多普勒组织成像评价肺动脉高压患者右室心功能应用

目的:应用多普勒组织成像技术(Doppler tissue imaging,DTI)测定肺动脉高压(Pulmonary hypertension,PHT)患者的三尖瓣环运动频普,探讨其评价右室心功能的价值。材料与方法:常规超声心动图检查28例PHT组及32例健康对照组,并检测三尖瓣口舒张早期速度(E)、舒张晚期速度(A),DTI检测三尖瓣环的收缩期峰值速度(Sa)、舒张早期速度(Ea)、舒张晚期速度(Aa),计算E/A、Ea/Aa,并对两组参数进行比较。结果:PHT组三尖瓣环及瓣口Sa、Ea、Ea/Aa及E/A均减低(P0.05),Ea/Aa更为明显(P0.01),Aa高于对照组(P0.05)。结论:应用DTI测定三尖瓣环运动,可以敏感地反映PHT患者右室功能的变化,是评价右室整体功能的较好指标。     

组织多普勒显像检测二尖瓣环速度评价冠心病左室舒张功能

目的：探讨应用组织多普勒显像（TDI）检测二尖瓣环运动速度评价冠心病左室舒张功能的应用价值。方法：冠心病患者45例,正常对照组30例,应用脉冲多普勒（PWT）检测二尖瓣口舒张早、晚期血流峰值流速（E、A）、计算E／A;应用TDI速度模式,在心脏四腔心切面检测二尖瓣内、外环运动速度（Ea、Aa）,计算Ea／Aa。结果：冠心病组左室舒张功能假性正常组（E／A〉1）与正常对照组比较,二尖瓣血流频谱E、A、E／A及二尖瓣环Aa差异无统计学意义（P〉0．05）,TDI检测二尖瓣环Ea及Ea／Aa较正常组明显减低,差异有统计学意义（P〈0．01）。冠心病组左室舒张功能减低组（E／A〈1）与正常对照组比较,二尖瓣环Aa差异无统计学意义（P〉0．05）,二尖瓣血流频谱A较正常对照组增高,E、E／A及二尖瓣环Ea、Ea／Aa较正常组明显减低,差异有统计学意义（P〈0．01）。结论：TDI检测二尖瓣内、外环运动速度Ea、Aa,计算Ea／Aa,可评价冠心病左室舒张功能,与二尖瓣血流检测左室舒张功能（E／A〈1）减低者有很好相关性,并可鉴别左室舒张功能假性正常化,估测舒张功能受损的程度。     

应用二尖瓣环运动速度评价冠心病患者左室功能的研究

目的 :探讨与常规超声相比 ,DTI测量二尖瓣环运动速度以评价左室功能的临床应用价值。方法 :研究对象为 33例冠心病的患者和 19例健康志愿者。常规超声心动图检查后 ,应用DTI测量二尖瓣环 6个节段的Sa、Ea和Aa及节段性等容舒张时间。结果 :(1)常规超声未检出冠心病不伴心梗组左室整体或节段性收缩功能减退 ,冠心病组常规二尖瓣血流E/A之比和肺静脉血流S/D之比与正常组相比也无显著性差别 ,然而DTI显示 ,冠心病不伴心梗组二尖瓣环 6个节段Sa、Ea、Ea/Aa之比显著低于正常组 ,冠心病伴心梗组上述参数降低更为显著。 (2 )冠心病组二尖瓣环 6个节段平均Sa与LVEF呈高度正相关 ,r值为 0 .746 (P <0 .0 0 1)。结论 :DTI测量二尖瓣环 6个节段的运动速度能定量评价冠心病患者左室整体和节段性功能 ,较常规超声敏感 ,有助于冠心病患者的早期诊断和随访。     

多普勒组织成像评价左室整体功能最佳部位的选择

目的应用DTI测量二尖瓣环6个节段的运动速度评价左室整体功能并探讨心尖窗最佳切面、二尖瓣环的最佳节段的选择.方法应用DTI测量33例冠心病患者和19例健康志愿者二尖瓣环后间隔、侧壁、下壁、前壁、前间隔和后壁处各位点的Sa、Ea、Aa及Ea/Aa之比.结果(1)冠心病组二尖瓣环6个节段Sa、Ea及Ea/Aa较正常组显著下降(P＜0.01).(2)冠心病组二尖瓣环6个节段平均Sa与左室射血分数呈高度正相关(r＝0.746,P＜0.001);平均Ea/Aa与二尖瓣血流频谱E/A之比也具有良好的相关性(r＝0.723,P＜0.001).(3)正常组和冠心病组心尖四腔切面的二尖瓣环侧壁缘Sa及Ea/Aa之比与6个节段平均参数的相关系数均为最大.结论测量二尖瓣环6个节段的平均运动速度可评价左室整体收缩和舒张功能,心尖四腔切面二尖瓣环侧壁缘是评价左室整体功能的最佳节段.     

