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To study the beneficial effects of ivabradine in dilated cardiomyopathy (DCM) mice, which evolved from coxsackievirus B3-induced chronic viral myocarditis. Four-to-five-week-old male balb/c mice were inoculated intraperitoneally with coxsackievirus B3 (Strain Nancy) on days 1, 14, and 28. The day of the first virus inoculation was defined as day 1. Thirty-five days later, the surviving chronic viral myocarditis mice were divided randomly into two groups, a treatment group and an untreated group. Ivabradine was administered by gavage for 30 consecutive days in the treatment group, and the untreated group was administered normal saline. Masson's trichrome stain was used to evaluate the fibrosis degree in myocardial tissue. The expression levels of tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), interleukin-6 (IL-6), collagen I, collagen III and p38-MAPK signaling pathway proteins were detected by Western blot. Electrocardiogram was used to investigate the heart rate and rhythm. The thickness of the ventricular septum and left ventricular posterior wall, left ventricular end diastolic dimension, left ventricular end systolic dimension, left ventricular ejection fractions and fractional shortening were studied by echocardiography. Compared with the untreated chronic viral myocarditis mice, ivabradine significantly increased the survival rate, attenuated the myocardial lesions and fibrosis, improved the impairment of the left ventricular function, diminished the heart dimension, decreased the production of collagen I and collagen III, reduced the expression of the proinflammatory cytokines TNF-α, IL-1ß, and IL-6, and lowered the production of phospho-p38 MAPK. The findings indicate the therapeutic effect of ivabradine in preventing the progression from viral myocarditis to DCM in mice with chronic viral myocarditis induced by coxsackievirus B3, is associated with inhibition of the p38 MAPK pathway, downregulated inflammatory responses and decreased collagen expression. Ivabradine appears a promising approach for the treatment of patients with viral myocarditis.
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Objective:To survey and supervise the risk of infection control and radiation safety in the radiological diagnostic workplace for COVID-19, and provide data support for the safety protection of radiographers and related staff.Methods:4 emergency hospitals for COVID-19 including 2 makeshift hospitals, module hospital and brick pattern hospital in Hubei province were performed for testing and evaluation of imaging performance and radiological protection for the 8 new installed CT scanners and places according to the national standards of WS 519-2019 and GBZ 130-2013. The infection control safety factors such as the layout of the equipment room were monitored and investigated. Two COVID-19 designated hospitals including general hospital and infectious disease specialized hospital were selected to carry out field investigation and sampling of environmental biological samples for 4 CT rooms. Then the samples were detected for the nucleic acid of novel coronavirus. The results of radiodiagnostic workplace overall arrangement, infection prevention and the nucleic acid testing were analyzed, and the biological safety reliability and risk point were evaluated.Results:The indicators of imaging performance and radiation protection for 8 CT scanners in emergency hospitals could meet the requirements of national standards.Each of 2 makeshift hospitals had 3 CT rooms with the area of 38.8 m 2 and 4 mm Pb equivalent thickness of protective shielding. The CT rooms in module hospital and brick pattern hospital were 20.0 m 2, and 35.8 m 2 in areas, with 4 mm Pb equivalent and 3 mm Pb equivalent thickness of protection shielding, respectively. The 8 radiological diagnostic workplaces of the emergency hospitals were designed and constructed based on " three zones with two passage ways" . The result of the nucleic acid test indicated that the positive samples were found at the multiple sites such as scanning bed, internal of gantry and ground touched by patients in CT scanning room. The areas such as console panel and ground were risked of pollution by the virus infected hands and feet of radiographers. In addition, the similar positive samples were found in the areas in scanning room with no touch of patients, such as observation window and air outlet. Conclusions:8 CT scanners and rooms in 4 emergency hospitals basically meet the requirements of imaging performance and radiation protection. The disinfection of COVID-19 radiodiagnostic workplace should be standardized.
