心肺复苏期间心脏氧利用率的临床研究

:目的 :通过心肺复苏期间对心脏氧利用率 (O2 UCc)的测量来评估心脏复跳的可能性。方法 :19例患者分别为 , 冠心病组 10例 ,男 8例 ,女 2例 ,年龄 36～ 6 2 (4 9.5± 10 .3)岁 ,血流动力学稳定 ,插入右心导管取冠状窦静脉血标本。 心肺复苏组 9例 ,男 8例 ,女 1例 ,年龄 2 0～ 70 (39.0± 15 .5 )岁 ,心脏停跳后 ,先按照标准心肺复苏步骤行胸外心脏按压抢救 2 0分钟 (胸外按压频率 12 0～ 140次 / min,血管活性药用药间隔为 2分钟 ,应用 4%碳酸氢钠液 2 5 0～ 5 0 0 m l)。如心脏未复跳 ,再继续开胸心脏按压复苏 2 0分钟 (按压频率为 80～10 0次 / m in)。此间用呼吸机控制呼吸 ,维持动脉血氧饱和度 (Sa O2 ) 0 .90 0以上。抢救停止后即刻抽取冠状静脉血和动脉血。所有血标本均即刻进行血气分析 ,并计算心脏氧利用率〔O2 UCc=(Sa O2 Sv O2 ) / Sa O2 〕。根据所得结果分析其对心肺复苏预后的预测价值。结果 : 组患者冠状静脉窦血的血气分析结果 :Pa O2 (4 .2 0±0 .41) k Pa(1k Pa=7.5 mm Hg) ,Sa O2 0 .5 32± 0 .0 90 ,O2 U Cc为 0 .46± 0 .0 9; 组患者 O2 U Cc=0 .85± 0 .11,其中 4例心脏复跳者 O2 UCc=0 .78± 0 .10 ,5例无效者 O2 UCc=0 .91± 0 .0 7,二者比较差异有显著性 (P<0 .0 0 1)。结论 :     

A型和B型行为模式原发性高血压患者的动态血压水平以及昼夜节律波动的变化

目的:比较具有A型和B型行为特征的原发性高血压患者24h动态血压、心率、血压昼夜下降百分比及节律形态分布的差异。方法:①选择2001-01/2005-01在汕头市中心医院及湘潭市第一人民医院心内科门诊就诊或住院的原发性高血压患者255例,男139例,女116例;年龄31～74岁,平均(53±14)岁;病程1～13年,平均(4.8±1.2)年。均知情同意,并自愿接受问卷评估。②原发性高血压患者255例行为类型评估采用A型行为问卷(分为时间紧迫感,争强好胜,怀有戒心和敌意和真实性核对3个分量表,共有60个小题。时间紧迫感和争强好胜,怀有戒心和敌意两个分量表的评分总和为A型行为总分,总分≥31分为A型行为,≤23分为B型行为,24～30分为中间型)。测评时间在入院后1周内。③动态血压监测使用无创便携式动态血压监测仪,日间(6:00～22:00)每15min测试1次,夜间(22:00～次日6:00)每30min测试1次,共记录80次。所采集数据经自动分析后,分别自动打印出24h、日间、上下午和夜间5个时段收缩压、舒张压和心率的平均值。夜间血压下降百分率=白天血压均值-夜间血压均值/白天血压均值。夜间血压平均值比日间下降10%以上称之为杓型改变,夜间血压平均值比日间下降<10%称之为非杓型改变。动态血压监测也在体检期间进行。④组间计量和计数资料差异性测定分别采用t和χ2检验。结果:纳入原发性高血压患者255例完成问卷评估,A型行为问卷总分≥31分73例(A型行为组),总分≤23分106例(B型行为组)进入结果分析。①24h和日间及夜间血压、心率比较:A型行为组24h平均收缩压、24h平均舒张压、白天平均收缩压、白天平均舒张压均明显高于B型行为组(149±22),(92±32),(153±25),(94±25)mmHg,1mmHg=0.133kPa;(140±29),(89±19),(140±30),(90±21)mmHg,t=2.457～2.958,P<0.05～0.01,但两组24h平均心率和白天平均心率差异不明显(P>0.05)。两组夜间平均收缩压、夜间平均舒张压和夜间平均心率差异不明显(P>0.05)。②血压昼夜下降百分比及节律形态分布:A型行为组平均收缩压夜间比白天下降百分比、平均舒张压夜间比白天下降百分比均明显低于B型行为组(7.24±2.55)%,(6.69±2.23)%;(9.49±1.98)%,(8.35±1.92)%,t=2.637,2.423,P<0.05);而A型行为组平均收缩压非杓型改变和平均舒张压非杓型改变患者构成比明显高于B型行为组(74.0%,70.0%;39.6%,33.0%,χ2=5.027,4.839,P<0.05)。结论:A型行为模式对原发性高血压患者24h动态血压、心率、血压昼夜下降百分比及节律形态分布的影响程度大于B型行为模型。     

