同时合并右室梗死可使心电图胸前导联 ST段趋于抬高 ;而合并侧后壁梗死则使胸前导联 ST段进一步降低 ,二者呈相反关系。     

急性前壁和前壁合并下壁心肌梗死患者入院时心电图与冠状动脉血管造影所示病变之间的关系及预测价值

目的：探讨急性前壁和前壁合并下壁心肌梗死患者入院时心电图对冠状动脉造影所示病变之间的关系及预测价值。方法回顾性分析2013年1月至2014年6月收治的248例前壁 ST 段抬高型心肌梗死（ASTEMI）患者入院心电图及冠状动脉造影资料。按心电图下壁导联 ST 段变化将其分为：急性前壁 ST 段抬高型心肌梗死合并下壁导联ST 段抬高组（ASTEMI + Ie）和急性前壁 ST 段抬高型心肌梗死合并下壁导联 ST 段压低组（ASTEMI + Id）;按冠状动脉造影结果分为：单支血管病变（SLAD）和多支血管病变（MAD）。结果心电图表现为 ASTEMI + Ie 者78例（31.5%）, ASTEMI + Id 者170例（68.5%）。冠状动脉造影有132例（53.2%）。ASTEMI + Ie 与 ASTEMI + Id 组中 SLAD、MAD 比率无显著差异（χ2=0.033,P >0.05）。ASTEMI + Id 患者中,aVL、V6导联出现 ST 段压低累及 MVD 情况均明显多于SLAD（χ2=17.015,χ2=21.147,P <0.01）。累及 LAD 的 MVD 患者中,aVL、V4、V5、V6导联 ST 段压低的比率明显多于SLAD 患者,差异均有统计学意义（ P <0.01）。结论当 ASTEMI 患者入院心电图下壁导联有对应性变化,前侧壁导联ST 段压低,则提示可能为 MVD 病变。     

急性前壁心肌梗死下壁导联ST段压低的临床意义

目的探讨急性前壁透壁性心肌梗死时下壁导联ST段压低的临床价值。方法比较任一下壁导联ST段压低≥1.0 mm的17例与压低均<1.0 mm的16例的CK-MB值、超声心动描记术、冠状动脉造影等结果。结果前组CK-MB值更高,射血分数减低更显著,左室收缩与舒张末期容积更大,造影术示致梗死狭窄病变多位于左前降支近端或呈多支病变。结论急性前壁心肌梗死下壁导联ST段压低≥1.0 mm时,其梗死面积较大,会发生较严重的左室射血功能损害及左心室重构。     

急性下壁心肌梗死患者的临床特点分析

目的 分析研究急性下壁心肌梗死患者的临床特点. 方法 将急性下壁心肌梗死患者100例根据冠状动脉造影结果分为两组:76例为右冠状动脉(RCA)闭塞(A组),24例为左回旋支冠状动脉(LCX)闭塞(B组). 结果 心电图ST段抬高STⅢ>STⅡ及ST段压低STAVL>ST I A组显著高于B组(均P<0.05);ST段抬高STⅢ0.1 mV A组显著高于B组(P<0.05);胸前导联V1～6ST段压低患者中,合并左前降支冠状动脉(LAD)病变的患者显著高于胸前导联V1～6ST段无压低者(P<0.05);左心室射血分数(LVEF)A组[(51±14)%]显著低于B组[(57±10)%](P<0.05);合并右心室心肌梗死A组显著高于B组(P<0.05);急性下壁心肌梗死患者总的住院病死率6%,均为A组,但心源性休克、心力衰竭、Ⅱ、Ⅲ度房室传导阻滞,室性心动过速/心室颤动及住院病死率,两组差异均无统计学意义(均P>0.05);死亡者中心源性休克占83.3%. 结论 心电图Ⅲ、Ⅱ、I、AVL、及V4R导联ST段变化能预测急性下壁心肌梗死相关血管,急性下壁心肌梗死患者伴胸前导联ST段压低提示LAD病变,RCA闭塞所致下壁心肌梗死LVEF低于LCX闭塞者,心源性休克为死亡主要原因.     