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Objective To study the association between serum albumin level and first-onset AMI.Methods A total of 2172 patients with first-onset AMI served as an observation group and 3395 CHD-free patients served as a control group.The association between serum albumin level and first-onset AMI was analyzed by logistic regression analysis.Results The serum albumin level was significantly lower in observation group than in control group (40.0 g/L vs 41.4 g/L,P=0.000).On a continuous scale,when serum albumin level decreased by 1 standard deviation (~4 g/L),adjusted OR (95%CI) was 1.87 (1.75-2.01),1.85 (1.71-2.01),1.48 (1.26-1.74) for AMI in the total patients,male patients and female patients,respectively.On a categorical scale,Q1 (albumin level ≥43.8 g/L) was used as reference.Stratifying by age showed that adjusted OR (95%CI) was Q2 1.43 (1.12-1.82),Q3 1.95 (1.53-2.47),Q4 2.52 (1.95-3.27),Q5 4.51 (3.40-6.00) for AMI in patients aged <65 years and was Q2 1.61 (1.042.5),Q3 2.21 (1.48-3.31),Q4 3.34 (2.244.99),Q5 4.77 (3.22-7.08) in patients aged ≥65 years (P-for-trend < 0.01).Stratifying by gender showed that serum albumin level was negatively associated with AMI in both sexes (P-for-trend <0.01).Conclusions Serum albumin level is negatively associated with the risk of first-onset AMI in a dose-response manner regardless of stratifying by age and/or gender.
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Objective To investigate the effect of remote ischemic postconditioning (RIPostC ) on the platelet reactivity in the patients with acute myocardial infarction (AMI) receiving reperfusion therapy .Methods Seventy-one cases of AMI entering the group received the reperfusion therapy .The patients were divided into the two groups .The treatment group received RIPostC ,while the control group received sham RIPostC .The venous blood samples were collected before transcutaneous coronary intervention (PCI) ,instantly after RIPostC and at 24 h ,48 h after PCI .The platelet activation indicators CD62P and PAC-1 ,and platelet apopto-sis indicator mitochondrial transmembrane potential(ΔΨm) were measured by flow cytometry .Results CD62P expression on plate-let surface at 24 h after PCI in the treatment group was significantly lower than that in the control group (P<0 .05) ,but which at other time points had no statistical difference between the two groups (P>0 .05);there was no statistical difference in platelet PAC-1 expression at each time point between the two groups (P>0 .05);the platelet ΔΨm at each time point had no statistical difference between the two groups(P>0 .05) .Conclusion RIPostC can somewhat reduce platelet activation in AMI patients without causing platelet early apoptosis .
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OBJECTIVE:To evaluate therapeutic efficacy of Aidi injection,Compound kushen injection,Kanglaite injection, Elemene injection and Brucea javanica oil emulsion injection in the treatment of malignant pleural effusion(MPE),and to provide evidence-based reference in clinic. METHODS:Retrieved from PubMed,EMBase,Cochrane library,CJFD,Wanfang database and CJFD,RCTs about Aidi injection,Compound kushen injection,Kanglaite injection,Elemene injection and B. javanica oil emulsion injection in the treatment of MPE were collected. Meta-analysis was conducted by using ADDIS 1.16.6 statistical software after data extraction and quality evaluation by modified Jadad scale. RESULTS:A total of 54 RCTs were included,involving 3404 patients. All RCTs were two legs with a total number of 108. Results of network Meta-analysis showed that compared with cisplat-in,Compound kushen injection [OR=2.19,95%CI(1.30,3.76),P<0.05],Elemene injection [OR=3.55,95%CI(2.43,5.32),P<0.05] and B. javanica oil emulsion injection [OR=1.92,95%CI(1.34,2.76),P<0.05] could significantly improve response rate of MPE patients,with statistical significance. Pairwise comparison showed response rate of Elemene injection was significantly higher than that of Aidi injection [OR=0.32,95%CI(0.17,0.56),P<0.05],Kanglaite injection [OR=0.30,95%CI(0.13,0.68),P<0.05] and B. javanica oil emulsion injection [OR=1.85,95%CI(1.10,3.17),P<0.05] in improving response rate. The probability ranking was Elemene injection>Compound kushen injection>B. javanica oil emulsion injection>Aidi injection=Kanglaite injection=cispl-atin. Compared with cisplatin,Aidi injection [OR=0.29,95%CI(0.16,0.54),P<0.05],Compound kushen injection [OR=0.44, 95%CI(0.18,0.96),P<0.05],Elemene injection [OR=0.21,95%CI(0.10,0.44),P<0.05] and B. javanica oil emulsion injection [OR=0.41,95%CI(0.23,0.70),P<0.05] could significantly improve the rate of quality of life improvement in MPE patients,with statistical significance. Pairwise comparison showed the rate of quality of life improvement of Elemene injection in MPE patients was significantly higher than that of Kanglaite injection [OR=4.84,95%CI(1.03,25.01),P<0.05]. The probability ranking was El-emene injection>Aidi injection>Compound kushen injection>B. javanica oil emulsion injection>Kanglaite injection>cisplatin.CONCLUSIONS:All 5 kinds of TCM injection can effective-ly treat MPE and improve the quality of life,among which El-emene injection is mostlikely to be the most effective interven-tion.
