Objective To explore the methods of induced tolerance in rats renal allotransplantation and provide a theoretical basis for clinical use. Methods Orthotopic renal transplantation from Wistar rats to SD rats was used as a model of study. The experimental rats were divided into the following groups: Group Ⅰ as isotransplantation control group, Ⅱ as acute rejection control group, respectively. Group Ⅲ, Ⅳ and Ⅴ were treated with aminoguanidine (AG), calcitriol and the combined use of calcitriol and AG, respectively. The survival time of recipients was observed, meanwhile, the donor specific mixed lymphocyte reaction (MLR) and concentrations of IFN-?, Ca 2+ and P 3+ in serum were measured. HE staining inspected all specimens of kidney grafts. Results The recipient survival time in the groups Ⅰ, Ⅱ, Ⅲ, Ⅳ and Ⅴ were ( 9.1 ? 1.9 ),( 5.3 ? 0.8 ),( 9.7 ? 2.1 ),( 8.6 ? 1.6 )and( 12.9 ? 3.4 )days, respectively. There was significant difference in recipient survival time between group Ⅴ and group Ⅱ, Ⅲ and Ⅳ (P

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)

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.

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 < 2 had much lower rate of thromboembolism than those with CHA2DS2-VASC score ≥ 2, (0% vs 5%), P=0.023 and (4.45% vs 17.24%), P=0.041. The patients with CHA2DS2-VASC score<2 in Non-recurrence group had lower rate of thromboembolism than those in Recurrence group (0%vs 4.45%), P=0.029. The rate of thromboembolism had no statistic meaning between 2 groups in patients with CHA2DS2-VASC score≥2 (5%vs 17.24%), P=0.054.
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.

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.

Objective: To compare the outcome of radiofrequency catheter ablation under local anesthesia/sedation (S) or general anesthesia(GA) in atrial fibrillation patients. Methods: Data of 498 patients with atrial fibrillation undergoing radiofrequency catheter ablation in our departmentfrom January 2014 to December 2015 were retrospectively analyzed. Two hundred and twenty patients assigned to the GA group, the other 278 patients to the S group. Patients were followed clinically every 3 months within one year after procedure. Immediate electrocardiogram was performed in patients with palpitation or choking sensation in chest. The end point of the study was recurrence of any atrial tachyarrhythmia lasting >30 seconds in device interrogation, 24-hour Holter monitoring or 12-lead electrocardiogram after a single procedure. After the ablation procedure, a blanking period of 3 months was allowed according to the guidelines. Procedure time, radiofrequency time, fluoroscopy time, the detection of paroxysmal supraventricular tachycardia, the success rate and the complications were compared between the two groups. Results: There was no difference in the baseline characteristics between the two groups, such as age, gender, BMI, complications, LVEF, LAD (all P>0.05). The duration of procedure ((117.8±51.7)minutes vs.(115.4±36.9)minutes, P=0.79), duration of fluoroscopy((12.5±11.2)minutes vs. (10.4±10.2)minutes, P=0.35), duration of radiofrequency((40.1±12.9)minutes vs. (48.6±44.3)minutes, P=0.48) were similar between the two groups (P>0.05). Compared with S group, discovery of the frequency of atrioventricular node reentrant tachycardia (AVNRT) was significantly lower in GA group (0 vs. 3.6%(10/278), P<0.01), but the difference disappeared with repeat electrophysiological examination when patients become conscious from GA(3.2%(7/220) vs. 3.6%(10/278), P=0.311). The difference of atrioventricular reentrant tachycardia (AVRT) was similar between the two groups(0.9%(2/220) vs. 0.7%(2/278), P=0.841). Compared with S group, reflection of vagus nerve was less in GA group (1.4%(3/220) vs. 8.6%(24/278), P=0.026). After following up of (356±92) days, freedom from atrial fibrillation/atrial flutter/atrial tachyarrhythmia was similar between the two groups(77.9%(162/208) vs. 79.9%(215/269), P=0.818). Conclusion General anesthesia is a promising method to atrial fibrillation ablation, in view of stable patient status and safety for the procedure. There is no difference in complications, recurrence of arrhythmia between the two groups, but detection rate of AVNRT is lower in GA group.