MRI形态学指标在肺动脉高压肺心病诊断中的意义

目的 :评价MRI形态学指标在肺动脉高压肺心病诊断中的应用价值。方法 :应用MRI检测肺动脉高压肺心病患者主肺动脉、右下肺动脉及右室流出道宽径、室间隔厚度、右室前后径、右房横径、右房长径等指标 ,与相应CR胸片及彩色多普勒超声检测指标比较。结果 :MRI与CR胸片测定右下肺动脉干宽径分别为 ( 16 5± 2 7)mm、( 17 7± 3 5 )mm ,差异无显著性 (P >0 0 5 ) ;MRI与彩超测定主肺动脉宽径、室间隔厚度分别为 ( 3 1 4± 5 3 )、( 2 5 1± 3 8)mm ;( 16 5± 3 1)mm、( 11 6± 2 0 )mm ,差异有显著性 (P <0 0 1) ;MRI与彩超测定右室流出道、右室前后径、右房横径、右房长径分别为 ( 3 2 2± 7 3 )mm、( 3 3 9± 7 7)mm ;( 2 4 9± 6 9)mm、( 2 3 1± 6 2 )mm ;( 4 0 0± 7 1)mm、( 3 9 3± 9 8)mm ;( 4 4 8± 7 1)mm、( 4 3 8± 10 1)mm ,差异无显著性 (P >0 0 5 ) ;对于临床确诊的病人 ,MRI右下肺动脉、MRI主肺动脉、彩超主肺动脉与CR胸片右下肺动脉检测对肺动脉高压的诊断与临床符合率分别为91 7%、10 0 0 %、5 0 0 %、91 7% ,MRI主肺动脉与彩超主肺动脉比较差异有显著性 (P <0 0 5 ) ;MRI、彩超与CR胸片对肺心病诊断与临床符合率分别为 10 0 0 %、10 0 0 %、41 7% ,MRI、彩超与CR胸     

慢性阻塞性肺疾病患者血氧变化特点及护理

目的　探讨慢性阻塞性肺疾病 (COPD)患者血氧变化特点及护理。方法　观察 5 0例COPD患者 2 4h动态SaO2 及心电图变化情况。结果　 5 0例患者夜间SaO2 均下降 ,其中 35例SaO2 下降幅度大于 10 % ,凌晨 1:0 0 3:0 0SaO2 最低 ;夜间房性早搏较白天明显增高 ,经t检验 ,t=10 .7,P <0 .0 1,具有显著性差异。结论　根据COPD患者夜间SaO2 明显下降的特点 ,加强夜间呼吸道管理 ,防止SaO2 下降 ,是提高COPD患者生存质量 ,降低死亡率的关键。     