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In this cross-sectional study, consecutive Chinese Han ethnic inpatients in the Division of Cardiology, the First Affiliated Hospital of Soochow University from January 1, 2010 to December 31, 2013 were included. According to the exclusion criteria, 9 587 patients [1 604 with type 2 diabetes mellitus (T2DM) and 7 983 without T2DM]were obtained for final analysis. Logistic regression model was used to analyze the association of ApoB/A-1 ratio with T2DM and the possible interactions between ApoB/A-1 ratio and other risk factors. The results showed that the distribution of ApoB/A-1 ratio was positively skewed in Chinese Han ethic population. The median of ApoB/A-1 ratio of female was lower than that of male (0.68 vs 0.73,P<0.01). In all groups, the proportion of T2DM was increased with the raised ApoB/A-1 ratio. By the stratification analyses of sex, age, coronary artery disease, and the use of statins, ApoB/A-1 ratio was still correlated with T2DM. There existed significant interactions between ApoB/A-1 ratio and the smoking status or creatinine in T2DM.
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Objective@#To investigate the determinants affecting the heart rate deceleration capacity (DC) in patients with dilated cardiomyopathy (DCM).@*Methods@#One hundred patients with DCM (DCM group) and 202 healthy subjects (control group) were respectively enrolled. Echocardiography and 24 hours electrocardiogram were performed in all subjects. DC value was compared between the two groups. Multiple regression analysis was made to evaluate the related determinants of DC ((age, sex, echocardiographic parameters including the left atrial diameter (LAD) and left ventricular ejection fraction (LVEF)).@*Results@#(1) DC value was significantly lower in DCM group than in control group( (4.40±2.03) ms vs. (7.30±1.81) ms, P<0.01), prevalence of DC value≤4.5 ms was significantly higher in DCM group than in control group (62% vs. 6%, P<0.01). (2) DC value in the DCM group decreased in proportion to increasing LAD dimension, DC value was (5.60±2.04) ms, (4.50±2.07) ms and (3.60±1.62) ms (P<0.05) in DCM patients with LAD≤40 mm, 40 mm<LAD≤50 mm and LAD>50 mm, respectively. (3) DC value in the DCM group was negatively related to the LAD (r=-0.366, P<0.01), positively related to the LVEF (r= 0.241, P<0.01), but not related with age and sex. Multiple factors regression analysis showed that increased LAD was related to the reduced DC values independtly.@*Conclusion@#DC value of the patients in the DCM group is decreased, which indicate the decrease of the vagus nerve tension, and increased LAD is related to the reduced DC value independtly in DCM patients.
