4.Feasibility and Stability of Right Ventricular Outflow Tract Pacing Under Current Technology
Ruohan CHEN ; Keping CHEN ; Fangzheng WANG ; Wei HUA ; Shu ZHANG
Chinese Circulation Journal 2009;24(3):202-205
Objectives: To assess the feasibility and stability of right ventricular outflow tract (ROVT) pacing under current technology by comparing the results of ROVT pacing with the traditional right ventricular apex (RVA) pacing. Methods: A total of 42 patients (at mean age of 63.5±10.4 years) without structural heart disease were randomly divided into two groups. RVA pacing group (n=14),and RVOT pacing group(n=28). An active fixation lead was implanted in all patients whose pacemaker could automatically measure the pacing threshold every day. The operation time,X-ray exposure time and lead parameters detected during the operation were collected to evaluate the feasibility of RVOT pacing. The complications related to lead and implantation procedure and the trend of threshold change during the follow-up time were used to assess the stability of RVOT pacing.Results: There were no statistic differences between RVA pacing group and RVOT pacing group in terms of operation time,X-ray exposure time and lead parameters. In RVOT group,the change of threshold during acute period was similar to those in RVA group (P=0.23). Chronic pacing threshold was also comparable between two groups,mean threshold at 6 months follow-up time was 0.55±0.11V and 0.54±0.09V at 0.4 pulse width in RVA group and RVOT group respectively (P=0.787).Conclusion: RVOT pacing was feasible and stable in operation time and lead characteristics compared with the conventional RVA pacing under current pacing technology.
6.Quantitative assessment of left ventricular systolic synchrony in patients with chronic renal failure using real-time three-dimensional echocardiography
Shu-jiao, JI ; Jian-jun, YUAN ; Chang-hua, WEI
Chinese Journal of Medical Ultrasound (Electronic Edition) 2008;5(2):267-272
Objective To quantitatively evaluate the left ventricular systolic synchrony in patients with chronic renal failure (CRF) by real-time three-dimensional echocardiography (RT-3DE). Methods Thirty patients with CRF and twenty-five normal subjects were enrolled in this study.The M-mode ejection fraction (M-EF), left ventricular end diastolic internal diameter (LVIDd), interventricular septum diameter (IVSd), left ventricular posterior wall diameter (LVPWd) were obtained on two-dimension. The global and regional volume-time curves were obtained on three -dimensional. The end diastolic volume (LVEDV),end systolic volume (LVESV) and ejection fraction (LVEF) of left ventricule, the time to minimal systolic volume (Tmsv) of 16,12,6-segmental standard deviation (Tmsv16, 12, 6-SD), maximal difference (Tmsv16, 12, 6-Dif) were derived from Qlab software . The above parameters as a percentage of the cardiac cycle with different heart rates between patients were also calculated from the Qlab software, which were Tmsv16, 12, 6-SD% and Tmsv16, 12, 6-Dif %, rspectively. Results The indices of HR, LVIDd, IVSd, LVPWd and LVESV were significantly higher while LVEF was significantly lower in the CRF group than those of the control group (P<0.05 or P<0.01); The indices of systolic asynchrony of Tmsv16,12-SD%, Tmsv16,12-Dif, Tmsv16 ,12 ,6-SD/R-R%,Tmsv16,12,6-Dif/R-R% were significantly larger in the CRF group than those of the control group(P<0.05 or P<0.01). Conclusions RT-3DE provides a simple, intuitional and noninvasive approach to assess the systolic synchrony of all the LV segments simultaneously and LVEF in patients with chronic renal failure.
8.Effects of sample digestion conditions on urinary iodine measurement results
Wei, MA ; Xiu-wei, LI ; Shi-chuan, LIU ; Shu-hua, LI ; Lie-jun, LIU
Chinese Journal of Endemiology 2013;32(6):694-696
Objective To study the effects of sample digestion conditions on measurement results of urinary iodine determined by As(Ⅲ)-Ce4+ catalytic spectrophotometry with ammonium persulfate digestion,and to promote the application of newly revised (the 2012 edition) national standard method for determination of urinary iodine.Methods According to the newly revised national standard method,various digestion conditions,such as ammonium persulfate concentration (0.8-1.3 mol/L,group interval 0.1),digestion instruments (heating block and drying oven) and standing time after digestion(0.5,1.0,2.0,4.0 and 22.0 h),were studied.The samples included 3 standard materials,which were GWB09108k,GWB09109f and GWB09110m containing iodine of (68.2 ± 9.0),(138.0 ± 10.0) and (221.0 ± 10.0) μg/L,and 5 urine samples with iodine concentration of 100-300 μg/L.Results Measurement results among the three groups of 0.9,1.0 and 1.1 mol/L ammonium persulfate digestion fluid showed no significant difference(P > 0.05).The digestive effect showed no significant difference between heating block and drying oven (P > 0.05) except one standard material in low concentration (GBW09108k).After digestion,samples were placed 0.5-22.0 h,the measurement results between groups showed no significant difference (P > 0.05).Conclusions Appropriate concentrations of ammonium persulfate are from 0.9 mol/L to 1.1 mol/L.Heating block is recommended for the digestion,however,when absent,drying oven can be used alternatively.The standing times from 0.5 h to 22 h after digestion have not affected the measurement results.