阻塞性睡眠呼吸暂停患者夜间多尿与心钠素的关系

目的研究阻塞性睡眠呼吸暂停综合征(OSAS)患者夜间多尿症状与昼夜心钠素(ANP)水平的关系.方法经多导睡眠图(PSG)确认的12例OSAS患者及非OSAS对照6例,记录夜尿量,测定夜尿渗透压和尿钠排泄量.在24h中每3h1次共计8次测定血浆ANP水平.其中8例OSAS患者经持续气道正压(CPAP)治疗后再次进行上述指标的检测.结果(1)OSAS患者组的夜间(23时,2时,5时)ANP明显高于对照组(均P＜0.05),CPAP治疗后ANP降至对照组水平.其它时间各组ANP无明显差异(均P＞0.05);(2)12例OSAS组患者夜间ANP平均值为(142±24.5)ng/L,夜尿量为(0.075±0.019)L/h,两者有显著的正相关r＝0.64,P＜0.05;8例OSAS患者CPAP治疗后夜间ANP下降平均值(38.6±11.7)ng/L,夜尿量下降值(0.033±0.015)L/h,两者之间有非常显著的正相关,r＝0.82,P＜0.01;(3)OSAS患者夜间平均ANP与夜尿渗透压(366±145)mmol/L之间有显著的负相关,r＝-0.69,P＜0.05;8例OSAS患者CPAP治疗后夜间ANP平均下降值与夜尿渗透压升高值(220±90)mmol/L有非常显著的正相关,r＝0.84,P＜0.01.(4)OSAS患者夜间平均ANP与尿钠排泄量(1.6±0.35)mmol/h有非常显著的正相关,r＝0.59,P＜0.05;CPAP治疗后夜间ANP平均下降值与夜尿钠排泄量降低值(0.51±0.11)mmol/h有非常显著的正相关,r＝0.81,P＜0.01.结论OSAS患者夜间ANP明显升高;OSAS患者夜尿量增多、夜尿渗透压降低以及夜尿钠排泄量增多与ANP升高有关;CPAP治疗后夜尿量减少、夜尿渗透压增高和夜尿钠排泄量降低与治疗后ANP下降有关.     

山莨菪碱对糖尿病肾病患者尿蛋白的影响

目的 :观察短期应用静脉滴注山莨菪碱 ( 65 4 Ⅱ )对不同时期糖尿病肾病患者肾功能及尿蛋白的影响。方法 :糖尿病肾病患者分为治疗组 46例和对照组 3 9例。两组患者均根据尿蛋白和肾功能的不同再分别分为早期肾病组、临床期肾功能正常组和临床期肾功能不全组 3个亚组。治疗组静脉滴注 65 4 Ⅱ 2 0mg ,每天 1次 ,连续 2 8d。对照组不给上述治疗。控制血压、血脂、血糖等其他治疗方法各组相同。结果 :和对照组比较 ,治疗组患者尿总蛋白和尿白蛋白明显降低 ,其中糖尿病肾病早期组尿总蛋白由治疗前的 ( 0 3 5± 0 0 5 )g/2 4h下降到 ( 0 2 0± 0 0 6)g/2 4h(P <0 0 1) ,尿白蛋白由 ( 192± 75 )mg/2 4h下降到 ( 98± 5 4)mg/2 4h(P <0 0 1) ;在临床期肾功能正常组尿总蛋白由 ( 3 73± 1 98)g/2 4h下降到 ( 2 3 9± 1 48)g/2 4h(P <0 0 1) ,尿白蛋白由 ( 2 85 3± 1791)mg/2 4h下降到( 163 3± 10 90 )mg/2 4h(P <0 0 1) ;在临床期肾功能不全组尿总蛋白由治疗前的 ( 1 90± 0 92 )g/2 4h下降到 ( 1 83± 1 0 9)g/2 4h(P >0 0 5 ) ;尿白蛋白由 ( 14 0 8± 83 6)mg/2 4h下降到 ( 1115± 5 5 6)mg/2 4h(P <0 0 5 )。结论 :短期静脉应用山莨菪碱治疗 ,对不同时期的糖尿病肾病患者均有减少尿蛋白的作     

