心室刺激诱发的房室结折返性心动过速规律探讨

目的　探讨心室刺激诱发的房室结折返性心动过速(ＡＶＮＲＴ)的规律 ,以助于射频消融的进行。方法　统计ＡＶＮＲＴ中经心室期前刺激和分级递增刺激诱发的例数、比例以及相关的电生理参数。结果　 90例ＡＶＮＲＴ中 85例经心房刺激诱发 ,仅 13例经心室刺激诱发 (90例中心室刺激为室房分离者有 7例 ) ,其中 5例仅能为心室分级递增刺激诱发 ,而不能为常规心室期前刺激 (Ｓ1 Ｓ2 刺激 )及心房刺激诱发 ;3例可经心室Ｓ1 Ｓ2 刺激诱发 ,并同时可经心室分级递增刺激及常规心房刺激诱发 ;4例经心室分级递增刺激诱发 ,并同时可经常规心房刺激诱发 ,…     

伴连续房室结功能曲线的房室结折返性心动过速的电生理特点

目的：探讨不存在房室结双径路特性的房室结折返性心动过速（AVNRT）的电生理特点。方法：102例AVNRT患分为3组：A组15例,存在连续房室结功能曲线,心房递增起搏时无AH间期跳跃（≥5ms)延长;B组21例,存在连续房室结功能曲线,心房递增起搏时有AH间期跳跃（≥50ms）延长;C组64例,存在不连续房室结功能曲线。比较3组患射频消融前后心房递增起搏时最大AH间期[AHmax(WCL)]、心房期前刺激时最大AH间期[AHmax(ERP)]、房室结前向和逆向传导有效不应期（ERP）、保持房室1：1传导的心房／心室起搏周长和心动过速周长。结果：3组患消融后AHmax(WCL)和AHmax（ERP）均明显短于消融前（P＜0．01）。B组和C组的消融后房室结前向ERP明显增加,而组无明显变化。A组消融前AHmax和房室结逆向ERP、消融后AHmax下降程度以及心动过速周长均小于B组和C组患。结论：伴连续房室结功能曲线的AVNRT患,心房刺激可表现或不表现房室结双径路的电生理特性,射频消融后心房刺激时AHmax明显缩短提示已成功根治了AVNRT。     

伴连续性房室结功能曲线的房室结折返性心动过速的电生理分析

目的：探讨无房室结双径路特性的房室结折返性心动过速(AVNRT)的电生理特点。方法：所有心动过速患射频消融前常规行心内电生理检查。结果：845例射频病人中325例为AVNRT，其中有21例患房室结功能曲线呈连续性，其电生理特征：希氏束图上心房回波(A)先出现，A波落在室波升支或其前，希氏柬不应期内刺激心室，不能提前夺获心房，射频消融后心房刺激时AHmax明显缩短。结论：伴连续性房室结功能曲线的AVNRT患心房刺激不表现房室结双径路的电生理特性，其消融终点初步定为：心房心室S1S1、S1S2刺激不诱发AVNRT；无AHvH传导曲线跳跃；房室结前传不应期明显缩短。     

连续房室结功能曲线的慢快型房室结折返性心动过速的电生理特点及射频消融

目的探讨连续房室结功能曲线的慢快型房室结折返性心动过速（AVNRT）电生理特点及射频消融。方法共分A、B、C三组，A组35例，典型AVNRT；B组21例，非典型AVNRT；C组16例，伴连续房室结功能曲线的慢快型AVNRT。比较三组消融前后心房递增起搏或心房程序刺激时最大的AH间期（AHmax）、房室结前向有效不应期（ERP）、保持房室1：1传导的最快心房刺激时的刺激信号至QRS波起始（SR）与RR间期比值（SR／RR）。结果消融前后A、B、C三组AHmax和SR／RR均明显减少，A组ERP明显增长；而组间比较，A组AHmax减少幅度比B、C组明显大，P〈0.01。C组患者经冠状静脉窦口处递增起搏或程序刺激均可诱发出AVNRT。B组和C组还要增加从三尖瓣环至冠状静脉窦口的划线消融，可以提高消融成功率。结论伴房室结功能曲线的慢快型AVNRT患者经冠状静脉窦口处递增或程序刺激可提高AVNRT诱发率，除慢径路消融外，增加从三尖瓣环至冠状静脉窦口划线消融可提高消融成功率，AHmax和SR／RR也可作为房室结消融成功的指标之一。     

心内电生理检查对快速性心律失常诊断和疗效评价

目的探讨心内电生理检查对快速性心律失常诊断、射频消融术（RFCA）后疗效评价的意义。方法198例快速性心律失常者均成功地进行RFCA,在RFCA前后均进行标准的心内电生理检查,并对心腔内心电图进行分析。结果198例中114例诊断为房室折返性心动过速（AVRT）,70例为房室结折返性心动过速（AVN—RT）,室速12例,Ⅰ型心房扑动（AF）1例、房速1例。198例在RFCA前心房和／或心室刺激均能诱发心动过速,RFCA后,则未能诱发心动过速。AVRT者心室刺激呈现房室分离,显性预激者6波消失,AVNRT者心房slS2刺激时,AH间期呈逐渐延长,未诱发AVNRT。结论心内电生理检查不仅能准确地揭示快速心律失常的电生理机制,而且是判断快速心律失常RFCA成功与否的可靠方法。     

