低剂量多巴酚丁胺超声心动图预测经皮腔内冠脉成形术后冬…

对经皮腔内冠脉成形术成功的２４例慢性冠心病患者术前低剂量多巴酚丁胺超声和术后平静超声进行分析。结果：术前基础状态室壁运动异常１５４节段：ＤＥ心肌收缩力储备阳性８４节段（５４．５％），ＰＴＣＡ术后功能改善９１节段（５９．１％），Ｐ〉０．０５，以ＤＥ心肌收缩力储备阳性预测ＰＴＣＡ术后节段室壁运动改善，敏感性８８．９％，阳性预测值９１．７％，阴性预测值８０％，结果表明：ＤＥ可识别冬眠心肌和准确地预测ＰＴ     

多巴酚丁胺负荷多普勒组织超声心动图预测PTCA术后冬眠心肌功能改善的价值

目的：探讨PWDTI结合LDDSK预测PTCA术后冬眠心肌功能改善的价值。方法：采用PWDTI结合LDDSK测量36例陈旧性心梗患者(静息下观察82个室壁运动异常节段)PTCA术前1天静息下和负荷下室壁运动异常节段峰值收缩速度Vs，并计算负荷下S％增长。PTCA术后4～6周随访分析。结果：PTCA术后，46节段室壁运动改善，36节段室壁运动未改善。以S％＞35％为裁断值，PWDTI结合LDDSK预测PTCA术后室壁功能改善的敏感性86．9％、特异性86．1％、准确性86．6％、阳性预测值88．9％、阴性预测值83．8％。结论：脉冲多普勒组织成像结合多巴酚丁胺负荷超声心动图可识别冬眠心肌并准确地预测PTCA术后局部左室功能改善。     

彩色室壁运动技术低剂量多巴酚丁胺负荷超声心动图预测PTCA术后局部收缩功能恢复价值的研究

目的：采用彩色室壁运动动力分析技术低剂量多巴酚丁胺负荷超声心动图（CK－LDDSE）评估经皮冠状动脉成形术（PTCA）术前确定罪犯血管变部位与预测术后局部收缩功能恢复的价值。方法20例经冠状动脉造影术（CAG）证实为冠心病的患者,术前全部行CK－LDDSE检查,初步确定罪犯病变血管或术后局部收缩功能可能改善的部位并与PTCA术后实际改善的心肌节段进行对比研究。结果CK－LDDSE预测病变血管或术后局部左室功能改善的敏感性为89．7％,特异性为77．8％,准确性为87．5％,阳性预测值为94．6％（70／74）,阴性预测值为63．6％（14／22）。结论CK－LDDSE可指导PTCA选择罪犯 血管并可较准确客观地预测术后左室局部缺血心肌功能的恢复部位。     

背向散射积分技术评价PTCA术前后左室肌回声与收缩功能

目的：用超声背向散射积分(IBS)评价经皮冠状动脉成形术(PTCA)前后左室肌回声及收缩功能变化。方法：对33例择期行PTCA 支架术的冠心病患者用HP 5500型超声诊断仪，于PTCA术前及术后3天、1～3个月对胸骨旁乳头肌短轴切面的前间壁、下壁、后壁、侧壁行二维超声心动图(2DE)检测各节段的室壁运动情况、声学密度一背向散射积分(AD-IBS)检测心肌背向散射积分平均值及其标化值，心肌整层及心内外膜下心肌层的周期变化幅度并计算跨壁梯度指数。结果：左室存活心肌背向散射积分参数值于术后3天就有了改善，与术前相比有统计学意义；术后1～3个月检测，左室存活心肌回声及收缩功能均有明显改善。结论：PTCA能够有效地挽救存活心肌，背向散射积分技术能够为早期检测存活心肌及早期评价或预测PTCA疗效提供敏感指标。     

