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。     

左侧房室慢旁路的电生理特征和射频消融靶点的定位

目的 探讨左侧游离壁慢传导旁路的电生理特点和射频消融方法。方法 5例患诱发心动过速后用心室感知S2程序刺激中止心动过速确立心室为房室折返环的一部分。结果 4例中止心动过速时无心房逆行A波，1例有逆行A波，旁路1例有递减传导特点，均在心室侧消融成功。结论 心室感知S2心室程序刺激中止心动过速是鉴别房性心动过速的可靠方法，成功消融靶点A波较冠状窦标测导管最早A波提前8～22ms。     

左室起搏标测消融左侧隐匿性旁道靶点的探讨

探讨左侧旁道 (AP)构成的房室折返性心动过速 (AVRT)的标测及射频消融 (RFCA)靶点定位方法。 15 4例左侧隐匿性AP构成的AVRT随机分成A、B两组 ,两组均经股动脉逆行法进入大头电极 (ABL)于二尖瓣环下RFCA。A组经大头电极以S1S135 0～ 5 0 0ms沿二尖瓣环起搏 ;以起搏信号S到CS上最早逆传A波之间的间距S -A最小处为靶点。B组以AVRT和 /或右室心尖部起搏时CS最早逆传A波处为靶点。结果 :A组 75例均经 1～ 2次放电即成功阻断AP ,且V、A分离均在放电后 5s内出现。其中有 9例靶点与CS上最早逆行A波处相距 10～ 15mm ,其靶点处S-A较其余 6 6例明显延长。B组 79例中 6 8例在 1～ 2次放电 ,5s内V、A分离 ,另 11例放电无效在改用A组方法后均在一次放电后即阻断AP ,靶点距CS最早逆A波处 10～ 2 0mm ,S -A显著长于该组其他病例。 15 4例中 2 0例靶点与CS上最早逆行A波有距离 ,其S -A明显延长 (5 6± 2 3msvs 4 5± 12ms,P <0 .0 1)。结论 :以最短S -A为靶点能快速有效地阻断各种类型的左侧隐匿性AP ;尤其在以最早逆行A波为靶点无法阻断AP传导时推荐使用该方法。     

前传递减性旁路的标测和消融

目的　总结Mahaim’s纤维参与折返的心动过速的电生理特点和射频消融结果。方法　对 7例患者 ,其中男 5例 ,女性 2例 ,平均年龄 2 6 7岁± 7岁 (18～ 35岁 )的左束支传导阻滞型心动过速患者进行了射频消融。在心动过速、窦性心律或心房起搏情况下 ,消融导管沿三尖瓣环心房面标测 ,标测到有明显Mahaim’s束电位处作为消融靶点。结果　 7例患者全部消融成功 ,旁路只有递减性前向传导功能 ,7例患者均属于Mahaim’s纤维分型中的房束纤维。靶点位置全部在三尖瓣环的心房侧 ,均能标测到明显的Mahaim’s束电位。术后平均随访 (2 1± 8)个月 ,1例复发后再次消融成功。结论　本文 7例患者均属于Mahaim’s纤维分型中的房束纤维 ,成功消融靶点均能记录到明显的Mahaim’s束电位。我们的体会是消融此类纤维最好能记录到Mahaim’s束电位 ,消融心房的插入点 ,此方法成功率高、并发症少且明显减少X光暴露时间     

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。     

阈下刺激终止室上性心动过速有助于旁路消融靶点的定位

房室折返性心动过速(AVRT)的导管射频消融(RFCA)房室旁路已取得很好的疗效,其消融靶点定位大多以激动标测为主要方法,尽管成功率高,但需消融的次数较多,平均为3～8次。已有报道表明,近折返环的阈下刺激(sub-threshold stimulation,STS)能终止室性心动过速(VT)和左侧旁     