不同时间服用依那普利对血压晨峰现象的影响

目的通过改变依那普利的服用时间来观察其对轻度高血压患者血压晨峰的影响。方法 42例轻度高血压患者给予依那普利10 mg上午(8～12点)服用,4周后监测24 h动态血压以观察白天、夜间和晨起血压情况;如果存在血压晨峰的患者则将依那普利改为晚上睡前服用,剂量不变,1周后再行24 h动态血压监测以观察白天、夜间和晨起血压情况。结果 4周后患者白天血压平均(129±10.5)/(80±6.7)mmHg,夜间血压平均(112±6.2)/(70±4.7)mmHg,晨起血压平均(142±9.5)/(89±5.5)mmHg,85.7%(36例)患者存在血压晨峰现象。改为睡前服用一周后白天血压平均(125±9.5)/(82±5.8)mmHg,与白天服用依那普利比较两者差异无统计学意义(P>0.05);夜间血压平均(110±7.3)/(68±6.6)mmHg,与白天服用依那普利比较两者差异无统计学意义(P>0.05);晨起血压平均(123±7.1)/(79±5.6)mmHg,与白天服用依那普利比较两者差异有统计学意义(P<0.05)。结论轻度高血压患者普遍存在血压晨峰现象,睡前服用依那普利能有效控制轻度高血压患者血压晨峰的发生。     

急性缺血性脑卒中动态血压变化临床研究

目的 :探讨急性缺血性脑卒中患者的血压昼夜变化规律。方法 :采用 2 4小时无创伤性全自动动态血压记录仪 ,对 4 6例急性缺血性脑卒中合并高血压患者及 3 0例正常人进行动态血压测量。结果 :急性缺血性脑卒中患者 2 4小时平均收缩压和舒张压、白天平均收缩压和舒张压、夜间平均收缩压和舒张压都比对照组明显增高 ( P<0 .0 1) ,而且血压夜间下降率收缩压为 6% ,舒张压为 7% ,均小于 10 % ,夜间 /白天收缩压为 0 .95 ,夜间 /白天舒张压为 0 .94 ,比正常值增高。结论 :高血压合并脑梗死患者血压昼夜波动减少 ,为“非杓型”改变。     

高原地区慢性肺心病夜间睡眠时血氧饱和度降低的预测和机制

目的:研究高原地区慢性肺心病患者夜间睡眠时血氧饱和度降低的发生、预测及机制。方法:对32 例高原肺心病患者白天肺功能、动脉血气及夜间血氧水平与16名正常对照进行比较和分析。结果:高原肺心病患者夜间睡眠时血氧水平较正常人明显下降(p<0.01),尤以快动眼睡眠(REM)期显著。夜间睡眠平均血氧饱和度(MsaO2)、夜间睡眠平均最低血氧饱和度(MmSaO2)下降程度均明显高于正常组(p<0.01)。高原肺心病患者夜间睡眠时动脉血氧饱和度(SaO2 )<85%的时间占睡眠时间百分比(T85)、SaO2<80%的时间占睡眠时间百分比(T80)显著高于正常组(p<0.01)。相关分析表明,白天SaO2、1用力呼气容积占预计值百分比(FEV1%)、最大跨膈压(Pdimax)与夜间睡眠MsaO2 呈显著正相关(r值依次为0.926,0.8400.837,p<0.01)。建立了夜间睡眠SaO2 的预测公式:MsaO2 (%)=1.258×SaO2 (%)+0.044×FEV1%(%)+1.203×Pdimax(cmH2O) 37.975。结论:高原地区慢性肺心病患者夜间睡眠时低氧血症加重,其MsaO2水平可通过白天SaO2、FEV1%Pdimax进行预测,夜间氧疗是治疗高原肺心病患者的必须手段。     

