重度阻塞性睡眠呼吸暂停低通气综合征患者心脏结构及左心室功能变化研究

目的 探讨重度阻塞性睡眠呼吸暂停低通气综合征(OSAHS)患者心脏结构及左心室功能变化,为临床诊断及治疗提供参考依据。方法 选择2014年1月至2015年1月收治的53例重度OSAHS患者作为病例组,并选择同时期门诊健康体检者50例作为对照组,分别接受常规超声心动图、组织多普勒(TDI)检查。比较两组对象心脏结构、左心室收缩功能及左心室舒张功能。结果 病例组各心脏结构指标均显著高于对照组(P0.05);病例组E峰、E/A峰、室间隔舒张早期峰值运动速度(Em)、舒张早期峰值运动速度/室间隔舒张晚期峰值运动速度(Em/Am)、二尖瓣环Em、二尖瓣环Em/Am、左室后壁Em、左室后壁Em/Am均低于对照组,室间隔Am、左室后壁Am均高于对照组(P0.05);病例组左室射血分数(EF)、左室短轴缩短率(FS)、室间隔收缩期峰值运动速度(Sm)、左室后壁Sm、二尖瓣环Sm均低于对照组,Tei指数高于对照组(P0.05)。结论 重度OSAHS患者的心脏结构出现明显改变,且左心室收缩功能及舒张功能明显减退,值得临床重视。     

二尖瓣环位移对正常胎儿左心功能的定量研究

目的 探讨M型超声心动图测量中晚孕期正常胎儿二尖瓣环位移(MAD)与常规方法评价胎儿左心功能参数之间的关系.方法 用M型超声心动图测量155例孕龄在19～38周的正常胎儿的MAD,脉冲多普勒(PW)测量房室瓣口血流频谱的舒张早期峰值流速(E),组织多普勒(TDI)测量房室瓣环处心肌运动频谱的舒张早期峰值流速(Em)及两者的比值(E/Em),定量分析MAD与孕周及常规胎儿左心功能参数之间的相关性.结果 正常胎儿MAD值为(7.05±1.17)mm.MAD与孕周呈显著正相关(r=0.82,P＜0.01),与其他评价左心功能的指数E、A、Em、Am、Sm呈正相关(r值分别为0.25、0.24、0.32、0.29、0.40,P值均＜0.01),但与E/A、E/Em、左室射血分数(LVEF)、左室短轴缩短率(LVFS)无显著相关性(P值均＞0.05).MAD在任何孕周均小于三尖瓣环位移.结论 MAD是评价胎儿长轴方向左室功能有价值的参考标准,正常中晚孕胎儿MAD值随孕周增加而增长,其评价胎儿左室功能与PW二尖瓣口E、A峰值流速及TDI二尖瓣瓣环Em、Am、Sm等传统左室功能评价参数有良a的相关性,与传统方法相比具有更好的简便性及可重复性.     

组织多普勒成像评价急性心肌梗死患者自体骨髓干细胞移植治疗后左室舒张功能

目的应用组织多普勒成像(TDI)技术评价心肌干细胞移植治疗急性心肌梗死对左室舒张功能的影响。方法自体骨髓干细胞移植治疗急性心肌梗死患者共26例,随访3个月,治疗前、后用TDI技术分别测量左室二尖瓣环水平的收缩期峰值速度(Sm),舒张早期峰值速度(Em),舒张晚期峰值速度(Am)及Em/Am,并与血流多普勒指标E峰速度(E),A峰速度(A)、E/A及E峰减速时间(EDT)进行比较,评价自体骨髓干细胞移植治疗急性心肌梗死对左室舒张功能的影响。结果治疗后EDT较治疗前降低(P<0.05),治疗后Em及Em/Am较治疗前升高(P<0.05),治疗后E、A、E/A、Sm、Am较治疗前比较差异无统计学意义。结论自体骨髓干细胞移植治疗急性心肌梗死后,左室舒张功能明显改善,TDI技术在评价左室舒张功能方面较二尖瓣血流频谱更准确、敏感。     