三维电解剖标测指导疑难右侧游离壁旁路的导管消融

目的应用三维电解剖标测技术详述常规消融无效的右侧游离壁旁路电解剖特征。方法本组共入选17例常规消融无效的右侧游离壁旁路患者,消融失败1～3（1．8±0．6）次。3例在顺向型心动过速下构建右心房电激动模型,14例在右心室心尖部起搏下构建右心房电激动模型。逆向传导的心房最早激动点代表旁路的心房插入端,冷盐水消融最早心房激动点。结果17例患者中,最早激动点距离对应部位三尖瓣环的宽度为9—20（13．6±3．4）mm,较相对部位三尖瓣环的局部激动时间提前18～80（31．5±16．3）ms。共14例患者记录到独立的旁路电位。1例患者在导管标测时阻断旁路逆传,冷盐水局部巩固消融;16例患者冷盐水消融均成功阻断所有旁路的传导,其中1例患者的旁路心房插入端呈广泛分布而行片状消融。无消融术相关并发症。随访了3～41（18．6±12．7）个月,无旁路传导恢复及心动过速发作。结论常规方法消融失败的右侧游离壁旁路可能具有特殊的解剖特征,如旁路在三尖瓣环水平沿心外膜走行,旁路的心房插入部位远离瓣环。三维电解剖标测有助于精确定位旁路的心房插入端并指导消融。     

射频消融室性早搏两种标测方法的比较

目的：比较起搏标测与激动标测在室性早搏(PVC)的射频消融术(RFCA)中的应用。方法：对16例顽固性、单源性、PVC患行(RFCA)术，按照“起搏标测为主，辅以激动顺序标测”的原则，在心内膜精标PVC起源灶，然后放电消融病灶，使PVC消失或显减少。静脉滴注异丙肾上腺素下反复程序电刺激，不再能诱发或自发与术前PVC相同的’PVC或VT，为消融成功。结果：9例患单行起搏标测到与自发PVC形态相同的心电图，7例消融成功，1例在消融出现成功迹象，静滴异丙肾上腺素验证疗效时，出现尖瑞扭转性室速(TdP)，立即经胸电击复律，后改行ICD植入，1例消融失败。7例患辅以激动顺序标测，5例消融成功。16例患经5～35月随访，无1例死亡或复发。结论：对PVC行RFCA术中起搏标测获得的定位信息多于激动顺序标测；提高成功率的关键是“以起搏标测为主辅以激动顺序标测”。     

三维电解剖标测指导疑难右侧游离壁旁路的导管消融

Objective To demonstrate the electroanatomic substrates of right-sided free wall (RFW)accessory pathways (APs) which were refractory to conventional catheter ablation utilizing three-dimensional (3D) mapping. Methods Seventeen patients with RFW APs that failed initial conventional catheter ablation(s)by a mean of 1～3(1.8±0.6) attempts were enrolled in the study. Electroanatomic mapping of the right atrium was performed during right ventricular pacing in 14 patients and orthodromic reciprocating tachycardia in 3patients. Radiofrequency energy was delivered via irrigation catheter to the earliest atrial activation site. Results The earliest atrial activation site, which represented the atrial insertion of the APs, was separated from the tricuspid annulus by an average of 9 ～ 20 ( 13.6 ± 3.4 ) mm, and the local activation time was 18 ～ 80(31.5±16.3) ms earlier than that of the corresponding annular point. The target electrogram demonstrated AP potential in fourteen patients and ventriculoatrial fusion in the rest three. Accessory pathway was blocked in one case during moving the catheter and RF ablation delivery on the areas. One patient exhibited an AP with wide branching on the atrial side during mapping. RF ablation with an irrigated catheter successfully interrupted AP conduction in remaining 16 patients without complications. After a mean follow-up of 3 ～ 41 (18.6±12.7) months, there were no recurrences of ventricular preexcitation or episodes of tachycardia. Conclusion RFW APs refractory to conventional catheter ablation might be due to unique anatomic AP features such as more epicardial course at the annulus level with atrial insertion distance from the tricuspid annulus. Electroanatomic mapping is helpful to accurately localize the atrial insertion sites of these APs and facilitates catheter ablation.     

射频导管消融左侧隐匿性房室旁路后裂隙现象:复发的表现之一

患者女性，43岁，6个月前因反复发牛心动过速，在本院接受电生理检查诊断为左侧隐匿性房室旁路，成功地进行了射频导管消融治疗，术后电生理检查以各种心房、心室起博和程序刺激方法证实心动过速不能被诱发。术后3个月，患者又发作类似于术前的心悸，发作时心率为160次／min以上，突发突止，临床考虑为室上性心动过速复发，再次入院接受电生理检查。     

A unipolar coronary sinus mapping study of patients with left-sided atrioventricular accessory pathways

