射频消融心外膜脂肪垫治疗犬肺静脉左房交界处起源的心房颤动

目的探讨射频消融心外膜脂肪垫对左房-肺静脉交界触发的局灶性心房颤动(简称房颤)治疗的有效性。方法成年杂种犬10只,心外膜脂肪垫注射氯化乙酰胆碱(Ach)+左房短阵快速电刺激诱发犬左房-肺静脉交界触发的局灶性房颤模型。4极电极分别缝置于左房、右房、左肺静脉与左房交界处,记录最快激动部位。直视下射频消融心外膜脂肪垫。于房颤模型建立前后,及消融脂肪垫后测量左、右房有效不应期(ERP),肺静脉-左房交界处ERP、计算房颤诱发率。术毕处死实验犬行组织学检查。结果所有犬均能通过脂肪垫注射氯化Ach+左房短阵快速电刺激诱发出左房-肺静脉交界触发的局灶性房颤,建模后左房、右房、肺静脉-左房交界处的ERP均较建模前显著缩短(分别为94±33 ms vs 139±9 ms,104±17 ms vs 137±9 ms,104±17 ms vs 137±9 ms;P均<0.01)。脂肪垫消融后房颤诱发率与消融前比较显著降低(45%±16%vs 86%±4%,P均<0.01);左房、右房ERP无变化,肺静脉-左房交界处不应期显著延长(137±8 ms vs 104±17 ms,P<0.01)。组织学未发现除脂肪垫外的其它消融损伤灶。结论射频消融心外膜脂肪垫对肺静脉-左房交界触发的局灶性房颤治疗有效。     

干预犬左心房峡部对心房颤动诱发率的影响及其机制研究

阐明干预左心房峡部对犬心房颤动 (简称房颤 )诱发率的影响及其与电学隔离Marshall韧带的关系。左心房峡部干预指经开胸手术自左下肺静脉下缘中点沿垂直于冠状静脉窦方向切割至冠状静脉窦上缘 ,切割后缝合关闭切口。共对 19只犬经心外膜途径对Marshall韧带进行标测和对左心房峡部干预。根据干预左心房峡部后Mar shall韧带电位是否消失分为A组 (Marshall韧带电位消失 ,n =12 )和B组 (Marshall韧带电位不消失 ,n =7)。A组干预后房颤诱发率明显降低 (16 .7%vs 83.3% ,P <0 .0 5 ) ;B组干预后房颤诱发率无明显变化 (77.4 %vs 85 .7% ,P >0 .0 5 )。干预左心房峡部后A组房颤诱发率显著低于B组 (16 .7%vs 77.4 % ,P <0 .0 5 )。干预左心房峡部前后左心房峡部传导时间A组 (98.33± 3.2 0msvs 97.5 8± 2 .81ms ,P >0 .0 5 )和B组 (96 .14± 2 .6 1msvs 97.4 2± 3.10ms,P >0 .0 5 )均无明显变化。结论 :干预犬左心房峡部可降低房颤诱发率 ,其机制可能是因电学隔离了Mar shall韧带。     

心房颤动导管消融术中迷走反射时肺静脉和心房电位周长的变化

目的评价心房颤动(简称房颤)导管消融过程中迷走反射对肺静脉和心房电位周长的影响。方法分析行环肺静脉消融且术中发生迷走反射的12例房颤患者(阵发性房颤10例,持续性房颤2例)心内电生理记录资料。分别测定迷走反射前10s、迷走反射过程中以及迷走反射后60s时的靶肺静脉电位和冠状静脉窦心房电位平均周长(PVCL及CSCL)。结果12例中5例消融时为房颤心律,迷走反射时平均最长RR间期为4025.42±1774.35ms。这5例中,迷走反射时PVCL及CSCL较迷走反射前明显缩短(分别为168.80±47.00msvs174.80±46.41ms;176.80±43.03msvs181.80±40.90ms,P均<0.05)。消融时为窦性心律者中,迷走反射后PVCL及CSCL较迷走反射前明显缩短(分别为882.86±86.74msvs1267.14±214.53ms,880.00±92.92msvs1261.43±209.95ms,P均<0.05)。结论房颤导管消融过程中迷走神经兴奋时,肺静脉和冠状静脉窦心房颤动波周长明显缩短,提示迷走神经兴奋可能在驱动或者加速肺静脉电位传导中起一定作用。     

