心房起搏法在射频消融房室结折返性心动过速中的应用

将射频消融治疗的９４例房室结折返性心动过速（ＡＶＮＲＴ）病人按心房起搏法和常规法进行分组（分别为３９及５５例），回顾性比较两组病人的消融治疗结果，以评价这两种方法在射频消融治疗ＡＶＮＲＴ中的安全性、成功率和复发率。随访１０．８±４．５个月，总成功率为９６．８％、复发率为２．１％。与常规组相比，起搏组有效放电时间明显延长（１４５±３８ｓｖｓ８２±２６ｓ，Ｐ＜０．０１）、慢径阻断成功率高（６１．５％ｖｓ４０．０％，Ｐ＜０．０１）、一过性房室阻滞发生率低（２．６％ｖｓ１２．７％，Ｐ＜０．０５），但各种类型的永久性房室阻滞发生率和复发率无显著性差异（Ｐ＞０．０５）。表明ＡＶＮ－ＲＴ消融术中采用心房起搏法较常规法更为安全有效。     

从慢径消融发生的交界区心律试探房室结双径的本质

７６例慢－快型房室结折返性心动过速（ＡＶＮＲＴ）患者接受房室结慢径消融术。６５例慢径阻断、９例双径存在但ＡＶＮＲＴ不能诱发、２例快径阻断。慢径阻断后，除快径的前传有效不应期（ＥＲＰ）缩短（２８７．０±７９．０ｍｓｖｓ３４４．０±８７．０ｍｓ，Ｐ＜０．０１）外，房室传导的文氏点、２１阻滞点、室房传导的１１点、快径逆传ＥＲＰ、前传和逆传功能不应期均无明显改变。共放电８４１次，其中无交界区心律的３１７次放电，无一次消融成功。６５例慢径阻断者，交界区心律减少或消失。以上结果提示快径和慢径可能是两条各具电生理特性的传导纤维。     

经皮球囊二尖瓣成形术对心率变异的影响

为了解经皮球囊二尖瓣成形术（ＰＢＭＶ）对风湿性心脏病二尖瓣狭窄病人心率变异（ＨＲＶ）的影响，自同期行ＰＢＭＶ的７１例病人中选择窦性心律者作为观察对象。于术前二日和术后第三日记录５ｍｉｎ的心搏数，经短时ＨＲＶ软件分析。结果表明术后ＲＲ间期均值标准差（３３．１８±１０．４２ｍｓｖｓ４２．８０±１５．８４ｍｓ，Ｐ＜０．０５）、相邻ＲＲ间期差值的均方根（２９．６１±１３．３８ｍｓｖｓ３７．５２±２６．０８ｍｓ，Ｐ＜０．０５）、相邻ＲＲ间期差值大于５０ｍｓ的百分比（６．７６±７．４９％ｖｓ９．０３±１０．２３％，Ｐ＜０．０１）、高频能谱（６１５．５８±４８５．６２ｂｐｍ２ｖｓ７０１．９７±６４９．９６ｂｐｍ２，Ｐ＜０．０５）均明显增大或升高。而平均心率（７４．３２±１１．３７ｂｐｍｖｓ６５．８８±７．７３ｂｐｍ，Ｐ＜０．０１）、最大心率（９５．６８±２８．６８ｂｐｍｖｓ７６．１４±８．５３ｂｐｍ，Ｐ＜０．０１）、低频能谱（４３８．２２±４０９．３１ｂｐｍ２ｖｓ２４０．１８±１９８．６８ｂｐｍ２，Ｐ＜０．０１）、极低频能谱（９７１．７４±５２９．５３ｂｐｍ２ｖｓ７２１．４３±５６４．０９ｂｐｍ２，Ｐ＜０．０１）均明显降?     