A型和B型行为模式原发性高血压患者的动态血压水平以及昼夜节律波动的变化

目的：比较具有A型和B型行为特征的原发性高血压患者24h动态血压、心率、血压昼夜下降百分比及节律形态分布的差异。方法：①选择2001—01／2005-01在汕头市中心医院及湘潭市第一人民医院心内科门诊就诊或住院的原发性高血压患者255例，男139例，女116例；年龄31～74岁，平均（53&;#177;14）岁；病程1～13年，平均（4．8&;#177;1.2）年。均知情同意，并自愿接受问卷评估。②原发性高血压患者255例行为类型评估采用A型行为问卷（分为时间紧迫感，争强好胜，怀有戒心和敌意和真实性核对3个分量表，共有60个小题。时间紧迫感和争强好胜，怀有戒心和敌意两个分量表的评分总和为A型行为总分，总分≥31分为A型行为，≤23分为B型行为，24～30分为中间型）。测评时间在入院后1周内。③动态血压监测使用无创便携式动态血压监测仪，日间（6：00-22：00）每15min测试1次，夜间（22：00～次日6：00）每30min测试1次，共记录80次。所采集数据经自动分析后，分别自动打印出24h、日间、上下午和夜间5个时段收缩压、舒张压和心率的平均值。夜间血压下降百分率=白天血压均值-夜间血压均值／白天血压均值。夜间血压平均值比日间下降10％以上称之为杓型改变，夜间血压平均值比日间下降〈10％称之为非杓型改变。动态血压监测也在体检期间进行。④组间计量和计数资料差异性测定分别采用t和χ^2检验。结果：纳入原发性高血压患者255例完成问卷评估，A型行为问卷总分≥31分73例（A型行为组），总分≤23分106例（B型行为组）进入结果分析。①24h和日间及夜间血压、心率比较：A型行为组24h平均收缩压、24h平均舒张压、白天平均收缩压、白天平均舒张压均明显高于B型行为组[（149&;#177;22），（92&;#177;32），（153&;#177;25），（94&;#177;25）mmHg，1mmHg=0．133kPa；（140&;#177;29），（89&;#177;19），（140&;#177;30）．（90&;#177;21）mmHg，t=2．457～2．958。P〈0．05～0．01]，但两组24h平均心率和白天平均心率差异不明显（P〉0．05）。两组夜间平均收缩压、夜间平均舒张压和夜问平均心率差异不明显（P〉0．05）。②血压昼夜下降百分比及节律形态分布：A型行为组平均收缩压夜间比白天下降百分比、平均舒张压夜间比白天下降百分比均明显低于B型行为组[（7．24&;#177;2．55）％，（6．69&;#177;2．23）％；（9．49&;#177;1．981％，（8．35&;#177;1．92）％，t=2．637，2．423，P〈0．05）；而A型行为组平均收缩压非杓型改变和平均舒张压非杓型改变患者构成比明显高于B型行为组（74．0％，70．0％；39．6％，33．0％，χ^2=5．027，4．839，P〈0．05）。结论：A型行为模式对原发性高血压患者24h动态血压、心率、血压昼夜下降百分比及节律形态分布的影响程度大于B型行为模型。     

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.     

Guns and Knives in New Mexico: Patterns of Penetrating Trauma, 1978–1993

Objective: To identify patterns of nonfatal and fatal penetrating trauma among children and adults in New Mexico using ED and medical examiner data.
Methods: The authors retrospectively sampled in 5-year intervals all victims of penetrating trauma who presented to either the state Level-1 trauma center or the state medical examiner from a 16-year period (1978–1993). Rates of nonfatal and fatal firearm and stabbing injury were compared for children and adults.
Results: Rates of nonfatal injury were similar (firearm, 34.3 per 100,000 person-years; stabbing, 35.1). However, rates of fatal injury were significantly different (firearm, 21.9; stabbing, 2.7; relative risk: 8.2; 95% confidence interval: 5.4, 12.5). From 1978 to 1993, nonfatal injury rates increased for children (p = 0.0043) and adults (p < 0.0001), while fatal penetrating injury remained constant. The increase in nonfatal injury in children resulted from increased firearm injury rates. In adults, both stabbing and firearm nonfatal injury rates increased.
Conclusions: Nonfatal injury data suggest that nonfatal violence has increased; fatal injury data suggest that violent death rates have remained constant. Injury patterns vary by age, mechanism of trauma, and data source. These results suggest that ED and medical examiner data differ and that both are needed to guide injury prevention programs.