典型心房扑动的CARTO系统标测和消融

评价非X线CARTO系统在指导导管射频消融典型心房扑动 (简称房扑 )中的临床应用。 5例典型房扑 ,均为男性 ,年龄 40 .4± 15 .7岁。除 1例为先天性三房心 (经外科矫正 )外 ,余均无器质性心脏病。心动过速周期 2 0 5± 2 8ms。位于三尖瓣环和下腔静脉口间的峡部为消融部位。运用CARTO系统实时标测右房三维结构 ,并指导导管标测和消融峡部。消融后分别在冠状静脉窦和低位后外侧右房以 5 0 0ms起搏重建三维电解剖图 ,判定完全双向传导阻滞。 5例均消融成功 ,房扑不再诱发及产生确定的峡部双向传导阻滞。放电次数为 12 .7± 6 .5。手术时间为 2 78± 49min ,曝光时间为 16± 7min。随访 1～ 3个月无病例复发。结论 :本研究表明在房扑标测和消融中应用CARTO系统是安全有效的。消融后峡部两侧分别起搏重建峡部三维电解剖图 ,可准确判断线性损伤的连续性 ,证实完全双向传导阻滞 ,有利减少复发率。同时可减少X线曝光时间。     

典型心房扑动峡部冷冻消融的短期疗效

目的观察冷冻消融治疗峡部依赖性心房扑动(简称房扑)的可行性和短期疗效。方法选择阵发性和持续性房扑患者5例,采用8mm冷冻消融导管,设定输出温度-85℃,每点消融4min,从三尖瓣环至下腔静脉行线性消融,以峡部双向阻滞并保持30min为消融成功。结果5例均峡部双向阻滞,达到有效消融的平均次数5.2±1.9次,出现冷冻有效的时间56.0±11.4s,1例双向阻滞4min后恢复,再消融3次后成功,每例平均消融次数6.0±2.9次。4例未完成完整的线性消融便已达到消融终点。手术总时间为102±26.8min,X线曝光时间为14.42±7.74min。患者均无疼痛等不适主诉。随访76±11.4天,未见房扑复发。结论经导管冷冻可以有效,快速的行典型房扑峡部消融,短期疗效好。     

简化三维电解剖标测指导峡部依赖性心房扑动的消融

目的探讨简化三维电解剖标测指导峡部依赖性心房扑动(简称房扑)消融的有效性。方法 59例峡部依赖性房扑患者,分别接受多极导管指导的常规法消融(n=22)及简化三维电解剖标测指导的消融(Carto法,n=37)。消融终点设定为双向跨越峡部的传导完全阻滞。结果 56例消融成功,两组成功率分别为86.4%和100%,(P=0.047);两组复发率分别为15.8%和0%,(P=0.035);Carto组较常规组手术耗时更短(68.2±6.9 min vs101.4±15.4 min,P<0.01)、X线暴露时间少(5.8±2.2 min vs 18.1±3.7 min,P<0.01),且射频消融时间更短(9.1±4.1 min vs 14.8±6.0 min,P<0.001)。3例常规组消融失败患者二次消融时交叉入Carto组均获得手术成功。Carto组显示峡部宽度的增加提示更长的X线暴露时间及射频消融时间。结论简化的峡部三维重建对指导峡部依赖性房扑的消融具有优势,且对常规法术后复发的房扑再次消融能获得有效成功。     

欧氏瓣对老年人Ⅰ型心房扑动射频消融的影响

目的探讨欧氏瓣对Ⅰ型心房扑动(简称房扑)导管射频消融即刻效果的影响。方法28例老年Ⅰ型房扑患者(呈逆钟向折返18例,顺钟向折返10例)在透视解剖标志和Halo电极三尖瓣环标测电图指引下,在房扑发作或冠状窦口起搏时以温控方式消融位于三尖瓣口和下腔静脉口之间的后峡部,消融方向从三尖瓣叶右室侧到下腔静脉开口。预设温度70℃,每点消融30s,每次移动消融电极3～5mm。观察下列指标:①房扑终止和后峡部阻滞时消融电极在消融线上所处的位置;②房扑终止后峡部残存传导间隙在消融线上所处的位置;③房扑终止后继续消融致后峡部完全阻滞的最终消融部位。结果根据右前斜位30°透视影像测得后峡部平均弧长(即消融线)为38.6±9.7mm。28例全部达到后峡部完全阻滞的消融终点,无并发症。与欧氏瓣有关的房扑终止率为100%(17/17),与欧氏瓣有关的后峡部完全阻滞发生率为92.9%(26/28)。结论欧氏瓣是Ⅰ型房扑后峡部消融线终点的重要标志,线性消融时欧氏瓣心室侧易残存传导间隙,消融该部位的残存传导间隙是Ⅰ型房扑后峡部消融的重要环节。     