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Objective To assess the medical radiation exposure frequency and find out the main factors related to the collective dose derived from X-ray diagnosis procedures. Methods A survey of 3 178 hospitals was conducted to collect the basic information such as types of medical radiation, allocation of radiological diagnosis and treatment devices, the frequency of radiologic examinations, etc. By using a stratified sampling method,36 hospital were selected and more specific details, including 26 types of diagnostic radiologic examinations, were collected to estimate the collective dose to the population in Hubei, combining with the previous literature. Results A total number of 6 843 radiological diagnosis and treatment devices were covered and 33 771 855 medical radiologic procedures were counted in this survey. The result showed a annual frequency of 569.79 examinations per 1 000 population for all types of procedures. A large variation was revealed among different areas and the highest area was with a 4-fold frequency of the lowest area. Although tertiary hospitals accounted for 4.40% of the total hospitals, 48.42% procedures were carried out in them. The collective effective dose from X-ray diagnosis in Hubei was 65 399.55man·Sv, and the average annual effective dose was 1.10mSv, while contribution from CT scans accounted for 86.90% of the dose. Conclusion The frequency of medical radiologic procedures presented a consistent increase in Hubei province, with a uneven development among hospitals from urban and rural areas, or from different regions, or from different levels. Among all types of X-ray examinations, CT scan frequency had the fastest growth rate and accounted for the major annual collective effective dose. In order to reduce the health risk from medical radiologic exposure, CT scan need to be applied more properly and the radiation dose per single CT scan need to be limited to a reasonable level.
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Objective K93T point mutation exists in the quinoid dihydropteridine reductase ( QDPR) of OLEFT rats which catalyzes QDPR into tetrahydrobinopterin(BH4), while dihydrofolate reductase(DHFR) can reduce QDPR to BH4, which implies crosstalk between hydrobiopterin and folate metabolism.By investigating the influence of QDPR expression on DHFR expression of NRK-52E cells, the article aimed to find out the possible underlying mechanism of QDPR gene in diabetic nephropathy ( DN). Methods Western blot was performed to identify the expression level in NRK-52E cell under high glucose ambience and DHFR pro-tein expression of OLETF rats.NRK-52E cells were transfected by the lentivirus to establish no-load overexpression, overexpressed QDPR and knockdown QDPR models.Each group was given 5.4 mmol/L normal sugar medium and 30mmol/L in high glucose ambi-ence for 72 hours'cell cultivation to simulate DN model.Observation was made on the influence of QDPR gene expression levels on DHFR in high glucose ambience. Results The western blot analysis revealed that DHFR protein decreased in NHG group( [0.33 ± 0.16] vs [0.64 ±0.5], P<0.05) and OLETF rats cortex ([0.56 ±0.16] vs [1.03 ±0.12], P<0.01).In high glucose ambi-ence, compared with LV-OCON-HG group, the protein expression of DHFR was significantly decreased in LV-QDPR-HG group ([0.12 ±0.09] vs [0.63 ±0.08], P<0.01).No difference was found in the comparison of DHFR expression levels between LV-SHQDPR-HG and LV-SHCON-HG group. Conclusion DHFR protein expression decreases in NRK-52E cells of high glucose and LOLETF rat model, which suggests that DHFR protein plays an important role in the development of DN.QDPR overexpression leads to the decreased expression of DHFR, which implies that overexpressed QDPR influences the occurrence and process of DN by down-regulating DHFR expression level.
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_ Objective_ To study whether quinoid dihydropteridine reductase ( QDPR ) expression level change can affect oxidative stress of NRK-52E renal tubular cells in a high glucose environment. Methods The NRK-52E model of overexpression, knockdown QDPR gene and respective control were constructed by lentivirus. All groups were given 5. 4 mmol/L and 30 mmol/L glucose culture medium respectively to imitate normal and high glucose condition. The level of superoxide anion ( O-2 ) was detected by flow cytometer dihydroethidium method. The protein expression level of superoxide dismutase 1 (SOD1)was tested by Western blot. Results QDPR over-expression can decrease O-2(P<0. 01)and SOD1(P<0. 05)levels in high glucose condition;QDPR knockdown increases O-2(P<0. 01) and does not change SOD1. Conclusion Under high glucose condition, overexpression of QDPR gene decreases NRK-52E cell oxidative stress. Knockdown QDPR gene increases NRK-52E cell oxidative stress. QDPR gene may influence the development of diabetic nephropathy by oxidative stress.
