Ionic Remodeling and Direct Effects of Valsartan on Ionic Currentsin Human Atrial Myocytes with Atrial Fibrillation

Objectives Previous studies demonstrated that angiotensin receptor antagonists had effects on some potassium channels in guinea pig myocytes and cloned channels that expressed in human cardiac myocytes. This study determined the direct effects of Valsartan on I caL, INa, IKur, IK1 and Ito1 in isolated human atrial myocytes. Methods and Results Specimens of right atrial appendage tissue were obtained from 39 patients with coronary artery and valvular heart diseases during cardiopulmonary bypass procedure. Pre- operation cardiac rhythm was sinus (SR)in 19 patients and was atrial fibrillation (AF) in the others. Single atrial myocyte was isolated by enzymatic dissociation with the chunk method. The ionic currents were recorded using the whole cell coffiguration of the voltage clamp technique. ICaL and Ito1 densities in AF patients were significantly lower than those in SR patients by 74% and 60%, respectively, while IK1density was significantly higher by 34% at command potential of - 120 mV. With 10 μmol/L Valsartan, INa density was significantly decreased by 59% in SR patients and by 66% in AF patients. IKur and IKl density were significantly decreased in only AF patients by 31% and23%, respectively. Conclusions Conclusions Decreased IcaL and Itol and increased IKl at hyperpolarizing potentials in AF patients‘ atrial myocytes may result from the electrophysiological remodeling by AF. Valsartan significantly decreases INa, IK1 and IKur current densities in AF patients‘ myocyte, but decreases only INa in SR patients‘ myocyte, suggesting that Valsartan may be beneficial to the recovering of remolded atria.     

起源于肺静脉的阵发性心房颤动导管射频消融治疗

目的　探讨环状电极 (Lasso电极 )标测指导起源于肺静脉的阵发性心房颤动 (房颤 )导管射频消融治疗的安全性和有效性。方法与结果　 2 0 0 1年 5～ 12月 ,12例药物治疗无效的阵发性房颤患者 ,男 8例 ,女 4例 ,平均年龄 (47 8± 14 9)岁 ,行心内电生理检查和射频消融术。在Lasso电极指导下标测肺静脉 ,以确定诱发房颤的房性早搏起源处。确定房性早搏的消融靶点后 ,在有房性早搏或冠状窦远端起搏或右心耳起搏下寻找优势肺静脉电位 (PVP)放电消融 ,或肺静脉口环状消融。消融终点设定为 :①肺静脉电位振幅明显减低或消失 ;②肺静脉自律性电位与心房电活动无关 ;③诱发房颤的房早消失。结果成功隔离 2 6条肺静脉 ;其中左上肺静脉 12条 ,右上肺静脉 8条 ,左下肺静脉 5条 ,右下肺静脉1条。有 2例仅消融 1条肺静脉 ,均为左上肺静脉 ;8例消融2条肺静脉 ,消融 3条与 4条肺静脉者各 1例。术程 (196 4±6 5 8)min ,X线曝光时间 (5 2 0± 14 4 )min。术后随访 2～ 8个月 ,有 1例频发房早发生 ,经口服胺碘酮后房早消失 ;4例有房颤短阵发作 ,其中 3例接受口服药物 (2例服用胺碘酮 ,1例服用索他洛尔 ) ,1例植入有抗房颤程序的DDDR起搏器 ,能够有效抑制房颤发作。术中选择性肺静脉造影发现 6例有轻度肺静脉狭窄 ,其     

