探索不用Halo电极射频消融治疗典型心房扑动的方法

目的探讨不用Halo电极消融典型心房扑动(AF)的方法和右心房峡部传导时间间期的意义.方法对9例AF患者进行了心脏电生理检查和射频消融.将普通标测电极分别放置高位右房(A点)、低位右房(B点)、希氏束(C点)、冠状窦(CS34为D点),标测AF发作时右房激动顺序,起搏时和消融后测量右心房峡部传导时间间期(BD、DB). 结果不用Halo电极成功消融9例AF病例.消融后于冠状窦口处起搏时起搏信号至右房下侧壁的时间间期(DB=140.7ms±66.1ms)和右房下侧壁起搏时起搏信号至冠状窦口CS34的时间间期(BD=123.2ms±42.1ms)均较消融前(DB=66.0ms±12.5ms,BD=62.5ms±13.0ms)明显延长,P＜0.01. 结论不用Halo电极能成功消融典型AF,该方法简便、费用低;右心房峡部传导时间间期的定量测定可作为判断峡部完全性双向传导阻滞的方法之一.     

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。     

探索不用Halo电极射频消融治疗典型心房扑动的方法

目的探讨不用Halo电极消融典型心房扑动(AF)的方法和右心房峡部传导时间间期的意义。方法对9例AF患者进行了心脏电生理检查和射频消融。将普通标测电极分别放置高位右房(A点)、低位右房(B点)、希氏束(C点)、冠状窦(CS34为D点),标测AF发作时右房激动顺序,起搏时和消融后测量右心房峡部传导时间间期(BD、DB)。结果不用Halo电极成功消融9例AF病例。消融后于冠状窦口处起搏时起搏信号至右房下侧壁的时间间期(DB=140.7ms±66.1ms)和右房下侧壁起搏时起搏信号至冠状窦口CS34的时间间期(BD=123.2ms±42.1ms)均较消融前(DB=66.0ms±12.5ms,BD=62.5ms±13.0ms)明显延长,P<0.01。结论不用Halo电极能成功消融典型AF,该方法简便、费用低;右心房峡部传导时间间期的定量测定可作为判断峡部完全性双向传导阻滞的方法之一。     

三尖瓣环传导时间在确定典型心房扑动消融终点中的价值

目的评价三尖瓣环的传导时间在确定心房扑动(房扑)消融终点中的价值。方法19例经体表心电图证实为典型房扑的患者,在心动过速中根据房扑激动顺序及拖带标测证明折返环沿三尖瓣环运行。测定房扑周长(tachycardial interval,TCL)及起搏后间期(post-pacing interval,PPI)。在三尖瓣环与下腔静脉之间的峡部消融,经冠状窦口及低位右心房起搏证明峡部双向阻滞。分别在冠状窦口、冠状窦远端及高位右心房刺激,用大头电极在峡部消融线上记录在3个部位起搏时的双电位间期(double potential interval,DPI),DPI=刺激信号至第二个电位间期(T2)-刺激信号至第一个电位间期(T1);三尖瓣环传导时间(tricuspid valve annulus conductiontime,TACT),TACT=(T1 T2)-(PPI-TCL);计算TACT/TCL。结果19例患者在消融术中均形成峡部双向阻滞,无并发症发生,停用任何抗心律失常药物,平均随访(27±8)个月,复发1例,经再消融后成功。TCL为210~385ms(平均267·21±36·64ms),冠状窦近端测得的PPI为235~390ms(平均291·32±42·88ms),冠状窦远端PPI为273~450ms(平均334·25±43·04ms),高位右心房的PPI为230~385ms(平均277·13±35·91ms)。提示高位右心房及冠状窦口接近折返环(与TCL相比,P>0·05),而冠状窦远端远离折返环(与TCL相比,P<0·05)。经冠状窦口及低位右心房起搏证实峡部双向阻滞后,分别于冠状窦口、冠状窦远端及高位右心房起搏测定DPI,分别为(152·56±56·66)ms,(150·08±48·35)ms及(85·6±34·47)ms。高位右心房起搏时DPI与冠状窦起搏时比较差异有统计学意义(P<0·05)。3个部位计算的TACT分别为(234·72±58·03)ms、(219·73±40·87)ms,(232·3±43·24)ms,差异无统计学意义。三个部位计算的TACT/TCL分别为(0·87±0·14),(0·82±0·12)及(0·91±0·15),差异无统计学意义。结论三尖瓣环传导时间不受起搏部位的影响,仅与环内折返运动时间长短有关。不论房扑周长的长短及双电位间期的大小,只要三尖瓣环传导时间与房扑周长之比接近于1,提示峡部完全阻滞。     

