高压氧对心肌梗死大鼠模型梗死面积及左室功能的影响

Objective To investigate effect of hyperbaric oxygen treatment on infarct size of acute myocardial infarction and on the function of left ventricle in rats. Methods An acute myocardial infarction model was developed by using 50 male SD rats, which were randomly divided into 3 groups: the sham group(12 rats), the acute myocardial infarction group (AMI) (16 rats) and the HBO group(17 rats). Hyperbaric oxygen treatment was applied to the HBO group for a succession of 7 days. Infarct sizes, differences between systolic and diastolic pressures of the three groups and changes in cardiac hemodynamics (± dp/dtmax) were measured 7 days after treatment. Results When compared with that of the AMI group, infarct size and left ventricle function of the HBO group improved significantly (P < 0. 05). Conclusions Early administration of HBO could significantly reduce infarct size and improve left ventricle function of rats with AMI.     

高压氧对心肌梗死大鼠模型梗死面积及左室功能的影响

Objective To investigate effect of hyperbaric oxygen treatment on infarct size of acute myocardial infarction and on the function of left ventricle in rats. Methods An acute myocardial infarction model was developed by using 50 male SD rats, which were randomly divided into 3 groups: the sham group(12 rats), the acute myocardial infarction group (AMI) (16 rats) and the HBO group(17 rats). Hyperbaric oxygen treatment was applied to the HBO group for a succession of 7 days. Infarct sizes, differences between systolic and diastolic pressures of the three groups and changes in cardiac hemodynamics (± dp/dtmax) were measured 7 days after treatment. Results When compared with that of the AMI group, infarct size and left ventricle function of the HBO group improved significantly (P < 0. 05). Conclusions Early administration of HBO could significantly reduce infarct size and improve left ventricle function of rats with AMI.     

白细胞去除对内毒素血症犬凝血功能及肺损伤的影响

目的 观察白细胞去除后凝血纤溶系统的变化,探讨这一变化对肺损伤的影响及其可能机制.方法 用内毒素(LPS)2 mg/kg建立内毒素血症犬模型.30只雄性杂种犬采用随机数字表法分为LPS组(L组)、伪白细胞去除对照组(S组)、白细胞去除治疗组(T组),每组10只.L组只给予LPS输注,不行白细胞去除(leukocytapheresis,LCAP);S组在LPS输注后12～14 h间行伪白细胞去除;T组在LPS输注后12～14 h间行LCAP.动态观察每组动物外周血活化蛋白C(activated protein C,APC)、可溶性血栓调节蛋白(soluble thrombomodulin,sTM)及纤溶酶原激活物抑制物-1(plasminogen activator inhibitor-1,PAI-1)在输注LIPS前及输注后2,6,12,14,16,24及36 h的变化.结果 (1)T组动物在14,16 h时血清APC水平[(50.805±4.422)μg/ml、(40.480±2.993)μg/,l]分别高于L组[(45.881 ±4.024)μg/,l、(35.935±4.057)μg/ml)(P<0.05);(2)T组在14,16 h时sTm水平[(9.688±0.914)μg/ml、(10.492±0.865)μg/ml]分别低于L组[(11.005±0.854)μg/ml、(12.04±O.954)μg/ml)(P<0.05);(3)T组在14,16 h时PAI-1水平显著低于L组(P<0.05);(4)T组急性肺损伤发生率显著低于L组(2/10:7/10,P<0.05).结论 LPS诱导的内毒素血症早期存在凝血纤溶功能异常,白细胞去除能改善凝血纤溶功能,可能是白细胞去除减少急性肺损伤发生率的作用机制之一.

