Objective To investigate the effects of erythropoietin(EPO) on extracellular matrix remodeling and the expressions of matrix metalloproteinase(MMPs) and tissue inhibitor of metalloproteinase-4(TIMP-4) after myocardial infarction in rats.Methods Eighty male SD rats were randomly divided into four groups:sham operation(SH) group,sham operation and drug(SHE) group,myocardial infarction(MI) group,and myocardial inferct and erythropoietin(MIE) group.Myocardial infarction in MI group and MIE group was reproduced by ligation of a branch of left anterior descending coronary artery.Hematocrit,echocardiography,capillary density,infarct area,fibrosis and collagen volume fraction were tested,and MMP-2,MMP-9 and TIMP-4 were measured by immunohistochemistry at 1-week and 6-week after myocardial infraction.Results One week after myocardial infraction,the protein expressions of MMP-2 and MMP-9 in MI and MIE groups were significantly higher than that in SH and SHE group(P0.05).Six weeks after myocardial infraction,echocardiography revealed that the left ventricular end-diastolic dimension(LVDd),left ventricular end-systolic dimension(LVDs),left ventricular end-diastolic volume(LVEDV) and left ventricular end-systolic volume(LVESV) were significantly increased,and left ventricular ejection fraction(LVEF) and left ventricular fractional shortening(LVFS) were significantly decreased in MI and MIE groups compared with those in SH and SHE groups(P

The data from clinical studies have shown that conventional dual chamber pacing results in high percentages of right ventricular apical pacing,which causes electromechanical desynchronization and has been linked to an increased risk of heart failure and atrial fibrillation.Nowadays,we can use some special algorithms to minimize ventricular pacing,promote atrioventricular conduction and improve hemodynamics in patients with pacemakers.This review summarizes the genesis,some algorithms and clinical studies about minimizing ventricular pacing.

Objective To study the effect of apoptosis signal regulating kinase 1(ASK1) protein expression in hypertrophic myocardium in rat models of hypertension.Methods The rat model of hypertension was established by abdominal aortic constriction.Six weeks later,the reactive oxygen species(ROS) level and ASK1 protein expression in myocardium of left ventricle were detected respectively by color matching and Western blotting.Results The left ventricular mass index,ROS level and ASK1 protein expression all increased significantly in hypertensive rats as compared with those underwent sham operation.Conclusion Under chronic pressure overload,the activated ASK1 with the increasing ROS may play an important role in signal transduction pathway of myocardial hypertrophy.

Objective To explore the expressions of cardiac protein kinase C(PKC),IGF-1(insulin-like growth factor 1) and the effect of drugs in the process of left ventricular remodeling(LVRM).Methods SD rats were randomly divided into four groups: sham operation group,infracted group,Captopril group and Valsartan group.Except for sham operation group,left anterior descending coronary artery was ligated in all rats of the other three groups and the intragastric administration of solvent,100 mg?kg~(-1)?d~(-1) Captopril and 20 mg?kg~(-1)?d~(-1) Valsartan was done on day 3 after operation for 8 weeks,then LVRM was evaluated by pathologic analysis.Expression changes of cardiac AgT_(1)R,PKC,and IGF-1 were detected by immunohistochemistry and computer image analysis.IGF-1 mRNA expression was analyzed by RT-PCR.Results LVW,LVWI and the expressions of AgT_(1)R,PKC,IGF-1 mRNA and proteins were significantly enhanced(P

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 evaluate the value of Vascular Closure Device(VCD)with the new Angio-Seal STS(Self-Tightening Suture)in femoral artery closure after coronary angiography(CAG)or percutaneous coronary intervention(PCI).Methods Totally 298 patients were divided into Angio-Seal STS group(group A,n=120)and manual compression group(group B,n=178).The success rate of hemostasis,the time of hemostasis,the time of bedrest and the complication rate were observed.Results Compared with group B,the time of hemostasis,the time of bedrest and the rate of distress on the waist were markedly decreased in group A(P0.05).Conclusion Angio-Seal STS vascular closure derice provided a safe and effective means of obtainig rapid arterial hemostasis after cardiac catheterization.It reduces the bedrest time and discomfort without increasing complications.Angio-seal STS device has the feature of self tightening suture,and doesn't need the post-placement tension spring.