多普勒组织成像评价冠心病患者的左室整体舒张功能

目的 :探讨应用多普勒组织成像 ( DTI)检测二尖瓣环舒张期运动速度评估冠心病左室整体舒张功能的应用价值。方法 :应用 DTI技术 ,对 5 4例临床确诊 (其中 30例经冠脉造影证实 )的冠心病患者和 30例正常对照者舒张期二尖瓣环运动速度进行测定 ,并与常规多普勒超声心动图检查结果对照分析。结果 :正常对照组二尖瓣环舒张早期峰值速度 ( Ea)及舒张早期与舒张晚期速度之比 ( Ea/ Aa)均与年龄呈显著负相关。在冠心病松弛受损 ( IR)组与假性正常 ( PN)组 ,Ea/ Aa均较正常组明显减低 ( p<0 .0 1) ;在限制型 ( RF)组 ,Ea与 Aa均较正常组明显减低 ( p<0 .0 1) ,但 Ea/ Aa与正常组无显著性差异。结论 :DTI技术检测二尖瓣环舒张期运动速度参数可用于无创评价冠心病左室整体舒张功能     

多普勒组织成像法评价窒息新生儿左心功能

目的探讨多普勒组织成像法（Doppler tissue imaging,DTI）评价窒息新生儿左心收缩功能。 方法足月窒息新生儿共62例（重度组31例,轻度组31例）,正常组新生儿30例,在出生后24、48、72h内采用DTI模式测定二尖瓣环收缩期运动速度（Sa）,舒张期早期运动速度（Ea）,舒张晚期运动速度（Aa）和舒张期早期/舒张晚期速度比值（Ea/Aa）来判断左心功能。 结果（1）重度组、轻度组Sa、Ea、Ea/Aa在3个时段均明显低于对照组（P〈0.001）;（2）3个时段重度组Aa均明显高于轻度组和对照组（P〈0.001）。 结论新生儿窒息时左心收缩和舒张功能降低,DTI能敏感地反映窒息新生儿左心功能的变化。     

多普勒组织成像技术对高血压患者左室舒张功能的评价

目的：探讨多普勒组织成像(DTI)技术评价高血压病(EH)患者左室舒张功能的价值，以寻求一种可靠、客观的评价高血压左室舒张功能的新方法。方法：采用放免法测定19例正常人和41例EH患者(伴心肌肥厚者19例和不伴心肌肥厚者22例)的血清I型前胶原(PC I)和Ⅱ型前胶原(PC Ⅱ)的浓度。用DTI法检测正常人及EH患者二尖瓣环舒张早期运动速度(Ea)、舒张晚期运动速度(Aa)及Ea／Aa，并用二尖瓣血流多普勒法检测舒张期血流速度E、A及E／A，比较两种方法测值与血清I、Ⅱ型前胶原的相关性。结果：1．EH患者非左室肥厚(non—LVH)组及左室肥厚(LVH)组二尖瓣口血流参数、二尖瓣环DTI参数均明显低于正常对照组(P＜0．01)；2．EH患者non—LVH组与LVH组间E、E／A无明显差别(P＞0．05)，但LVH组Ea、Ea／Aa明显低于non—LVH组(P＜0．05)；3．EH患者non—LVH组血清PC I、PC Ⅱ与E／A及Ea／Aa均呈负相关(r＝—0．58P＜0．01、r＝—0．61P＜0．01及r＝—0．62P＜0．01、r＝—0．49P＜0．05)；而LVH组血清PC I、PCⅡ与Ea／Aa亦呈负相关(r＝—0．50P＜0．05、r＝—0．55P＜0．05)，与E／A无明显相关(r＝—0．41P＞0．05、r＝0．02P＞0．05)。结论：DTI能更准确定量高血压患者二尖瓣环舒张期运动速度的改变，DTI法检测二尖瓣环运动速度之比与反应心肌纤维化程度的血清PC I、PC Ⅱ浓度相关良好，有利于舒张功能受损程度的判断，优于传统的二尖瓣口血流法。     