Abstract：

Objective To observe the effect of leukocytapheresis(LCAP)on the coagulation,fibrinolysis system and lung injury in the endotoxemia dog and explore the mechanism in the endotoxin-induced lung injury dog. Methods Endotoxemia-induced model in dogs was established by administration of lipopolysaccharide(LPS,2 mg/kg).Separation of the leucocytes wag performed with the automated continuous flow blood cell separators.A total of 30 male mongrel dogs were randomly divided into LPS group(group L,only injected with LPS,with no LCAP),sham LCAP group(group S,received sham LCAP at 12-14 hours after administration of LPS)and LCAP treatment group(group T,received LCAP at 12-14 hours after administration of LPS),10 dogs per group.The dynamic changes of the activated protein C(APC),soluble thrombomodulin and plagminogen activator inhibitor-1 in the serum were measured at 0 hour before LPS administration,at 2,6,12,14,16,24 and 36 hours after administration of LPS.Results Through LCAP,there found the following four results:(1) the APC level in the serum of the group T wag(50.805±4.422)μg/ml and(40.480±2.993)μg/ml at 14 hours and 16 hours respectively,which were significantly higher than(45.881±4.024)μml and(35.935±4.057)μg/ml in the group L(P<0.05).(2)The expressions of soluble thrombomadulin in the group T was (9.688±O.914)μml and(10.492±O.865)μg/ml at 14 hours and 16 hours respectively,which was statistically lower than(11.005±0.854)μg/ml and(12.04±0.954)ug/ml in the group L(P<0.05).(3)Thelevel of plagminogen activatorinhibitor-1 in the group T was lower than that in the group the group T Wag statistically lower than that in the group L(ALI/ARDS occurred in 2 and 7 dogs of the groups T and L respectively within 36 hours after infusion of LPS.P<0.05). Conclusions At the decrease the incidence of acute lung injury partly due to its role in improving the function of coagulation and fibrinolysis.     

盐酸肾上腺素在骨水泥型髋关节置换术中预防骨水泥植入综合征发生的作用

Objective To investigate the clinical application of epinephrine hydrochloride in the prevention of bone cement implantation syndrome in the cemented hip replacement. Methods The clinical data of 48 patients treated with cemented hip replacement from July 2008 to April 2009 were retrospectively analyzed. All the patients were divided into control group and intervention group. The bone marrow cavities of 24 patients in the control group were not pretreated with saline epinephrine hydrochloride before implantation of bone cement; the bone marrow cavities of 24 patients in the intervention group were pretreated with saline epinephrine hydrochloride before implantation of bone cement. Systolic blood pressure (SBP), diastolic blood pressure (DBP), the mean arterial pressure (MAP), heart rate (HR)and pulse oxygen saturation ( SPO2 ) were compared between the two groups before bone cement implantation and 1,2, 3, 4, 5, 6, 7, 8, 9, 10 minutes after bone cement implantation. The data were analyzed with variance analysis and Q test. Results (1) In the control group: the blood pressure was decreased in control group one minute after bone cement implantation and a significant decrease of the blood pressure was observed at 2-6 minutes after the implantation ( P ＜ 0. 01 ). The blood pressure was increased seven minutes after the implantation, with the most significant increase of DBP ( P ＜ 0.05 ).The blood pressure recovered to normal 10 minutes later. The SPO2 was decreased significantly ( P ＜0.05 ) but no significant change was observed in HR ( P ＞ 0.05). (2) In the intervention group: the bone marrow cavity was pretreated with saline epinephrine hydrochloride before implantation of bone cement.ity. No significant difference was found in SBP, DBP, MAP, HR and SPO2 at different time points before and after bone cement implantation (P ＞0.05 ). Significant decrease of blood pressure and SPO2 was observed in control group and a significant hemodynamic change was detected at 2-6 minutes after the bone cement implantation. In the intervention group, no hemodynamic change was found in all the patients except that one patient was found with decrease of blood pressure and another one with the occasional premature ventricular contractions. Conclusion Pretreatment of bone marrow cavity with saline epinephrine hydrochloride can effectively prevent bone cement implantation syndrome.     

Enhanced myocardial fluorodeoxyglucose uptake following Adriamycin-based therapy: Evidence of early chemotherapeutic cardiotoxicity?