非接触球囊导管标测系统指导心房扑动消融的初步经验

目的　评价非接触球囊导管标测系统在心房扑动 (房扑 )标测和射频消融中的临床应用。方法　 7例房扑患者 ,年龄 (6 0± 10 )岁 ,男 4例 ,女 3例。其中 1例为房间隔缺损修补术后 ,2例为采用常规方法消融典型房扑后复发患者。应用非接触球囊导管标测系统构建右房三维几何模型 ,标测心动过速的折返激动顺序和关键峡部 ,并利用其导航系统指导峡部的线性消融。消融后分别于峡部两侧起搏判断峡部阻滞情况。结果　 6例患者诱发出房扑 ,心动过速周长 (2 16± 2 2 )ms。6例房扑均为峡部依赖型 ,2例呈逆钟向传导 ,4例呈顺钟向传导 ;4例房扑呈双环折返激动 ;7例消融均成功 ,房扑不再诱发 ,峡部呈完全双向传导阻滞 ;手术时间 (30 0± 12 9)min ,X线曝光时间 (2 5 0± 6 5 )min ,放电次数 (2 5 7± 12 1)次。无手术并发症。随访 3～ 14个月无复发病例。结论　在房扑标测和消融中应用非接触球囊导管标测系统是安全有效的 ,不仅能确定折返环路 (特别是双环折返激动 )的顺序和关键峡部 ,而且能准确判断线性损伤的连续性 ,同时可减少X线曝光时间。     

典型心房扑动的经导管射频消融治疗

回顾分析 35例典型心房扑动 (简称房扑 )患者电生理检查和射频消融治疗的临床结果。心内激动标测显示沿三尖瓣环 (TA)逆钟向折返性房扑 2 7例 ,顺钟向折返 2例 ,同时存在二种折返 6例。 8例行TA峡部拖带起搏者均呈隐匿性拖带 ,起搏后间期与房扑周长差值为 1± 4(- 3～ 5 )ms。采用TA峡部双线性消融、后峡部或 /和间隔峡部消融的方法治疗所有患者均成功。 15例以房扑不能再诱发为手术终点 ,随访 10例 ,3例复发 ,复发率 30 % ;2 0例达到TA峡部双向阻滞 ,随访 19例 ,1例复发 ,复发率 5 % ,两组比较P <0 .0 5。随访的 2 9例中 ,7例发生心房颤动 (简称房颤 ) ,发生率 2 4%。与无房颤发作者相比 ,合并器质性心脏病、心房扩大和有房颤病史者的比例明显增加 (6 / 7比 9/ 2 2 ,6 / 7比 4/ 2 2和 7/ 7比 2 / 2 2 ,均P <0 .0 5 )。结果表明 ,心内激动标测结合拖带起搏技术可确定典型房扑的诊断 ,后峡部或间隔峡部消融是治疗房扑的有效方法 ,以TA峡部双向阻滞为手术终点较房扑不能被再诱发为终点可明显降低复发率。房扑消融术后发生房颤与合并器质性心脏病、心房扩大和术前存在房颤有关     