两种三维电解剖标测系统指导房室结折返型心动过速

目的：比较国产Columbus及强生CARTO三维电解剖标测系统指导房室结折返型心动过速（AVNRT）射频消融的安全性及有效性。方法：回顾分析2016年1月-2019年11月在郑州大学附属洛阳中心医院心内科确诊为AVNRT并接受RFCA术的患者140例,分为进口CARTO消融组和国产Columbus消融组。其中CARTO消融组患者40例,Columbus消融组100例,比较两组患者的手术时间、X 线曝光时间、放电消融时间、即刻消融成功率、并发症发生率。结果：两组患者在整体手术时间（58.2±23.1min Vs 61.3±12.6min,P＞0.05）、X线曝光时间（4.5±5.6min Vs 5.3±1.8min,P＞0.05）、即刻手术成功率及并发症方面无明显差异。结论：国产Columbus和进口强生CARTO系统指导下的AVNRT消融,其安全性及有效性良好     

温控自动监测和阻抗上限监测消融老年人Ⅰ型心房扑动效果比较

目的　比较采用温控和阻抗监测消融法电隔离右心房后峡部治疗老年人Ⅰ型房扑的效率和优缺点。方法　在透视解剖标志的指引下 ,在Halo电极三尖瓣环标测电图监测下 ,在房扑发作或冠状窦口起搏时 ,随机选择温控监测和阻抗监测射频消融法电隔离位于三尖瓣口和下腔静脉口之间的后峡部 ,消融方向从右心室到下腔静脉。采用温控监测消融时 ,预设温度 70℃ ;采用阻抗监测消融时 ,能量选择 2 0W ,预设阻抗 15 0 。消融方法都是每点放电 30s,每次移动消融电极 5mm。消融终点是后峡部完全阻滞。比较下列指标 :(1)放电次数 ;(2 )放电时间 ;(3)消融操作时间 ;(4 )消融能量 ;(5 )高阻抗报警次数 ;(6 )病人胸痛反应。结果　 37例老年Ⅰ型房扑病人平均年龄 (6 9.2± 3.7)岁 ,男 /女为 2 6 / 11,合并高血压病 13例 ,糖尿病 5例 ,冠心病 3例 ,卵圆孔未闭 1例。房扑心室率(12 8.4± 2 7.5 )次 /min ,呈逆钟向折返 2 5例 ,顺钟向折返 12例。温控监测消融 19例 ,非温控监测消融 18例 ,两组病人在性别、年龄、基础心脏病、房扑心室率和折返方式方面无显著差异 (P >0 .0 5 )。 37例病人全部达到后峡部完全阻滞的消融终点 ,无并发症。温控监测和阻抗监测消融观察指标比较 :(1)放电次数为 6 .4± 3.5比 11.3± 5 .8(P <0 .0 5 )。     

三尖瓣峡部消融对心房颤动导管消融术后复发的影响

目的:评估三尖瓣峡部消融对伴有典型心房扑动(房扑)和不伴典型房扑发作的心房颤动(房颤)患者术后复发的影响.方法:连续入选房颤射频消融治疗患者113例,根据有无典型房扑分为三尖瓣峡部消融组(CTI组)和未行三尖瓣峡部消融组(Non-CTI组),比较临床特征及手术特点,并随访术后典型房扑和房颤发生率.结果:Non-CTI组左房内径更大,持续性和永久性房颤的比例、左房线性消融的比例更高.而CTI组射频消融时间较Non-CTI组更长.术后典型房扑和房颤发生率2组无显著区别.结论:无典型房扑发作的房颤患者,不行三尖瓣峡部消融,不会升高术后典型房扑发生率和房颤复发率,同时射频消融时间缩短.     