房室结传导的加速性、疲劳性对房室结功能不应期的影响

房室结传导的加速性、疲劳性对心室免于各种类型的室上性心动过速包括心房颤动的影响起决定作用，但对房室结功能不应期（ＡＶＮ－ＦＲＰ）的影响不明。旨在通过对离体兔心施以多种方案电生理刺激以阐明两者的相互关系。实验结果表明：①房室结传导的加速性使ＡＶＮ－ＦＲＰ缩短（Ｂ方案１４６±３．３ｍｓｖｓＡ方案１５９±３．５ｍｓ，Ｐ＜０．０１，ｎ＝６），疲劳性使ＡＶＮ－ＦＲＰ延长（Ｃ方案１８７±４．９ｍｓｖｓＡ方案１５９±３．５ｍｓ，Ｐ＜０．０１，ｎ＝６）；②加速性和疲劳性诱导的ＡＶＮ－ＦＲＰ的变化是在１１房室传导范围内产生的，并在快速频率下达到它的最大效应（１００％频率下，Ｂ方案１５４±６．０ｍｓ、Ｃ方案１８７±８．３ｍｓ分别与Ａ方案１６８±６．９ｍｓ相比，Ｐ均＜０．０１，ｎ＝６）。结论：ＡＶＮ－ＦＲＰ受房室结传导之加速性、疲劳性相互作用的共同影响，ＡＶＮ－ＦＲＰ的变化可以用来反映房室结的传导功能     

辅用SR_0长鞘在慢径路消融治疗房室结折返性心动过速价值探讨

目的　探讨辅用ＳＲ０ 长鞘在慢径路消融治疗房室结折返性心动过速（ＡＶＮＲＴ）中的应用价值。方法　应用复合定位法慢径路消融治疗１７４ 例典型ＡＲＮＲＴ 患者,未用长鞘与辅用长鞘组各８７ 例。比较两组消融结果。结果　辅用长鞘组较对照组手术时间（６８±１７ ｍ ｉｎ ｖｓ ８５±２１ ｍ ｉｎ,Ｐ＜ ０．０１）,Ｘ 线曝光时间（１４±１６ ｍ ｉｎ ｖｓ １８±９ ｍ ｉｎ,Ｐ＜ ０．０５）,放电次数（３．２±２．５ ｖｓ ５．３±３．４,Ｐ＜ ０．０１）均显著减少。且辅用长鞘组８７ 例中,消融后慢径路消失者较多（５７ 例,６６％ ｖｓ ３９ 例,４５％ ,Ｐ＜ ０．０１）。结论　慢径消融中辅用ＳＲ０ 长鞘有明显应用价值     

心房起搏法在射频消融房室结折返性心运过速中的应用

将射频消融治疗的９４例房室结折返性心动过速（ＡＶＮＲＴ）病人按心房起搏法和常规法进行分组（分别为３９及５５例），回顾性比较两组病人的消融治疗结果，以评价这两种方法在射频消融治疗ＡＶＮＲＴ中的安全性、成功率和复发率。随访１０．８±４．５个月，总成功率为９６．８％，复发率为２．１％。与常规组相比，起搏组有效放电时间明显延长（１４５±３８ｓｖｓ８２±２６ｓ，Ｐ〈０．０１），慢径阻断成功率高（６１．５％ｓ     

房室结折返性心动过速与冠状静脉窦关系的初步研究

为探讨房室结双径路导致折返性心动过速的发病机制，以更准确的选择消融靶点和减少并发症。对经电生理检查诊断的３３例室上性心动过速（ＳＶＴ）病人进行冠状静脉窦（ＣＳ）造影的对比研究。分为两组，其中房室结折返性心动过速（ＡＶＮＲＴ）组１７例，对照组（为其他室上性心动过速）１６例。两组病人均经ＣＳ造影，观察ＣＳ形态、走行及分支情况，测量ＣＳ口（ＣＳＯ）大小、窦体直径、长度及窦口上缘与Ｈｉｓ束之间的距离。结果发现ＡＶＮＲＴ组ＣＳ近端形态多呈漏斗状，占８２．４％，而对照组漏斗状仅占２５．０％，其余多呈管状（Ｐ＜０．０１）。ＡＶＮＲＴ组ＣＳＯ明显扩张，两组ＣＳＯ直径分别为１６．４±４．７和１０．２±３．９ｍｍ（Ｐ＜０．０１）。ＡＶＮＲＴ组窦口上缘到Ｈｉｓ束的距离明显较对照组近（８．０３±６．１２ｍｍｖｓ２１．３±６．４８ｍｍ），Ｐ＜０．００１。结果提示：ＡＶＮＲＴ患者的ＣＳＯ扩张对局部心房肌的压迫和牵拉，使ＣＳＯ周围的心房肌各向异性程度增高，可能是导致各向异性折返的病理机制。由于ＣＳＯ扩张使ＣＳＯ上缘距Ｈｉｓ束距离变近，给射频消融（ＲＦＣＡ）造成困难和危险，对此类ＡＶＮＲＴ病人行ＲＦＣＡ应谨慎从事。     