AIM: To analyze changes in myocardial glucose metabolism using fluorodeoxyglucose (FDG)-positron emission tomography (PET) in patients treated with adriamycin and to investigate the clinical significance of these changes.METHODS: Considering that FDG-PET scanning has the ability to show changes in glucose metabolism in the myocardium, we retrospectively analyzed the FDGPET studies of 18 lymphoma patients treated with adriamycin-based chemotherapy in both the preand posttherapy setting. Cardiac contractile parameters such as left ventricular ejection fraction were not available for correlation in all patients due to the short duration and the level of cumulative dose administered in these patients during the time of the follow-up FDG-PET study. The change in myocardial glucose utilization was estimated by change in standard uptake values (SUV) in the myocardium.RESULTS: We observed a significant change in SUVmean values in the myocardium (defined as more than change in cardiac SUVmean between pre-and post-chemotherapy PET) in 1 patients, whereas 6 patients did not show any significant cardiac FDG uptake in both preand post-therapy PET scans. Patients were divided into three groups based on the changes observed in myocardial tracer uptake on the followup 18 F-FDG-PET study. Group A (n = 8): showed an increase in cardiac 18 F-FDG uptake in the post-therapy scan compared to the baseline scan carried out prior to starting adriamycin-based chemotherapy. Group B (n = 6): showed no significant cardiac 18 F-FDG uptake in post-therapy and baseline PET scans, and group C (n = 4): showed a fall in cardiac 18 F-FDG uptake in the posttherapy scan compared to the baseline scan. Mean cumulative adriamycin dose (in mg/m 2 ) received during the time of the follow-up FDG-PET study was 256. 25, 250 and 137.5, respectively.CONCLUSION: Our study shows three different trends in the change in myocardial glucose metabolism in patients undergoing adriamycin-based chemotherapy. A further prospective study with prolonged follow-up of ventricular function is warranted to explore the significance of enhanced FDG uptake as a marker of early identification of adriamycin-induced cardiotoxicity.     

Use of carbon dioxide as negative contrast agent for magnetic resonance cholangiopancreatography

AIM: To evaluate the effects of using CO2 as negative contrast agent in decreasing the overlapping on the pancreaticobiliary system from intestinal fluids.METHODS:We evaluated the magnetic resonance cholangiopancreatography(MRCP) images in 117 patients divided into two groups(group 1,without taking gas producing crystals to produce CO2,n=64;group 2,with CO2,n=53)in a 1.5T unit using MRCP sequence.Anatomic locations of intestinal fluids distribution,overlapping with common bile duct(CBD)and pancreatic duct(PD),were evaluated.RESULTS:In the group with CO2,the decrease in distribution of intestinal fluids was significant in the gastric antrum(P=0.001)and duodenal bulb(P<0.001),but not in the gastric fundus and body and in the second portion of the duodenum(P=1.000,P=0.171,and P=0.584 respectively).In the group with CO2,the decrease in overlapping with CBD was significant(P< 0.001),but the decrease in overlapping with PD was not (P=0.106).CONCLUSION:MRCP with carbon dioxide as negative contrast agent would decrease intestinal fluids in the gastric antrum and duodenal bulb,thereby decreasing overlapping with the CBD.     