CARTO标测指导心肌梗死后室性心动过速的射？…

心肌梗死(MI)后室性心动过速(VT)的基质存在解剖上的复杂性并且血液动力学常常是不稳定的,因此射频导管消融的成功率是有限的。本研究的目的是运用电解剖标测(CARTO)指导VT的射频消融,以便弄清折返环和梗死区的关键峡部,此可能增加临床消融的效率。19例MI的病人(年龄66±7岁,其中男性17例)因VT拟作20次消融［17例在服用抗心律失常药,7例已安装埋藏式心脏转复除颤器(ICD)］。所有病例均反复发作临床型VT(周期为423±87 ms)。在VT时或窦律/右室起搏(SR/RVP)行左室CARTO标测。对13例14次血液动力学稳定的VT实施标测,包括2例无休止性慢VT。仅8例临床性VT,在心动过速时完成了整个左室的重建,另6例因反复机械损伤MI区内关键性峡部,使临床型VT不再诱发。12例在SR/RVP时完成左室标测,包括6例关键性峡部损伤及6例血液动力学不稳定者。在8例CARTO标测的VT中,有3例呈现典型的“8字”型折返环,2例沿二尖瓣(MA)激动心室。在8例VT中,于关键性峡部放电消融,其中6例VT终止,平均放电2次;然后行线性消融连接两个疤痕区域或连接疤痕与MA环,平均放电16次。在SR/RVP时标测,可见1个或多个疤痕区域,4例在诱发VT时放电,均终止了VT;另8例因极不稳定的血液动力学或机械损伤,在SR/RVP时行放电消融。消融后仍有2例可诱发临床型VT。平均随访11个月,1例临床型VT复发,另5例病人也安装ICD。结论①对VT病例,尤其是血液动力学不稳定的VT,通过CARTO标测可清楚地呈现整个或部分折返环以及梗死心肌区内的关键性峡部,于两疤痕或一个疤痕与MA之间行线型消融可消除临床型VT并预防复发。②在临床型VT标测时,常常发生关键性峡部的机械损伤,这高度提示关键性峡部位于心内膜下浅层,此利于导管消融。     

典型心房扑动消融术后峡部时间间期的变化预测双向阻滞的价值

通过比较心房扑动 (简称房扑 )成功消融前后右心房峡部时间间期 ,分析峡部时间间期的延长程度对峡部完全性双向阻滞的预测价值。选择 1996～ 2 0 0 2年在我院行射频消融治疗的典型房扑患者 30例 ,男 2 3例、女 7例 ,年龄 4 7.85± 9.35岁 ,采用解剖和影像定位法 ,在冠状静脉窦口持续起搏下消融峡部。结果 :2 9例消融成功 ,达到双向传导阻滞的标准 ,成功率 96 .6 7%。消融后起搏信号至右房下侧壁的时间间期 (SAH1 2 )和起搏信号至冠状窦口CS3 4的时间间期明显延长 (14 0 .4 7± 2 0 .4 8msvs73.82± 13.0 1ms ;138.17± 15 .5 5msvs77.6 3± 8.36ms ,P <0 .0 0 0 1)。 2 9例中有 17例在完全性传导阻滞前可以记录到不完全性传导阻滞 ,峡部不完全性传导阻滞时SAH1 2 比术前增加 4 5 .4 9%± 8.7%。消融前后右心房峡部传导时间间期增加≥ 5 0 % ,预测峡部完全性双向传导阻滞的灵敏度 10 0 % ,特异度 83.3%。结论 :右心房峡部传导时间间期的定量分析是判断峡部完全性双向传导阻滞的有价值的方法。     