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Objective To evaluate the influence of different clinic pathways on the time from first medical contact to balloon (FMC2B) and the time from door to balloon (D2B) for emergency patients with ST-segment elevation myocardial infarction (STEMI) treated with primary percutaneous coronary intervention as well as the prognosis. Methods 183 consecutive patients were divided into emergency easy access group and normal access group. The two groups were compared in terms of the FMC2B time, D2B time and outcomes during hospitalization and follow-up. Results Compared with the normal access group, the FMC2B time in the emergency easy access group was significantly shorter (100.3 min vs. 145.6 min, P < 0.05) and so it was with the D2B time (77.1 min vs. 115.4 min, P<0.05). Meanwhile, in-hospital mortality was significantly lower (5.0%vs. 15.7%, P<0.05). The follow-ups showed the rates of re-hospitalization related to heart diseases, and the mortality rate of cardiovascular disease were significantly lower in the emergency easy access group. Conclusion The optimized emergency easy access could reduce the FMC2B time and D2B time and improve the prognosis of patients with STEMI.
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Objective To evaluate the effects of preventive cardiac pacing on acute inferior wall myocardiac infarction ( AIMI ) . Methods A total of 52 patients were given preventive cardiac pacing before Percutaneous coronary intervention (PCI) (group T),while another 68 patients were not (group N).Heart rate and average blood pressure level before reperfusion, average blood pressure level after reperfusion,TIMI flow grade before and after reperfusion,the incidence of malignant ventricular arrhythmia after reperfusion and adverse cardiovascular events during hospitalization were compared in two groups. Results There were no significant differences in heart rate before reperfusion , average blood pressure levels before and after reperfusion , and the TIMI flow grade before and after reperfusion between two groups. The malignant ventricular arrhythmia after reperfusion in group T was significantly higher than that in group N while heart failure and nonfatal myocardial infarction were no significantly different between them. Mortality rate and mortality rate of cardiovascular disease in group T were higher than those in group N, but there were no significant differences between them. Conclusions The temporary cardiac pacing has no additional preventive effect on hemodynamic , but increases the occurrence of malignant ventricular arrhythmia , and the risk of death and cardiovascular events.
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Objective To investigate the dynamic characteristics of the pacemaker current of canine sino-atrial node cells and compare them with the wild type mHCN2 pacemaker current overexpressed in neonatal rat myocardial cells.Methods Fresh canine sino-atrial node cells were enzymatically isolated in a calcium-free solution containing collagenase and elastase,and the funny current was recorded and compared with the mHCN2 current overexpressed in cultured neonatal rat myocardial cells under the same experimental conditions.Results The canine sinus node cells were elongated,spindle-shaped or polygonal,with well-defined boundaries,and showed spontaneous beating.The elicited pacemaker current was an inward current and its rise in amplitude quickened as the hyperpolarization potential increased.At V =-75 mV,the canine sinus atrial node pacemaker current was (-2.1±0.3) pA/pF and had the same activation kinetics as those of the mHCN2 channel current overexpressed in neonatal rat myocardial cells [τact:(728±137) ms vs.(530±65) ms,P>0.05].Conclusions Within the physiological range,the pacemaker current in canine sino-atrial node cells and the wild type mHCN2 pacemaker current over expressed in neonatal rat myocardial cells have similar activation kinetics.
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Objective To identify the causes of coronary angiographic hazy lesions by intravascular ultrasound (IVUS) to avoid inappropriate stenting. Methods Twenty-five cases with hazy regions on coronary angiogram were consecutively identified from July 2009 to March 2010. Hazy regions were defined by coronary arteriongraphy as reduced contrast density without a clearly defined intimal tear, dissection,thrombus,or stenosis ( > 50% ). This cohort of patients were subsequently underwent IVUS examinations and treated according to the results of IVUS. Results The lumen CSAs were settled as > 4. 0 mm2 in all examinations. Among all 25 cases,hazy lesions were located in left anterior descending in 12 patients, right coronary artery in 6 patients, left circumflex in 5 patients, and left main artery in 2 patients. According to the IVUS findings, 2 cases showed absolutely normal or near-normal arterial wall structure image, 10 cases showed calcified plaque,5 cases showed plaque rupture,3 cases showed eccentric plaque ,2 cases showed thrombosis formation,2cases showed dissection,1 case showed subintimal hematoma. Seven patients received stent implantation, and the rest accepted medical therapy. There were no in-hospital MACEs reported among all patients. Conclusion Nearly half of the coronary arteriongraphic hazy lesions were caused by calcified plaque. IVUS can distinguish calcified plaques from intimal tears, thrombus and other underlying etiologies,and help to avoid unnecessary stenting.