不同起搏方式对病窦综合征患者远期效果的影响

为了解不同起搏方式对病窦综合征特别是慢－快综合征患者心功能及房性心律失常的影响，利用超声心动图、体表心电图及Ｈｏｌｔｅｒ检查，对２１１例病窦综合征患者采用自身对照方法进行回顾性分析。结果发现：生理性起搏（ＡＡＩ／ＤＤＤ）组术后左室射血分数（ＬＶＥＦ）、心输出量（ＣＯ）明显增加（ＡＡＩ：５３．５±６．１％ｖｓ４７．２±７．８％，４．９５±０．５７Ｌ／ｍｉｎｖｓ４．２０±０．６２Ｌ／ｍｉｎ；ＤＤＤ：５２．５±６．８％ｖｓ４４．３±０．１％，５．１２±０．７１Ｌ／ｍｉｎｖｓ４．４１±０．３８Ｌ／ｍｉｎ；Ｐ均＜０．０１），左房内径（ＬＡＤ）无明显变化；ＤＤＤ组Ｅ／Ａ比值明显增加（０．９８±０．０９ｖｓ０．８７±０．１５，Ｐ＜０．０１），ＡＡＩ组Ｅ／Ａ比值呈增加趋势（Ｐ＝０．０５７）。房性心律失常发生率明显减少（１５．９％ｖｓ５０％，Ｐ＜０．０１）。非生理性起搏（ＶＶＩ）组术后ＬＶＥＦ、ＣＯ明显下降（４４．１±４．７％ｖｓ４８．３±４．３％，３．７７±０．４２Ｌ／ｍｉｎｖｓ４．１７±０．８５Ｌ／ｍｉｎ，Ｐ均＜０．０１），ＬＡＤ明显增大（３９．２６±２．３７ｍｍｖｓ３６．８１±２．３５ｍｍ，Ｐ＜０．０１），Ｅ／Ａ比值呈?     

切割前房结通路对家兔房室结电生理特性的影响

为进一步了解房室结整体电生理特性以及消融治疗房室结折返性心动过速的机制，选择性切割无房室结双径现象离体家兔心的前房结通路（Ｋｃｈ三角前区）观察其对房室结电生理参数的影响。与切割前相比，切割后ＡＨ间期、房室结功能不应期、房室结前传文氏周长、室房逆传文氏周长及ＶＡ间期延长（分别为４５．６４±８．６８ｍｓｖｓ３８．２３±６．１３ｍｓ，１６６．３４±１５．３３ｍｓｖｓ１４４．４８±１０．８６ｍｓ，１６３．３７±１７．２２ｍｓｖｓ１３８．３６±１２．４３ｍｓ，２０２．６０±４１．５０ｍｓｖｓ１６８．５０±２０．３０ｍｓ，６８．６０±１．６０ｍｓｖｓ５４．５０±７．１０ｍｓ，Ｐ均＜０．０５）。提示毁损房室交界区特定部位可以影响房室结整体电生理特性。     