术中峡部传导间期百分比对典型心房扑动导管消融终点判定的有效性评估

目的 通过术中测量三尖瓣-下腔静脉峡部（CTI）依赖心房扑动（房扑）消融前后峡部传导间期百分比,探讨峡部传导间期百分比在CTI线性阻滞消融终点评估的临床价值。方法 本研究入组2021年2月至2023年2月诊断CTI依赖房扑并行射频消融治疗患者共37例（首都医科大学附属北京安贞医院35例,河北省儿童医院2例）,术中均诱发CTI依赖房扑,并采用解剖消融方法沿三尖瓣环至下腔静脉行线性消融,术后经右心房激动标测验证CTI呈线性阻滞。分别统计入组患者心动过速周长（TCL）、冠状窦起搏下消融前局部传导间期（P-ABL1）、冠状窦起搏下消融后局部传导间期（P-ABL2）,计算局部传导期间百分比（P-ABL2/TCL）。评估P-ABL2/TCL对诊断CTI双向传导阻滞的价值,并通过消融后激动顺序验证其有效性。结果 所有入组患者均采用解剖方法行射频消融,并行激动标测验证CTI呈线性阻滞。术中诱发TCL为（310.00±46.32）ms。术前测定P-ABL1为（92.16±27.65）ms,术后测量P-ABL2为（173.65±16.35）ms,两组数据差异有统计学意义（P <0.001）。术后P-...     

应用CARTO系统射频消融儿童快速右房房性心律失常的初步体会

目的　初步总结应用CARTO系统指导射频消融儿童快速右房房性心律失常的经验。方法　右房房速（AT）3例,典型房扑（AF）l例,心动周期(277±31)ms,在心动过速时应用CARTO系统标测右房,重建三维电解剖图并指导射频消融靶点;房扑消融后分别在低位右房和冠状窦以500ms起搏作电解剖图,判断完全双向传导阻滞。结果　2例为局灶性房速,起源点分别在希氏束旁（Koch三角）和高位右旁;1例为右房壁疤痕介导的折返性房性心动过速(IART)。4例成功消融,放电次数(10.6±5.5)次,透视时间(18±9)min,术程(110±38)min。结论　(1)CARTO系统容易寻找最佳靶点;(2)房扑消融后在低位右房和冠状窦起搏作电解剖图,判断完全双向传导阻滞,大幅度减小X线透视时间,提高成功率,降低复发率。     

典型心房扑动下腔静脉-三尖瓣环峡部电传导特性

目的比较典型心房扑动(房扑)与无房扑患者，下腔静脉-三尖瓣(TV—IVC)峡部的电传导特性。方法 12例同期来本院作射频消融的患者，A组6倒为频繁发作的典型房扑，B组6例为无房扑史的室上性心动过速(室上速)。观寨右房下侧壁(H1-2)和冠状窦口(CS9-10)以周期为600，500，400，300ms起搏时以及房扑和室上速时，TV—IVC峡部传导时间变化。基本刺激周期500ms时，分别测定峡部内、外侧局部心房不应期。结果 ①H1-2起搏时，A组蛱部传导时间较B组平均延长20.3%±11.6%(3.9％～28．9%，但P＞0．05)。CS9-10起搏时，A组峡部传导时间较B组传导时间平均延长27.1％±10.5%（12．5％～35.8％．但P>0．05)。②房扑时峡部传导时间133±6．6ms。室上速峡部传导时间61．1±12．7ms．两组(P<0．05)。③A、B组峡部局部心房有效不应期(ERP)差异无显著性。结论下腔静脉-三尖瓣峡部是折返环的一部分。但窦性心律时蛱部无显著传导延迟。房扑功能慢传导区不一定局限于该部位。     

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     

Role of transisthmus conduction intervals in predicting bidirectional block after ablation of typical atrial flutter