局灶性心房颤动模型的建立及其射频消融

建立一种稳定的局灶性心房颤动 (简称房颤 )的动物模型以探索其电生理特点及射频消融方法与安全性。选用 18只犬开胸直视下以乌头碱在心脏局部肌注加猝发电刺激建立模型。观察房颤射频消融前后的病理、生理、生化及房颤诱发率的变化 ,以及有效靶点的电生理特点。结果 :①所有犬均能以单次用药加猝发刺激诱发房颤 (诱发率 10 0 %)。②消融组犬在电生理标测指导下行单线射频消融 ,消融前房颤持续时间 94 2± 4 80s,消融后房颤诱发率为 13 .8%,持续时间为 7.3± 6.8s ,与消融前比较差异有统计学意义 (P <0 .0 1)。③消融前后窦性心率 ( 163 .9±2 0 .8次 /分vs 15 8.4± 2 3 .3次 /分 )、校正窦房结恢复时间 ( 89.0± 3 9.6msvs 93 .9± 3 8.0ms)、心房有效不应期 ( 14 7.3± 2 0 .9msvs14 0 .3± 18.3ms)及血清磷酸肌酸激酶 ( 5 3 0 .5± 2 0 4 .7U/Lvs 4 73 .5± 2 2 6.1U/L) ,均无明显变化 (P均 >0 .0 5 )。结论 :应用乌头碱制备局灶性房颤方法简单、诱发率高。电生理标测指导下局部消融可终止局灶性房颤。结果初步提示此法能以较少的损伤达到治疗目的 ,是较安全的 ,有一定的临床价值。     

窦房结脂肪垫对犬右上肺静脉电生理特性影响的研究

目的研究不同水平刺激窦房结脂肪垫(SANFP)对右房(RA)及右上肺静脉(RSPV)的有效不应期(ERP)及心房颤动(简称房颤)诱发率的影响,探讨SANFP对房颤发生维持的作用。方法6只犬麻醉后经右侧开胸暴露RSPV及SANFP,以0.6～2,5,8mV三种不同电压强度水平、60ms频率刺激SANFP,同时以S1S2刺激观察三种水平下RA游离壁远、中、近端及RSPV远、中、近端ERP的变化;同样方法刺激SANFP以S1S1和S1S2程序刺激诱发房颤,测定房颤的诱发率。结果以5mV电压刺激窦房结脂肪垫RSPV近端ERP较基础时明显缩短(90±24msvs109±16ms,P<0.05),其房颤诱发率50%;以5,8mV电压刺激SANFP时RA游离壁近端、中端ERP变化较基础时明显缩短(96±20msvs117±14ms,65±20msvs117±14ms,P均<0.05),其房颤诱发率100%。结论窦房结脂肪垫可能在肺静脉起源的房颤的诱发和维持中起了重要作用。     

射频消融房室交界区慢、快经区域对犬和人心房颤动时心室率的影响

本文观察经导管射频消融房室交界区慢、快径区域对大和人心房颤动时心室率的影响.方法 杂种犬4条,体重11±1.2kg.房室结折返性心动过速患者7例,年龄29～65岁.阵发性房颤患者4例,年龄62～70岁,其中2例为短P-R间期综合征.均先采用“下位法”消融慢径区域后,若房室结有效不应期或房颤时平均R-R间期无明显变化,则加行“快径”区域消融.房颤诱发采用猝发脉冲电刺激(人)或静滴氯化乙酰胆碱后猝发脉冲电刺激(犬).结果 7例房室结折返性心动过速患者中5例经下位法射频消融阻断慢径,房室结前传有效不应期及诱发房颤时平均R-R间期明显延长(222±33ms vs 285±42ms和539±44ms vs 656±53ms P<0.01),无并发症.4条大及4例阵发性房颤患者经心内电生理检查证实均无房室结双径路表现,选择性消融“慢径区域”后,房室结有效不应期和房颤时平均R—R间期无明显变化,加行“快径区域”消融后,房室结有效不应期和房颤时平均R—R间期明显延长(犬145±16ms vs 185±22ms和305±13ms vs 403±17ms P<0.01,人220ms vs 490ms和367ms vs 690msP<0.01),1例房颤患者术后3天出现Ⅲ°AVB,2周后恢复为Ⅰ°AVB.本文还在动物实验中观察到消融快径区域时,房侧靶点(A/V>1)较室侧靶点(A/V<1)更易于造成Ⅲ°AVB.结论 选择性射频消融慢径区域对减?     

