Objective:To investigate the correlation between heart rate turbulence(HRT)and heart rate variability(HRV)indices,and the impact of mean R-R interval,?-blocker and other factors on HRV and HRT.Methods:76 postinfarction patients were recruited.24-hour,three-lead ambulatory electrocardiography was performed in all subjects for the analysis of HRV(including SDNN,PNN50,RMSSD,HF,LF)and HRT(including TO and TS).And the general clinical data of each case were collected.Results:TS was positively correlated with SDNN(r=0.559,P

Although the evidence-based medicine(EBM) plays an important role in modern medicine,there has been a growing conflict between EBM and the clinical teaching practice in the department of cardiology.By analyzing the reasons,the author has brought forward some suggestions to solve these problems.

Objective To investigate whether taking diastolic potential(DP)and earliest Purkinje potential(PP)as ablation targets together is superior to taking earliest PP alone in patients with left posterior fascicular ventricular tachycardia(VT).MethodsTotally 18 patients who were admitted in our department from May 2006 to May 2009 were enrolled,and the results of their electrophysiological examination were analyzed.According to radiofrequency(RF)ablation targets,patients were classified into 2 groups:DP+PP group(DP and PP as ablation targets together)and PP group(PP as the target alone).Successful RF ablation was established when the ventricular tachycardia was no longer inducible.The acute success rate,recurrent rate,number of ablation application,procedure time,X-ray exposure and complications were compared between DP+PP and PP groups.ResultsThere was 1 case receiving no ablation because of not being induced to clinical VT.Seventeen cases were induced to clinical VT and displayed right bundle branch block(RBBB)and left axis morphology(DP+PP group 7 cases,and PP group 10 cases).All cases were successfully ablated,their DP-Q interval and PP-Q interval were 60.17?8.16 and 30.64?7.19 ms,respectively.There was no significant difference between the 2 groups in the age,ventricular tachycardial cycle,procedure time and recurrent rate.Compared to the PP group,the number of RF application in DP+PP group was fewer(4.55?2.07 vs 7.50?1.64,P=0.04),and X-ray exposure time was a little longer(18.33?1.51 min vs 15.37?2.77 min,P=0.03).There was neither left posterior fascicular block nor other complications seen in the 2 groups.The follow-up period was 14.29?10.05 months,and during this there was 1 case recurrence in DP group(2 months after procedure)and 1 case in PP group(1 month after procedure)respectively.ConclusionThe 2 methods are effective and safe for successful ablation of left posterior fascicular VT.Compared to ablation of earliest PP site alone,ablation of DP+PP might need fewer times of RF application but longer X-ray exposure time.

Objective To investigate the feasibility of transplantation of human fetal liver-delivered mesenchymal stem cells(HFMSCs) and porous microcarries into normal heart tissue and whether it can improve heart function and regeneration of heart tissue.Methods SD rats were divided into HFMSCs injection group(n=9),microcarrier injection group(n=9) and control group(n=4),in which 80-100 ?l Perfadex with HFMSCs or gelatin porous microcarriers or pure Perfadex was injected into the wall of left ventricle.Heart function was evaluated by UCG before and 7 d after transplantation.On day 7,14,the survival of HFMSCs was tested by fluorescent in situ hybridization(FISH),regeneration or cardiac differentiation by immunohistological staining against desmin,tropomyosin and lectin,cellular immune response by the infiltration of macrophages,and lymphocyte reaction to HFMSCs by mixed lymphocyte culture(MLC) in vitro.Results Seven days after injection,the HFMSCs survived and improved the heart function,though no sign of differentiation into cardiomyocytes was seen.On day 14,a large amount of macrophages infiltrated into injection sites,and MLC showed prominent enhancement of proliferation of lymphocytes,when no transplanted cells were detected in the myocardium.On day 7,14,the microcarriers retained their round shape at the injection sites and were attatched by a large quantity of cells which were proven not cardiomyocytes or capilaries by immunohistological staining.Conclusion Transplantation of HFMSCs into normal heart improves heart function by short-period survival without differentiation,but the transplanted cells disappeared because of immune reaction.Transplantation of porous microcarriers into normal heart could not improve heart function either by regeneration of heart tissue or capilaries.

