Objective To set up an experiment model on cellular level in order to investigate the effects of aconitine on Connexin43(Cx43)in cardiomyocytes of rat.Methods The cultured cardiomyocytes of rat were incubated with aconitine at 6 different concentrations of 0.25,0.5,0.75,1.0,1.5 and 2.0 ?mol/L.The changes of Cx43 phosphorylation status of each group were investigated by Western blot analysis and immunofluorescent microscopy techniques.Results The total amount of Cx43 had not changed in cardiomyocytes after aconitine incubation by western blot analysis,but it began to induce Cx43 dephosphorylation after incubation of the cultures with 0.5 ?mol/L aconitine and Cx43 underwent significant dephosphorylation when the concentration of aconitine elevated to 1.0 ?mol/L,and the dephosphorylation effects of 1.5 and 2.0 ?mol/L aconitine on Cx43 were similar to that of 1.0 ?mol/L aconitine.Quantitative immunofluorescent microscopy revealed that Ser368,one of the serine amino acid phosphorylation sites in the C-terminal domain of Cx43,underwent significant dephosphorylation when incubation of the cardiomyocytes with 1.0 ?mol/L aconitine.Conclusion Under certain concentration conditions,aconitine can induce significant dephosphorylation of Cx43 in the cardiomyocytes of rat.

Objective Atrioventricular block (AVB) is a common and serious arrhythmia. At present, there is no perfect method of treatment for this kind of arrhythmia. The purpose of this study was to regenerate cardiac atrioventricular conduction by autologous transplantation of bone marrow mesenchymal stem cells (MSCs), and explore new methods for therapy of atrioventricular block. Methods Eleven Mongrel canines were randomized to MSCs transplantation (n=6) or control (n=5) group. The models of permanent and complete AVB in 11 canines were established by ablating His bundle with radiofrequency technique. At 4 weeks after AVB, bone marrow was aspirated from the iliac crest. MSCs were isolated and culture-expanded by means of gradient centrifugal and adherence to growth technique, and differentiated by 5-azacytidine in vitro. Differentiated MSCs (1ml, 1.5×107cells) labeled with BrdU were autotransplanted into His bundle area of canines by direct injection in the experimental group, and 1ml DMEM in the control group. At 1-12 weeks after operation,the effects of autologous MSCs transplantation on AVB models were evaluated by electrocardiogram, pathologic and immunohistochemical staining technique. Results Compared with the control group, there was a distinct improvement in atrioventricular conduction function in the experimental group. MSCs transplanted in His bundle were differentiated into analogous conduction system cells and endothelial cells in vivo, and established gap junction with host cardiomyocytes. Conclusions The committed-induced MSCs transplanted into His bundle area could differentiate into analogous conduction system cells and improve His conduction function in canine AVB models.

Objective Right ventricular outflow tract septum has become widely used us an electrode placement site. However, data concerning lead performances and complications for lead repositioning with this technique were scant. The purpose of this study was to observe long-term lead performances and complications of right ventricular outflow tract septal pacing and provide evidences for choosing an optimal electrode implantation site. Methods Thirty-six patients with septal active electrode implantation and 39 with apical passive electrode implantation were enrolled in this study. Pacing threshold, R-wave sensing, lead impedance, pacing QRS width and pacing-related compli-cations for two groups at implantation and follow-up were compared. Results There were higher pacing threshold and shorter pacing QRS width at implantation in the septal group compared with the apical group. There were no differences between the septal and the apical groups in pacing threshold, R-wave sensitivity, lead impedance and pace-related complication during a follow-up. Conclusions Right ventricular outflow tract septum could be used as a first choice for implantation site because it had long-term stable lead performances and no serious complications compared with the traditional apical site.

AIM:Chronic heart failure (CHF), caused by ischemic cardiomyopathy (ICM) and nonischemic cardiomyopathy (NICM), is among the leading causes of mortality and morbidity worldwide .Low-density lipoprotein receptor-related protein 6 (LRP6) plays a criti-cal role in regulating Wnt signaling .Dysregulated Wnt signaling contributes to high incidence of arrhythmias .Thus, there might be an association between genetic variations of LRP6 and sudden cardiac death ( SCD) .The objective of the study was to examine the associ-ation between common variants of LRP6 and prognosis of CHF patients .METHODS:From July 2005 to December 2009, patients with CHF referred from 10 hospitals and participants without structural heart disease in China were undergone a prospective study .The sin-gle-nucleotide polymorphism rs 2302684 was selected to evaluate the effect of LRP6 polymorphisms on the survival of the patients .RE-SULTS:A total of 1 887 patients (1 437 with CHF and 450 in the control group)were finally enrolled for the analysis.During a medi-an follow-up of 61 months, a total of 546 (38.00%) patients died, including 201(36.81%) cases with SCD and 345 (63.19%) ca-ses with NSCD.No end point event occurred in the control group .Patients carrying A allele of rs2302684 had increased risks of all-cause death (P<0.01) and SCD (P<0.01).After adjusted for the other risk factors , the associations remained significant in all-cause death (P<0.01) and SCD (P<0.01).In patients with CHF caused by ICM , those carrying A allele of rs2302684 also had in-creased risks of all-cause death (P<0.01) and SCD (P<0.01).After adjusted for the other risk factors , the associations remained significant in all-cause death (P<0.01) and SCD (P<0.01).However, there was no association between A allele of rs 2302684 and prognosis in patients with CHF caused by NICM .CONCLUSION:The SNP rs2302684 T>A in LRP6 is associated with an increased risk of all-cause death and SCD in patients with CHF in Chinese Han population , and the association is more prevalent in patients with CHF caused by ICM.Thus, LRP6 might be added as a novel predictor of SCD and could provide an attractive and direct therapeutic target in SCD prevention .

Objective: To study the predictive value of 12-lead electrocardiogram (ECG) abnormality on prognosis of chronic heart failure in patients with dilated cardiomyopathy (DCM-CHF).
Methods: A prospective, multicenter follow-up study in 787 DCM-CHF patients was conducted, and the endpoints were obtained by clinical visit, mail contact and telephone conversation. The independent predictors for all cause death were determined by Cox regression analysis, QRS duration > 120 ms was studied and the survival rates were investigated by Kaplan-Meier analysis.
Results: There were 203 patients died during the follow-up period. Cox regression analysis found that the following indexes were related to all cause death: atrial fibrillation (AF) (HR=2.064, 95% CI 1.102-3.864,P<0.05), non-sustained ventricular tachycardia (NSVT) (HR=3.887, 95% CI 1.554-9.724,P<0.05) and QRS duration (HR=1.010, 95% CI 1.002-1.018, P<0.05). Kaplan-Meier analysis revealed that the survival rates were different by each stratiifcation of QRS duration,P<0.05.
Conclusion: ECG indexes of AF, NSVT and QRS duration had the important impact on the survival rate in DCM-CHF patients; there were signiifcant differences between QRS durations and survival rates.