Objective To investigate the mechanism by which rosiglitazone affects no-reflow following reperfusion after acute myocardial infarction(AMI).Methods Forty-five SD rats were randomly divided into sham-operated group,normal saline treated group and rosiglitazone treated group(at dose of 3 mg?kg-1?d-1,for 14 d),15 rats in each group.To establish no-reflow model,the rats of the latter two groups received coronary artery ligation for 3 h and reopening for 2 h.Then pathological staining for no-reflow area,chemical assay for MPO activity,immunohistochemistry and RT-PCR for protein and mRNA expressions of ICAM-1 and P-selectin in myocardium were performed.Results No-reflow area in rosiglitazone treated group was significantly reduced,compared with that in normal saline treated group(P

0.05).Compared with those in Sham group,LVWI,the typeⅠCVF,type Ⅲ CVF andⅠ/Ⅲ ratio in NIZ were increased significantly in MI group.Compared with those in MI group,the LVWI,the type ⅠCVF,type Ⅲ CVF andⅠ/Ⅲ ratio in NIZ were decreased significantly in Sim groups(but higher than those in Sham group).Compared with MI groups,left ventricular function in rats treated with simvastatin was also obviously improved.(2) Contrasted to those in MI group,the expressions of TGF-?1 and Smad3 were down-regulated in simvastatin treatment groups(but higher than those in Sham group).Conclusions Sim can ameliorate ventricular remodeling and ventricular function in rats induced by MI,and the mechanisms can be independent of its lipid-lowering and associated with inhibition of TGF-?1/Smad3 signal transduction.

Objective To investigate the beneficial effects of simvastatin on ventricular remodeling in rats after myocardial infarction and the possible mechanisms involved.Methods The myocardial infarction rat model was reproduced.Twenty-four hours after infarction,the survived rats were randomly divided into myocardial infarction group(MI group,n=9),simvastatin 10mg group [10mg/(kg?d),Sim1 group;n=8],simvastatin 20mg group [20mg/(kg?d),Sim2 group;n=10] and simvastatin 40mg group [40mg/(kg?d),Sim4 group;n=9].A sham-operated group(Sham group;n=10) served as control.Four weeks later,the serum lipid level,hemodynamic indexes and left ventricular weight index(LVWI) were measured.The changes in rats' myocardial tissue were observed with HE staining;the cross-sectional area of myocardial cells was calculated.The expressions of transforming growth factor ?1(TGF-?1) and TGF-?-activated kinase 1(TAK1) in non-infarction area were determined by Western blotting and reverse transcription polymerase chain reaction(RT-PCR).Results The hemodynamic indexes,LVWI,cross-sectional area of myocardial cells and the pathological changes were improved,and mRNA and protein expressions of TGF-?1 and TAK1 were down-regulated significantly in the 3 Sim-treated groups compared with that in MI group.The indices mentioned above were significantly different in Sim2 and Sim4 group compared with Sim4 group(P0.05).Conclusion The inhibitory effect of simvastatin on ventricular remodeling after acute myocardial infarction is independent of its lipid-regulating effect,but possibly attributed to its action in inhibiting the TGF-?1/AK1 signal transduction.Within the concentration of 20mg/(kg?d),the therapeutic efficacy of simvastatin may be more obvious with an increase in its dosage.

Objective To explore a new way for the treatment of distal segment finger amputations.Methods From Aug 2001 to Feb 2005,the method of subcutaneous pocket was applied to 122 complete distal segment finger amputations in 70 patients.After the nail of amputated parts was removed,fractured bone segments fixed with K-wires and amputated part de-epithelialized to the middermal layer,the reattached parts were separately inserted into the subcutaneous pocket of chest,abdominal or ipsilateral palm.After 16 to 20 days,the reattached parts were removed from the subcutaneous pocket. Results One hundred and twenty-two finger amputations of 70 cases had recovered completely.The replanted fingers had satisfactory sensation and appearance.Conclusion It is a simple and effective method for the treatment of distal segment finger amputations,particularly for the finger amputations when the vascular anastomosis is not feasible.