左侧隐匿性斜行旁路的标测及消融靶点定位方法

射频导管消融(RFCA)治疗左侧隐匿性旁路(AP)构成的房室折返性心动过速(AVRT)时，冠状静脉窦电极导管(CS)是极为重要的参照路标；但偶尔也会遇到二尖瓣环处消融部位CS的逆行心房波最早但放电不能阻断AP，而成功消融部位的逆行心房波反而不足最为领先的情况；有作者认为这是一种斜行AP，即AP行走的方向与房室环之间有一定的     

显性旁道在心房颤动时的标测与消融

目的　探讨心房颤动 (Af)时对显性旁道 (AP)的标测与消融方法。方法　 7例 AP患者 ,年龄 2 4～ 6 0岁。均有阵发性 Af史。Af发作伴旁道前传时的心室率为 12 0～ 2 0 0 bpm。采用经主动脉逆行法消融左侧旁道 ,经股静脉途径消融右侧旁道 ,以心室前向激动点最早、且有小 A波为靶点。结果　 7例患者标测到了较体表心电图预激波起点提前 2 5～ 5 0 ms的 V波 ,首次消融以 15 W能量放电 ,均在 1s～ 8s内旁道前传阻断。3例在旁道前传阻断的同时转为窦性心律 ;1例 30 min内自行转为窦性心律 ;3例经药物转为窦性心律。行心室起搏 ,6例旁道逆传已阻断 ,1例经消融后逆传阻断。随访 5～ 45个月 ,无旁道前传恢复的证据 ,亦无室上性心动过速发作。结论　在掌握适应证的前提下 ,Af时行射频消融阻断显性旁道是可行的。     

左侧显性房室旁路有效消融靶点旁路电位形态特征探讨

目的 分析37例左侧显性房室旁路(AV-AP)有效靶点局部电图特征，探讨旁路(AP)电位的形态特点。方法37例患者在实性心律下经左室二尖瓣环消融AV—AP。确定有效靶点后20～30W放电5s内阻断AV—AP后暂停放电以使AVAP传导恢复并记录图形后再次放电彻底阻断AV—AP。分析AV—AP传导恢复前后的靶点局部电囤。结果37例患者有效靶点A波和V波间均有AP电位，其起始部融入A波终末部，终末部与V波起始部相连，其间无等电位线。AP电位表现为1～3个主波(48．6％，18／37例)或1～2个主波后相连2～3个小碎裂波，后者与V波起始部相连(51．4%，19／37例)；37例患者的A波间期为26．3±6．5ms，A—AP间期20．9±66ms，AP间期12．2±3．5ms，AP—V间期15.1±4t6ms,AP-De问期26±3．5mstV—De问期10．95±55ms。结论显性AV-AP消融中有效靶点可记录到AP电位，分析其形态特点和测定相应问期有助于靶点判断。     

左侧斜行旁道心腔内心电图特征及射频导管消融

目的 探讨快速、准确标测左侧斜行旁道消融靶点的方法，提高导管消融成功率。方法 对66例AVRT患者在高位右心房刺激、心室刺激或室性期前收缩、诱发室上性心动过速及窦性心律时进行心腔内电生理检查，确定旁道的走行方向，标测心室及心房侧靶点图，记录消融靶点位置及消融时间。结果 发现6例旁道走行方向斜跨二尖瓣环并确定为斜行旁道，经主动脉逆行法最终全部消融成功，部分病例耗时较长。结论 如果冠状窦标测电极(CS)记录到的最早逆行心房激动点和最早顺传心室激动点不在同一记录直线上，在排除多旁道后应考虑斜行旁道的可能，同时可判断其斜行程度。最早逆行心房激动点和最早顺传心室激动点分别是心房侧和心室侧的消融靶点。如能标测到旁道电位，成功率更高。对于隐匿性左侧旁道，左心室起搏信号s到cs上最早逆传至A波的最短间隔处是很好的消融靶点。     