9.Surveillance of pathogens from patients with hospital infection in intensive care unit
wei, XIE ; wei-lin, XIE ; wen-hua, LI ; shu-yun, WANG
Journal of Shanghai Jiaotong University(Medical Science) 2006;0(03):-
Objective To analyze the distribution and antimicrobial resistance of pathogens from patients with hospital infection in intensive care unit(ICU),and to discuss the corresponding strategy of prevention and treatment. Methods Clinical data of 891 patients hospitalized in the ICU of our hospital between Jan 2002 and Dec 2005 were collected.All the specimens were analyzed for pathogen distribution and resistance to antibiotics. Results Of all the isolated 1 155 strains,Gram-negative(G-)bacteria were the most popular pathogen(57.84%),whereas Gram-positive(G+) bacteria and fungi accounted for 21.39% and 20.78%,respectively.Most G-bacteria were less sensitive to imipenem(0-10.16%),and Pseudomonas aeruginosa was least sesitive to amikacin(6.89%) and cefoperazone-sulbactam(33.97%).G+ bacteria were most sensitive to vancomycin.Most fungus were Candida albicans(42.92%) and yeast species(22.90%). Conclusion Epidemiological investigation of pathogens in ICU is of great importance to the rational use of anti-biotics and may help to reduce the emergence of resistant strains.
10.The role of contrast enhanced ultrasound in evaluating and guiding radiofrequency ablation of hepatocellular carcinoma and feeding vessels
Jin-yu, WU ; Shu-zhi, LIN ; Min-hua, CHEN ; Wei, WU ; Wei, YANG
Chinese Journal of Medical Ultrasound (Electronic Edition) 2013;(11):907-912
Objective To investigate the role of contrast enhanced ultrasound (CEUS) in evaluating and guiding radiofrequency ablation (RFA) of hepatocellular carcinoma (HCC) and its feeding vessels. Methods From January 2006 to June 2007, 71 patients with 75 hypervascular HCC in Peking University Cancer Hospital who underwent RFA were included in the study. The diagnosis was conifrmed by ultrasound guided biopsy for all patients. These patients were not suitable for transcatheter arterial chemoembolization (TACE) or had poor responds to TACE. They were divided into two groups, which included group percutaneous artery ablation (PAA) combining RFA and group RFA. There were 38 patients with 39 HCC in group PAA combining RFA and CEUS were used to identify the range of HCC inifltration. Firstly, PAA of the feeding vessels was conducted under the guidance of color doplor lfow imaging (CDFI). Then CEUS was performed to evaluate HCC perfusion after blocking the feeding vessels. Finally, the rest of the tumor was ablated by RFA. In group RFA, there were 33 patients with 36 HCC, who did not undertake PAA before RFA. Generally, the RFA was planned based on tumor size and location, and the ablation started with deep part of HCC or portion close to nearby organs. Contrast CT was used as a post-RFA imaging for follow-up at 1, 3 and 6 months post-RFA. T test was used to compare the difference in focal lesions number between two groups, andχ2 tests were used to compare the difference in necrosis rate between two groups after treatment. Results In group PAA combining RFA, post-PAA CEUS showed intratumor perfusion decreased more than 70%in 31 HCC (79.5%, 31/39). Of them, 13 HCC (33.3%, 13/39) showed complete perfusion defect with clear margin, called“solar eclipse sign”. The rest 8 HCC (20.5%, 8/39) showed 40%-70%of perfusion defect. In group PAA combining RFA, CDFI showed 35 (83.3%, 35/42) feeding vessels were blocked, and 3 vessels (7.1%, 3/42) showed signiifcant decreased lfow signal after PAA. There were average 3.18±1.42 ablations per HCC in group PAA combining RFA, and 4.32±1.56 in group RFA. The number of ablations per HCC in group PAA combining RFA was signiifcantly less than group RFA (t=2.524, P=0.015). The tumor necrosis rate at 1 month post-RFA in group PAA (92.3%, 36/39) combining RFA was signiifcantly higher than that of group RFA (66.7%, 24/35) (χ2=8.264, P=0.001). Conclusions With CEUS, PAA can effectively block the feeding vessels of HCC, enhance ablated necrosis in the tumor and signiifcantly increase necrosis rate post-RFA for large hypervascular HCC. CEUS-assisted PAA can improve efifciency of RFA with less ablation number and better result.