经皮冠状动脉腔内成形术对不稳定型心绞痛患者心率变异的影响

应用长程心电图分析系统对１６例不稳定型心绞痛患者（ＵＡＰ组）入院后第２日、经皮冠状动脉腔内成形术（ＲＴＣＡ）后第１，３，３０日以及１４８例健康中、老年人（对照组）２４ｈ心电图进行心率变异（ＨＲＶ）分析。结果：ＵＡＰ组２４ｈ连续正常ＲＲ间期的标准差（ＳＤＮＮ）、２４ｈ内连续５ｍｉｎ节段平均正常ＲＲ间期的标准差（ＳＤＡＮＮｉ）、相邻ＲＲ间期差的均方根（ｒＭＳＳＤ），相邻两个正常心动周期差值大于５０ｍｓ个数占总搏数的百分比（ＰＮＮ５０）、低频功率（ＬＦ）及高频功率（ＨＦ）均明显低于对照组（分别为９２．７±１４．３ｍｓｖｓ１２８．９±１７．８ｍｓ、７８．８±１０．６ｍｓｖｓ１１８．６±１９．１ｍｓ、１９．３±７．７ｍｓｖｓ２９．８±１２．７ｍｓ、３．６±１．７％ｖｓ６．５±５．５％、３１７．２±１４８．３ｍｓ２ｖｓ４７６．５±２８７．３ｍｓ２，Ｐ均＜０．０５），而ＬＦ／ＨＦ高于对照组（３．５±１．３ｖｓ２．４±１．１，Ｐ＜０．０５）。ＰＴＣＡ术后３０天ＵＡＰ患者ＨＲＶ逐渐恢复正常。结果提示ＵＡＰ患者交感神经和迷走神经张力下降，而以后者更明显；ＰＴＣＡ后ＨＲＶ逐渐恢复，说明ＰＴＣＡ能改善ＵＡＰ患者的ＨＲＶ。     

心房起搏时PR与RR间期比值对阵发性室上性心动过速鉴别诊断的意义

为探讨快速心房起搏最短１∶１房室传导时最大ＰＲ间期（ＰＲｍａｘ）与ＲＲ间期比值（ＰＲｍａｘ／ＲＲ）在鉴别阵发性室上性心动过速中的意义，分析比较了２０例房室结折返性心动过速（ＡＶＮＲＴ，有房室结前传跳跃现象者１２例、无跳跃现象者８例）和２０例房室折返性心动过速（ＡＶＲＴ）患者消融前、后快速心房起搏时最短１∶１房室传导的ＰＲｍａｘ／ＲＲ。ＡＶＮＲＴ组消融前、后心房快速起搏时最短１∶１房室传导的ＰＲｍａｘ／ＲＲ为１．１２±０．１２和０．４２±０．０７，两者比较差异有高度显著性，Ｐ＜０．０１；ＡＶＲＴ组为０．５２±０．１６和０．５１±０．１８，两者比较差异无显著性，Ｐ＞０．０５。消融前，ＡＶＮＲＴ组ＰＲｍａｘ／ＲＲ与ＡＶＲＴ组相比有显著性差异（１．１２±０．１２ｖｓ０．５２±０．１６，Ｐ＜０．０１）。ＰＲｍａｘ／ＲＲ＞１诊断ＡＶＮＲＴ的敏感性为９０％、特异性９１％。提示ＰＲｍａｘ／ＲＲ＞１在消融前可用来鉴别ＡＶＮＲＴ与ＡＶＲＴ；对无房室结前传跳跃的ＡＶＮＲＴ，消融后ＰＲｍａｘ／ＲＲ＜１可作为慢径消融成功的指标     

房室结折返性心动过速患者房室结功能曲线连续性的电生理分析

分析房室结折返性心动过速 (AVNRT)中房室结功能曲线呈连续性者的电生理特点。将AVNRT分为房室结功能曲线连续组 (Ⅰ组 )及房室结功能曲线不连续组 (Ⅱ组 ) ,行慢径消融 ,进行消融前后和组间的电生理比较 ,分析房室结功能曲线呈连续性者的特点。结果 :I组心房程序刺激对AVNRT的诱发率仅 42 % (5 / 12 ) ,低于Ⅱ组的 6 6 %(2 3/ 35 )。Ⅰ组房室结前传有效不应期 (ERP AVN)消融前后无显著变化 (2 18.2± 2 9.3msvs 2 5 3.3± 80 .3ms,P >0 .0 5 ) ;心房程序刺激最长A2 H2 间期 (AHmax)消融前后无显著变化 (2 2 5 .8± 71.8msvs 175 .4± 41.9ms,P >0 .0 5 )。Ⅱ组ERP AVN消融后显著延长 (2 78.9± 5 8.9msvs 2 35 .8± 39.6ms,P <0 .0 5 ) ;AHmax消融后显著缩短 (172 .0± 6 7.1msvs 331.6± 86 .6ms ,P <0 .0 5 ) ;消融后房室结快径前传有效不应期 (ERP FP)显著缩短 (2 78.9± 5 8.9msvs 330 .0±5 5 .3ms,P <0 .0 5 )。消融前Ⅰ组AHmax短于Ⅱ组 (P <0 .0 5 ) ,Ⅰ组心动过速时A2 H2 间期 (AHSVT)与消融前AHmax比较差异无显著性 (P >0 .0 5 ) ;Ⅱ组AHSVT短于消融前AHmax(P <0 .0 5 )。结论 :房室结功能曲线连续性者较难经常规心房程序刺激诱发心动过速 ;慢径消融后曲线“尾巴”消失可作为消融终点的一项指     