组织多普勒超声评价母体糖尿病胎儿的心脏纵向功能

目的 利用组织多普勒成像(tissue Doppler imaging,TDI)测量母体糖尿病时胎儿心脏的纵向功能.方法 应用TDI测量14例母体糖尿病胎儿(fetuses of diabetic mothers,FDM)和30例正常妊娠胎儿左室游离壁、室间隔、右室游离壁与房室环交界处收缩期Sm波、舒张早期Em波和舒张晚期Am波,计算Em/Am比值;M-超测量房室瓣环位移(D).分别测量右室游离壁、左室游离壁及室间隔厚度.记录左心室射血分数(EF).结果 (1)FDM组左室游离壁Sm增高,左室游离壁、右室游离壁及室间隔Am增高,左室游离壁及室间隔Em/Am比值降低;(2)FDM组左室及室间隔心肌运动幅度增加;(3)FDM组室间隔增厚;(4)FDM组Sm、Em、Am、Em/Am、D及心肌厚度与血糖水平无相关关系.结论 母体糖尿病时,即使血糖控制较理想,胎儿心脏纵轴功能也会发生改变.TDI是评价胎儿心脏纵轴功能的敏感指标.     

组织多普勒成像评价儿童单心室心功能的研究

目的探讨组织多普勒成像技术在单心室心功能检测中的价值。方法应用组织多普勒检测47例功能性单心室患儿和28例正常儿童的房室瓣环运动速度等指标,并和有创、无创心功能指标对比。结果单心室患者邻近残余心腔侧的房室瓣环Sm、Em、Em/Am比值显著低于非残余心腔侧的相应指标。与正常儿童相比,单心室患者房室瓣环两侧的Sm、Em、Em/Am比值显著降低;QSm间期显著延长。正常儿童的二尖瓣环Em/Am比值与二尖瓣血流E/A比值呈显著正相关;单心室组房室瓣环Em/Am比值与房室瓣血流E/A比值有较好的一致性。单心室患者的QSm间期与心导管测定Max(dp/dt)之间呈显著负相关(r=-0.657),Sm与Max(dp/dt)之间无显著相关性。结论组织多普勒在检测单心室异常室壁运动、评价舒张功能方面具有一定的价值,QSm间期是评价单心室收缩功能的有用指标。     

组织多普勒显像评价二尖瓣置换术后左心室功能

目的 探讨应用组织多普勒显像(TDI)评价二尖瓣置换(MVR)术后左室功能的临床价值.方法 45例接受MVR术后3个月以上患者为病例组,根据心律分为心房颤动组和窦性心律组,并选取30例正常人为对照组.应用常规超声心动图测量左房室腔大小、机械瓣口流速、射血分数等指标;应用TDI测量心尖四腔观二尖瓣环间隔处和侧壁处运动收缩期峰值速度(Sm)、舒张期峰值速度(Em)、等容舒张时间(IVRT);计算E/Em.结果 ①与对照组相比,MVR组二尖瓣环Sm、Em均明显减低,IVRT延长(P＜0.001),但窦性心律组与心房颤动组之间差异无统计学意义(P＞0.05);②MVR组E/Em较对照组明显增高,二者差异有统计学意义(P＜0.001),且E/Em与IVRT呈正相关;以E/Em＞15.0为最佳截断值,评价左室舒张功能变化的敏感性为91.11%,特异性为90.32%,ROC曲线下面积为0.9548±0.0402.结论 TDI能够准确评价MVR后左室功能,E/Em作为一种评价心肌舒张和左室充盈压的量化指标可以评价MVR术后患者左室舒张功能.     

超声心动图评价高血压患者右室重构与右室功能的研究

目的 探讨超声心动图评价高血压右室重构及右室功能的临床价值.方法 高血压患者62例,按左室重量指数分为无左室肥厚组(A组,33例)和左室肥厚组(B组,29例).对照组为28例健康者.二维超声测量右室前壁厚度(RVAWTd)、右室舒张期内径(RVEDd);三尖瓣反流法估测肺动脉收缩压(PASP);脉冲组织多普勒成像技术(PW-TDI)测量三尖瓣环心肌运动收缩期峰值速度(Sm)、舒张早期峰值速度(Em)、舒张晚期峰值速度(Am)和S峰速度时间积分(Sm-VTI),分别采用PW-TDI与脉冲多普勒测量右室Tei指数.结果 与对照组比较,A、B组Em和Em/Am下降,Am和Tei指数升高(均P＜0.01);与A组比较, B组Em、Em/Am、Sm下降,Am、Tei指数、RVAWTd及PASP升高(P＜0.05,P＜0.0 1).两种方法所测Tei指数存在相关性:对照组(r＝0.78,P＜0.01),高血压组(r＝0.72,P＜0.01).结论 高血压患者右室功能减低,在左室肥厚同时可发生右室重构并进一步影响右室功能,TDI测定右室Tei指数能简便有效评价高血压右室功能.     