心外膜射频消融治疗心房颤动的实验研究

目的 :探讨电学隔离肺静脉治疗心房颤动 (AF)的可行性和连续透壁径线的重要性。方法 :实验分为完全阻断组和未完全阻断组 ,每组犬各 7只。建立AF模型后 ,围绕肺静脉在心外膜进行射频消融。结果 :完全阻断组消融后AF持续时间与消融前比较差异有极显著性意义 (15 2 .7svs4 2 6 .3s ,P <0 .0 1) ;完全阻断组消融后在持续时间与未完全阻断组消融后比较差异也有极显著性意义 (15 2 .7svs 36 7.3s ,P <0 .0 1) ,而窦房结功能和房室传导功能无显著性变化。结论 :电学隔离肺静脉治疗AF是可行的 ,形成确切的连续透壁肺静脉损伤可简化消融治疗AF的径线。     

消融犬右肺静脉脂肪垫对心房及右上肺静脉电生理特性及房颤诱发的影响

目的探讨消融右肺静脉脂肪垫对心房及右上肺静脉电生理特性及房颤诱发的影响。方法犬18只分别在颈部迷走神经未刺激和刺激的情况下,观察射频消融肺静脉脂肪垫前后心房不同部位及右上肺静脉有效不应期、房颤诱发率及房颤诱发窗口的变化。结果在刺激迷走神经的情况下,与消融前相比,消融后高位右心房有效不应期延长（P<0.05）,其余部位有效不应期无显著差异,消融后高位右心房房颤诱发率降低（P<0.01）,房颤诱发窗口变窄（P<0.05）,左心房（P<0.01）及右上肺静脉（P<0.01）房颤诱发率升高,诱发窗口增宽。同时,心房有效不应期离散度增加（P<0.01）。结论消融右肺静脉脂肪垫使高位右心房房颤诱发率降低及房颤诱发窗口变窄,却使左房、右上肺静脉房颤诱发率升高及房颤诱发窗口增宽。     

心房颤动周长与导管消融效果的关系

目的分析不同类型以及不同因素心房颤动(简称房颤)患者房颤周长(AFCL)的特点以及与导管消融效果的关系。方法选取本院行导管消融的房颤患者35例,其中阵发性房颤和持续性房颤分别为20例和15例。所有患者术前房颤心律下行食管电生理检查,记录左房后壁电活动,测量房颤周长。结果持续性房颤AFCL显著短于阵发性房颤患者(143±33 ms vs 151±31 ms,P<0.05)。AFCL与性别、是否合并高血压、糖尿病等因素无关,但AFCL在老龄、房颤病史较长、左房较大的患者中明显缩短。房颤消融术后无复发的患者AFCL明显长于复发患者(152±28 ms vs 133±22 ms,P<0.05)。左房直径和AFCL是房颤消融效果的独立预测因素。结论房颤周长可作为预测房颤预后的重要指标。     

起源于肺静脉的阵发性心房颤动发作初始的电生理特征

目的探讨起源于肺静脉的阵发性心房颤动(简称房颤)在发作初始时的电生理特征。方法记录因阵发性房颤行电生理检查和射频消融术的患者在房颤自发初始时的心内心电图,电生理检查证实起源于肺静脉,分析①房颤发作前10个心动周期的特点及计算平均周长(CL);②诱发房颤或短阵心房激动的房性早搏(简称房早)的配对间期(CI);③早搏指数(PI):即CI/CL。结果共42例患者,由房早诱发房颤85阵(Ⅰ组),诱发短阵心房激动23阵(Ⅱ组)。两组间比较,前者的CI和PI均明显短于后者,分别为(210±62msvs291±65ms,0.36±0.12vs0.48±0.12,P均<0.001)。房颤的诱发方式可分为2类:类型1(ⅠA组)为房颤发作前的10个心动周期相对恒定;类型2(ⅠB组)为房颤发作前的10个心动周期不恒定,表现为长短序列形式。85阵房颤中,ⅠA组有47阵(55%),ⅠB组有38阵(45%)。ⅠA组的CI与ⅠB组的CI无明显差异;ⅠA组的PI较ⅠB组的PI明显缩短(0.33±0.11vs0.39±0.12,P=0.02)。结论起源于肺静脉的阵发性房颤的诱发方式存在周期相对恒定与长短序列两种形式;诱发房颤的房早发生较早。     

