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Objective To observe the influence of tea pigment on myocardial contractility,electrocardiogram(ECG) and heart rate in exsomatized toads under the condition of myocardialischemia.Methods Sixty toads were divided into the normal exsomatized toad heart group(A) and myocardial ischemia toad heart(B).Then the group A was re-divided into the Ringer's solution group (A1),tea pigment low dose(200 mg/L) group(A2) and the high dose(400 mg/L) group(A3);the group B was re-divided into the pituitrin model group(B1),pituitrin + tea pigment low dose(200 mg/L) group(B2) and high dose(400 mg/L) group(B3).The BL-420S biological function experiment system was used to record the myocardial contractile force and ECG change curve of exsomatized toad.Results Compared with the group A1,the myocardial contractility in the group A3 was obviously increased(P＜0.05),the difference in the group A2 had no statistical significance(P＞0.05);the QRS peak value of ECG and heart rate had no statistically significant difference(P＞0.05);compared with the group A1,the myocardial contractility,ECG QRS peak value and heart rate in the group B1 were significantly decreased(P＜0.05);compared with the group B1,the myocardial contractility,ECG QRS peak value and heart rate in the group B2 and B3 were significantly increased(P＜0.05).Conclusion Tea pigment can obviously improve the decrease of the exsomatized toad cardiac activity caused by myocardial ischemia.
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The Long-term Thromboembolic Event Analysis in Atrial Fibrillation Patients With Radiofrequency Catheter Ablation Objective: To observe the thromboembolic event in atrial fibrillation (AF) patients with long-term successful radiofrequency catheter ablation (RFCA), and to study the relationship between thromboembolic event and CHA2DS2-VASC score in order to guide the anticoagulation strategy for AF patients. Methods: A total of 321 AF patients who received RFCA in our hospital from 2000-01 to 2009-05 were studied. There were 261 patients with paroxysmal AF and 60 with persistent AF, they were followed-up for (66.7±26.9) months. The patients were divided into 2 groups according to AF recurrence condition as Non-recurrence group, n=204 and Recurrence group, n=117. The relationship between thromboembolic event and CHA2DS2-VASC score was studied. Results: The Non-recurrence group had significantly lower rate of thromboembolism than that in Recurrence group (1.96% vs 7.69%), P=0.017. In both groups, the patients with CHA2DS2-VASC score Conclusion: The AF patients who received RFCA without AF recurrence in long-term follow-up had the lower rate of thromboembolic event, CHA2DS2-VASC score was important for evaluating such event. The patients with CHA2DS2-VASC score < 2 could consider stopping warfarin anticoagulation, while the patients with CHA2DS2-VASC score ≥ 2 might be beneifted for warfarin anticoagulation.
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<p><b>OBJECTIVE</b>To explore the clinical characteristics and risk factors of peripheral arterial thromboembolism (PAT) in patients with non valvular atrial fibrillation (NVAF).</p><p><b>METHODS</b>A total of 18 456 patients admitted in our hospital and diagnosed with NVAF were included in this study. The study population was divided into three groups [PAT group, cerebral thromboembolism (CT) group and no thromboembolism group]. Risk factors of PAT were assessed by multivariate logistic regression.</p><p><b>RESULTS</b>The incidence of PAT and CT was 1.1% (204 cases) and 27.8% (5 132 cases), respectively. The in-hospital mortality of PAT group was 11.8% (24/204), in which the in-hospital mortality due to mesenteric arterial thromboembolism (37.5%, 6/16) was the highest. Multivariate logistic regression indicated that vascular disease (OR = 3.9, 95% CI 2.13-7.08, P < 0.01), age ≥ 65 years (OR = 2.7, 95% CI 1.66-4.27, P < 0.01), hypertension (OR = 2.1, 95% CI 1.36-3.34, P < 0.01), history of stroke/TIA/arterial thromboembolism (OR = 2.0, 95% CI 1.26-3.17, P < 0.01) and congestive heart failure (OR = 1.9, 95% CI 1.22-2.86, P < 0.01) were independent risk factors of PAT. Prevalence of vascular disease and histories of PAT was higher in PAT group than in CT group (P < 0.01), while CHADS2 and CHA2DS2VASc scores were similar between the PAT and CT groups.