INTRODUCTION: Complete bidirectional cavotricuspid isthmus block is the endpoint for ablation of typical atrial flutter. The purpose of this study was to determine whether the extent of prolongation of the transisthmus interval after ablation predicts complete bidirectional block. METHODS AND RESULTS: Fifty-seven consecutive patients underwent 60 ablation procedures for isthmus-dependent atrial flutter. The clockwise and counterclockwise transisthmus intervals were determined before and after ablation during pacing from the low lateral right atrium and the coronary sinus. Bidirectional block was achieved with ablation in 55 (96%) of 57 patients. The transisthmus intervals before ablation and after complete transisthmus block were 100.3 +/- 21.1 msec and 195.8 +/- 30.1 msec, respectively, in the clockwise direction (P < 0.0001), and 98.2 +/- 24.7 msec and 185.7 +/- 33.9 msec, respectively, in the counterclockwise direction (P < 0.0001). An increase in the transisthmus interval by > or = 50% in both directions after ablation predicted complete bidirectional block with 100% sensitivity and 80% specificity. The positive and negative predictive values were 89% and 100%, respectively. The diagnostic accuracy of a > or = 50% prolongation in the transisthmus interval was 92%. CONCLUSION: Prolongation of the transisthmus interval by > or = 50% in the clockwise and counterclockwise directions is associated with a high degree of diagnostic accuracy and an excellent negative predictive value in determining complete bidirectional transisthmus block. This may be a useful and simple adjunctive criterion for assessment of complete transisthmus conduction block.     

Double Potential Interval and Transisthmus Conduction Time for Prediction of Cavotricuspid Isthmus Block after Ablation of Typical Atrial Flutter

Background: Complete bi-directional isthmus block is the endpoint of typical atrial flutter ablation. The purpose of this study was to investigate the feasibility of the local double potential (DP) interval and the change in transisthmus conduction time for predicting complete isthmus block after ablation of the cavotricuspid isthmus. Methods: The study population consisted of 32 patients with typical atrial flutter after a procedure of radiofrequency (RF) ablation of the cavotricuspid isthmus (16 had incomplete block and 16 had complete block). The transisthmus conduction time was determined during pacing from the proximal coronary sinus and low lateral right atrium before and after RF ablation. The DP interval close to the ablation line was evaluated after final RF energy application. Results: In the counterclockwise direction, transisthmus conduction time had an increase of 37 ± 25.4% and 127.3 ± 35.5% (P < 0.001), and the DP interval was 63.3 ± 8.7 ms and 120 ± 17.4 ms (P < 0.001) after achievement of incomplete and complete block, respectively. The sensitivity, specificity, positive and negative predictive values of an increase in the transisthmus conduction time 50% were 100%, 81%, 84% and 100%, respectively; those of DP interval 100 ms were 100%. In the clockwise direction, transisthmus conduction time had an increase of 38.8 ± 28.6% and 135.7 ± 63.6% (P < 0.001), and the DP interval was 63.6 ± 13.8 ms and 127.7 ± 27.1 ms (P < 0.001) after achievement of incomplete and complete block, respectively. The sensitivity, specificity, positive and negative predictive values of an increase in the transisthmus conduction time 50% were 100%, 67%, 83% and 100%, respectively; those of the DP interval 100 ms were 100%. Conclusions: The transisthmus conduction time 50% increase or DP interval 100 ms was feasible to predict complete bi-directional isthmus block.     

Double potentials along the ablation line as a guide to radiofrequency ablation of typical atrial flutter

OBJECTIVES: The purpose of this study was to determine the characteristics of double potentials (DPs) that are helpful in guiding ablation within the cavo-tricuspid isthmus. BACKGROUND: Double potentials have been considered a reliable criterion of cavo-tricuspid isthmus block in patients undergoing radiofrequency ablation of typical atrial flutter (AFL). However, the minimal degree of separation of the two components of DPs needed to indicate complete block has not been well defined. METHODS: Radiofrequency ablation was performed in 30 patients with isthmus-dependent AFL. Bipolar electrograms were recorded along the ablation line during proximal coronary sinus pacing at sites at which radiofrequency ablation resulted in incomplete or complete isthmus block. RESULTS: Double potentials were observed at 42% of recording sites when there was incomplete isthmus block, compared with 100% of recording sites when the block was complete. The mean intervals separating the two components of DPs were 65 +/- 21 ms and 135 +/- 30 ms during incomplete and complete block, respectively (p < 0.001). An interval separating the two components of DPs (DP(1-2) interval) <90 ms was always associated with a local gap, whereas a DP(1-2) interval > or =110 ms was always associated with local block. When the DP(1-2) interval was between 90 and 110 ms, an isoelectric segment within the DP and a negative polarity in the second component of the DP were helpful in indicating local isthmus block. A DP(1-2) interval > or =90 ms with a maximal variation of 15 ms along the entire ablation line was an indicator of complete block in the cavo-tricuspid isthmus. CONCLUSIONS: Detailed analysis of DPs is helpful in identifying gaps in the ablation line and in distinguishing complete from incomplete isthmus block in patients undergoing radiofrequency ablation of typical AFL.     