The comparison of epicardial focused ultrasound circumferential pulmonary vein ablation and BOX ablation—results from experimental acute atrial fibrillation

Purpose

The purpose of this study was to compare the efficacy of focused ultrasound circumferential pulmonary vein ablation (CPVa) and BOX ablation (BOXa) in an acute atrial fibrillation (AF) model.

Methods

Twenty mongrel dogs were divided into either CPVa or BOXa groups. CPV or BOX focused ultrasonic ablation was conducted in each group after successful establishment of the AF model. Before-and-after ablation left atrial effective refractory period (LAERP), AF inducibility, and induced AF lasting time were measured in both groups.

Results

The LAERP after AF model establishment was significantly shorter than that before establishment (102?±?10 vs. 140?±?10?ms, p?p?p?p?p?p?p?=?0.021; 34?±?22 vs. 70?±?29?s, p?=?0.048, respectively).

Conclusions

In the experimental AF model, the epicardial focused ultrasound BOX ablation may be more effective to prevent the recurrence of AF compared with the CPV approach.     

Reversal of pulmonary vein remodeling after catheter ablation of atrial fibrillation

Background Pulmonary veins (PV) and the atria undergo electrical and structural remodeling in atrial fibrillation (AF). This study aimed to determine PV and left atrial (LA) reverse remodeling after catheter ablation for AF assessed by chest computed tomography (CT). Methods PV electrophysiologic studies and catheter ablation were performed in 63 patients (68% male; mean ± SD age: 56 ± 10 years) with symptomatic AF (49% paroxysmal, 51% persistent). Chest CT was performed before and 3 months after catheter ablation. Results At baseline, patients with persistent AF had a greater LA volume (91 ± 29 cm³ vs. 66 ± 27 cm3; P = 0.003) and mean PV ostial area (241 ± 43 mm² vs. 212 ± 47 mm²; P = 0.03) than patients with paroxysmal AF. There was no significant correlation between the effective refractory period and the area of the left superior PV ostium. At 3 months of follow-up after ablation, 48 patients (76%) were AF free on or off antiar?rhythmic drugs. There was a significant reduction in LA volume (77 ± 31 cm³ to 70 ± 28 cm³; P < 0.001) and mean PV ostial area (224 ± 48 mm² to 182 ± 43 mm²; P < 0.001). Patients with persistent AF had more reduction in LA volume (11.8 ± 12.8 cm³ vs. 4.0 ± 11.2 cm³; P = 0.04) and PV ostial area (62 mm² vs. 34 mm²; P = 0.04) than those who have paroxysmal AF. The reduction of the averaged PV ostial area was significantly correlated with the reduction of LA volume (r = 0.38, P = 0.03). Conclusions Catheter ablation of AF improves structural remodeling of PV ostia and left atrium. This finding is more apparent in patients with persistent AF treated by catheter ablation.     