Objective To explore the cardiac differentiation of human embryonic stem cells(ESCs)in coculturing with human fetal cardiomyocytes.Methods Fetal cardiomyocytes and fibroblasts were obtained from the aborted fetus,and human ESCs were from the inner cell mass(ICM)of the surplus embryos for tube babies,with the treated fibroblast as feeder layer.Human ESCs of passage 2 to 5 were cocultured with fetal cardiomyocytes at the ratio of 1∶2,and the XY chromosome types of these two kinds of human cells were different to each other in order to be marked.At the same time,human ESCs without coculture were used as negative control.The cocultured cells were harvested 5 days later and were double-stained with human XY chromosome probe and cardiac specific antibody(desmin or cardiac troponin I,cTnI).Results On coculture day 5,40%-50% human ESCs expressed cardiac specific antigens,and human ESCs without coculture did not express those antigens.Conclusion Human ESCs could be induced into cardiac differentiation by the coculture with fetal cardiomyocytes,and hopefully they will be the candidate for cell transplantation of heart.

OBJECTIVETo assess the correlation of CHADS₂and CHA₂DS₂-VASc scores for left atrial thrombus in patients with nonvalvular atrial fibrillation and the differences in the results between the two scoring systems.

METHODSA total of 397 patients with nonvalvular atrial fibrillation were enrolled in this study. The CHADS₂and CHA2DS2-VASc scoring systems were used for evaluating the risk of left atrial thrombus and their differences in the scores and risk stratifications were compared. The correlation of CHADS₂ and CHA₂DS₂-VASc scores with left atrial thrombus was analyzed.

RESULTSThe average score of CHA₂DS₂-VASc was significantly higher than that of CHADS₂in these patients (1.37 ± 1.19 vs 0.63 ± 0.78, P<0.001). The proportion of high-risk group was significantly higher (P<0.001) while that of low-risk group significantly lower as stratified by CHA₂DS₂-VASc scores than by CHADS₂scores (P<0.001). Transesophageal echocardiography detected left atrial thrombus in 44 of the total patients. The prevalence of left atrial thrombus increased significantly with a higher risk stratification by CHADS₂or CHA₂DS₂-VASc scores (P<0.05). Univariate analysis showed that female gender, age ≥ 65 years, left atrium diameter ≥ 38 mm, left ventricular ejection fraction ≤ 40%, hypertension, diabetes, coronary heart disease, stroke history, CHADS₂≥ 2, and CHA₂DS₂-VASc ≥ 2 were all correlated with left atrial thrombus, but multivariate logistic analysis identified only CHA₂DS₂-VASc ≥ 2 as the independent risk factor for left atrial thrombus (OR=9.85, 95% CI: 2.178-44.542, P < 0.01).

CONCLUSIONThe average score of CHA₂DS₂-VASc is higher than that of CHADS₂and has better predictive ability for left atrial thrombus.

Atrial Fibrillation ; complications ; Echocardiography, Transesophageal ; Female ; Heart Atria ; pathology ; Humans ; Male ; Risk Factors ; Thrombosis ; complications ; diagnosis

Objective To explore the effect of web problem-based learning in electrocardiography (ECG) teaching.Methods 100 clinical medical students from Grade 2014 were randomly selected and divided into two groups,with 50 in each.The control group received traditional methods in ECG teaching,while the WPBL teaching method was conducted in experimental group.The effect of ECG teaching in two groups were evaluated and analyzed by test scores and questionnaire survey.Continuous variables were expressed as mean ± standard deviation and were compared by t-test.Categorical variables were expressed as counts and percentages.Counting data were test by Chi-square.Results Comparing with control group,students in the experimental group performed better on independent learning capability,interesting of learning ECG,ability to analyze and solve problems,team cooperation,self-presentation and presentation skills (P＜0.05).The average experimental score in experimental group was higher than that in control group [(32.91 ± 3.56) vs.(27.38 ± 4.63),P＜0.05].There were no significant differences of theoretical scores between the two groups [(54.16 ± 3.87) vs.(52.84 ± 4.56),P＞0.05].Conclusion WPBL teaching could improve medical students' interest in electrocardiogram learning and cultivates their ability of active learning and problem solving,which is worthy of promotion.