对比观察射频消融右房后位峡部和间隔峡部治疗典型心房扑动的疗效

对比观察射频消融右房后位峡部和间隔峡部治疗心房扑动 (简称房扑 )两种方法的疗效。 41例房扑患者随机分为后位峡部组 ( 18例 )和间隔峡部组 ( 2 3例 ) ,消融线径分别为三尖瓣环—下腔静脉和三尖瓣环—欧氏嵴。成功消融终点为房扑不能诱发和峡部呈完全性双向阻滞。结果 :40例消融成功 ( 97.6 % ) ,无并发症。后位峡部组 3例和间隔峡部组 2例在首选消融方法失败后 ,改用另一种消融方法获得成功。两组患者的放电次数和手术时间均无显著性差异。平均随访 12 .4± 6 .8个月 ,在后位峡部消融成功者中 ,有 2例房扑复发。结论 :射频消融右房后位峡部和间隔峡部治疗房扑均安全有效 ,两种方法互补可以提高消融的成功率     

The electroanatomic characteristics of the cavotricuspid isthmus: implications for the catheter ablation of atrial flutter

Introduction: Radiofrequency ablation (RFA) of typical AFL is sometimes difficult because of the poor electroanatomic approach to the cavotricuspid isthmus (CTI). The aim of this study was to correlate the anatomy of the CTI between contact mapping (NavX) and right atrial angiography (RAG), and to investigate the impact of the electroanatomic characteristics of the CTI on the RFA of typical atrial flutter (AFL).
Methods: One hundred patients with typical AFL undergoing RFA were studied. The image-guided group consisted of 50 consecutive patients with the guidance of NavX. NavX geometry and RAG were performed to investigate the morphology of the CTI. The bipolar voltages of the CTI were collected during sinus rhythm by a NavX. The control group consisted of 50 consecutive patients with the guidance of conventional fluoroscopy.
Results: There was a good correlation between the angiography and NavX for the anatomy of the CTI. The pouch type had a longer length of CTI than the flat type (33.4 ± 5.0 vs 22.6 ± 8.4 mm, P < 0.0001) and deeper depth than the concave type (6.5 ± 2.2 vs 3.7 ± 0.8 mm, P < 0.0001) on the angiography. The pouch-type CTI had a longer ablation time and larger pulses of RFA than the other two types. The control group had a longer ablation time, fluoroscopy time, and larger pulses of RFA than image-guided group.
Conclusions: The 3-D mapping system provided a good reconstruction of CTI, which may help in the RFA in patients with a complex anatomy of the CTI.     

Atypical Electrocardiographic Features of Cavotricuspid Isthmus‐Dependent Atrial Flutter Occurring during Left Atrial Fibrillation Ablation

Background: Patients who have undergone percutaneous catheter ablation for atrial fibrillation (AF) may develop cavotricuspid isthmus (CTI)‐dependent atrial flutter (AFL), which can occur either spontaneously during left atrial (LA) ablation for AF or by induction from sinus rhythm during the procedure. The electrocardiographic (ECG) characteristics of CTI‐dependent AFL occurring during LA ablation have not been described. The purpose of this study was to describe the ECG features of CTI‐dependent AFL occurring during percutaneous LA catheter ablation for AF. Methods and Results: Of 223 patients presenting for first AF ablation at our institution between May 2004 and February 2008, 20 patients (9%) developed CTI‐dependent AFL during LA ablation for AF. CTI‐dependent AFL developed spontaneously in 4 patients (20%) and was induced in 16 patients (80%). Among these 20 patients, 3 (15%) had typical ECG patterns and 17 (85%) had atypical ECG patterns. Flutter waves in the inferior leads were biphasic in 10 patients (50%), downward in 3 patients (15%), positive in 3 patients (15%), and not fitting the above classifications in 4 patients (20%). There was no statistically significant association between AFL pattern and LA size, left ventricular ejection fraction, total ablation time, duration of prior AF, or type of prior AF. Conclusion: A majority of patients with CTI‐dependent AFL occurring during LA ablation have atypical ECG patterns. Biphasic flutter waves in the inferior leads are common ECG features, occurring in one‐half of patients. Right atrial CTI‐dependent AFL should be suspected even if the ECG appearance is atypical. Ann Noninvasive Electrocardiol 2010;15(3):200–208     

Ablation of Atrial Fibrillation at the Time of Cavotricuspid Isthmus Ablation in Patients With Atrial Flutter Without Documented Atrial Fibrillation Derives a Better Long‐Term Benefit