歼(强)击机飞行员心脏瓣膜生理性返流调查分析

Objective To investigate the prevalence of physiological valvular regurgitation and its influence in fighter (attacker) pilots. Methods One hundred pilots were divided into high performance fighter pilot group (56 pilots) and common fighter pilot group (44 pilots). Their cardiac structure and function were examined by echocardiography. Results 55 pilots were diagnosed with physiological valvular regurgitation (55.00%), including 32 high performance fighter pilots (57.14%) and 23 common fighter pilots (52.27%). The prevalence of tricuspid, mitral and combined valvular regurgitation was 33. 00%, 9.00% and 13.00% respectively. There were 11 cases of mitral combined tricuspid valvular regurgitation, 1 case of tricuspid combined pulmonic valvular regurgitation and 1 ease of tricuspid combined aortic valvular regurgitation. In common fighter pilot group, right ventricular internal dimension (RVID) of the pilots with regurgitation was significantly higher than that of the pilots without regurgitation (t= 1.69, P＜0.05). No other significant differences were observed between groups (P＞0. 05). The cardiac structure and function of 100 pilots were in normal range. Conclusions High prevalence of physiological valvular regurgitation is found in fighter pilots, and in which tricuspid valvular regurgitation takes the highest. It is necessary to further investigate if the fighter pilot's specificity makes the different mechanism of physiological regurgitation from other eareer's and its long-term influence on pilot's cardiac structure and function.     

辛伐他汀预处理减轻缺血再灌注心肌损伤的实验研究

Objective To investigate the effects of pretreatment with simvastatin on iscbemia reperfusion induced myocardial injury, and to further explore related mechanism with respect to inflammation modulation. Methods The rat myocardial ischemia reperfusion model was established by the method of coronary artery ligation. The animals were divided into 3 groups: the sham group, the control group and the simvastatin group. In the simvastatin group, the animals were pretreated with simvastatin (5 mg/kg) one week before by intragastric administration. Ventricular arrhythmia was monitored and scored, infarct size and area at risk of myocardium were determined, and uhrastructural changes were observed. The serum levels of myocardial enzymes and lipids were measured. The content of myocardial inflammatory cytokines [tumor necrosis factor (TNF) -α、interleukin(IL) -6, and monocyte chemoattractant protein(MCP) - 1]were also evaluated. Results When compared with those of the control group, the amount and duration of ventricular arrhythmia in simvastatin group were less and score of ventricular arrhythmia was significantly lower. When pretreated with simvastatin, the serum levels of CK-MB and LDH in simvastatin group were significantly lower than those of the control group. The infarct size/area at risk ratio of the simvastatin treated group was significantly less than those of the control group. The uhrastructures of myocardial cells were better maintained in simvastatin group. No significant differences were observed in the serum concentrations of total cholesterol, triglycerides, low density lipoprotein and high density lipoprotein when comparisons were made each other among the three groups. However, the levels of TNF-α,IL-6 and MCP-1 in heart tissue of the treated animals were significantly lower than those of the control group. Conclusions Pretreatment with simvastatin ameliorates ischemia reperfusion induced myocardial injury, which is partly related with the down-regulation of inflammatory cytokines expression in heart tissue but independent of its role of lipids modulation.     

辛伐他汀预处理减轻缺血再灌注心肌损伤的实验研究

Objective To investigate the effects of pretreatment with simvastatin on iscbemia reperfusion induced myocardial injury, and to further explore related mechanism with respect to inflammation modulation. Methods The rat myocardial ischemia reperfusion model was established by the method of coronary artery ligation. The animals were divided into 3 groups: the sham group, the control group and the simvastatin group. In the simvastatin group, the animals were pretreated with simvastatin (5 mg/kg) one week before by intragastric administration. Ventricular arrhythmia was monitored and scored, infarct size and area at risk of myocardium were determined, and uhrastructural changes were observed. The serum levels of myocardial enzymes and lipids were measured. The content of myocardial inflammatory cytokines [tumor necrosis factor (TNF) -α、interleukin(IL) -6, and monocyte chemoattractant protein(MCP) - 1]were also evaluated. Results When compared with those of the control group, the amount and duration of ventricular arrhythmia in simvastatin group were less and score of ventricular arrhythmia was significantly lower. When pretreated with simvastatin, the serum levels of CK-MB and LDH in simvastatin group were significantly lower than those of the control group. The infarct size/area at risk ratio of the simvastatin treated group was significantly less than those of the control group. The uhrastructures of myocardial cells were better maintained in simvastatin group. No significant differences were observed in the serum concentrations of total cholesterol, triglycerides, low density lipoprotein and high density lipoprotein when comparisons were made each other among the three groups. However, the levels of TNF-α,IL-6 and MCP-1 in heart tissue of the treated animals were significantly lower than those of the control group. Conclusions Pretreatment with simvastatin ameliorates ischemia reperfusion induced myocardial injury, which is partly related with the down-regulation of inflammatory cytokines expression in heart tissue but independent of its role of lipids modulation.     