隐匿性房室旁道心电图定位特征探讨

回顾分析射频消融成功的３６５例隐匿性房室旁道患者房室折返性心动过速时的逆传Ｐ（Ｐ－）波特点，并比较Ｖ１及食管导联的ＲＰ－（ＲＰ－Ｖ１和ＲＰ－Ｅ）间期，以探讨隐匿性房室旁道的定位特征。结果显示：①Ｉ、ａＶＬ导联（简称Ⅰ－Ｌ导联）显示Ｐ－波倒置的１７５例均为左心旁道，其中左游离壁旁道１５５例、左后隔旁道２０例；Ⅱ、Ⅲ、ａＶＦ导联（简称Ⅱ－Ｆ导联）显示Ｐ－深倒７０例，其中左后隔旁道５０例中有３５例（７０．０％）、右后隔旁道３０例中有２５例（８３．３％）、右游离壁旁道６０例中有１０例（１６．７％），前两者与后者分别相比差异有显著性，Ｐ均＜０．００１。②在左心旁道中，ＲＰ－Ｖ１间期与ＲＰ－Ｅ间期相比（１６６．２±１７．８ｍｓｖｓ１１８．１±１９．２ｍｓ），差异有显著性，Ｐ＜０．０１；在右心旁道中，右前膈、右游离壁旁道ＲＰ－Ｖ１间期与ＲＰ－Ｅ分别相比（１０７．１±１８ｍｓｖｓ１５７．１±１８ｍｓ，１３２．５±１８．６ｍｓｖｓ１８９．２±２３．５ｍｓ），差异有显著性，Ｐ＜０．０１）。Ⅰ－Ｌ导联Ｐ－波倒置为左心旁道的重要表现，Ⅱ－Ｆ导联Ｐ－波深倒是后隔旁道的重要特点，两个导联上Ｐ－波均直立提示右前隔旁道，左心旁道ＲＰ－Ｅ间?     

Atrioventricular Nodal Reentry Tachycardia in Patients with Sinus Node Dysfunction: Electrophysiologic Characteristics, Clinical Presentation, and Results of Slow Pathway Ablation

AVNRT and Sinus Node Dysfunction. Introduction: Sinus node dysfunction (SND) is frequently associated with impaired AV conduction. This study investigated the electrophysiologic properties of dual AV nodal pathways in patients suffering from both SND and AV nodal reentrant tachycardia (AVNRT). Methods and Results: Two groups of patients with slow-fast AVNRT underwent invasive electrophysiologic testing and catheter ablation of the slow pathway. Group A comprised 10 patients with SND (age 70 ± 8 years), (Group B included 10 age-matched patients without SND (age 69 ± 7 years; P = NS) who served as controls. Patients of group A exhibited prolongation of the anterograde Wenckebach cycle lengths (WBCLs) of both the fast pathway (559 ± 96 vs 361 ± 38 msec; P < 0.01) and the slow pathway (409 ± 57 vs 339 ± 32 ms; P < 0.01). However, the delta between the WBCLs of the fast and the slow pathways was larger in patients of group A (150 ± 80 vs 22 ± 20 msec; P < 0.01). Retrograde fast pathway conduction was well preserved with no difference in WBCLs (356 ± 42 vs 330 ± 47 msec; P = NS). Cycle lengths of AVNRT were longer in group A (468 ± 46 vs 363 ± 37 msec; P < 0.01). Clinically, all patients of group A suffered from multiple episodes of AVNRT per week, which was not the case in any patient of group B (P < 0.01). Catheter ablation of the slow pathway eliminated AVNRT in all patients without complications. Conclusions: Patients with AVNRT and SND exhibit characteristic electrophysiologic alterations of both AV nodal pathways. Clinically, this results in significantly more frequent episodes of tachycardia. Slow pathway ablation appears to be safe and effective in these patients.     