AF Ablation in Patients With Only Documentation of Atrial Flutter. Objectives: The aim of the study was to evaluate whether isolation of the pulmonary veins (PVs) at the time of cavotricuspid isthmus (CTI) ablation is beneficial in patients with lone atrial flutter (AFL). Background: A high proportion of patients with lone persistent AFL have recurrent episodes of atrial fibrillation (AF) after CTI ablation. However, the benefit of AF ablation in patients with only documentation of AFL has not been determined. Methods: Forty‐eight patients with typical lone persistent AFL (age 56 ± 6; 90% male) were randomized to CTI ablation (Group A; n = 25) or to CTI + PV isolation (PVI) (Group B; n = 23). In addition to PVI, some patients in group B underwent ablation of complex fractionated electrograms and/or creation of left atrial roof and mitral isthmus ablation line in a stepwise approach when AF was induced and sustained for more than 2 minutes. Mean follow‐up was 16 ± 4 months with a 48‐hour ambulatory monitor every 2 months. Results: There were no recurrences of AFL in either group. Six patients in group B (22%) underwent a stepwise ablation protocol. AF organized and terminated in 5 patients during ablation (83%). Complication rate was not significantly different among the groups. Twenty patients in group B (87%) and 11 patients in group A (44%) were free of arrhythmias on no medications at the end of follow‐up (P < 0.05). Conclusions: Ablation of AF at the time of CTI ablation results in a significantly better long‐term freedom from arrhythmias. (J Cardiovasc Electrophysiol, Vol. 22, pp. 34‐38, January 2011)     

法洛四联症术后房性心动过速的临床特点及射频导管消融

目的观察法洛四联症（TOF）根治术后心房扑动（房扑）的临床特点及消融长期随访结果。方法选择2004年1月至2012年5月间,因TOF根治术后并发房扑于阜外心血管病医院行射频消融治疗的11例患者,收集相关资料并进行随访。结果共11例患者入选,TOF根治术后出现房扑的时间为9—32（19．5±6．5）年,消融时的平均年龄为31～47（39．3±5．8）岁,术中共对15种房扑进行了标测,8例表现为单纯围绕三尖瓣环折返的房扑,5例为单纯围绕右心房瘢痕的房扑,2例为同时围绕三尖瓣环及右心房瘢痕的“8”字型折返。单纯围绕三尖瓣环折返的房扑患者与瘢痕相关性房扑患者相比,右心室较小[（27．3±2．8）mm对（38．4±10．9）mm,P=0．039]。术后经过（56．7±26．7）个月的随访,有3例患者再发房扑并接受再次消融,长期成功率为72．7％。结论TOF根治术后患者房扑的发病时间晚,瘢痕相关l生房扑的比例较高,射频消融有较高的成功率。相对于单纯右心房峡部依赖性房扑,瘢痕相关性房扑患者的右心室较大。     

心房颤动导管消融中可调弯鞘使用的经验

目的报道心房颤动（简称房颤）导管消融过程中使用可调弯韒（Agilis NxT鞘）的经验。方法 15例房颤患者采用Agilis NxT鞘进行导管消融。阵发性房颤11例,持续性房颤4例。穿刺房间隔,双侧肺静脉造影后,在EnSite VelocityTMv.3.0指导下构建左房几何模型,先行双侧肺静脉电学隔离,持续性房颤或阵发性房颤合并典型心房扑动患者继行三尖瓣峡部线性消融,而后持续性房颤患者电复律,在窦性心律下行左房高密度标测,若有低电压区或碎裂电位,继续行基质改良。结果 15例均完成4根肺静脉电学隔离。持续性房颤中,4例完成三尖瓣峡部线性消融;复律后在窦性心律下行左房高密度标测2例后壁有低电压区,遂完成两侧消融圈后壁线消融;2例右下肺静脉前庭双电位与碎裂电位,行基质改良。阵发性房颤患者中,2例合并典型心房扑动行三尖瓣峡部线性消融,1例合并冠状窦口房性心动过速消融。右、左肺静脉隔离时间分别为（20.9±5.7）min、（19.2±7.1）min。没有1例出现严重并发症。随访（5.2±1.6）个月,1（6.7%）例3月后有房颤发作。结论在房颤导管消融过程中,使用Agilis NxT鞘,能便利消融且安全有效。     