无左心房和肺静脉三维重建的阵发性心房颤动导管消融术

Objective To investigate the differences between modeling and non-modeling left atrium in Carto XP system guided catheter ablation for paroxysmal atrial fibrillation. Methods Thirty-one cases of par-oxysmal atrial fibrillation treated by the same electrophysiologist with guidance of Carto XP during Jan to Dec in 2008 were enrolled. Catheter ablation was accomplished without left atrium and pulmonary veins modeling in 17 patients (non-modeling group) and with left atrium modeling in 14 patients (modeling group). The detailed ablation method was based on circumferential pulmonary veins isolation (CPVI). And linear ablation of tricus-pid valvular isthmus was selectively proceeded individually. The ablation endpoint was set to complete isolation of pulmonary vein potential from left atrium and no continuous fast atrial arrhythmia including atrial fibrillation, atrial flutter and atrial tachycardia could be induced. Comparisons for each step during procedure and the fol-low-up outcomes had been done. Results The male: female ratio of the 2 groups were 10:4 and 11 : 6 (P >0.05). The average age were (54.64 ± 15.58) and (59.41 ± 10.59) (P >0.05) ,the diseased courses were (5.05 ±10.4) years and (7.34±7.74)years(P >0.05),the left atrial sizes were (35.29±4.73) mm and (36.47 ±6.15)mm (P > 0.05), the total procedure time was (107.23±28.92) rain and (93.47 ±26.09) win (P>0.05). The X-ray exposure time was (21.09 ±6.49)min (modeling group) and (14.16±5.35)min (non-modeling group,P < 0.05). The CPVI time of fight pulmonary veins was (27.29±18.53) rain (model-ing group) and 18.00 ±4.51 min (non-modeling group, P < 0.05). The CPVI time of left pulmonary veins was (28.14 ±9.26) rain (modeling group) and (23.94±7.10) rain (non-modeling group, P < 0.05). The successful rates was 85.7% (modeling group) and 82.4% (non-modeling group, P > 0.05) over follow-up for 2 to 13 months. Conclusion Carto system guided catheter ablation of paroxysmal atrial fibrillation without modeling of left atrium and pulmonary veins could take less time in X-ray exposure and ablation steps, compa-ring with left atrium modeling one.     

Lasso电极导管指导下标测与射频消融局灶性房性心动过速

目的 探讨10极Lasso电极导管对局灶性房性心动过速(房速)标测及射频消融的指导作用.方法 局灶性房速病人5例,接受电生理检查,初步判断房速起源于左心房或右心房;应用Lasso电极标测心房,指导消融导管寻找局灶性房速最早心房激动(A波)点,于最早心房激动点处消融.结果 局灶性房速病人5例均在房速持续发作时进行Lasso电极标测;消融导管在Lasso电极指导下分别于左心房耳部(2例)、左上肺静脉口部(1例)、上腔静脉(1例)、右心房侧壁(1例)标测到最早A波;较P波提早30～40 ms;Lasso电极记录的A波顺序均呈离心性;在上述最早激动点处消融,均成功终止房速,放电次数为1～3次;未出现并发症;随访2～20个月,无复发;手术时间40～60 min,X线照射时间8～12 min.结论 应用Lasso电极指导标测与射频消融局灶性房速,快速、准确,可提高消融成功率,减少X线照射时间,缩短手术时间,特别对病灶位于心内大静脉、心房耳部病例尤有帮助.     

导管射频消融治疗持续性心房颤动的体会

目的研究持续性心房颤动(房颤)导管射频消融最佳手术方式及复发心律失常的处理策略。方法2005年3月~2007年8月共40例持续性房颤患者接受导管射频消融治疗,三维电解剖标测系统指导下行环同侧肺静脉左心房线性消融;2005年的12例患者部分附加左心房峡部、右心房峡部、左心房顶部线性消融;2006年的12例患者常规进行左心房峡部、右心房峡部射频消融,部分患者附加碎裂电位、左心耳或根据术中的房性心律失常附加其他部位射频消融;2007年的16例患者则在上述基础上进行冠状窦左心房心内膜面射频消融。结果2005年复发8例(66.7%),2006年复发3例(25.0%),2007年复发4例(25.0%)。复发的患者中8例接受第二次导管射频消融术,其中5例维持窦性心律。平均随访(17.6±10.4)个月,总治疗成功率82.5%。结论持续性房颤患者在以肺静脉口为核心的导管射频消融前提下,适当改进导管射频消融策略,可以显著提高成功率。     