So-called unipolar 'PQS pattern' is widely accepted as a hallmark of successful catheter ablation of the left-sided atrioventricular accessory pathway. However, the unipolar nature of the electrogram and the site-dependent appearance of this characteristic pattern are poorly understood. Therefore, unipolar coronary sinus (CS) mapping was performed using a multipolar fine electrode in patients with Wolff-Parkinson-White (WPW) syndrome associated with an antegrade left-sided accessory pathway (case group) and those with a concealed left-sided accessory pathway or atrioventricular nodal reentrant tachycardia (control group) under sinus rhythm and fixed high right atrial, CS ostial, and distal pacing. In both groups, the unipolar CS atrial electrogram showed intrinsic negative deflection (initial positive followed by negative parts) with considerable variation depending on the recording site. This unipolar configuration of the atrial electrogram was not influenced by different activation sequences during pacing at various sites. The case group exhibited a unipolar 'PQS pattern' at successful ablation sites for the left lateral to anterolateral accessory pathway. However, this was not true for the left posteroseptal accessory pathway, possibly because the negative part of the atrial electrogram distorted the 'PQS pattern' as an intervening dip. In conclusion, the site-dependent variations of the unipolar CS atrial electrogram underlie the limited usefulness of the 'PQS pattern' in left posteroseptal accessory pathway localization.     

单用消融电极标测和消融左侧隐匿性旁道

目的 单用消融电极于二尖瓣下直接标测（不放置冠状窦电极）对35例左侧隐匿性旁道进行射频消融。方法 右室心尖起搏下用消融电极沿三尖瓣口标测,确认旁道不在右侧后,将消融电极送至二尖瓣下进行标测和消融。结果 34例左侧隐匿性旁道标测到消融靶点,33例消融成功,1例消融失败,1例复发。与使用冠状窦电极标测相比,消融电极直接标测的X线曝光时间、手术时间均增加。结论 单用消融电极可标测和消融左侧隐匿性旁道。     

Sites of conduction block in accessory atrioventricular pathways. Basis for concealed accessory pathways

Catheter recordings of accessory pathway (AP) activation were used to identify the site of antegrade and retrograde AP conduction block in 126 consecutive patients undergoing electrophysiological testing. Activation was recorded from 89 of 121 left free-wall and posteroseptal pathways (left APs) and from 12 of 24 right free-wall, midseptal, and anteroseptal pathways (right APs). The recorded APs were further subdivided into those exhibiting consistent antegrade conduction during sinus rhythm (overt APs: 50 left APs, eight right APs), those exhibiting intermittent antegrade conduction (intermittent APs: six left APs, two right APs), and those exhibiting only retrograde conduction (concealed APs: 33 left APs, two right APs). The sites of block were recorded during decremental atrial and ventricular stimulation. The sites of both antegrade and retrograde block were determined in 40 of 50 overt left APs and six of eight overt right APs. Antegrade and retrograde block occurred at or near the AP-ventricular (AP-V) interface in 37 of 40 overt left APs and two of six overt right APs and at the atrial-AP (A-AP) interface in one of 40 overt left APs and four of six overt right APs. In three of three overt left APs with no retrograde conduction, retrograde block occurred at or near the AP-V interface. The site of antegrade and retrograde block differed in only two of 58 overt pathways. There was no difference between overt APs limited at the A-AP or the AP-V interface in the shortest atrial or ventricular pacing cycle length maintaining 1:1 antegrade or retrograde AP conduction, respectively. Both antegrade and retrograde block occurred near the AP-V interface in four of six intermittent left APs and zero of two intermittent right APs and near the A-AP interface in two of six intermittent left APs and one of two intermittent right APs. The sites of both antegrade and retrograde block were determined in 28 of 33 concealed left APs, and both occurred at or near the AP-V interface in 26 and A-AP interface in two APs. In two of two concealed right APs, antegrade block occurred at the AP-V interface. These findings suggest that both antegrade and retrograde conduction are limited by factors operating near the AP-V interface in overt left APs and at the A-AP or AP-V interface in overt right APs. Factors limiting antegrade conduction in concealed APs appear to be located almost always near the AP-V interface.     

Open-window mapping of accessory pathways utilizing high-density mapping

Journal of Interventional Cardiac Electrophysiology - Accessory pathway (AP) mapping is currently based on point-by-point mapping and identifying if a local electrogram’s origin is atrial,...     

射频消融具有Mahaim纤维特性的左侧旁路三例

Mahaim纤维参与的心动过速临床上相对少见,多呈左束支阻滞型,报道3例呈右束支阻滞(RBBB)型,在左侧房室瓣环处成功消融且具有Mahaim纤维旁路特性的心动过速.2002年3月至2010年10月我院有3例经电生理检查和射频消融治疗证实为Mahaim纤维特性的左侧旁路.