Phased-array intracardiac echocardiography for defining cavotricuspid isthmus anatomy during radiofrequency ablation of typical atrial flutter

INTRODUCTION: Cavotricuspid isthmus (CTI) topography includes ridges, pouches, recesses, and trabeculations. These features may limit the success of radiofrequency ablation (RFA) of typical atrial flutter (AFL). The aim of this study was to assess the utility of phased-array intracardiac echocardiography (ICE) for imaging the CTI and monitoring RFA of AFL. METHODS AND RESULTS: Fifteen patients (mean age 64 +/- 9 years) underwent ICE assessment (imaging frequency 7.5-10 MHz) before and after RFA of AFL. The ICE catheter was positioned at the inferior vena cava-right atrial junction and the following parameters were measured: (1) CTI length from the tricuspid valve to the eustachian ridge; (2) extent of CTI pouching; and (3) thickness pre/post RFA of the anterior, mid, and posterior CTI. CTI length was 35 +/- 6 mm at end-ventricular systole but shorter (30 +/- 6 mm) and more pouched at end-ventricular diastole (P = 0.02). A pouch or recess was seen in 11 of 15 patients (mean depth 6 +/- 2 mm). The septal CTI was more pouched than the lateral CTI, but the latter had more prominent trabeculations. Trabeculations were seen in 10 of 15 patients, and at these locations the CTI was 4.6 +/- 1 mm thick. Anterior, mid, and posterior CTI thickness pre-RFA was 4.1 +/- 0.8, 3.3 +/- 0.5, and 2.7 +/- 0.9 mm, respectively (P < 0.001 by analysis of variance). ICE guided RFA away from unfavorable CTI features (recesses/thick trabeculations). RFA applications created discrete CTI lesions that coalesced, forming diffuse CTI swelling. Post-RFA thickness was as follows: anterior 4.8 +/- 0.8 mm (P = NS vs pre); mid 3.8 +/- 0.8 mm (P = 0.05 vs pre); and posterior 3.8 +/- 0.8 mm (P = 0.02 vs pre). CONCLUSION: Phased-array ICE permits novel real-time CTI imaging with excellent endocardial resolution and may facilitate RFA of AFL.     

Characteristics of the Cavotricuspid Isthmus in Predicting Recurrent Conduction in the Long-Term Follow-Up

Background: The characteristics of cavotricuspid isthmus (CTI) in patients with atrial fibrillation (AF) and flutter that may predict recurrence of flutter is not known. We aimed to investigate the CTI characteristics in patients who underwent a second ablation procedure for recurrent AF after previous combined pulmonary vein (PV) and CTI ablation.
Methods: Among 196 consecutive patients with drug-refractory symptomatic AF who underwent PV isolation and CTI ablation with bidirectional isthmus block, 49 patients (age 50 ± 12 years, 43 males) had recurrent AF and received a second procedure 291 ± 241 days after the first procedure. Right atrial angiography for the evaluation of the CTI morphology, and the biatrial contact bipolar electrograms were obtained before both procedures.
Results: In the second procedure, 11 (group 1) of the 49 patients demonstrated recovered CTI conduction. Compared with the patients without CTI conduction (group 2, n = 38), group 1 patients had a higher frequency of a pouch-type anatomy (82% vs 13%, P < 0.001), longer CTI (34.0 ± 8.6 vs 25.5 ± 7.5 mm, P = 0.01), longer ablation time, and larger number of radiofrequency applications; furthermore, the preablation bipolar voltage decreased along both the CTI and ablation line in group 2, whereas it remained similar in group 1 in the second procedure.
Conclusions: A high (22%) percentage of CTIs exhibited recurrent conduction in the long-term follow-up. The CTIs with recurrent conduction had a higher incidence of a pouch and longer length compared with those without recurrent conduction.     