差异性起搏法对典型心房扑动消融后峡部完全传导阻滞的预测价值

目的探讨一种简单的方法用以鉴别峡部消融线是完全阻滞还是存在缓慢传导,以降低典型心房扑动(简称房扑)消融后的复发率。方法前瞻性研究30例典型房扑患者消融后峡部的传导,放置20极Halo电极,使最远端的两对电极靠近阻滞线,分别起搏这两对电极并在消融线上标测局部双电位或多电位,我们假设局部电位的初始成分和终末成分分别代表消融线两侧的激动,当起搏部位由离消融线较近的电极对转为较远电极对起搏时,刺激信号到局部电位初始电位成分的时间将会延迟,而刺激信号到局部电位终末成分的时间变化取决于阻滞线是否完整。终末电位提前或不变提示完全阻滞,终末电位延迟提示阻滞线上有传导缝隙。结果用传统判断峡部阻滞的方法做参照标准,选取位点进行差异性起搏共54次,峡部完全阻滞前18次,峡部完全阻滞后36次。当起搏部位转为较远电极对时,初始电位均延迟,平均18±9ms,峡部不全阻滞时,终末电位延迟13±7ms,峡部完全阻滞后,终末电位提前12±8ms。差异性起搏对预测峡部完全阻滞的灵敏度达100%,特异度达88.9%。结论差异性起搏可准确鉴别峡部形成完全阻滞还是存在缓慢传导。     

New insights into typical atrial flutter ablation: extra-isthmus activation time on the flutter wave is predictive of extra-isthmus conduction time after isthmus block

Purpose

Catheter ablation of typical atrial flutter (AFl) is succesful if double electrograms on the ablation line are widely separated. Nevertheless, a small interval may also be compatible with complete isthmus block. Predicting such a situation may avoid useless additionnal radiofrequency (RF) applications. We postulated that measuring the extra-isthmus activation time (EIAT) on the counterclockwise (CCW) flutter wave is correlated with the extra-isthmus conduction time after a proven block.

Methods

Files of 76 patients (71 males, 71?±?12 years) ablated for typical CCW AFl were reviewed. Ten had 2/1 conduction prohibiting reliable measurement. Three patients with proven crista terminalis shunt were also excluded. In the remaining 63 patients, EIAT was measured on the surface ECG before the first RF pulse from the beginning of the negative deflection of the F wave in lead III to the end of the positive deflection (or beginning of the plateau). After successful ablation and completion of block, right atrial (RA) CCW (during low septal pacing), and clockwise (CW) (during low lateral pacing) activation times were measured.

Results

Flutter cycle length was 247?±?34 ms and EIAT was 142?±?25 ms. A bidirectionnal isthmus block was obtained in all patients after an RF delivery time of 623?±?546 s. At a pacing cycle length of 681?±?71 ms, RA CCW and CW activation times were 147?±?23 and 139?±?26 ms, respectively. There was a good correlation between EIA, RA CCW (r?=?0.75, p?<?0.0001), and CW (r?=?0.69, p?=?0.0002) activation times.

Conclusion

EIAT on the flutter wave is an easy and feasible measure. It is correlated with extra-isthmus RA conduction time after block completion. EIAT can be used as a measure to predict the post cavo-tricuspid isthmus block RA activation time.     