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Objective To investigate the risk factors of in-stent restenosis (ISR) after coronary implantation of drug-eluting stent Methods One hundred and fifty-seven patients including 118 males and 39 females,who underwent successful implantation of drug-eluting stent, were recruited in the study. The patients were divided into the restenosis group (33 patients) and non-restenosis group ( 124 patients) according to the angiographic results. The associations of ISR with clinical and coronary angiographic characteristics were analyzed using univiriate analysis and logistic regression. Results In the restenosis group,there were 18 cases of diabetes mellitus ( 54. 5% ), 26 cases of frequency angina ( 78. 8% ), which were significantly higher than those of 31 cases of diabetes (25.0%) and 72 case of frequent angina (58. 1% ) in the non-restenosis group (χ2 = 10. 60, P < 0. 01, χ2 = 4. 77, P = 0. 03 for diabetes mellitus and frequent angina, respectively). Compared to non-restenosis group, the occurrence rates of chronic total occasion, bifurcatus lesions, diffuse lesions were significandy higher in the restenosis group ( 19. 3% vs 7. 6% χ2 =5.92,21.1% vs 10. 2% χ2 =4. 34,26. 3%vs 12. 1% χ2 =6. 32,Ps <0. 05). Fifty-seven stents were implanted into the restenosis group,and one hundred and fifty-seven into the non-restenosis group. Logistic regression analysis showed that diabetes, frequent angina,chronic total occlusion lesions, bifurcatus lesions, diffuse lesions, stent length and diameter were significantly associated with restenosis ( OR value were 3.52,2. 59,3.05,3. 14,3.08,0. 93,95% CI were 1.56 - 7.90,1.02 - 6. 59,1.11 - 8. 36,1.30 - 7.59,1.34 - 7.05,0. 88 - 0. 98 respectively, Ps < 0. 05 ). Conclusion After implantation of drug-eluting stent, diabetes mellitus, chronic total occasion lesions, frequent angina, diffuse lesions, bifurcatus lesions and stent length and diameter are associated with follow-up restenosis.
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Objective To study the relationships between hemoglobin concentration,cytokine and cardiac function in patients with ischemic cardiomyopathy.Methods Hemoglobin concentration,sernm TNF-α,IL-6 in 121 patients with ischemic cardiomyopathy were measured,left ventricular ejection fraction(LVEF)by echocardiography,according to hemoglobin concentration,these patients were distributed to the anemic group and the non-anemic group,contrasting to 27 healthy persons.Results The levels of serum TNF-α,IL-6 in the anemic patients group were higher than those in the non-anemic group subjects,but LVEF Wag lower.With the increase of anemia severity,the levels of serum TNF-α,IL-6 significantly increased;there was a positive correlation between LVEF and the levels of serum TNF-α,IL-6(P<0.01),and a negative correlation between LVEF and Hb concentration.Conclusion The levels of cytokine promote the pathophysiological procedure between cardiac failure and anemic in ICM.
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Objective To evaluate the safety and efficacy of the temporary bedside cardiac pacing in controlling torsades de points (TdP) in patients with acquired long QT syndrome (LQTS). Methods Twelve patients with acquired LQTS were enrolled from April 2003 to August 2007 consecutively and their clinical data were analyzed. Bedside cardiac pacing was adopted when other methods couldn't terminate the repeated TdP. Results Twelve patients successfully experienced the temporary bedside cardiac pacing via femoral venous. The average time spent in bedside cardiac pacing was about (10.5±2.4) min. After cardiac pacing the interval of QT and QTc were shortened [ (0.42±0.03 ) svs (0.52±0.06) s, P < 0.05; (0.43± 0.04 ) s vs (0.53±0.05 ) s, P <0.05 ]. The TdP occurred (4.6±1.2 ) times per day before cardiac pacing and it didn't reoccur any more after bedside cardiac pacing. The average time for cardiac pacing was(3.8±1.4) d. When the patients were discharged, the interval of QT and QTe were (0.41±0.02) s and (0.42±0.05) s respectively, there were significant differences compared with that before cardiac pacing(P< 0.05). During 1 year follow-up, the patients didn't experience TdP any more, and the interval of QT and QTe were (0.41± 0.06) s and (0.42±0.05) s respectively. Conclusion The immediate bedside cardiac pacing is a safe and effective way to control the repeated TdP.