经右锁骨下静脉途径导管射频消融三尖瓣环下的室性心律失常

目的探讨经右锁骨下静脉途径结合应用长鞘(SR0)导管射频消融三尖瓣环下起源的室性心律失常有效性及安全性。方法 8例患者,根据心电图和/或动态心电图诊断为三尖瓣环附近起源室性早搏(PVC)/室性心动过速(VT),均接受心脏电生理检查及射频消融治疗。术前曾经或术中采取常规下腔静脉途径消融失败后,改经右锁骨下静脉途径并辅用长鞘SR0进行标测与消融。消融成功后,结合靶点位置分析心电图及消融结果。结果 8例消融均获成功。根据消融导管的X线影像特征、电解剖证实其起源于三尖瓣环下6～9点。12导联体表心电图的PVC/VT的QRS波均呈左束支传导阻滞伴电轴左偏图形,Ⅰ、aVL导联主波向上,Ⅱ、Ⅲ、aVF导联主波向下,2例肢体导联见切迹,QRS波时限174.75±13.44 ms,消融靶点局部V波较体表心电图QRS波提早27.5±3.16 ms。8例成功消融靶点图只见V波,6例有峰电位。随访2～12个月,1例PVC复发。结论在长鞘辅助下,经右锁骨下静脉途径能够安全、有效地消融治疗三尖瓣环下PVC/VT,是经股静脉途径消融失败的有效补充。     

丹参素对豚鼠心室肌细胞L-型钙通道的影响

目的　研究丹参素对豚鼠心室肌细胞膜L 型钙通道的影响 ,探讨丹参素在离子通道水平的药理机制。方法　急性酶解法获得豚鼠的单个心肌细胞 ,用标准的全细胞膜片钳技术记录钙电流。结果　在保持电位 (Holdingpoten tial,HP)为 - 80mV ,预先去极化至 - 4 0mV ,再去极化至0mV ,波宽为 30 0mS的刺激参数下 ,可记录到一具有电压和时间依赖性内向的电流 ,当用含 1μmol/L硝苯地平的台氏液灌流时该电流被迅速消除 ,在灌流液中加入丹参素 1mg/mL和 10mg/mL ,1mg/mL组对钙电流无明显改变 (P >0 0 5 ,n =5 ) ,10mg/mL组使钙电流减少 [- (7 76± 0 85 )pA/pFvs - (2 6 2 6± 0 5 9)pA/pFP <0 0 5 ,n =8],并使心肌细胞钙电流 -电压曲线上移 ,原有的电流 -电压依赖特征不变。结论　丹参素浓度依赖性地抑制心肌L 型钙通道     

Ensite非接触标测系统在室性心律失常患者射频消融中的应用

目的探讨Ensite系统标测室性心律失常的方法,并评价其指导射频消融的有效性和安全性。方法入选症状性室性期前收缩(室早)或室性心动过速(室速)患者98例,年龄(42±16)岁,其中男43例,女55例。经外周血管进非接触多极球囊导管至右心室或左心室三维重建心腔。心室激动时根据虚拟单极电位的等电位图,结合起搏和激动标测对起源点和突破口及优势传导通道进行消融。结果消融即时成功率95%(93/98)。起源于右心室流出道占96种,间隔部和游离壁各82、14种,起源于其他不典型部位21种,三尖瓣环8种。起源后传导突破呈快反应点爆发方式占78%(91/117),采用点消融覆盖相近的起源点和突破口;呈慢反应突破方式占22%(26/117),采用线性或片状消融策略。随访(6±3)个月,3例复发,1例经再次消融成功。结论 Ensite心内非接触式标测系统用于室性心律失常的三维标测有效安全。室速或室早自最早起源点后经优势传导通道向突破口传导有两种传导方式。     