经静脉实时心肌造影超声心动图评估心肌梗死后存活心肌

目的探讨经静脉实时心肌造影超声心动图（RT-MCE）评估心肌梗死后存活心肌。方法18例准备进行血运重建术心肌梗死患者,于术前1-5天行RT-MCE检查,并于术后3个月再次行常规超声心动图检查,室壁运动分析采用18节段分析法,分为运动正常、运动减弱、无运动和反常运动。心肌存活定义为术后超声检查室壁运动明显改善。将造影结果分为3种情况：充盈缺损,造影剂充盈延迟、回声稀疏不均匀或心内膜下充盈缺损,回声均匀性增强。其中后两种情况定义为存活心肌。结果在18例心肌梗死患者中共检出109个室壁运动异常节段,运动减弱为47个,无运动为56个,反常运动为6个。注射造影剂后回声均匀性增强的心肌节段中有2个节段术前室壁运动减弱,术后运动均改善;回声不均匀或心内膜下充盈缺损的心肌节段中术前室壁运动减弱有24个节段,术后运动改善14个,术前室壁无运动有24个节段,术后运动改善20个;充盈缺损的心肌节段中术前室壁运动减弱有21个节段,术后运动均未改善,术前室壁无运动32个,术后运动改善2个。RT-MCE检出存活心肌的敏感性、特异性分别为94.7%、78.9%。结论RT-MCE能比较准确的判断心肌梗死后心肌的存活性。     

应变率成像评价冠状动脉成形术后心肌功能的临床价值

目的 探讨应变率成像技术在评价冠心病患者PTCA术后心肌功能改善情况的临床价值。方法 分别测量28例陈旧性心肌梗死患者（静息下观察96个室壁运动异常节段）PTCA术前术后（≥6周）各节段收缩期峰值应变率（SSR）、等容收缩期峰值应变率（SRIVC）及等容收缩期（IVCT）。结果 按室壁运动情况分为正常组（240节段）,存活组（66节段）和坏死组（30节段）。PTCA术前术后,三组心肌的SSR、SRIVC及IVCT之间均有显著性差异,SSR与SRIVC依次降低（P〈0．01）,而IVTC则依次延长（P〈0．05）。PTCA术后,存活组心肌IVCT显著缩短（P〈0．05）,SSR与SRIVC显著增大（P〈0．01）,而正常组和坏死组心肌SSR、SRIVC和IVCT改变均无统计学意义（P〉0．05）。结论 应变率成像技术下测量的定量指标SSR及SRIVC,均能很好地鉴别出冠心病患者正常心肌、存活心肌及坏死心肌,从而评价PTCA术的疗效。     

负荷超声心动图对心肌梗死后存活心肌的识别与评价

目的采用小剂量多巴酚丁胺负荷超声心动图(LDDSE)对心肌梗死患者的存活心肌进行评估,评价心肌梗死后冠状动脉血运重建术(CRV)对有存活心肌和无存活心肌室壁运动、心室重构及心功能改善的恢复状况。方法 80例心肌梗死患者于CRV术前1周内行静息超声心动图和LDDSE,观察患者室壁运动异常节段的变化,评估存活心肌情况,并在CRV术后3~5个月内复查LDDSE。于术前术后测定左心室收缩功能,并进行对比分析。结果 LDDSE对室壁节段功能恢复情况的预测准确性为86.4%,术前LDDSE检测的心肌节段数与术后左室舒张末容积(LVEDV)呈显著正相关(r=0.47,P﹤0.05),CRV术后改善收缩功能的心肌节段数与术后LVEDV呈线性显著正相关(r=0.61,P﹤0.05)。结论 LDDSE除评价存活心肌的数量外,还可评估、预测CRV术后心室的收缩功能,能够指导临床选择治疗方案,预测疗效和评估预后。     

小剂量多巴酚丁胺超声心动图识别存活心肌的临床研究

目的：探索国人应用多巴酚丁胺(Dob)二维超声心动图（2DE）识别存活心肌的最适剂量。方法：以不同剂量（3、5、10μg／kg／min）Dob连续静注，用2DE观察心肌梗塞（MI）患者室壁运动异常（WMA）节段的收缩功能变化，以检出存活心肌，与冠状动脉血运重建术后同一节段收缩功能改善与否的实际情况对比，计算各剂量Dob-2DE识别存活心肌的敏感性、特异性和准确性。结果：Dob3、5、10μg／kg／min－2DE的敏感性分别是76．92％、82．05％、86．30％，特异性分别是8260％、78．26％、80．00％，准确性分别是78．22％、81．19％、84．95％。不良反应主要是心悸、频发室早和高血压，以Dob10μg／kg／min－2DE较多。结论：小剂量Dob-2DE是识别MI区域存活心肌有价值的方法，以5μg／kg／min为国人的合适剂量。     

