彩色多普勒超声心动图在合并肺动脉高压先天性心脏病封堵术中的应用

目的 探讨彩色多普勒超声心动图在先天性心脏病合并肺动脉高压(PH)封堵术中的应用价值.方法 209例伴有PH的先天性心脏病患者在超声全程临测下实施封堵治疗,其中房间隔缺损(ASD)86例,室间隔缺损(VSD)17例,动脉导管未闭(PDA)106例,超声心动图观察肺动脉收缩压(PASP)有无降低及降低的程度.结果 试封堵30～60 min后,合并轻度PH的136例患者PASP均降至正常;中度PH的46例中30例PASP降至正常,16例降至轻度;重度PH的17例中9例PASP降至中度,6例PASP下降≥30 mm Hg.以上患者均行永久性封堵治疗.2例重度PH患者PASP无明显变化,为阻力性PH,未行封堵治疗.结论 彩色多普勒超声心动图可在伴有PH的先天性心脏病封堵术前、术中及术后评估PASP的变化.     

超声心动图定量测量先天性心脏病肺动脉高压全肺阻力的方法学研究

目的探索超声心动图定量测量先天性心脏病（CHD）肺动脉高压患者全肺阻力（TPR）的方法,实现无创评价肺动脉高压（PH）。 方法选择先天性心脏病室间隔缺损（VSD）及动脉导管未闭（PDA）合并PH的患者15例。通过测量肺动脉瓣最大反流压差（PPR）,加上右房压（PRA）得到肺动脉平均压（PAMP）;PRA根据下腔静脉内径估测。测量收缩期肺动脉瓣环内径（PVD）计算出肺动脉瓣瓣口面积（PVA）。利用脉冲多普勒测量肺动脉瓣口血流流速时间积分（PVVTI）。按照公式肺循环血流量（QP）=PVA×PVVTI×HR（心率）计算QP。根据TPR=PAMP/QP×BSA（体表面积）公式,即可计算出TPR。同样方法测量主动脉瓣口通过的血流量可得到体循环血流量（QS）,进而可计算出肺、体循环血流量比值（QP/QS）。对于PDA患者,由于动脉水平分流,而使主动脉口通过的血流量相当于肺循环血流量,肺动脉口通过的血流量相当于体循环血流量。全部患者超声检查完毕后3d内完成右心导管检查。对2种测量结果进行了对比。 结果2种方法所测量的结果高度相关,超声心动图能够较为准确地测量肺高压患者的TPR、QP/QS等右心导管所能测量的参数,进而定量诊断PH。 结论利用超声心动图通过测量肺动脉压力及肺循环血流量,从而获得TPR及QP、QS等“右心导管参数”,作为无创右心导管检查技术有着潜在的应用前景。     

彩色多普勒超声心动图在单纯室间隔缺损中肺动脉压力的研究

彩色多普勒超声心动图是室间隔缺损（VSD）的首选诊断手段,往往确诊VSD后发现肺动脉高压,或确诊VSD同时发现肺动脉高压。肺动脉高压是VSD常见且严重并发症,肺小动脉病变期,及时手术矫治心内畸形,可阻止疾病的继续发展,如果发展成不可逆阶段,即使手术矫正心内畸形,肺动脉高压仍持续存在并进一步发展,失去了治疗的意义,因此,肺动脉高压的诊断对VSD的病情评估、手术指征确定及预后判断十分重要。彩色多普勒超声心动图有无创、简便、易重复等优点,已被广泛用来评估肺动脉高压程度,已部分取代创伤性的心导管。     

先天性心脏病患儿血浆氨基末端脑钠肽前体水平检测的意义——附49例报告

目的：探讨检测左向右分流先天性心脏病（congenital heart disease,CHD）患者血浆氨基末端脑钠肽前体（N—terminal pro-brain natriuretic peptide,NT-proBNP）的临床意义。方法：研究对象为49例左向右分流CHD患儿,其中房间隔缺损（atrial septal defect,ASD）25例（ASD组）,室间隔缺损（ventricular septaldefect,VSD）24例（VSD组）,另选同期在门诊体检的19名健康儿童作为对照组。利用电化学发光法测定与比较3组的血浆NT-proBNP水平;通过心导管检查测定ASD组与VSD组的肺动脉收缩压、平均肺动脉压以及肺体循环血流比值;分析NT-proBNP和肺动脉收缩压、平均肺动脉压以及肺循环、体循环血流比值的关系。结果：与对照组比较,CHD患儿的血NT—proBNP水平较高;ASD组、VSD组的血浆NT—proBNP水平与肺动脉收缩压、平均肺动脉压以及肺体循环血流比值呈正相关。结论：血浆NT—proBNP水平是反映左向右分流CHD患儿肺动脉压力敏感指标,临床可用其作为检测CHD患儿有否肺动脉高压的辅助指标。     