</p><p><b>CONCLUSION</b>PAT is not uncommon in NVAF patients, risk factors for PAT in NVAF patients are vascular disease, advanced age, hypertension, history of stroke/TIA/arterial thromboembolism and congestive heart failure.</p>
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Humans , Atrial Fibrillation , Case-Control Studies , Heart Failure , Hospital Mortality , Hospitalization , Hypertension , Incidence , Risk Factors , Stroke , Thromboembolism , Epidemiology , Vascular DiseasesABSTRACT
<p><b>OBJECTIVE</b>To investigate the efficacy and safety of intravenous ibutilide for conversion of atrial fibrillation (AF) and flutter (AFL) to sinus rhythm.</p><p><b>METHODS</b>Ninety-nine consecutive patients aged 18-75 y with AF/AFL were included. The duration of arrhythmia was <90 d (1 h-90 d) and ventricular rate was >60 beats/min. Patients were assigned randomly into two groups: 49 patients in ibutilide group received ibutilide 1 mg, then repeated if AF/AFL was not converted after 10 min; 50 patients in propafenone group received propafenone 70 mg, then repeated if AF/AFL persisted after 10 min. Two drugs were diluted by 50 ml of 5% glucose and injected intravenously within 10 min.</p><p><b>RESULTS</b>Ventricular rates were decreased in both groups. AF/AFL were converted in 34 of 49 patients (69.4 % ) in ibutilide group and in 22 of 50 patients (44.0 %) in propafenone group (P <0.05). The converting time of ibutilide was significantly shorter than that of propafenone [(16.79 ± 12.31) min compared with (36.92 ± 11.38)min, P <0.01]. The most serious adverse effect of ibutilide was non-sustained monomorphic ventricular tachycardia (3/49,6.12 %). Transient hypotension and heart pause were the main adverse events in patients who received propafenone, acute left heart failure occurred in one patient of propafenone group.</p><p><b>CONCLUSION</b>Intravenous ibutilide is a safe and effective agent for cardioversion of recent-onset AF/AFL. Furthermore,strict processing under electrocardio-monitoring is important.</p>
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Adolescent , Adult , Aged , Female , Humans , Male , Middle Aged , Young Adult , Atrial Fibrillation , Drug Therapy , Atrial Flutter , Drug Therapy , Propafenone , Therapeutic Uses , Sulfonamides , Therapeutic Uses , Treatment OutcomeABSTRACT
ObjectiveTo analyze the characteristic of the T peak-end interval (Tpe) in dilated cardiomyopathy(DCM) patients with heart failure and its significance in evaluation of global dispersion of ventricular repolarization.MethodsFifty-three inpatients were enrolled in this study,which included 28patients with DCM and heart failure (DCM group),and 25 patients with supraventricular tachycardia and without structural heart disease (control group).The Tpe and the dispersion of QT interval (QTd) from the 12-lead surface electrocardiogram(ECG) were acquired and measured,and consequently the corrected numerals of the average of Tpe (Tpe-AVEC),the maximal Tpe (Tpe-MAXC) were acquired.ResultsThe levels of Tpe-AVEC,Tpe-MAXC and QTd in DCM group were significantly higher than those in control group [ ( 106.31 ±26.34) ms vs.(82.72 ± 10.01 ) ms,(234.05 ± 69.75) ms vs.( 119.15 ± 11.55 ) ms,( 119.17 ± 67.62) ms vs.( 39.74 ± 17.04 ) ms ] ( P ＜ 0.05 or ＜ 0.01 ).ConclusionsThe global dispersion of ventricular repolarization is significantly increased in patients with DCM and heart failure.The Tpe-AVEC and Tpe-MAxc are recommended to be used for evaluating the dispersion of ventricular repolarization as the prognostic index in patients with DCM and heart failure.