冠脉造影分析急性下壁心肌梗死前侧壁导联ST段压低

目的　应用冠状动脉造影 ,分析急性下壁心肌梗死患者心电图前壁或侧壁导联上ST段压低的临床义意。方法　 31例患者发病后第 1天标准 12导联心电图记录 ,前壁导联范围为V1 ～V4 ,侧壁导联范围为I、AVL、V5、V6 。患者均进行冠脉造影 ,2 5例 (80 % )自发病后 1个月内接受检查 ,6例于发病后2个月内接受冠脉造影 ,冠脉狭窄≥ 5 0 %被视为异常。结果　冠脉双支或双支以上病变者 ,特别是左旋支存在病变者 ,易发生侧壁导联ST段压低 ,P <0 0 5。前壁导联ST段低压者中 ,也以双支或双支以上病变为多。结论急性下壁心肌梗死时 ,出现前侧壁导联的ST段压低 ,为心肌缺血扩展的标志     

急性下壁心梗心电图特点与冠脉造影梗死相关动脉相关性分析

目的 探讨根据急性下壁心肌梗死心电图(ECG)特点来判断梗死相关动脉(IRA).方法 对照研究76例急性下壁心肌梗死患者的冠脉造影资料,分析梗死相关动脉及体表心电图变化.结果 梗死相关动脉为右冠状动脉(RCA)可能性大的有:心电图ST段抬高Ⅲ＞Ⅱ(83.6％),心电图ST段压低AVL＞Ⅰ(82.1％),V3导联ST段压低与Ⅲ导联ST段抬高比值≤1.2(83.3％),aVL S/R＞ 1/3伴ST段压低＞1 mm(90％),梗死相关动脉为左回旋支动脉(LCX)可能性大的有:ST段抬高Ⅲ≤Ⅱ(80％),ST段压低aVL≤Ⅰ(71.4％),V3导联ST段压低与Ⅲ导联ST段抬高比值＞1.2(83.4％),如S/R≤1/3伴ST段压低≤1mm(85.7％).结论 急性下壁心肌梗死时体表心电图与梗死相关动脉有明显相关性,且有较好的预测价值.     

急性下壁心肌梗死中心电图与梗死相关动脉间的关系

目的 探讨急性下壁心肌梗死（AMI）时体表心电图对梗死相关动脉（IRA）的判断价值.方法 选择经冠状动脉造影确诊的急性下壁AMI患者98例,观察其心电图表现与冠状动脉造影的关系.结果 98例下壁AMI患者中,右冠状动脉（RCA）病变68例,左回旋支（LCX）病变30例.以RCA病变为主时,心电图表现为Ⅲ导联ST段抬高幅度〉Ⅱ导联ST段抬高幅度、aVL 导联ST段压低和aVR导联ST段抬高;以LCX病变为主时,心电图表现为Ⅲ导联ST段抬高幅度〈Ⅱ导联ST段抬高幅度、aVL 导联ST段抬高和aVR导联ST段压低.结论 临床医师可通过心电图上的ST段移位对急性下壁AMI的患者的IRA作出初步判断.     

ST段偏移模式预测急性心肌梗死罪犯血管和罪犯病变部位

目的评价ST段偏移模式对急性心肌梗死罪犯血管、罪犯病变部位的预测效果。方法对完成介入手术的急性心肌梗死患者(分为下壁和前壁)判断罪犯血管、罪犯病变部位以及分析各导联ST段偏移特点,并对相关性进行分析。结果在急性下壁心肌梗死患者中,ST_Ⅲ抬高程度＞ST_Ⅱ以及ST_(Ⅰ、aVL)导联压低＞1 mm预测右冠罪犯病变具有良好的敏感性(75%)和特异性(100%)。对于前壁心肌梗死患者,ST_(Ⅱ、Ⅲ、aVF)压低＞1 mm预测前降支近段罪犯病变敏感性(39%)稍差,但特异性(93%)良好。结论心电图是判断罪犯血管和罪犯病变重要、可行的方法。     

急性下壁心肌梗死心前导联ST段压低的临床意义

目的　评价急性下壁心肌梗死伴心前导联 ST段压低的临床意义。方法　 36例急性下壁心肌梗死患者早期心电图与入院后 2～ 3周冠脉造影对照 ,观察急性下壁心肌梗死伴心前导联 ST段压低与右冠脉病变、多支血管病变关系。结果　急性下壁心肌梗死病变血管多涉及右冠状动脉 ,伴心前导联 ST段压低者有 1 4例 ( 70 % ) ,心前导联 ST段正常者有 1 2例 ( 75% )。且伴心前导联 ST段压低者较心前导联 ST段正常者病变血管大部分为多支病变 ( 6 5% V2 5% )。结论　急性下壁心肌梗死合并心前导联 ST段压低 ,表示多支冠脉病变或梗死面积大 ,应给予积极治疗 ,以改善患者病程和预后。     

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.