双探头符合线路SPECT正电子显像衰减校正实验研究

Objective The photons from the body would be attenuated in their intensity by the soft tissue before they reach the detectors. Some of them lost more intensity than others when coming from the deeper body. Attenuation of the photons would distort the image, affect the image quality, and may lead to misdiagnosis. In this research the X-ray and γ-ray were used as transmission resources for accurate assess-ment of attenuation in each part of the body. The transmission data was used to correct the emission data from the body. Iteration algorithm was used for the reconstruction of attenuation corrected tomography ima-ges. Evaluate the efficacy of attenuation correction in duel head hybrid SPECT/coincidence PET systems (SPECT/PET) and SPECT using both the Jaszczak and the myocardial phantoms. Methods For PET phantom study, the Jaszczak phantom was filled with the aqueous solution of 18F-fluorodeoxyglucose (FDG) and was scanned with two hybrid SPECT/coincidence PET systems respectively (Vertex Plus, Netherlands Philips ADAC Company and Hawkeye, USA GE Company). The PET images were acquired and reconstruc-ted. Results The "cold" lesion, which the diameter was less than 12 mm of uncorrected image, could not be identified. But it, after correction, diameter 9 mm, would be recognized clearly, less than 7 mm would not be distinguished. Noncorrected image could only identify "hot" lesions which the diameter were 9, 12, 14, 18, 22 and 38 mm, while in the corrected image, not only it was much better, but also the "hot" le-sion of 6 mm was distinguished. In Hawkeye, the same situation, the corrected image of was improved obvi-ously; the disparity of counts between surrounding and deep center less, and the counts in deep center were compensated. There were only 3 round " cold" lesions could be recognized, the diameter: 14, 18 and 20 mm; all of them which diameter were less than 12 mm could not be distinguished. One in the center was al-most as background, and could not be identified. The radioactive accounts of surrounding and center were quite different. The corrected image 5 "cold" lesions could be found, 9, 12, 14, 18 and 20 mm, but7 mm could not be found. The noncorrected image, only 12, 14, 18, 22 and 38 mm " hot" lesions could be found, and by the surrounding, there was an arc shape "hot" lesion. But it could distinguish 9, 12, 14, 18, 22 and 38 mm "hot" lesions on the corrected image, and the image was much better than noncorrected one. Conclusions The corrected image of Vertex Plus was improved obviously with the disparity of counts between surrounding and deep center less, and the counts in deep center was compensated. The result of at-tenuation with phantom showed that 137Cs was better than CT in both image quality and spatial resolution.     

射频导管消融犬左束支电位对心脏电机械活动的影响

目的 探讨射频导管消融犬左束支电位(LBP)对心脏传导及心功能的影响,以及犬左束支传导阻滞(LBBB)模型的制备方法.方法 应用射频消融导管在10只实验犬左心室内膜标测到LBP处进行消融,观察能否成功制备犬LBBB模型以及其对心脏传导的影响.对成功复制LBBB的模型犬应用超声心动图比较LBBB前后心脏收缩功能及舒张功能的变化.结果 10只犬接受LBP处消融后,8只(80％)成功制备LBBB模型.消融靶点处心房与心室电压比值＜1:10,局部记录的LBP至心室电位间期为17.1±3.2(12～22)ms,消融后QRS波宽度由52.8±4.8ms增至100.5±11.1ms(P＜0.001),而PR间期、AH间期、HV间期无明显变化.另外2只犬在LBP至心室电位间期分别为30ms、32ms处消融,导致完全性房室传导阻滞.8只犬发生LBBB后超声心动图检查示:收缩功能指标左室射血分数和主动脉血流速度积分降低(P＜0.05);舒张功能指标E/A下降为＜1,伴有等容舒张时间和二尖瓣减速时间延长(P＜0.05);出现显著室间与室内不同步,表现为间隔后壁运动延迟及左右心室射血前期时间差明显延长(P＜0.001).结论 射频导管消融左束支电位可导致LBBB,是制备犬LBBB模型成功率较高的方法,但有发生完全性房室传导阻滞的危险.LBBB即刻可导致左室激动延迟,左右室间及左室内收缩不同步,左心室收缩及舒张功能降低.     

