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.     

心脏电生理学新概念 (20)房性心律失常射频导管消融治疗的现状与展望

房性快速性心律失常是临床上常见的心律失常 ,它包括房性心动过速 (房速 )、心房扑动 (房扑 )及心房颤动 (房颤 )。经射频导管消融治疗取得了令人鼓舞的成果 ,特别是局灶性房速、典型房扑效果尤为显著 ,借助于新的标测工具如三维电磁导管标测 (Ｃａｒｔｏ)系统 ,切口性房速、不典型房扑消融成功率得到了明显提高 ;局灶性房颤的射频导管消融也是近几年的研究热点 ,治疗效果尚好。1　局灶性房性心动过速局灶性房速表现为心房某部位激动呈离心性扩布 ,好发于某些特殊解剖区域如界嵴、房间隔部、肺静脉口、房室瓣环上等。其电生理机制包括自律性…     

主动脉无冠状动脉窦内射频消融治疗频发室性早搏和(或)短阵室性心动过速三例

报道3例无冠状动脉窦内射频消融频发室性早搏和短阵室性心动过速的心电图特点和射频消融结果。室性早搏或室性心动过速均呈左束支传导阻滞图形,胸导联V3R/S>1,1例Ⅰ导联呈现R波,2例Ⅰ导联呈顿挫r波,Ⅱ、Ⅲ、aVF均为高大R波,标测消融确定成功靶点在无冠状动脉窦,术中无并发症,随访20~29个月,1例偶发室性早搏。结论:在主动脉无冠状动脉窦内射频消融是可行的。     

Carto系统标测和指导射频消融快速心律失常

目的　评价Carto系统电解剖标测和指导射频消融治疗快速心律失常应用价值。方法　选择各种快速心律失常患者共 5 6例 ,其中室上性心动过速 (室上速 ) 4 9例 [房室结双径路 8例 ,房性心动过速 (房速 ) 12例 ,心房扑动 (房扑 ) 10例 ,左、右房室旁道 19例 ],室性心动过速 (室速 ) 7例 ,在心动过速或窦性心律时应用Carto系统标测 ,从其电解剖传导图中判断心律失常起源和发生机制 ,并指导射频消融。结果　 5 3例消融成功 ,消融成功率 94 6 %。 1例右侧游离壁旁道、1例右房房速和 1例不典型房扑消融不成功。房室结双径路 8例。左、右房室旁道 19例。 12例房速中左房房速 4例 ,右房房速 8例。 7例典型房扑 ,3例不典型房扑。特发性右室流出道室速 3例 ,特发性左室室速 3例 ,心肌梗死后室速 1例。手术时间为 (12 8± 5 9)min ,曝光时间为 (14± 12 )min。 1例穿剌左锁骨下静脉时发生气胸并发症。随访 1～ 14个月 ,1例左房房速复发 ,经Carto系统再次标测和消融成功。结论　Carto系统可安全有效应用于各种快速心律失常的标测和消融 ,减少X线曝光时间。它将心内电图与三维解剖结构联系起来 ,判断不同心律失常机制及起源部位 ,对指导消融有较大价值。利用其定位记忆功能 ,可避免损伤传导系统及进行补充放电 ,减少并     

射频导管消融电学隔离心脏大静脉治疗阵发性心房颤动的临床应用

目的评价射频导管消融电学隔离心脏大静脉预防阵发性心房颤动(房颤)发作的疗效。方法83例患者,男性58例、女性25例,年龄15～76平均(605±185)岁,有阵发性房颤病史2～15年,曾服数种抗心律失常药物疗效不佳。41例患者合并有高血压病,所有患者均无明显器质性心脏病改变。常规行心脏大静脉造影,测量靶静脉直径,将10极肺静脉环状标测导管(Lasso导管)放置在靶静脉开口内05cm处,以Lasso导管为指导,把温控大头电极导管放置于靶静脉开口处行电学隔离。结果83例患者共电学隔离大静脉343条。包括左上肺静脉(LSPV)83条,右上肺静脉(RSPV)83条,左下肺静脉(LIPV)82条,右下肺静脉(RIPV)42条,上腔静脉(SVC)53条,其中2例LSPV与LIPV共同开口。每条肺静脉行1～4段消融(平均每条消融25段),即刻电学隔离成功大静脉337条。随访2～31个月,其中50例停服抗心律失常药物后无房颤发生,13例患者房颤发作明显减少,20例患者房颤发作消融前后无明显变化。并发症有2例术中出现左侧大量胸腔积血,1例心肺复苏5天后出现脑死亡。发现肺静脉狭窄21例,其中轻度狭窄15例,重度狭窄6例,无肺静脉闭塞。结论(1)成功的心脏大静脉电学隔离治疗阵发性房颤的总有效率达到75%左右;(2)由于很难确定靶肺静脉,成功电学隔离各心脏大静脉有可能提高治愈率;(3)此     