无左心房和肺静脉三维重建的阵发性心房颤动导管消融术

Objective To investigate the differences between modeling and non-modeling left atrium in Carto XP system guided catheter ablation for paroxysmal atrial fibrillation. Methods Thirty-one cases of par-oxysmal atrial fibrillation treated by the same electrophysiologist with guidance of Carto XP during Jan to Dec in 2008 were enrolled. Catheter ablation was accomplished without left atrium and pulmonary veins modeling in 17 patients (non-modeling group) and with left atrium modeling in 14 patients (modeling group). The detailed ablation method was based on circumferential pulmonary veins isolation (CPVI). And linear ablation of tricus-pid valvular isthmus was selectively proceeded individually. The ablation endpoint was set to complete isolation of pulmonary vein potential from left atrium and no continuous fast atrial arrhythmia including atrial fibrillation, atrial flutter and atrial tachycardia could be induced. Comparisons for each step during procedure and the fol-low-up outcomes had been done. Results The male: female ratio of the 2 groups were 10:4 and 11 : 6 (P >0.05). The average age were (54.64 ± 15.58) and (59.41 ± 10.59) (P >0.05) ,the diseased courses were (5.05 ±10.4) years and (7.34±7.74)years(P >0.05),the left atrial sizes were (35.29±4.73) mm and (36.47 ±6.15)mm (P > 0.05), the total procedure time was (107.23±28.92) rain and (93.47 ±26.09) win (P>0.05). The X-ray exposure time was (21.09 ±6.49)min (modeling group) and (14.16±5.35)min (non-modeling group,P < 0.05). The CPVI time of fight pulmonary veins was (27.29±18.53) rain (model-ing group) and 18.00 ±4.51 min (non-modeling group, P < 0.05). The CPVI time of left pulmonary veins was (28.14 ±9.26) rain (modeling group) and (23.94±7.10) rain (non-modeling group, P < 0.05). The successful rates was 85.7% (modeling group) and 82.4% (non-modeling group, P > 0.05) over follow-up for 2 to 13 months. Conclusion Carto system guided catheter ablation of paroxysmal atrial fibrillation without modeling of left atrium and pulmonary veins could take less time in X-ray exposure and ablation steps, compa-ring with left atrium modeling one.     

CartoXP Guided Catheter Ablation for Paroxysmal Atrial Fibrillation Without Three-dimensional Modeling of Left Atrium and Pulmonary Veins

Objectives This study was to investigate the differences between modeling and non-modeling left atrium （LA） in CartoXP system guided catheter ablation for paroxysmal atrial fibrillation （PAF）. Methods From Jan to Dec in 2008 total 31 cases with PAF were enrolled. All were treated by the same electrophysiologist with CartoXP guidance. Catheter ablation was accomplished without left atrium and pulmonary veins modeling in 17 patients （non-modeling group） and with left atrium modeling in 14 patients （modeling group）. The detailed ablation method was based on circumferential pulmonary veins isolation （CPVI）. And linear ablation of tricuspid valvular isthmus was performed individually. The ablation endpoint was a complete isolation of pulmonary vein potential from left atrium and no further induced continuous fast atrial arrhythmia including atrial fibrillation （AF）, atrial flutter （AFL） and atrial tachycardia （AT）. Each step for the procedures and the follow-up outcomes were compared correspondingly. Results The total procedure time was 107.23 ± 28.92 min in modeling group vs 93.47 ±26.09 min in non-modeling group （ P 〉 0.05 ）. The X-ray exposure time was significantly longer in modeling group （21.09 ±6. 49 rain） than in non-modeling group （14. 16 ± 5.35 min）. The CPVI times of right pulmonary veins and left pulmonary veins were 28. 14 ± 9. 26 min was 27.29 ± 18.53 min in modeling group respectively, vs 18.00 ±4. 51 min and 23.94 ± 7. 10 min in non-modeling group respectively, （P 〈 0. 05 ）. There is no significant difference between modeling group （85.7%） and non-modeling group （82.4%） over follow-up period of 2 to 13 months. Confusions CartoXP system guided catheter ablation of PAF without modeling of left atrium and pulmonary veins took less time in X-ray exposure and ablation steps, comparing with left atrium modeling procedure.