风湿性心脏病心房颤动患者心房细胞外信号调节蛋白与纤维化的关系

探讨风湿性心脏病 (简称风心病 )心房颤动 (简称房颤 )患者心房组织细胞外信号调节激酶 (ERK)与心房纤维化的关系。 33例风心病二尖瓣病变患者行心脏外科手术时取右心耳组织。通过逆转录 聚合酶链反应和免疫组织化学技术 ,测量ERK2 mRNA和激活的ERK2 蛋白相对表达量 ,测定心房组织血管紧张素Ⅱ (AngⅡ )含量和胶原纤维容积分数 (CVF)。结果 :阵发性和慢性房颤患者的心房组织CVF、AngⅡ均明显高于窦性心律患者 (10 .4 4 %±1.83% ,15 .0 1%± 2 .30 %vs 7.4 8%± 1.2 6 % ;10 .17± 1.73,12 .13± 1.95vs 6 .6 9± 1.18ng/mg,P均 <0 .0 1) ,而慢性房颤患者的CVF、AngⅡ又明显高于阵发性房颤患者 (P <0 .0 1,P <0 .0 5 ) ;阵发性和慢性房颤患者的心房组织ERK2mRNA表达量显著高于窦性心律患者 (1.2 0 9± 0 .2 85 ,1.30 5± 0 .2 6 3vs 0 .92 3± 0 .2 71;P <0 .0 5 ,P <0 .0 1) ,而阵发性和慢性房颤患者之间无明显差别 (P >0 .0 5 ) ;阵发性和慢性房颤患者的心房间质细胞激活的ERK2 蛋白表达量显著高于窦性心律患者 (0 .2 5 2± 0 .0 75 ,0 .2 88± 0 .0 6 3vs 0 .175± 0 .0 74 ;P均 <0 .0 1) ,而阵发性和慢性房颤患者之间无明显差别 (P >0 .0 5 )。结论 :心房间质ERK途径的激活是风心病房颤患者心房纤维     

三维电解剖标测指导下经导管射频消融治疗心房颤动的初步体会

目的探讨在三维电解剖标测系统(CARTO)指导下经导管射频消融治疗心房颤动(房颤)的安全性和有效性。方法将接受治疗的30例患者(阵发性房颤28例,持续性房颤2例)利用CARTO进行左心房重建后,对阵发性房颤患者行环绕同侧肺静脉的线性消融,射频消融终点为房颤终止且不能诱发;对持续性房颤患者进行左心房和冠状静脉窦的重建,标测射频消融复杂心房碎裂电位区,至房颤终止或行直流电转复。并检测其中16例阵发性房颤患者术后心脏生化标记物动态变化。结果28例阵发性房颤均达到射频消融终点,2例持续性房颤患者中,1例在射频消融中转为窦性心律,1例行直流电转复。术后随访2~14(5.6±3.5)个月,25例患者无房颤复发,单次手术成功率83.3%。16例患者术后第1天肌钙蛋白T由术前的(0.01±0.00)μg/L升至(2.20±0.99)μg/L(P<0.01)。结论在CARTO指导下射频消融治疗房颤安全有效,但肌钙蛋白T明显增高。     

人类自发的阵发性心房颤动导致的心房有效不应期及其频率适应性的变化

探讨人类自发的阵发性心房颤动 (AF)导致的心房有效不应期 (ERP)及其频率适应性的变化。对 12例在我院进行心腔内电生理检查和 或射频消融术且术中出现阵发性AF的患者 ,于AF发生前及AF终止后分别以基础周长 5 0 0 ,40 0和 30 0ms的刺激测量心房ERP。结果 :AF持续时间为 8.9± 2 .0min ,以周长为 5 0 0 ,40 0和 30 0ms行S1 S1 刺激 ,在AF发生前 ,ERP分别为2 2 3± 39,2 13± 33和 2 0 1± 2 1ms ,AF终止后 ,ERP分别为 189± 32 ,186± 35和 180± 2 3ms ,其缩短率分别为 15 .5 %± 4.0 % ,12 .9%± 3.1%和 10 .8%± 3.0 % ,与AF发生前相比 ,P均 <0 .0 1。心房ERP在低频率时的缩短程度大于在高频率时 ,各起搏周长下ERP缩短的程度比较具有显著统计学差异 (P <0 .0 5 )。AF终止后 10minERP恢复至AF前水平。结论 :人类几分钟的阵发性AF可使ERP缩短 ,并且可造成ERP频率适应不良     

Selective segmental ostial ablation and circumferential pulmonary veins ablation. Results of an individualized strategy to cure refractory atrial fibrillation