慢性缺血性功能异常心肌血管重建术后跨壁收缩的背向散射研究

目的利用超声背向散射（IBS）技术研究慢性缺血性功能异常心肌在血管成功再灌注后跨壁收缩的变化特征。方法分别在血管重建术前、术后3d、术后6～8周，检测58例慢性冠心病伴有左室壁节段性功能障碍患者（共88个异常心肌节段，43个正常心肌节段）相关心肌节段心内膜下层心肌及心外膜下层心肌的IBS周期变化幅度（cycle variation of IBS，CVlB），并在常规超声下测量相应心肌节段的室壁增厚率（WT）。结果正常心肌节段心内膜下心肌CVIB明显高于心外膜下心肌CVIB（P〈0．001）。血管重建术前，慢性缺血性功能异常心肌节段心内膜下和心外膜下心肌的CVIB均减低，以前者为著，二者间无显著性差异（P=0．067）。成功再灌注后，心内膜下心肌CVIB恢复较心外膜下慢，出现“心内膜下顿抑”。术后WT的恢复与心内膜下心肌层CVIB的恢复相平行（r=0．816，P〈0．0001），而与心外膜下心肌CVIB的恢复无明显相关性（r=0．125，P=0．056）。结论CVIB可以无创检测心肌的跨壁收缩性。在慢性缺血心肌的再灌注恢复过程中，心内膜下心肌跨壁收缩性的变化与心脏收缩功能的恢复密切相关。     

低剂量多巴酚丁胺超声心动图检测心肌梗塞后可逆的功能障碍

应用低剂量多巴酚丁胺负荷超声心动图（LDDSE）试验对21例心肌梗塞患者梗塞区心肌功能障碍的可逆性进行研究。可逆的可能障碍是指室壁运动得到改善。结果表明静息超声心动图（RE）至LDDSE时室壁运动得分指数（WMSI）在急性心肌梗塞（AMI）从1．83±0．32下降到1．45±0．19（P＜0．01）；而陈旧性心肌梗塞（OMI）从1．96±0．35下降到1．70±0．20（P＜0．05）。RE时336个节段中有82个节段室壁运动异常，LDDSE时46（56．1％）个节段室壁运动改善，7（8．5％）个节段室壁运动明显改善。提示心肌梗塞后梗塞区有存活心肌细胞成分。LDDSE试验能够简便准确地检测心肌梗塞后梗塞区心肌功能障碍的可逆性。     

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.     

手转胎头术失败的原因与分娩结局临床分析

目的 探讨手转胎头术失败的原因与分娩结局.方法 选择2008年1月至2010年12月于我院住院分娩的持续性枕横位、枕后位产妇198例,根据行手转胎头术后结果分为成功组126例、失败组72例.比较两组分娩结局,对比分析失败原因.结果 失败组胎儿体质量≥3500 g的发生率[76.4％(55/72)]明显高于成功组[31.7％(40/126)],差异有统计学意义(x2=30.177,P=0.001)、失败组宫缩乏力发生率[58.3％(42/72)]高于成功组[38.1％ (48/126)],差异有统计学意义(x2=7.569,P=0.006)、失败组骨盆临界或轻度狭窄发生率[38.9％ (28/72)]高于成功组[23.8％(30/126)],差异有统计学意义(x2 =5.030,P=0.002)、失败组手转胎头时机不当(宫口开大＜6 cm、胎头位于坐骨棘上及宫口开大8～10 cm、胎头位于坐骨棘下≥2 cm)发生率[61.1％(44/72)]高于成功组[38.9％(49/126)],差异有统计学意义(x2=9.084,P=0.003).失败组母儿并发症(产后出血、产褥病率、胎儿窘迫、新生儿窒息)发生率高于成功组(x2 =9.586,P=0.002、x2=9.334,P=0.002、x2=5.910,P=0.015、x2=5.240,P=0.022)、失败组剖宫产发生率[72.2％(52/72)]明显高于成功组[34.1 ％(43/126),x2=26.641,P=0.001)].结论 手转胎头术能使难产变顺产,降低剖宫产率,减少母儿并发症,但须积极预防、处理导致手转胎头术失败的原因,对矫正失败后继续矫正及试产应慎重.