心脏再同步化治疗慢性充血性心力衰竭患者舒张功能的评价

目的 应用超声心动图评价心脏同步化治疗对重度心衰患者左室舒张功能的长期影响.方法 18例左室非同步的慢性充血性心衰患者行心脏同步化治疗.并于治疗前,治疗后1周、6个月、12个月行超声心动图检查,测量左室射血分数(LVEF),二尖瓣血流E、A峰值,应用组织多普勒技术测量二尖瓣瓣环收缩期峰值速度(Sm),舒张早期峰值速度(Em),舒张晚期峰值速度(Am).结果 起搏后第1周LVEF明显高于起搏前(P<0.001).二尖瓣环间隔部Am术后6个月[(11.3±2.9)cm/s]、1年[(12.5±3.6)cm/s]明显高于起搏前[(9.2±1.7) cm/s](P<0.05).二尖瓣环侧壁Am术后6个月[(12.1±3.2)cm/s]和术后1年[(13.5±3.2)cm/s]高于起搏前[(11.8±2.9)cm/s](P<0.05).二尖瓣环间隔部Em起搏前后未见显著性变化.结论 超声心动图是评价心脏同步化治疗左室运动不同步的心衰患者舒张功能明显改善的一种可靠方法.     

前负荷对组织多普勒成像技术评价左心室舒张功能的影响

目的探讨应用组织多普勒成像(TDI)技术评价心室舒张功能时是否受前负荷改变的影响。方法对30例血液透析的慢性肾功能不全患者,根据其透析前后体质量变化是否>2kg分为A组(<2kg)和B组(≥2kg),分别在透析前后用脉冲多普勒测量二尖瓣口及肺静脉血流频谱(E峰、A峰、S峰、D峰),并用TDI测量二尖瓣瓣环及各室壁中段的收缩期峰值速度(Sa和Sm)、舒张早期峰值速度(Ea和Em)及舒张晚期峰值速度(Aa和Am)。结果与透析前相比较,A组透析后Em减低(P<0.01),Em/Am降低(P<0.05),其余参数差异均无统计学意义;B组E峰、E/A、S峰及D峰降低(P<0.05),S/D值增加(P<0.05),Ea、Em、Ea/Aa及Em/Am均减低(P<0.01)。结论TDI在评价心室舒张功能时,与彩色多普勒血流显像一样受前负荷的影响,且与前负荷变化程度有关。     

多普勒组织成像技术评价肥厚型心肌病患者心室运动的协调性

目的应用多普勒组织成像技术（doppler tissue imaging,DTI）评价肥厚型心肌病（hypertrophic cardiomy-opathy,HCM）患者心室运动的协调性。方法对38例HCM患者和38例对照组进行常规超声心动图检查,分别测量左室内径、左室壁厚度、左室射血分数（LVEF）、二尖瓣舒张早期血流速度峰值（E）、二尖瓣舒张晚期血流速度峰值（A）、二尖瓣峰值速度比值（E/A）、等容舒张期（IVRT）、心室间机械运动延迟（IVMD）,转换DTI速度模式,分别测量二尖瓣环室间隔、侧壁、下壁及三尖瓣环右室侧壁的心肌收缩期峰值速度（Sm）、舒张早期峰值速度（Em）、舒张晚期峰值速度（Am）、Em/Am、Q-Sm（Q波起始到Sm起始的时间间期）,计算心室内收缩延迟时间（intra-V-Del）和心室间收缩延迟时间（inter-V-Del）。结果HCM组的IVSTI、VST/PWTI、VRTI、VMD、LVDd、A、E、E/A与对照组比较差异均有统计学意义（P〈0.05,P〈0.01）。HCM组室间隔、侧壁、下壁、右室侧壁节段Sm、Q-smi、ntra-V-Del、inter-V-Del、Em、Em/Am与对照组比较差异均有统计学意义（P〈0.05,P〈0.01）。结论HCM患者存在心室收缩功能下降和心室收缩运动协调障碍,DTI对HCM患者治疗效果和预测预后具有重要的临床指导意义。     

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.