小儿原发性心脏肿瘤的超声心动图诊断及心功能评估

目的 探讨超声心动图诊断小儿原发性心脏肿瘤的临床价值,评价多普勒超声心肌活动指数(myocardial performance index,MPI)估测心脏肿瘤患儿心功能的准确性.方法 58例心脏肿瘤患儿及58例正常儿童为研究对象,分析肿瘤患儿的超声心动图资料,并计算MPI.结果 16例手术者超声漏诊率为6％.58例肿瘤患者的左、右心室MPI与对照组无显著差异(P ＞0.05).其中16例患儿行手术治疗,肿瘤手术组MPI较对照组明显升高(P＜0.05),手术后多普勒超声MPI明显下降(P＜0.05).结论 超声心动图可以准确的诊断心脏肿瘤的部位、大小、数目,但是不能确定肿瘤的性质;MPI可以准确反映肿瘤患者的心功能变化.     

右心腔声学造影及定量组织速度成像评价犬右心收缩功能

目的:探讨心腔声学造影时间-强度曲线(TIC)各项参数及三尖瓣定量组织速度成像(QTVI)参数定量评价右心收缩功能的价值。方法:对10只犬分别在基础状态及注射心得安后心功能减退状态下经股静脉重复注射5%声振白蛋白注射液,剂量0.08 ml/kg。于心尖四腔切面观察右心室对比剂的充盈及清除,采用拟合曲线定量分析方法获取心腔声学造影TIC各项参数,并分析各项参数在不同的心功能水平的差异。应用多普勒超声心动图分别在基础状态及注射心得安后心功能减退状态下记录三尖瓣环组织多普勒图像,测量三尖瓣环收缩期运动速度(Vs)。结果:随心功能的减退,TIC各项参数中时间常数(k)明显减小,而对比剂峰值强度减半时间(HT)及对比剂平均通过时间(MTT)明显延长,三尖瓣环收缩期运动速度(Vs)明显减慢(P<0.001),k与Vs呈明显正相关(r=0.71)。结论:右心腔声学造影TIC参数与QTVI参数在定量评估右心收缩功能时具有重要价值。     

Factors modifying contrast media induced fibrillation

Factors effecting contrast media induced ventricular fibrillation were studied in anesthetized dogs using contact time as the measured parameter. Injections of meglumine/sodium diatrizoate (370 mg I/ml) were made into the right coronary artery at 0.4 ml/s until fibrillation occurred. A contrast medium containing calcium chelators was found to produce fibrillation in a significantly shorter contact time than a similar medium without calcium chelators. Pre-treatment by the cardiac glycoside, ouabain, increased the contact time for fibrillation as did the production of a sub-acute infarction in the left coronary artery and a previous fibrillation and resuscitation. The data suggest that calcium binding additives increase the risk of fibrillation while pre-treatment with cardiac glycosides, the presence of stable infarcts in the non-injected areas, or a previous fibrillation and resuscitation do not increase risk.     