心房颤动时显性房室旁道的射频消融治疗

对 2 6例预激综合征患者于心房颤动 (简称房颤 )时射频消融显性房室旁道。其中左侧旁道 9例、右侧旁道17例 ,2 2例有阵发性房颤史。房颤发作伴旁道前传时的心室率为 171± 32 ( 132～ 2 37)bpm。采用经主动脉逆行法或穿间隔法消融左侧旁道、经股静脉途径消融右侧旁道 ,以最早心室前向激动点且有小A波处为消融靶点。房颤时成功消融靶点的V波较体表心电图预激波的起点提前 37.2± 8.1( 2 6～ 5 3)ms。放电 6± 3( 1～ 16 )次后 ,2 6例中有2 5例 ( 96 % )旁道前传被阻断 ,1例失败。阻断旁道前传后 30min ,3例自行恢复窦性心律 ,2 2例经直流电复律后恢复窦性心律 ,心室起搏示 2 5例中有 2 3例旁道逆传已被阻断 ,2例仍存在 ,经继续消融获得成功。随访 19.2± 11.7( 1～ 38)个月 ,除 1例复发正向前传型房室折返性心动过速 (O AVRT) ,经再次消融旁道逆传成功外 ,其他患者无O AVRT发作及旁道前传恢复的证据。结论 :心房颤动时射频消融显性房室旁道方法可行、成功率高     

起源于Marshall韧带特殊旁道消融一例

患者女性，45岁，因“反复心悸5年，再发6 h”入院，诊断：阵发性室上性心动过速。在CARTO标测系统指导下行射频消融术，心动过速发作时：冠状静脉窦(CS)1-2逆传A波最早，考虑左侧显性旁道，消融后仍有CS1-2逆传A波最早；建立二尖瓣模型，对V波最提前处进行消融，诱发第二种心动过速，建立左房模型，以CS7-8为参考进行激动标测，于靶点提前参考84 ms处消融后预激波消失，靶点位置在Marshall韧带位置处。     

儿茶酚胺依赖性左侧隐匿旁道射频消融一例

患者男,45岁。发作性心悸3年,多发于紧张、活动或“感冒”时。心电图:窦性心律时正常;发作时呈宽QRS波心动过速(完全性左束支阻滞图形)。右室S1S1刺激600ms即出现室房分离,右房S1S1、S1S2刺激无异常发现。静脉滴注异丙肾上腺素后右房S1S1刺激诱发窄QRS波心动过速,此时冠状静脉窦电极远端逆A波最早。左室起搏下于靶点放电成功阻断旁道逆传。随访1个月无复发。考虑为儿茶酚胺依赖性左侧隐匿旁道。     

左侧隐匿性房室旁路靶点局部慢电位的临床意义

目的 在射频消融左侧隐匿性房室旁路部分病例的靶点图中发现存在提前于常规心电图QRS波的局部低振幅慢电位,本文旨在探讨该电位在隐匿性旁路消融靶点中出现的可能原因、隐匿性旁路隐匿性前传的可能机制及临床意义。方法2000年1月～6月经二尖瓣瓣下成功射频消融的46例左侧隐匿性旁路,以 200mm/s描记速度分析射频消融术前、术后窦性心律和术前成功靶点的心室起搏与心动过速时心内电图,尤其注意分析窦性心律时成功靶点心内电图在射频消融术前与术后的区别与特点,以及心室起搏、心动过速时靶点电图与窦性心律时靶点电图的区别,并测量术前常规心电图QRS波最早起点至成功靶点V波起点之间的距离（QV间期）。结果46例患者中有16例（3.78％）术前存在提前于常规心电图QRS波的局部低振幅慢电位;QV间期为-5～-58ms,平均（-14.94±-13.40）ms。所有16例患者的这些局部低振幅慢电位在心室起搏和心动过速时不能显露,并在射频消融术后全部消失。结论 左侧隐匿性旁路部分病例的瓣下消融靶点存在提前于体表QRS波的低振幅慢电位,推测该电位可能为隐匿性房室旁路隐匿性前传所致;存在局部慢电位的靶点提示为有效的消融靶点。     

房性心动过速的射频导管消融术治疗

目的：为治疗房性心动过速（房速）,对8例患者进行了射频导管消融术（RFCA）治疗。方法：采用两根大头消融导管,在房速发作时标测心房最早激动点放电消融。结果：8例房速（包括房速伴心房扑动及房速伴房室结折返性心动过速各1例）RFCA治疗全部成功,无并发症;其中4例在冠状静脉窦口附近、2例在右心房侧壁、2例在右心耳处放电消融成功,成功靶点局部电位（A波）较体表心电图P波平均提前34.23±5.23（22～46）ms。结论：心房激动顺序标测是房速消融的基本方法,AP间期≥30ms的部位可作为试消融靶点;对房速伴其他类型心动过速者可一次消融成功。     