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     

CARTO标测指导射频消融治疗非峡部依赖性心房扑动的初步研究

初步探讨非峡部依赖性心房扑动 (简称房扑 )———非典型房扑CARTO标测的方法学和射频消融效果。 4例经电生理标测证实的非典型房扑患者 ,男、女各 2例 ,年龄 2 4～ 5 7岁。 1例为先天性心脏病 (简称先心病 )三房心外科术后 ,1例为慢 快综合征。房扑发作时在右房或左房CARTO标测 ,三维重建右房或左房 ,寻找房扑折返径路的关键峡部区域行线性消融。结果 :3例为右房非峡部依赖性房扑 ,1例消融径线为 2条 ,即三尖瓣环至下腔静脉(IVC)口和右房后外侧至IVC ,1例消融径线为右房前中外侧 ,1例为右房下外侧。 1例左房房扑 ,消融径线位于右上肺静脉口下方至卵园窝。 4例均即时消融成功。随访 8～ 2 4个月 ,有 1例先心病术后房扑复发 ,再次行CARTO标测发现房扑折返环位于左房 ,划线消融未成功。结论 :CARTO标测非峡部依赖性房扑有一定的优势 ,能显示房扑折返环和关键峡部 ,并能指导线性消融     

起源于肺静脉的阵发性房颤的电生理特点及射频消融治疗

目的探讨环状电极(Lasso电极)标测诱发阵发性房颤的肺静脉电位的电生理特点并对射频消融靶点进行评介。方法16例阵发性房颤者在Lasso电极标测寻找优势肺静脉电位(PVP),温控消融放电。结果起源于肺静脉的局灶性房颤其电生理特征包括:①异位激动灶主要分布于两上肺静脉。②肺静脉内可观察到从肺静脉内至心房传导阻滞。消融成功的靶点与体表心电图P′波提前(74±33)ms。成功隔离38条肺静脉:其中左上肺静脉16条,右上肺静脉12条。术程(186.7±63.8)min,X线曝光时间(51.5±15.0)min。术后随访1～12个月,11例(68.7%)无需药物而维持窦性心律。结论阵发性房颤异位起源点大多数位于左房肺静脉,起源于肺静脉的局灶性房颤有其特殊的电生理表现。     

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.     

导管消融治疗45岁以下心房颤动患者的随访分析

目的研究不同类型的年轻心房颤动（房颤）患者（阵发性房颤、持续性房颤和持久的持续性房颤）导管消融治疗成功率和安全性。方法收集广东省心血管病研究所年龄〈45岁,诊断为房颤并接受导管消融治疗的132例患者的临床、电生理及随访资料,应用COX比例风险模型分析初次消融和重复消融后复发的预测因子。结果患者年龄（38.0±5.6）岁,男101例,女31例,既往房颤病程2.05年;阵发性房颤91例,非阵发性房颤包括持续性房颤15例和持久的持续性房颤26例。初次消融后随访24.2个月,阵发性、持续性、持久的持续性房颤成功率分别为86.8%（79例）、66.7%（10例）、57.7%（15例）,总体成功率78.8%。复发的患者有20例（71.4%）再次消融,随访14.3月,12例（75%）维持窦性心律。阵发性、持续性、持久的持续性房颤经过重复消融后窦性心律维持率分别为93.4%（85例）、86.7%（13例）、73.1%（19例）,总体成功率88.6%。COX回归分析提示,初次消融后复发的预测因子分别是非阵发性房颤（HR=3.393,P=0.004）、左心房扩大（HR=1.066,P=0.004）、高血压病史（HR=4.203,P=0.006）和甲状腺疾病史（HR=5.280,P=0.001）;重复消融后复发的预测因子则为右心房扩大（HR=1.133,P〈0.001）和甲状腺疾病（HR=6.942,P=0.003）。无影响预后的严重并发症。结论年轻的房颤患者导管消融安全性好,成功率高。早期对年轻房颤患者进行消融治疗是合理的,但应注意心房扩大及甲状腺疾病对成功率的影响。