组织多普勒成像技术评价高危妊娠对胎儿心脏功能影响的临床价值

目的 探讨组织多普勒成像技术在评价高危妊娠胎儿心脏功能的临床价值.方法 应用组织多普勒成像技术测量50例高危妊娠胎儿二、三尖瓣环处心肌运动速度( Ea,Aa,Sa 峰) 来反映左、右心室的心肌舒张及收缩功能.另外测定了与其年龄匹配的120例正常妊娠胎儿心脏的组织多普勒参数作为对照组.结果 (1)高危妊娠组及正常妊娠组胎儿二、三尖瓣环的运动速度( Ea,Aa )均与孕周呈正相关,随孕周的增长而增加;高危妊娠组及正常妊娠组胎儿二、三尖瓣环的运动速度(Sa)均与孕周无相关性.(2)高危妊娠组及正常妊娠组胎儿三尖瓣环的速度均大于相应二尖瓣环的运动速度(Ea、Aa、Sa峰).(3)高危妊娠组胎儿二、三尖瓣环的运动速度( Ea,Aa,Sa 峰) 均低于正常妊娠组.结论 高危妊娠组胎儿左、右心室心肌收缩及舒张功能均受到影响,组织多普勒技术可以评价高危妊娠胎儿心脏的收缩及舒张功能.     

多普勒组织成像技术对冠心病患者二尖瓣环运动曲线的探讨

目的 本文旨在运用多普勒组织成像技术观察冠心病患者二尖瓣环运动曲线以评估其左室收缩和舒张功能。 方法32例冠心病患者和20例正常人作对照研究,测定其二尖瓣环后间隔、侧壁、下壁、前间隔和后壁六处各位点的Sa、Ea、Aa及Ea/Aa之比。 结果 1.冠心病患者和正常人二尖瓣环的DTI运动曲线为规律波群,有三个主波,收缩波Sa波,舒张早期Ea波,舒张晚期Aa波 2.冠心病患者二尖瓣环六个节点Sa、Ea及Ea/Aa较正常组显著下降(P<0.01)3.冠心病患者二尖瓣环六个节点平均Sa与左室射血分数呈正相关(r=0.689,P<0.01)平均Ea/Aa与二尖瓣血流曲线E/A之比也有良好相关性(r=0.427 P<0.05)4.正常组与冠心病组心尖四腔观二尖瓣环侧壁Sa、Ea/Aa之比与六个节点平均参数相关系数最大。 结论 DTI测量二尖瓣环运动曲线能同时测定左室收缩、舒张功能,从而提供了一种新的、安全的、直接可靠的、简便的方法。     

组织多普勒超声心动图评价冠心病患者心室舒张功能

目的采用组织多普勒技术观察冠心病患者心室舒张功能的改变及左室和右室舒张功能的关系。方法研究24例正常健康人和20例冠心病患者,应用多普勒超声技术测量二尖瓣口及三尖瓣口舒张期血流速度;应用组织多普勒超声技术测量二尖瓣环一左室侧壁交界处及三尖瓣环一右室侧壁交界处心肌运动频谱。测量二尖瓣及三尖瓣舒张早期血流速度（E）、舒张晚期血流速度（A）及E／A,心肌舒张早期运动速度（Em）、晚期运动速度（Am）及Em／Am,测量E／Em。结果与正常组比较,冠心病组左室舒张期二尖瓣血流速度E／A显著减小（P〈0．01）,三尖瓣血流E／A亦显著减小（P〈0．01）;组织多普勒所测左右心室Em、Am、Em／Am均减小（P〈0．01）,E/Em增大（P〈0．01）;冠心病组左室与右室间E/Em比值高度相关（r=0．83）。结论冠心病患者的左室舒张功能异常,伴有右室舒张功能的改变,右室与左室舒张功能的改变相关。应用组织多普勒和频谱多普勒联合评价心室舒张功能,纠正了频谱多普勒评价心室舒张功能出现的假正常现象。     

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.