左室起搏对判断左侧旁道射频消融终点的意义

探讨左室起搏对判断左侧旁道射频消融终点的价值。 6 4例左侧旁道患者进行了常规电生理检查和射频消融。按消融终点不同分二组 :A组消融后显性预激以delta波消失、右室心尖部 (RVA)起搏无旁道逆传 ;隐匿性旁道以RVA起搏旁道无逆传作为成功标准。B组除了A组标准外 ,再加上左室消融电极 (ABL)直接起搏 ,如旁道也无逆传 ,则终止消融。所有患者术后随访 1个月～ 1年。结果A组 5 0例 :显性预激 17例、隐匿性旁道 33例。显性预激即刻成功消融 16例 ,因反复发作心房扑动、心房颤动而未消融 1例 ;隐匿性旁道即刻成功 31例 ,因未诱发出心动过速及导管无法到位而未消融各 1例 ,术后 1～ 35天复发 5例 ,再次消融成功。B组 14例 :9例显性预激、5例隐匿性旁道。 9例显性预激消融后ABL起搏发现 4例残存隐匿性旁道 ,巩固消融后消失。 1例隐匿性旁道RVA起搏偶尔经左侧旁道逆传 ,而ABL起搏则旁道显示逆传 ,消融成功。B组术后无复发。结果提示 :左室起搏可揭示右心室起搏不显示的左侧隐匿性旁道、对判断旁道消融是否彻底以及减少旁道消融术后复发具有重要意义     

Evidence for an incomplete mitral isthmus block after failed ablation of a left postero-inferior concealed accessory pathway.

We report the case of a young woman in whom previous ablation of a concealed left-sided accessory pathway (AP) created an iatrogenic mitral block. The mitral block was responsible for a split retrograde atrial activation pattern during orthodromic atrioventricular re-entrant tachycardia (AVRT). The differential diagnoses are discussed. The AP was ablated at the site with the shortest interval between the ventricular signal and the earliest component of the retrograde atrial activation. Meticulous mapping is paramount during AVRT with an unusual retrograde atrial activation pattern.     

Atrial activation during atrioventricular nodal reentrant tachycardia: studies on retrograde fast pathway conduction.

BACKGROUND: Detailed right and left septal mapping of retrograde atrial activation during typical atrioventricular nodal reentrant tachycardia (AVNRT) has not been undertaken and may provide insight into the complex physiology of AVNRT, especially the anatomic localization of the fast and slow pathways. OBJECTIVES: The purpose of this study was to investigate the pattern of retrograde atrial activation during typical AVNRT by means of right-sided and left-sided septal mapping and implementation of pacing maneuvers for separating atrial and ventricular electrograms recorded during tachycardia. METHODS: Twenty-two patients with slow-fast AVNRT were studied by means of simultaneous His-bundle recordings from the right and left sides of the septum. Patterns of retrograde atrial activation were recorded during tachycardia following specific pacing maneuvers and during right ventricular apical (RVA) pacing at the tachycardia cycle length. RESULTS: The pattern of retrograde atrial activation could be mapped in 17 of 22 patients during AVNRT. In 9 (53%) patients, the earliest retrograde atrial activation was recorded on the left side of the septum, in 3 (17%) patients on the right side, and in 5 (29%) patients both right and left atrial septal electrograms occurred simultaneously. Stimulus to atrial electrogram times recorded during RVA pacing in 14 patients were 138.5 ms from the right His bundle, 134.5 ms from the left His bundle, and 148.0 ms from the ostium of the coronary sinus (P <.001). The predominant site of earliest retrograde atrial activation during RVA pacing was the left side of the septum (10 patients [71%]). Only 8 (57%) of 14 patients demonstrated concordance in the pattern of retrograde atrial activation during AVNRT and RVA pacing. CONCLUSION: Earliest retrograde atrial activation during AVNRT is most often recorded on the left side of the septum. Breakthrough of atrial activation may be discordant from that observed during RVA pacing.     

Importance of retrograde atrial activation in atrial fibrillation genesis in the initiation of atrial fibrillation in Wolff-Parkinson-White syndrome. Comparison of atrial electrophysiologic parameters between patients with different atrial fibrillation genesis (initiation sites) in atria.