老年原发性高血压患者BNP、hs-CRP与房颤关系的研究

目的探讨老年原发性高血压患者血清B型利钠肽(BNP)、高敏C反应蛋白(hs-CRP)水平与心房颤动之间的关系。方法对我院2008年10月—2011年10月连续诊治的老年原发性高血压患者209例,根据超声心动图(UCG)测量左室舒张末内径(LVEDD)、室间隔厚度(IVSD)、左室后壁厚度(LVPWD)、左室射血分数(LVEF)、左房内径(LA),计算左室质量指数(LVMI)。根据ECG将患者分为房颤组(AF组,105例)及无房颤组(NAF组,104例),测定两组患者的血清BNP、hs-CRP水平。结果 AF组中阵发性房颤48例,持续性房颤24例,永久性房颤33例。AF组患者的BNP[(198.66±118.85)ng/L与(86.37±66.96)ng/L]与LVMI[(127.19±28.04)g/m2与(83.70±17.23)g/m2]明显高于NAF组(P<0.01)。永久性房颤患者BNP明显高于阵发性房颤患者[(242.45±134.36)ng/L与(178.95±102.73)ng/L,P<0.05],而阵发性房颤、持续性房颤患者BNP无统计学差异(P>0.05);三组间hs-CRP均无统计学差异(P>0.05)。老年原发性高血压房颤患者BNP与患者LVMI、LA、房颤持续时间成正相关,与LVEF成负相关。Logistic回归分析表明,老年原发性高血压患者血清BNP水平升高,房颤的可能性增大。hs-CRP与房颤之间无相关性(P>0.05)。结论 BNP与老年原发性高血压房颤之间关系密切。BNP可作为老年原发性高血压左心室心肌肥厚的标志物。     

射频消融犬心室流出道间隔初步实验研究

目的 初步探讨射频消融犬心室流出道间隔对左心室结构与功能的影响.方法 以健康实验犬为模型,射频消融心室流出道间隔处肌肉.术前经胸超声检测左心室流出道宽度、收缩期室间隔厚度和射血分数等指标,消融成功后即刻检测超声指标,术后1、3个月分别复查存活犬超声指标,作组织病理学检查.结果 10只实验犬中9只消融成功,1只术中发生室颤死亡;1只消融成功但麻醉过深,出现呼吸抑制死亡.手术即刻成功率为80％,8只术后存活至预定随访时间点.与术前相比,存活犬术后即刻、术后1个月、术后3个月左心室流出道宽度、收缩期室间隔厚度差异均有统计学意义(P＜0.05),射血分数差异均无统计学意义(P＞0.05);组织病理学检查可见明显改变;心电图、血压未见明显变化.结论 初步验证射频消融实验犬心室流出道间隔心肌具有一定的安全性和有效性,为进一步动物实验和临床试验提供了有用参数和实验依据.     

主动脉缩窄术后磁共振脉搏波传导速度法评估主动脉顺应性

目的 使用磁共振脉搏波传导速度法(PWV)评估主动脉缩窄(CoA)术后主动脉顺应性.方法 回顾性分析22例CoA术后患儿心脏磁共振,使用MRI相位对比序列测量并计算主动脉PWV,同时期行超声心动图测量双侧心室功能及心肌厚度.另选取年龄、性别匹配的22例健康儿童组成对照组测量主动脉PWV.结果 研究组平均PWV明显高于对照组[(4.42±3.02)m/s vs(2.73±0.76)m/s,P=0.02].在研究组中,吻合口中度狭窄患儿PWV值最高,受试者工作特征(ROC)曲线分析发现,取PWV为3.37 m/s时,区分轻、中度吻合口狭窄的敏感性、特异性最高.左侧心室舒张末期容积、收缩末期容积、射血分数及左室壁厚度与PWV无明显相关性.结论 CoA术后患儿PWV升高,中度吻合口狭窄患儿存在较显著主动脉重构.     