室间隔缺损合并肺动脉高压病人的术后重症监护

室间隔缺损（VSD）合并肺动脉高压（PH），是先天性心脏病中较常见的疾病，在儿童中尤为多见。近年来，国外已用气囊漂浮导管测定VSD肺、体循环血量比值和肺血管阻力，国内尚未见报道。但国内已开展在体外循环下行VSD修补术根治不能自愈的VSD。现就其术后的重症监护（ICU）总结如下。[第一段]     

室间隔缺损合并肺动脉高压病人的术后重症监护

室间隔缺损(VSD)合并肺动脉高压(PH),是先天性心脏病中较常见的疾病,在儿童中尤为多见。近年来,国外已用气囊漂浮导管测定VSD肺、体循环血量比值和肺血管阻力,国内尚未见报道[1]。但国内已开展在体外循环下行VSD修补术根治不能自愈的VSD。现就其术后的重症监护(ICU)总结如下。1     

超声心动图对室间隔缺损并主动脉瓣脱垂的诊断价值

目的：探讨超声心动图对室间隔缺损并主动脉瓣脱垂的诊断价值.方法：运用彩色多普勒超声心动图检测室间隔缺损并主动脉瓣脱垂病人11例,并与手术结果作对照.结果：11例室间隔缺损均为干下型,超声测得室间隔缺损大小与手术所见相符者5例,略小于手术所见者4例,略大于手术所见者2例.结论：超声心动图可根据室间隔缺损部位进行分型,根据室水平分流压差排除失去手术时机的以右向左分流为主的重度肺动脉高压,检测室间隔缺损大小及主动脉瓣脱垂部位,评价主动脉瓣病变程度,并与主动脉窦瘤鉴别,为外科手术治疗缺损的室间隔和脱垂的主动脉瓣及室间隔缺损封堵筛选病例提供重要信息.     

二尖瓣血流传播速度在室间隔缺损伴肺动脉高压患者左心室舒张功能评价中的应用

室间隔缺损(VSD)是最常见的左向右分流型先天性心脏病,不及时治疗往往伴有肺动脉高压(PH)[1].笔者应用M型号彩色多普勒测量舒张早期左心室内血流传播速度(即二尖瓣血流传播速度)(V<,p),用来评价VSD患者的左心室舒张功能,并与二尖瓣口血流E、A峰相比较,以探讨V<,p在评价室间隔缺损伴肺动脉高压(VSD PH)患者左心室舒张功能中的临床应用价值.     

主动脉弓离断的超声心动图诊断

目的 提高超声对主动脉弓离断（IAA）的诊断能力。方法 回顾性分析5例IAA胸前及胸骨上窝二维及多普勒超声表现。结果 A型中断4例，B型中断1例，均伴有室间隔缺损（VSD）和重度肺高压（PH）。结论 术前超声心动图能够对LAA作出明确诊断。二维超声心动图（2DE）检查发现升主动脉细小，粗大肺动脉及其肺高压应高度怀疑本病，在胸骨上窝主动脉弓长轴观作重点探测。     

舒张末期右心室前壁厚度与舒张末期左心室后壁厚度比值对室间隔缺损患者肺动脉压评估的价值

目的评价超声心动图舒张末期右心室前壁厚度与舒张末期左心室后壁厚度比值(RVAW/LVPW)评估肺动脉高压(PAH)的临床价值。方法采用受试者工作特征曲线(ROC)评价RVAW/LVPW比值对入选202例单纯先天性室间隔缺损(VSD)患者肺动脉高压的诊断价值。结果 RVAW/LVPW比值与右心导管所测肺动脉平均压(MPAP)有良好相关性(r=0.732,P0.001)。选RVAW/LVPW比值≥0.6为诊断肺动脉高压阳性(MPAP≥25 mm Hg)界点时,敏感性和特异性分别是80%和69%。选RVAW/LVPW比值≥0.9为诊断重度肺动脉高压(MPAP≥60 mm Hg)界点时,敏感性和特异性分别是93%和94%。结论超声心动图RVAW/LVPW比值可以用来评估室间隔缺损患者肺动脉高压的严重程度。     

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.