The changes in the duration of atrial electrograms during different atrial activation sequences from a sinus rhythm were evaluated to test the hypothesis that the prolongation of atrial electrogram duration caused by the different atrial activation sequence is more prominent at the site of atrial fibrillation (Afib) genesis (initiation site) than other areas. In 39 patients with single retrograde left-sided accessory connection who had inducible transient atrial fibrillation during an electrophysiologic study, the site of Afib genesis was determined and classified into three groups, i.e., 1) high right atrial genesis (HRA), 2) low right atrial genesis (LRA), and 3) left atrial genesis (LA). Single premature extrastimuli after 8 basic drive trains (600 ms) were delivered at the HRA and the right ventricular apex. Three atrial electrophysiologic parameters were evaluated at three atrial sites, i.e., 1) HRA, 2) LRA, and 3) coronary sinus. The atrial vulnerability parameters were as follows; 1) %A2/A1: % prolongation of atrial electrogram duration during premature beat (A2) in comparison with basic drive (A1), 2) wavelength index (WLI): calculated as [effective refractory period]/[A2], and 3) retrograde activation index (RAI): calculated as [A1 during retrograde activation; i.e., RVA pacing/[A1 during antegrade activation, i.e., HRA pacing], shown as a percentage. The Afib genesis was HRA in 20, LRA in 12 and LA in 7 patients. At the HRA recording site, %A2/A1 and RAI were the largest and WLI the shortest in the HRA genesis group in comparison with the other two groups. Similarly, at the LRA and LA recording sites, %A2/A1 and RAI were the largest and WLI the shortest in the groups with Afib genesis at these recording sites. In patients with inducible Afib, %A2/A1 and RAI were the highest and WLI the shortest at the atrial recording site close to the site of Afib genesis. Atrial wave prolongation during retrograde atrial activation, possibly the anisotropic conduction, was considered to play a role in initiating Afib as well as a conduction delay during the atrial premature beat.     

主动脉无冠窦内射频消融前间隔房室旁路

目的 报道经主动脉无冠窦内射频消融前间隔房室旁路.方法 7例患者,男性4例,女性3例,平均年龄（38.4±14.7）岁.电生理检查证实存在房室旁路,并检查其前传逆传功能和诱发旁路参与的房室折返性心动过速.在心动过速时标测最早心房逆传激动点作为消融靶点.结果 7例心动过速时最早心房激动部位均位于前间隔区域,但经右心房途径反复消融均不能成功阻断旁路,而在无冠窦内可标测到最早逆传心房激动点并消融成功,无并发症出现.结论 主动脉无冠窦内消融可作为治疗前间隔房室旁路的一种新途径,特别适用于右心房前间隔区域消融失败的病例.     

Para-Hisian entrainment: a novel pacing maneuver to differentiate orthodromic atrioventricular reentrant tachycardia from atrioventricular nodal reentrant tachycardia

INTRODUCTION: Para-Hisian pacing during sinus rhythm can help to identify the presence of an accessory pathway (AP). In this maneuver, the retrograde activation time and pattern are compared during capture and loss-of-capture of the His bundle while pacing from a para-Hisian position. However, identification of a retrograde AP does not necessitate that it is operative during the tachycardia of interest; conversely, slowly conducting or "distant" bypass tracts may not be identified. We evaluated the utility of entrainment or resetting of tachycardias from the para-Hisian position to help distinguish atrioventricular nodal reentrant tachycardia (AVNRT) from orthodromic atrioventricular tachycardia (AVRT). METHODS AND RESULTS: Para-Hisian entrainment/resetting was evaluated in 50 patients: 33 with AVNRT and 17 with AVRT. The maneuvers were performed using a standard quadripolar catheter placed at the His position: low output for right ventricular (RV) capture and high output for both RV and His capture. The retrograde atrial activation sequence, SA interval (interval from stimulus to earliest retrograde atrial activation), and "local" VA interval (interval between the ventricular and atrial electrograms at the site of earliest retrograde atrial activation) were compared between His and His/RV capture. The DeltaSA was > 40 ms in patients with AVNRT and was < 40 ms in all but one patient with AVRT. In concert with the DeltaSA interval, the DeltaVA interval was able to fully define the mechanism of the tachycardia in all patients studied. CONCLUSION: Para-Hisian entrainment/resetting can determine the course of retrograde conduction operative during narrow complex tachycardias. It is a useful diagnostic maneuver in differentiating AVNRT and orthodromic AVRT.     

