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Objective To evaluate the effects of cardiac resynchronization therapy with pacemaker (CRT- P) and cardiac resynchronization therapy with defibrillator (CRT -D) on the outcomes of patients with heart failure.Methods MEDLINE,Cochrane Controlled Trials Register,EMBASE and Chinese Wan Fang,CNKI database were searched to collect data from randomized controlled trials and cohort trials of CRT - P versus CRT - D for the treatment of heart failure from January 1,1990 through September 30,2011.Meta - analysis of data including all causes leading to mortality and mortality of sudden cardiac arrest and heart failure was carried out by using the RevMan 5.0 package.Results A total of 3 404 patients were collected from seven studies.Pooled analysis demonstrated CRT - D significantly reduced mortalities of all causes in comparison with CRT - P [ odds ratio (OR) =0.61,95％ confidence interval (CI) =0.47 ～0.79,P =0.0001 ].Sub - group analysis showed that an increased benefit was seen after extended follow -up period ( after 1 year,OR =0.56,95 ％ CI =0.41 ～ 0.77,P =0.0004),but not after relatively short follow - up period ( within one year,OR =0.76,95 ％ CI =0.54 ～ 1.06,P =0.11 ).Mortalities of sudden cardiac arrest ( OR =0.20,95％ CI =0.07 ～ 0.59,P =0.003) and heart failure ( OR =0.72,95％ CI =0.54 ～ 0.96,P =0.02) of patients treated with CRT - D were lower than those of patients treated with CRT- P.Conclusions This study suggests that CRT - D is superior over CRT - P in respect of better outcome of patients with heart failure.
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Objective To assess the change of left ventricular wall motion at ventricular pacing(VP)by using global circumferential strain (GCS) and segmental circumferential strain of speckle tracking imaging(STI). Methods Seven adult pigs were sedated,followed by median sternotomy and opening of the pericardium. Temporary pacing leads were placed on the right ventricular (RV) epicardium and LV epicardium for RV or LV pacing. A LV short axis view at the mid-level LV was acquired at sinus and VP rhythm. Analysis of circumferential strain by STI was performed offline. The onset of QRS wave was used to characterize the beginning of the cardiac cycle, and the ratio of beginning systolic time, end systolic time and total systolic time to cardiac cycle dyssynchrony was analyzed at sinus and VP rhythm. Results Compared with sinus rhythm,in VP rhythm all of the ratio of the beginning systolic time,end systolic time and total systolic time to cardiac cycle were increased (all P ＜0.05), and the construction of six segments were dyssynchrony,even segmental paradoxical movement. At VP ≥130 beats/min,both LV global and LV segments sometimes showed irregular motion while the EKG remained normal, which included: ( 1 ) multiple construction and diastole in one heart cycle; (2) A large variability of construction amplitude in several consecutive cardiac cycles. Conclusions VP can lead to several kinds of disturbance of left ventricular wall motion, including delay and lengthening of LV systole, dyssynchrony, and irregularity of systole and diastole.
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BACKGROUND:Alterations in secondary hemodynamics around the stent edge can be caused by stent planted. Is there different effect of shear stress on platelet growth factors-A, B (PDGF-A, B) and basic fibroblast growth factor (bFGF) of endothelial cells around stent edge after stent planted?OBJECTIVE: To explore the effect of shear stress on growth factors of endothelial cells around stent edge.DESIGN: Observational comparative study.SETTING: Department of Cardiology, Yijishan Hospital, Wannan Medical College; Laboratory of Biomechanics (National Laboratory), Medical College of Shanghai Jiao Tong University.MATERIALS: The experiment was carried out in the Laboratory of Biomechanics, Medical College of Shanghai Jiaotong University from April to October 2006. The main reagents were detailed as follows: trypsin (Hyclon Company); M-199 medium (Gibco BRL Company); fetal bovine serum (Hangzhou Sijiqing Bioengineering Material Institute); aFGF, Heparin and Hepes (Sigma Company); thymide, Ⅷ factor monoclonal antibody (Rabbit anti-human),biotinylated horse anti-rabbit IgG and propidium lodide (Sigma Company); neonate belly band (Delivery Room of Shanghai the Fifth People's Hospital); trizol (Invitrogene Company); reverse transcription polymerase chain reaction (RT-PCR) kit (Fermentas Company); penicillin/streptomycin (AB/M), objective gene primer (Shanghai Bioengineering Company).METHODS: Traditional parallel-plate streaming cavity was modified into rectangular and gradient shear stress models;while static group was established at the same time. Two shear stress groups were subjected to 11.37 dyne/cm2 and 5.66-14.38 dyne/cm2 shear stress, respectively for 3 hours, 6 hours and 12 hours.MAIN OUTCOME MEASURES: The expressions of PDGF-A, B and bFGF mRNA of human umbilical endothelial cells (HUVECs) were measured by RT-PCR at different time points.RESULTS: Compared with static group, the maximal expression of PDGF-A, B and bFGF mRNA was reached peak at 3 hours in gradient shear stress group and this level of PDGF-A mRNA expression remained till 12 hours. in rectangle shear stress group, the peak value of mRNA expression of these growth factors was all reached at 6 hours, and then gradually decreased.CONCLUSION: Over-expressions of PDGF-A, B and bFGF induced by gradientshear stress after stent planted may play an important role in stent restenosis through intimal hyperplasia.
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Antithrombotic therapy is essential to success of percutaneous cardiovascular intervention(PCI)and reduction of postprocedural thrombotic complications.Antiplatelet and anticoagulant therapies are central to current antithrombotic therapy.The mechanism of thrombogenesis,related factors,clinical guidelines and considerations associated with antithrombotic drugs are illustrated in this paper.