快速心房起搏时SV间期与SS间期的比值在房室结折返性心动过速慢径消融中的应用

评价快速心房起搏时最快 1∶1房室传导的SV间期 (SV间期 )与 1∶1房室传导的最短S1S1间期 (SS间期 )的比值 (SV/SS)在房室结折返性心动过速 (AVNRT)慢径消融中的应用 ,将AVNRT分为房室结功能曲线连续组 (Ⅰ组 ,10例 )及房室结功能曲线不连续组 (Ⅱ组 ,17例 )测量心房分级递增刺激时的SS间期与SV间期及SV/SS ,并进行消融前、后和组间比较。结果显示 ,两组消融后SV间期较消融前明显缩短 (Ⅰ组 :2 2 1.0± 2 2 .3vs 35 7.0± 43.7ms;Ⅱ组 :2 0 2 .1± 30 .6vs 379.4± 44 .2ms,P均 <0 .0 5 ) ;消融前后SS间期无明显变化 (Ⅰ组 :310 .0± 40 .6vs 30 8.0± 36 .8ms;Ⅱ组 :332 .9± 48.1vs 336 .5± 6 2 .3ms) ;两组中所有患者消融前SV/SS比值均 >1,而消融后SV/SS比值均 <1。结论 :SV/SS可作为慢径消融成功终点的辅助观察指标之一 ,尤其对于房室结传导曲线呈连续性者 ,使用此方法可简便地观察消融终点 ,增加消融的目的性。     

美托洛尔对冠心病患者QT离散度的影响

为探讨β－受体阻断剂美托洛尔（Ｍｅｔｏｐｒｏｌｏｌ）对冠心病（ＣＡＤ）患者ＱＴ离散度（ＱＴｄ）的影响，采用随机分组、单盲处理、前瞻性研究的方法，观察６２例ＣＡＤ患者Ｍｅｔｏｐｒｏｌｏｌ治疗前、后ＱＴｄ及ＲＲ间期、心率校正ＱＴ间期离散度（ＱＴｃｄ）、最大ＱＴ间期（ＱＴｍａｘ）、最小ＱＴ间期（ＱＴｍｉｎ）的变化。试验组Ｍｅｔｏｐｒｏｌｏｌ治疗后ＣＡＤ患者ＱＴｍｉｎ延长（３８６±３１．８ｍｓｖｓ３５２±２２．４ｍｓ，Ｐ＜０．０１），而ＱＴｍａｘ无明显改变（４３０±３５．６ｍｓｖｓ４２３±３４．９ｍｓ，Ｐ＞０．０５），ＱＴｄ、ＱＴｃｄ则显著缩小（分别为４４±１２．９ｍｓｖｓ７１±２８．６ｍｓ，４５±１１．５ｍｓｖｓ７９±３４．９ｍｓ，Ｐ均＜０．０１）。对照组治疗前、后ＱＴｄ、ＱＴｃｄ、ＱＴｍａｘ、ＱＴｍｉｎ均无改变（Ｐ＞０．０５）。表明Ｍｅｔｏｐｒｏｌｏｌ通过显著延长ＣＡＤ患者的ＱＴｍｉｎ缩小心肌复极化离散的程度，使心肌复极化趋向同步，这有利于防止恶性室性心律失常的发生     

Dimension and Related Anatomical Distance of Koch's Triangle in Patients with Atrioventricular Nodal Reentrant Tachycardia

