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Objective Implantable cardioverter defibrillator(ICD)can effectively treat lifethreatening ventricular arrhythmias.The most common side effect is inappropriate discharge.This study analyzes the incidence and causes of inappropriate discharges of ICD in our hospital.Methods Forty.threepatients implanted with ICD in our hospital from November 2001 to October 2007 were involved in our study.Patients were followed-up regularly.All episodes recorded and stored in the ICD were analyzed.Results Seven of the 43 patients underwent ninety-six inappropriate discharges.Inappropriate discharges in six patients were caused by supraventricular tachyarrhythmias(SVT).In one patient the discharge was caused by noise.Most inappropriate discharges occurred in the first year after implantation.The history of atrial fibrillation before implantation is an independent predictor of inappropriate discharges.Conclusions The incidence of inappropriate discharge is 16.3%in our study and the most common cause is SVT.Most inappropriate discharges occur in the first year after implantation.Patients with atrial fibrillation history have a higher risk of inappropriate discharges.
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Objective To investigate the expression and significance of activator protein-1 (AP-1)and matrix metalloproteinases (MMPs) in acute myocardial infarction (AMI) subjects. Methods Immunohistochemical techniques were used to detect the subunit of AP-1 (c-Jun), MMP-2 and MMP-9 in human AMI and normal heart tissue and the expressions of c-Jun and MMPs were measured with computer image analysis system. Results (1) There were expressions of c-Jun, MMP-2 and MMP-9 in normal heart tissue, mainly in myocardial cells and cardiac fibroblasts, and their expressions in AMI myocardial tissues were all significantly higher than those in normal myocardial tissues (P <0.05). (2) The level of MMP-9expression was significantly and positively correlated with c-Jun in AMI heart tissue (r=0.773, P < 0.01).Conclusions The expressions of AP-1 and MMPs increase in human myocardial infarction. These findings suggest that AP-1 transcription activation pathway and MMPs may play an important role in ventricular remodeling of myocardial infarction.
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Objective To analyze the clinical and electrophysiological features of one geneology with limbgirdle muscular dystrophy(LGMD). Methods Twenty-seven members of one family with limb-girdle muscular dystrophy(LGMD)were investigated.Fourteen of them were examined with electromyography(EMG)and their motor conduction velocities(MCV)and sensory conduction velocities(SCV)were measured.Among them,10 had no clinical manifestations,while 4 demonstrated symptoms and signs of LGMD. Results Three of the 4 patients had suffered from LGMD when young.They demonstrated the typical clinical features,including the progressive muscle weakness in the upper and lower extremities,positive Gower signs,duck gait,muscle atrophy distributed tO the proximal extremity,and no gastrocnemius hypertrophy.One subject presented atypical characteristics.The MCVs and SCVs of the 4 patients were normal,but neuropathic manifestations were found in the EMGS of 3 of them.and mixed neuropathic and myopathic manifestations were found in the EMG of the other.Conclusion LGMD patients in the same family can vary in their clinical characteristics.The longer the duration,the more severe the clinical features.Electrophysiological examination can reveal normal MCV and SCV but abnormal elctromyography.
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AIM:To investigate the effects of ox-LDL on TLR2 and TLR4 expression and production of TNF-?,IL-10,IL-12,NO and MDA in macrophages and to observe intervention effect of GW1929 in above procedure.METHODS:The mouse peritoneal macrophages were pretreated with ox-LDL(50 mg/L,100 mg/L)and GW1929(20 ?mol/L)respectively for 24 h.The concentrations of MDA,NO-2/NO-3,TNF-?,IL-10 and IL-12 in the culture fluid were detected.Flow cytometry was used to observe TLR2 and TLR4 expressions after the mouse peritoneal macrophages were pretreated with ox-LDL(50 mg/L)and GW1929(20 ?mol/L)respectively for 6 h,12 h,and 24 h.RESULTS:The concentrations of MDA,NO-2/NO-3,TNF-? and IL-10 in ox-LDL(50 mg/L,100 mg/L)group were higher than those in control and GW1929 group obviously,but the concentrations of above index in ox-LDL(50 mg/L,100 mg/L)+GW1929 group were lower than those in ox-LDL(50 mg/L,100 mg/L)group apparently.No IL-12 in every group was detected.Expressions of TLR-2 in ox-LDL+GW1929(6 h,12 h,24 h)group were lower than those in ox-LDL(6 h,12 h,24 h)group respectively.TLR-4 expressions in ox-LDL+GW1929(12 h)were lower than those in ox-LDL(12 h)apparently.CONCLUSION:ox-LDL up-regulates TLR2 and TLR4 expressions and promotes the production of ROX,NO,TNF-? and IL-10 in macrophages.GW1929 is capable of inhibiting the above ox-LDL effects.
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AIM: The aim of this study was to investigate the possibility of establishing a chronic atrial fibrillation model with long-term rapid atrial stimulation ( 1 000 bpm), which was performed in rabbits in vivo. METHODS: 20 rabbits were randomly divided into 2 groups: 1) control group (n=10): pacemaker was implanted but no pacing; 2) experimental group (n=10): a left intercostal thoracotomy was performed and the pericardium was opened to expose the heart and a steel-wire pacing electrode was fixed on the epicardium of the left atria in 10 rabbits. Then the rapid pulse generator was implanted subcutaneously in the left abdominal region and rapid atrial pacing ( 1 000 beats/min) was initiated and continued for 30 days. Electrocardiogram (ECG) was monitored and recorded on day 1, 3, 5, 7, 14, 21 and 30. The atrial effective refractory period (AERP) was measured before pacing and at the time of fibrillation. RESULTS: On day 14, atrial fibrillation was developed in 8 rabbits (80%) and sustained at least till to day 30 (P