Long term outcome of cavotricuspid isthmus cryoablation for the treatment of common atrial flutter in 180 patients: A single center experience

Objective Recent literature has shown that common type atrial flutter (AFL) can recur late after cavotricuspid isthmus (CTI) catheter ablation using radiofrequency energy (RF). We report the long term outcome of a large group of patients undergoing CTI ablation using cryothermy for AFL in a single center. Methods Patients with AFL referred for CTI ablation were recruited prospectively from July 2001 to July 2006. Cryoablation was performed using a deflectable, 10.5 F, 6.5 mm tip catheter. CTI block was reassessed 30 min after the last application during isoproterenol infusion. Recurrences were evaluated by 12-lead ECG and 24 h Holter recording every clinic visit (1/3/6/9 and 12 months after the procedure and yearly thereafter) or if symptoms developed. Results The 180 enrolled patients had the following characteristics: 39 women (22%), mean age 58 years, no structural heart disease in 86 patients (48%), mean left atrium diameter 44 ± 7 mm and mean left ventricular ejection fraction 57 ± 7%. The average number of applications per patient was 7 (3 to 20) with a mean temperature and duration of −88°C and 3 min, respectively. Acute success was achieved in 95% (171) of the patients. There were no complications. After a mean follow-up of 27 ± 17 (from 12 to 60) months, the chronic success rate was 91%. The majority of the recurrences occurred within the first year post ablation. One hundred and twenty three patients had a history of atrial fibrillation (AF) prior to CTI ablation and 85 (69%) of those remained having AF after cryoablation. In 20 of 57 (35%) patients without a history of AF prior to CTI ablation, AF occurred during follow-up. Conclusions This prospective study showed a 91% chronic success rate (range 12 to 60 months) for cryoablation of the CTI in patients with common type AFL and ratified the frequent association of AF with AFL. Disclosures: Drs Rodriguez and Timmermans have received a modest research grant from CryoCor, San Diego, CA, USA. Dr Wellens is a consultant for CryoCor, San Diego, CA, USA.     

Use of double-potential barrier to identify functional isthmus at the cavotricuspid isthmus for facilitating catheter ablation of isthmus-dependent atrial flutter

INTRODUCTION: The aim of the study was to identify an alternative target for more effective radiofrequency catheter ablation (RFCA) of isthmus-dependent atrial flutter (AFL). METHODS AND RESULTS: We hypothesized that a functional isthmus formed by preexisting double potential barrier at the cavotricuspid isthmus (CTI) could serve as a new target site for facilitating RFCA of AFL. Forty-three consecutive patients with recurrent isthmus-dependent AFL were studied using three-dimensional navigated magnetic mapping and ablation technique. Twenty patients (47%, group A) were shown to have a narrower functional channel at the CTI (functional isthmus). The remaining 23 patients did not have this feature (53%, group B). In group A, double potentials were clustered near the border of the inferior vena cava (IVC) of the CTI and served as a functional channel along the tricuspid annulus (TA). The interspike interval of double potentials was 87 +/- 26 ms near the IVC border and 45 +/- 17 ms (P < 0.0001) near the TA border of CTI. RFCA targeting at the functional isthmus in group A resulted in interruption of bidirectional transisthmus conduction with fewer radiofrequency pulses (6.7 +/- 4.7 in group A vs 21.1 +/- 17.1 pulses in group B, P < 0.001), shorter ablation line (11.6 +/- 4.0 mm vs 37.8 +/- 7.2 mm, P < 0.0001) with no arrhythmia recurrence. These functional isthmuses were found to be located at the lateral third of CTI in 12 patients, middle third in 7, and medial third in 1. This finding is different from that obtained by the conventional method in group B (lateral in 5, middle in 16, medial in 2, P < 0.038). CONCLUSION: In our study, a functional, rather than anatomic, isthmus formed by preexisting double-potential barrier at the CTI was identified in 47% of patients with isthmus-dependent AFL. It is a useful guide to facilitate RFCA of isthmus-dependent AFL.     

成人先心病合并典型心房扑动患者导管消融术后新发心房颤动的临床研究

目的 探讨成人先天性心脏病(先心病)合并典型心房扑动(房扑)患者导管消融术后新发心房颤动(房颤)的发生率和高危因素.方法 选取2013年7月至2019年7月于河南省人民医院心血管内科接受典型房扑导管消融的32例成人先心病患者为研究对象,并对消融术后新发房颤的发生情况随访.分析新发房颤的发生率及高危因素.结果 平均随访(...