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BACKGROUND: The implantation of electronic devices has become the preferred treatment tor symptomatic bradyarrhythmias.However,there are many shortcomings in electronic pacemakers.The usage of molecular biology principle to develop biological pacemaker has become a topic of discussion in research.When sinoatrial node is lnhlblted,pacemaker effect runs by transfecting hyperpolarization-activated cyclic nucleotide-gated(HCN)channel gene of If current,overexprcssing HCN,and increasing inward current in diastolic phase of the heart.Construction of biological pacemakefs by gene therapy and cell therapy may become an optimal substitute of electronic pacemakers in the near future.OBJECTIVE:To sum up the research advancement in application of HCN channel gene to the development of biological pacemaker.RETRIEVAL STRATEGY:The relevant articles published between January 1979 and June 2007 were searched for in Pubmed database by researcher of this article with the key words of"hyperpolarization-activated cyclic nucleotide-gated chartnel,biological pacemaker"in English.157 articles were selected and reviewed by the inclusive cntena of:① articles closely related with the application of HCN to the development of biological pacemaker;②the late articles and articles in anthority journals in the same field.Exclusive criterion:repetitive studies.LITERATURE EVALUATION:The main sources of literatures were randomized clinical trial(RCT)on biological pacemaker by HCN.Among 36 selected articles,10 were reviews,and others were elementary expenInental studles.DATA SYNTHESIS:①Of all four HCN isoforms,HCNI,HCN2,and HCN4 are the main isoforms in the heart.HCN3 only expresses in embryonic pacemaker cells in a low level.HCN2 highly expressed in low pacing regions(Ventricular muscle),whereas HCN4 highly expressed in high pacing regions.Moreover,HCN2 are the main isoforms in the ventricle.Expression ratio of HCN2 to HCN4 is 5:1 in neonate rats and 13:1 in adult rats.②Defects in HCN channels may underlie sick-sinus syndrome.③Up to now,HCN genes of If current contribute importantly to the generataon of the regular pacemaker potential.CONCLUSION:Gene therapy and cell therapy have become an optimal approach to improve biological paccmakers.Application of HCN channel gene in development of biological pacemaker may hold great promlse In the treatment of chronic arhythmia.
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Objective To investigate the relationship between infarct location and prognosis after emergency percutaneous coronary intervention (PCI) treatment in patients with acute myocardial infarction.Methods Consecutive 121 patients with ST elevation myocardial infarction (STEMI) who underwent primary PCI were divided into 3 groups according to the infarct location.Their clinical,ECG,echocardiography and coronary angiography features were analyzed,and the follow-up was made. Results Compared with inferior wall infarction group and inferior wall infarction combined with right ventricular infarction group,anterior wall myocardial infarction group had higher CPK-MB and cTnT,less frequent collateral,reduced ST-segment resolution,higher mortality rates in hospitalization and one year after discharge.On the other hand,inferior infarction combined with right ventricular infarction group had more occurrences of shock and atrial vetricular block or ventricular arrhythmia,more incidence of multivessel disease and thrombus,and higher readmission rate.Conclusion Patients with anterior wall myocardial infarction and inferior wall in
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Objective To analyze the effect of dominant accessory atrioventricular pathways (AP) on the end vector of ventricular depolarization. Methods All patients had single AP confirmed by radiofrequency cathteter abalation (RFCA) and were free from organic heart disease (including 102 cases of dominant accessory AP and 38 cases of concealed AP). The AP was divided into posterior septal(P3) ,mediate septal (MS) ,anterior septal (AS), left posterior free wall (LP), left anterior free wall (LA), right posterior free wall (RP) and right anterior free wall (RA). Results The end 40 ms vector of QRS wave changed in 102 patients with manifested AP and in 4 patients with concealed AP (P < 0. 05). Conclusion The end 40 ms vector of QRS wave of any site manifested AP can change and the changes have the specihty of leads.