Aims Previous studies have analyzed the efficacy of atrial fibrillation (AF) ablation in series of consecutive patients or comparing methods in a randomized way, without taking account individual patient characteristics. The purpose of this study was to evaluate the results of a strategy based on selecting the ablation method according to patient clinical features in drug-refractory paroxysmal or persistent AF. Methods and results Patients with left atrial diameter ≤40 mm and runs of atrial tachycardia of more than ten beats during Holter recording were selected for selective segmental ostial ablation (SSOA) in order to disconnect only those pulmonary veins with electrical potentials. The remaining patients underwent circumferential pulmonary veins ablation (CPVA) to modify left atrial substrate by extensive linear lesions. A group of 131 consecutive patients were included. Mean follow-up was 21.5 ± 15.2 months. In paroxysmal AF, 44 and 55 patients were selected for SSOA and CPVA, respectively, and the efficacy of the procedure was similar in the two groups (77 vs 74%; log-rank test p = NS). In persistent AF, 6 and 26 patients underwent SSOA and CPVA, respectively, and greater efficacy was observed in the second group (17 vs 65%; log-rank test p = 0.004). Conclusions Selecting the ablation method according to patient characteristics achieved good results and reduced the overall amount of ablated atrial tissue in patients with paroxysmal AF. However, in persistent AF the SSOA technique showed very limited efficacy despite the previous patient selection and a CPVA-like procedure may be the appropriate choice in all cases.     

Catheter ablation of atrial fibrillation in patients with severely impaired left ventricular systolic function

Little is known about the outcome of catheter ablation of atrial fibrillation (AF) in patients with heart failure (HF) and a severely reduced left ventricular ejection fraction (LVEF). We aimed to clarify the effectiveness of catheter ablation of AF in patients with a severely low LVEF. This retrospective study included 18 consecutive patients with HF and an LVEF of ≤35 % who underwent catheter ablation of AF. We investigated the clinical parameters, echocardiographic parameters and the incidence of hospitalizations for HF. During a median follow-up of 21 months (IQR, 13–40) after the final procedure (9 with repeat procedures), 11 patients (61 %) maintained sinus rhythm (SR) (6 with amiodarone). The LVEF and NYHA class significantly improved at 6 months after the CA in 12 patients (67 %) who were in SR or had recurrent paroxysmal AF (from 25.8 ± 6.3 to 37.0 ± 11.7 %, P = 0.02, and from 2.3 ± 0.5 to 1.5 ± 0.7, P < 0.01, respectively) but not in patients who experienced recurrent persistent AF. The patients with SR or recurrent paroxysmal AF had significantly fewer hospitalizations for HF than those with recurrent persistent AF after the AF ablation (log-rank test; P < 0.01). Catheter ablation of AF improved the clinical status in patients with an LVEF of ≤35 %. A repeat ablation procedure and amiodarone were often necessary to obtain a favorable outcome.     

Efficacy of adjuvant anterior left atrial ablation during intracardiac echocardiography-guided pulmonary vein antrum isolation for atrial fibrillation

Background: Recent data have shown that the septum and anterior left atrial (LA) wall may contain “rotor” sites required for AF maintenance. However, whether adding ablation of such sites to standard ICE‐guided PVAI improves outcome is not well known. Objective: To determine if adjuvant anterior LA ablation during PVAI improves the cure rate of paroxysmal and permanent AF. Methods: One hundred AF patients (60 paroxysmal, 40 persistent/permanent) undergoing first‐time PVAI were enrolled over three months to receive adjuvant anterior LA ablation (Group I). These patients were compared with 100 randomly selected, matched first‐time PVAI controls from the preceding three months who did not receive adjuvant ablation (Group II). All 200 patients underwent ICE‐guided PVAI during which all four PV antra and SVC were isolated. In group I, a decapolar lasso catheter was used to map the septum and anterior LA wall during AF (induced or spontaneous) for continuous high‐frequency, fractionated electrograms (CFAE). Sites where CFAE were identified were ablated until the local EGM was eliminated. A complete anterior line of block was not a requisite endpoint. Patients were followed up for 12 months. Recurrence was assessed post‐PVAI by symptoms, clinic visits, and Holter at 3, 6, and 12 months. Patients also wore rhythm transmitters for the first 3 months. Recurrence was any AF/AFL >1 min occurring >2 months post‐PVAI. Results: Patients (age 56 ± 11 years, 37% female, EF 53%± 11%) did not differ in baseline characteristics between group I and II by design. Group I patients had longer procedure time (188 ± 45 min vs 162 ± 37 min) and RF duration (57 ± 12 min vs 44 ± 20 min) than group II (P < 0.05 for both). Overall recurrence occurred in 15/100 (15%) in group I and 20/100 (20%) in group II (P = 0.054). Success rates did not differ for paroxysmal patients between group I and II (87% vs 85%, respectively). However, for persistent/permanent patients, group I had a higher success rate compared with group II (82% vs 72%, P = 0.047). Conclusions: Adjuvant anterior LA ablation does not appear to impact procedural outcome in patients with paroxysmal AF but may offer benefit to patients with persistent/permanent AF.     