非接触标测系统用于典型心房扑动的右房标测和导航消融

应用非接触标测系统实施典型心房扑动 (AFL)的右房 (RA)全心腔标测和导航射频消融。 6例典型AFL ,男 5例、女 1例 ,年龄 5 6 .2± 15 .3(35～ 76 )岁。常规放置冠状静脉窦和His束电极 ,将标测球囊置于RA中下部 ,构建RA心内膜模型 ,分别于低位RA和冠状窦口 (CSO)S1S16 0 0ms起搏观察峡部传导 ,诱发并标测AFL的激动顺序和折返路径。 1例为顺钟向AFL ,4例为逆钟向AFL ,1例未能诱发AFL。AFL周期 2 0 7± 34ms,非接触标测可显示整个折返环路、激动顺序和缓慢传导区。AFL的激动可以穿过界嵴上部并且传导相对缓慢 ,提示RA平滑部是折返环的一部分。后位峡部线性消融在导航系统指导下进行 ,无需X线透视。消融完成后重复上述起搏验证峡部双向传导阻滞。除 1例术中出现心房颤动 (AF)外 ,其余病例即刻均达到峡部双向阻滞 ,未出现其他并发症 ,随访 8.1± 6 .7(3～15 )个月未见复发。非接触标测系统可安全、有效和直观地实现典型AFL的右房全心腔标测并导航消融 ,验证峡部双向阻滞 ,减少X线曝光时间和无效放电次数。界嵴在典型AFL时具备传导功能 ,RA平滑部和粗糙部共同参与折返环的组成。     

心房颤动消融术后二尖瓣峡部房性心动过速的发生机制及消融治疗

目的探讨心房颤动(简称房颤)患者环肺静脉左房线性消融术后二尖瓣峡部房性心动过速(简称房速)的发生机制及其消融策略。方法122例房颤患者采用EnSite-NavX和环状电极行环肺静脉左房线性消融,术后32例复发房颤或房速,8例经EnSite-NavX激动标测及拖带标测证实存在二尖瓣峡部房速,在三维导航下于左下肺静脉口部下缘至二尖瓣环之间行线性消融,对不能成功阻断二尖瓣峡部传导者予以冠状静脉窦内消融。术中同时探查双侧肺静脉电位,如传导恢复予以再次隔离。结果8例中2例呈无休止性发作,6例为阵发性,可被程序刺激诱发。房速的周长217.5±20.6ms,其中顺钟向折返5例,逆钟向折返3例。二尖瓣峡部线性消融至完全性双向传导阻滞5例,3例心内膜途径失败者经冠状静脉窦内消融,其中1例获得成功。术后随访5.5±4.3个月,6例无房颤及房速发作,1例仍有阵发性房速发作。另1例术后房速呈无休止发作,予以胺碘酮及美托洛尔控制心室率治疗。结论环肺静脉线性消融术后发生的二尖瓣峡部房速与左房线性消融治疗房颤的致心律失常作用有关,其主要的机制是消融线相关的大折返性心动过速,阻断峡部传导可以治疗此类房速。     

射频消融心房扑动拖带刺激的电生理特征

探讨射频消融心房扑动 (简称房扑 )拖带刺激的电生理特征 ,更好的理解房扑机制 ,以期提高消融成功率、减少复发率。 5例阵发性典型房扑患者 ,诱发房扑后 ,在高位、低位右房 ,冠状窦口 (CSO)及右房下部的峡部分别进行拖带刺激 ,分析心房激动顺序 ,然后进行三尖瓣环至下腔静脉之间的线性消融。 5例房扑折返环均为逆钟向旋转 ,峡部 ,高位、低位右房及CSO呈现隐匿拖带 ,左房和卵圆窝呈现显性拖带 ,平均放电 9± 6次 ,均达到右房峡部双向阻滞。CSO起搏时体表心电图Ⅱ、Ⅲ、aVF导联P波形态发生改变。结论 :隐匿、显性拖带对判断峡部依赖性逆钟向房扑有较高价值 ,CSO起搏时心内电图激动顺序和体表心电图P波改变可做为判断峡部消融达到双向阻滞的标志