The use of programmed electrical stimulation to assess the fibrillatory propensity of ionic and nonionic contrast media

Coronary angiography occasionally results in ventricular fibrillation. To compare the fibrillatory propensity of conventional ionic and nonionic contrast media, we measured QT intervals and performed programmed electrical stimulation during intracoronary injection of Renografin 76 (R76), Hypaque 76 (H76), and iopamidol (IOP) in 16 open chest dogs. In ten dogs the incidence of ventricular fibrillation following induction of a single premature ventricular beat after every fourth atrial paced beat was 19/20 with R76, 8/20 with H76, and 0/20 with IOP (P less than .001). When two premature beats were induced, the incidence of ventricular fibrillation was 20/20 with R76, 19/20 with H76, and 1/20 with IOP (P less than .001). In six additional dogs, the mean prolongation of the QT interval was 170 +/- 20 msec with R76, 105 +/- 14 msec with H76, and 63 +/- 9 msec with IOP (P less than .001). Thus, programmed electrical stimulation readily induces ventricular fibrillation during intracoronary injection of conventional ionic contrast media. The incidence of ventricular fibrillation parallels the amount of QT interval prolongation produced. H76, which lacks EDTA and sodium citrate, is less fibrillatory than R76. However, the nonionic medium IOP appears far less fibrillatory than either R76 or H76.     

Hemodynamic and electrophysiologic effects of low osmolar contrast agents during coronary angiography in the dog and the rabbit

The electrophysiological tolerability of ioxaglate (160 mgI/ml) and iohexol (140 mgI/ml) was assessed in rabbits (n = 12 per group). There was a significant induction of ventricular fibrillation in the group given iohexol. An explanation for this phenomenon could be the lack of sodium in this preparation. Ioxaglate, iopamidol and iohexol (all at 320 mgI/ml) were also compared during coronary angiography in the dog (n = 10) after bolus administration, using the carotid approach (5 and 8 ml-0.5 ml/sec). Each dog received all the compounds in the left coronary artery and selectively in the left anterior descending artery, at random. Four dogs had lethal ventricular fibrillations after iohexol. Iopamidol and iohexol induced significant bradycardia in comparison with saline. A biphasic effect on myocardial contractility was observed with all contrast media: a short-lasting, typical decrease in dP/dt was seen with ioxaglate by the end of injection, while iohexol and iopamidol caused a similar negative inotropic effect in some cases (25%) after increasing dP/dt. The positive inotropic effect was greater with iopamidol and iohexol than with ioxaglate (p less than 0.05). The possible clinical consequences of the lack of sodium in contrast media preparations and of the changes in myocardial function are discussed in the light of the present results.     

时间-空间相关成像技术评估中孕期胎儿心功能的初步研究

目的 评估时间-空间相关成像( STIC)技术在中孕期胎儿心功能检查中的应用.资料与方法 110例孕20～27+6周胎儿常规超声筛查心脏无异常,用STIC技术扫描获得胎儿心脏整个心动周期的容积数据,存盘后采用体器官计算机辅助分析软件(VOCAL)进行脱机分析,手动描画出心室舒张末期容积(EDV)、收缩末期容积(ESV).计算心室的每搏量(SV)、心排血量(CO)、射血分数(EF),评价SV、CO、EF与孕龄的相关性.结果 110例胎儿中,94例(85.5％)获得满意的心脏容积数据.左、右心室SV从孕20周的(0.33±0.06) ml和(0.40±0.07) ml增加至孕27+6周的(1.13±0.11) ml和(1.29±0.11) ml,左、右心室CO从孕20周的( 49.66±8.10) ml/min和(59.96±9.43) ml/min增加至孕27+6周的(163.51±17.68) ml/min和(187.57±15.98) ml/min;左、右心室SV和CO随孕龄增加而增加,与孕龄呈正相关(左心室SV及CO r=0.93,P＜0.05.右心室:SV r =0.95,P＜0.05; CO r=0.94,P＜0.05).左、右心室EF分别为(49.48±4.12)％和(51.07±4.00)％,与孕龄无明显相关性(r=0.02、0.04,P＞ 0.05).结论 STIC技术能较为准确客观地测量胎儿心室容积,评价胎儿心功能,有望成为胎儿心功能检查的一种新方法.