Koch's Triangle in AVNRT. Introduction: The dimension of Koch's triangle in patients with AV nodal reentrant tachycardia has not been well described. Understanding the dimension and anatomical distance related to Koch's triangle might be useful in avoiding accidental AV block during ablation of the slow pathway. The purposes of this study were to define the dimension of Koch's triangle and its related anatomical distance and correlate these parameters with the successful ablation sites in patients with AV nodal reentrant tachycardia. Methods and Results: We studied 218 patients with AV nodal reentrant tachycardia. The distance between the presumed proximal His-bundle area and the base of the coronary sinus orifice (D_His-Os) measured in the right anterior oblique view was used to define the dimension of Koch's triangle. The distance of the proximal His-bundle recording site from the successful ablation site (D_His-Ab) and the distance as a fraction of the entire length of Koch's triangle (D_His-Ab/D_His-Os) were determined. The mean D_His-Os, and D_His-Ab were 25.9 ± 7.9 and 13.4 ± 3.8 mm, respectively. D_His-os negatively correlated with patient age (r = -0.41, P < 0.0001) and body mass index (r = -0.18, P = 0.004). Among the patients with successful ablation sites in the medial area, D_His-Os was longer (27.2 ± 6.6 vs 24.6 ± 8.4 mm, P < 0.005), D_His–Ab was similar (12.9 ± 3.1 vs 13.9 ± 4.0, P > 0.05) and D_His-Ab/D_His-Os was smaller (0.48 ± 0.04 vs 0.74 ± 0.11, P < 0.05). Furthermore, the patients with successful ablation sites in the medial location needed more radiofrequency pulse numbers than those in the posterior location (6 ± 4 vs 4 ± 3, P < 0.05). Conclusion: The site of successful slow pathway ablation was consistently about 13 mm from the site recording the proximal His-bundle deflection in patients with AV nodal reentrant tachycardia despite marked variability in the dimensions of Koch's triangle: therefore, patients with large triangles required ablation in the medial region rather than the posterior region. Care should be taken when delivering radiofrequency energy to the posteroseptal area in patients with shorter D_His-Os to avoid injury to AV node.     

房室结折返性心动过速合并束支阻滞时心内电图特征

探讨房室结折返性心动过速 (AVNR)合并束支阻滞时心内电图特征及其机制。 6 0例AVNRT患者 ,男 2 3例、女 37例 ,年龄 39± 11岁。将病例分为 3组 :Ⅰ组合并左束支组滞 (CLBBB) ;Ⅱ组合并右束支阻滞 (CRBBB) ;Ⅲ组无束支阻滞。心内电生理测定心动过速的频率 (HR)、冠状窦口A波至V波的距离 (AVcs)、His束处A波到V波的距离 (AVH)。三组心动过速的心率分别为 171± 2 3,16 6± 19,170± 17次 /分 ,三组之间差异无显著性 (P >0 .0 5 ) ;Ⅰ组与Ⅱ、Ⅲ组AVcs、AVH 比较 ,差异有显著性 ( 81± 12msvs 46± 11ms,49± 9ms;5 6± 13msvs 5 1± 10ms、5 0± 10ms,P均 <0 .0 5 ) ;Ⅱ组与Ⅲ组之间AVcs、AVH 差异无显著性。结论 :AVNRT合并束支阻滞时心动过速的心率无明显变化 ;当合并CLBBB时 ,His束到心室的传导时间延长 ,导致冠状窦与His束处的A、V间距延长 ;合并CRBBB时无上述现象发生。     

Effects of Slow Pathway Ablation on Fast Pathway Function in Patients with Atrioventricular Nodal Reentrant Tachycardia

Effects of Slow Pathway Ablation. Introduction: This study investigated whether fast pathway conduction properties are altered by slow pathway ablation in patients with AV nodal reentrant tacbycardia. Methods and Results: Forty consecutive patients who underwent successful ablation of the slow pathway were prospective subjects for the study. Isoproterenol was used to enhance conduction and to differentiate interactive mechanisms. Potential electrotonic interactions were assessed by comparing patients with and those without residual dual AV node pbysiology after slow pathway ablation. Paired and unpaired t-tests were used when appropriate. P < 0.05 was considered statistically significant. In the entire study population, heart rates were not significantly different before and after slow pathway ablation (RR = 770 ± 114 msec before and 745 ± 99 msec after, P = 0.07). Anterograde fast pathway conduction properties were unchanged after slow pathway ablation (effective refractory period, 348 ± 84 msec before and 336 ± 86 msec after, P = 0.13; shortest 1:1 conduction, 410 ± 93 msec before and 400 ± 82 msec after, P = 0.39). Retrograde fast pathway characteristics also were similar before and after ablation. Neither anterograde nor retrograde last pathway conduction properties during isoproterenol infusion were changed by slow pathway ablation. When the study population was further divided into patients with (n= 13) or without (n = 27) residual dual AV node pbysiology, no significant change was detected in fast pathway function in either group after slow patbway ablation. Conclusions: Fast pathway conduction characteristics were not affected by slow pathway ablation. In patients with AV nodal reentrant tachycardia, observations suggest that fast and slow pathways are functionally distinct.