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Objective Mechanisms of pulmonary vein isolation (PVI) for atrial fibrillation remain controversy.This study aimed to investigate the impact of PVI on vagal modulation to atria.Methods Eighteen adult mongrel dogs under general anesthesia were randomly divided into two groups.Bilateral cervical sympathovagal trunks were decentralized and sympathetic effects was blocked by metoprolol administration.Atrial electrical remodeling (AER) was established by rapid right atrial pacing at the rate of 600 bpm for 30 minutes.PVI was performed in group A.Atrial effective refractory period (ERP),vulnerability window (VW) of atrial fibrillation,and sinus rhythm cycle length (SCL) were measured at baseline and during vagal stimulation before and after atrial rapid pacing with and without PVI at fight atrial appendage (RAA),left atrial appendage (LAA),distal coronary sinus (CSd) and proximal coronary sinus (CSp).Results (1) Effects of PVI on vagal modulation:Shortening of SCL during vagal stimulation decreased significantly after PVI compared with that before PVI in group A (P＜0.001).Shortening of ERP during vagal stimulation decreaseed significantly after PVI compared with that before PVI (P＜0.05).VW of atrial fibrillation during vagal stimulation decreased significantly after PVI compared with that before PVI (P＜0.05).(2) Effects of PVI on AER:shortening of ERP before and after atrial rapid pacing increased significantly at baseline and vagal stimulation in group B compared with that in group A (P＜0.05).VW during vagal stimulation increased significantly after atrial rapid pacing in group B (P＜0.05).Conclusion PVI attenuates the vagal modulation to the atria,thereby decreases the susceptibility to atrial fibrillation mediated by vagal activity.PVI releases AER,which maybe contributes to the vagal denervation.Our study indicates that PVI not only can eradicate triggered foci but also modify substrates for AF.(J Geriatr Cardiol 2008;5:28-32)
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Background Atrial electrical remodeling(AER)plays an important role in the pathogenesis and maintenance of atrialfibrillation.However,little is known about modulation of vagal activilty to AER.This study aimed to investigate the relationshipbetween vagal moduation and AER. Methods Twenty four adult mongrel dogs under general anesthesia were randomized into 3groups.Sympathetic activity was blocked by administration of metoprolol in 3 groups.The changes in vagal modulation to atria afterAER were observed in 10 dogs without vagal interruption in group A.The effects of vagal intervention on AER were investigated in 8dogs with administration of atropine in group B.The impact of aggressively vagal activity on AER was studied in 6 dogs with bilateralcervical vag sympathetic trunLks stimulation during AER in group C.Bilateral cervicall vagosympathetic trunks were decentralized.Multipolar catheters wereplaced into high right atria(RA),coronary sinus(CS)and rightventricle(RV).AER was induced by 600 bpmpacing through RA catheter for 30 minutes.Attial effective refractory period(ERP)and vulnerability window (VW)of atrial fibrillationwere measured with and without vagal stimulation before and after AER.Results In group A,ERP decreased significantly at baselineand during vagal stimulation after AER compared with that beforeAER(all P＜0.05).In group B,ERP remaind unchanged at baselineand vagal stimulation after AER compared with tbat before AER (all P＞0.05).In group C,ERP shortened significantly at baseline andvagal stimulation after AER compared with that before AER(all P＜0.05).ERP shortening after AER in Groups A and C increasedsignificantly than that in group B (all P＜0.05).Atrial fibrillation could not be induced at baseline(VW close to 0) before and after AERin three groups.VW became widen significantly during vagal stimulation after AER compared with that before AER in Groups A and C(all P＜0.05),while VW remained unchanged in group B (VW close to 0).Conclusions Short-term AER results in the decrease inERP.AER is accompanied by the increases in atrial vagal modulation.The increased vagal activity and vagal stimulation promote AER,thereby increase the susceptibility to atrial fibrillation.The interrupted vagal activity attenuates AER.thereby suppresses the atriaIfibrillation mediated by vagal stimutlation.
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0.05]. Conclusion:Besides the enlargement of LA,the volume of LAA and the area of LAA ostium were significantly increased in AF patients.Preprocedural assessment of LAA ostium should be helpful for the selection of occlusion devices.Because LAA is be very close to LCX,the selection of AF ablation strategies should be carefully taken to avoid possible damage of LCX.
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0.05) but the distal coronary sinus was out of the reentrant loop (compared with TCL, P
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3 months) were involved in this study PV electrogram was divided into disorganized and organized patterns Segmental PV isolation was performed during AF guided by the earliest PV potential recorded on the basket catheter determined by the lone pause during disorganized pattern or organized PV electrogram The sites with the most disorganized activity during fast and irregular fibrillatory activity had been regarded as ablative target Elimination of PV potential in all PVs during AF, and confirmed by remapping of PV during sinus rhythm or atrial stimuli after cardioversion had been considered as the ablative end point (segmental PV isolation was performed repeatedly if PV potential still existed during sinus rhythm) Results Of the total 76 PVs in 20 patients who achieved PV isolation, 68 (89 5%) PV isolations were performed during AF Reappearance of PV potential occurred in 23(33 8%) during sinus rhythm after cardioversion, and isolation was achieved during sinus rhythm Procedure duration was 5 3?3 7 hours Fluoroscopy time was 2 7?3 8 minutes Recurrence of AF occurred in 11 (55%) patients during the 8?9 month follow up No operation related complication occurred Conclusion Segmental PV isolation for chronic AF is feasible, safe and effective Ablation guided by electrophysiological mapping can result in the elimination of PV potential Remapping of PV and repeated ablation during sinus rhythm after cardioversion is essential