Overdrive suppression of atrial pacemaker tissues in the alert, awake dog before and chronically after excision of the sinoatrial node

In characterizing pacemakers of the canine right atrium, cycle lengths after rapid atrial pacing were measured in the alert, conscious dog. Using implanted bipolar electrodes on the atrial appendage, pacing was established at a rate 100 percent above the spontaneous heart rate and was continued for 30, 60, 120 or 180 seconds. The average control cycle length subtracted from the first recovery cycle after cessation of pacing was termed the corrected recovery time. To study comparative responses of the Sinoatrial (S-A) node and subsidiary atrial pacemakers, corrected recovery time was measured before and at intervals after excision of the S-A node. Junctlonal regions frequently (but not invariably) assumed control instantaneously after sinus nodal excision, with subsidiary atrial pacemaker dominance occurring within a few minutes to hours; such control was relatively unstable for a few days. Subsidiary atrial pacemaker dominance gradually stabilized with development of consistent P waves and P-R intervals of 80 to 100 ms. Corrected recovery time after 1 minute of rapid atrial pacing averaged 267 ms before excision of the S-A node, 3,500 to 4,500 ms immediately after and for the 1st week after excision, but progressively decreased toward control levels during the 1st to 20th week thereafter. Thus, corrected recovery time first increased greatly, then regularly decreased with time after excision of the S-A node, but remained high for several weeks in subsidiary atrial pacemakers as compared with control dominance by S-A pacemaker tissues. However, the ultimate assumption of comparable corrected recovery time by the subsidiary pacemakers implies important alterations in electrophysiologic characteristics. One minute of fast pacing elicited longer periods of overdrive suppression than did 30 seconds of pacing, but these periods were not systematically further increased by 2 or 3 minutes of pacing. Although atropine greatly attenuated overdrive suppression in the awake dog model, propranolol altered it little or not at all during quiet rest, with modest exaggeration during alert attention.     

Ablation of posteroseptal and left posterior accessory pathways guided by left atrium-coronary sinus musculature activation sequence

Introduction: While some posteroseptal and left posterior accessory pathways (APs) can be ablated on the tricuspid annulus or within the coronary venous system, others require a left-sided approach. "Fragmented" or double potentials are frequently recorded in the coronary sinus (CS), with a smaller, blunt component from left atrial (LA) myocardium, and a larger, sharp signal from the CS musculature.
Methods and Results: Forty patients with posteroseptal or left posterior AP were included. The LA–CS activation sequence was determined at the earliest site during retrograde AP conduction. Eleven APs (27.5%) were ablated on the tricuspid annulus (right endocardial), 9 (22.5%) inside the coronary venous system (epicardial), and 20 (50%) on the mitral annulus (left endocardial). A "fragmented" or double "atrial" potential was recorded in all patients inside the CS at the earliest site during retrograde AP conduction. Sharp potential from the CS preceded the LA blunt component (sharp/blunt sequence) in all patients with an epicardial AP, and in 10 of 11 (91%) patients with a right endocardial AP. Therefore, 18 of 19 (95%) APs ablated by a right-sided approach produced this pattern. The reverse sequence (blunt/sharp) was recorded in 19 of 20 (95%) patients with a left endocardial AP.
Conclusion: During retrograde AP conduction, the sequence of LA–CS musculature activation—as deduced from analysis of electrograms recorded at the earliest site inside the CS—can differentiate posteroseptal and left posterior APs that require left heart catheterization from those that can be eliminated by a totally venous approach.     

Atrial pacing at multiple sites in the Wolff-Parkinson-White syndrome.

Atrial pacing at multiple sites was used in an attempt to predict the site of pre-excitation in 5 patients with Wolff-Parkinson-White syndrome with 5 different anomalous pathway locations (right anterior, right posterior, septal, left posterior, and left lateral). At least 3 atrial pacing sites were tested in each patient. Pacing sites tested included high right atrium, low lateral right atrium, low septal right atrium, proximal coronary sinus, and distal coronary sinus. Atrial stimulation sites with shortest and longest stimulus-delta intervals could be identified in each patient, the shortest stimulus-delta interval in each case ranging from 60 to 80 ms. The difference between the shortest and longest stimulus-delta interval in each case ranged from 60 to 110 ms. It was suggested that the site with the shortest stimulus-delta interval corresponded to a site close to the atrial insertion of the anomalous pathway. This hypothesis was confirmed in all cases (3 with epicardial mapping and 2 with retrograde atrial activation data). In conclusion, atrial pacing at multiple sites is helpful in predicting the site of anterogradely conducting anomalous pathways, and appears particularly useful for differentiation of right posterior, left posterior, and septal pre-excitation.