Different patterns of atrial remodeling after catheter ablation of chronic atrial fibrillation

Atrial Substrate Remodeling After Chronic AF Ablation . Background: Multiple remodeling patterns have been observed after catheter ablation of atrial fibrillation (AF). Objective: We aimed to clarify the electrical/structural properties associated with recurrences after ablation of chronic AF. Methods: After a stepwise ablation procedure in 120 consecutive patients with persistent/long‐lasting persistent AF, 36 had a recurrence of AF (Group 1/Group 2: recurrence with paroxysmal/persistent AF, n = 16/20). Results: During the first procedure, the left atrial (LA) bipolar voltage did not differ between the 2 groups, and the LA volume was smaller in Group 1 than in Group 2 and it was the only factor predicting the recurrent types (P = 0.009, OR = 1.04). In the second procedure, the bipolar voltage of the global left atrium increased (1.33 ± 0.11 mV vs 1.76 ± 0.16 mV, P = 0.001) in Group 1 and decreased (1.31 ± 0.14 mV vs 0.90 ± 0.12 mV, P = 0.01) in Group 2, when compared with that of the first procedure. The LA low‐voltage area (<0.5 mV) decreased in Group 1, and increased in Group 2. The LA volume (90 ± 8 cm³ vs 72 ± 8 cm³, P = 0.002) decreased in the second procedure in Group 1. It remained the same in Group 2. The right atrial substrates did not change between the procedures. After a follow‐up of 27 ± 3 months, all patients in Group 1 and 14 patients in Group 2 remained in sinus rhythm (P = 0.02). Conclusion: A better outcome with reverse electrical and structural remodeling occurred after the ablation of chronic AF when the recurrence was paroxysmal AF. Progressive electrical remodeling without any structural remodeling developed in those with a recurrence involving persistent AF. (J Cardiovasc Electrophysiol, Vol. 22, pp. 385‐393)     

The different mechanisms between late and very late recurrences of atrial fibrillation in patients undergoing a repeated catheter ablation

Introduction: The mechanisms of late (<1 year after the ablation) and very late (>1 year after the ablation) recurrences of paroxysmal atrial fibrillation (AF) after catheter ablation have not been reported.
Methods and Results: Fifty consecutive patients undergoing a repeated electrophysiologic study to investigate the recurrence of paroxysmal AF after the first ablation were included. Group 1 consisted of 12 patients with very late (26 ± 13 months) and group 2 consisted of 38 patients with late (3 ± 3 months) recurrence of paroxysmal AF. In the baseline study, group 1 had a lower incidence of AF foci from the pulmonary veins (PVs) (67% vs 92%, P = 0.048) and a higher incidence of AF foci from the right atrium (50% vs 13%, P = 0.014) than group 2. In the repeated study, group 1 had a higher incidence of AF foci from the right atrium (67% vs 3%, P < 0.001) and a lower incidence of AF foci from the left atrium (50% vs 97%, P < 0.001), including a lower incidence of AF foci from the PVs (50% vs 79%, P = 0.07) and from the left atrial free wall (0% vs 29%, P = 0.046) than group 2. Furthermore, most of these AF foci (64% of group 1, 65% of group 2) were from the previously targeted foci.
Conclusion: The right atrial foci played an important role in the very late recurrence of AF, whereas the left atrial foci (the majority were PVs) were the major origin of the late recurrence of AF after the catheter ablation of paroxysmal AF.