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     

非跳跃性房室结功能曲线的房室结折返性心动过速消融成功的电生理特点

目的 :探讨呈非跳跃性房室结功能曲线 (AVNFC)的房室结折返性心动过速 (AVNRT)射频消融成功的电生理特点。方法 :将 75例AVNRT患者分为 3组 :A组 16例 ,心房递增起搏和A1A2 程序刺激均呈非跳跃性AVNFC ;B组 10例 ,仅心房递增起搏呈跳跃性AVNFC ;C组 4 9例 ,心房递增起搏和A1A2 程序刺激均呈跳跃性AVNFC。比较 3组患者射频消融前后组内及组间的电生理参数。结果 :消融后 3组患者心房递增起搏时最大AH间期 (A1H1max)均比消融前显著缩短 (P <0 .0 5 )。A组消融前、后A1H1max的缩短程度均小于B组和C组 (P <0 .0 5 )。A组非典型AVNRT的诱发率明显高于B组和C组。结论 :对于心房递增起搏和A1A2 程序刺激均呈非跳跃性AVNFC的AVNRT患者 ,消融后A1H1max的显著缩短可作为消融成功的指标之一。AVNFC呈非跳跃性的房室结双径路患者易诱发非典型AVNRT。     

不典型房室结折返性心动过速与房室折返性心动过速的电生理鉴别

房室结折返性心动过速(AVNRT)与房室折返性心动过速(AVRT)的鉴别有时较困难,尤其是不典型AVNRT与间隔旁道参与的AVRT鉴别,不典型AVNRT在心动过速发生时最早心房激动位于后间隔区域,与后间隔旁道引起的AVRT相似。通常检测房室结双径路的电生理方法仅能鉴别63%的不典型AVNRT。该文介绍了两者的主要电生理鉴别方法,包括希氏束旁起搏、在希氏束不应期给予心室期前程序刺激、心室或希氏束旁起搏后间期与心动过速周长之差(PPI-TCL)和刺激信号至心房波减去室房(SA-VA)间期的区别、校正的心室PPI-TCL和VA间期、心动过速时VA分离现象及TCL行心室起搏时的VA间期与心动过速时的VA间期之差等9种方法。     

经食管心房调搏中房室结折返性心动过速的诱发因素分析

目的 探讨经食管心房调搏(transesophageal atrial pacing,TEAP)检查中诱发房室结折返性心动过速(atrioventricular nodal reentrant tachycardia,AVNRT)的因素.方法 随机抽取接受TEAP检查的163例患者进行回顾性研究,心内电生理检查均可诱发...     

房室折返性心动过速合并房室结折返性心动过速的腔内电生理及射频消融特征二例

房室折返性心动过速(AVRT)病例中可发现有房室结双径现象(AVNDP),但并非都合并AVNRT,如果AVRT与AVNRT合并存在,不仅要消融旁路,还必须行房室结改良,方能根治室上性心动过速。本文报道2例AVRT合并AVNRT的电生理及射频消融特点。　　临床资料　例1　女性,48岁,因阵发心悸6年入院,发作心慌时,心率在160～190bpm。1997年1月28日在我院行射频消融术。心室频率递增刺激诱发阵发性室上性心动过速(PSVT),频率180～190bpm,标测为冠状窦远端(CSd)逆A领先。心房程序刺激,A2HA跳跃140ms,但未发作PSVT。大头电极至二尖瓣环下距冠状窦…     

Differentiating atrioventricular nodal reentrant tachycardia from atrioventricular reentrant tachycardia by DeltaHA values during entrainment from the ventricle

BACKGROUND: Differentiating atrioventricular nodal reentrant tachycardia (AVNRT) from orthodromic atrioventricular reentrant tachycardia (AVRT) can be difficult. The His bundle and atria are activated sequentially over the AV node during entrainment of AVNRT from the ventricle but simultaneously during supraventricular tachycardia (SVT). They are activated in parallel during entrainment of AVRT but sequentially during SVT. OBJECTIVE: The purpose of this study was to test the hypothesis that a DeltaHA (HA((entrainment)) - HA((SVT))) cutoff value of 0 reliably differentiates AVNRT from AVRT. METHODS AND RESULTS: Of 61 patients undergoing electrophysiologic evaluation for paroxysmal SVT, retrograde His-bundle potentials were recorded in 57 (93%) and entrainment performed in 49 (34 AVNRT, 15 AVRT). DeltaHA values during entrainment from the ventricle were significantly longer during AVNRT than AVRT (31 +/- 24 ms vs -38 +/- 31 ms, P <.001). All DeltaHA values were positive (minimum: 3 ms) for AVNRT and negative (maximum: -2 ms) for AVRT. DeltaHA of 0 had sensitivity, specificity. and positive predictive value of 100% for correct diagnosis. CONCLUSION: The DeltaHA criterion during entrainment of tachycardia from the ventricle reliably differentiates AVNRT (positive values) from AVRT (negative values).     

Unique electrophysiologic characteristics of atrioventricular nodal reentrant tachycardia with different ventriculoatrial block patterns: Effects of slow pathway ablation and insights into the location of the reentrant circuit

BACKGROUND: The electrophysiologic mechanisms of different ventriculoatrial (VA) block patterns during atrioventricular nodal reentrant tachycardia (AVNRT) are poorly understood. OBJECTIVES: The purpose of this study was to characterize AVNRTs with different VA block patterns and to assess the effects of slow pathway ablation. METHODS: Electrophysiologic data from six AVNRT patients with different VA block patterns were reviewed. RESULTS: All AVNRTs were induced after a sudden AH "jump-up" with the earliest retrograde atrial activation at the right superoparaseptum. Different VA block patterns comprised Wenckebach His-atrial (HA) block (n = 4), 2:1 HA block (n = 1), and variable HA conduction times during fixed AVNRT cycle length (CL) (n = 1). Wenckebach HA block during AVNRT was preceded by gradual HA interval prolongation with fixed His-His (HH) interval and unchanged atrial activation sequence. AVNRT with 2:1 HA block was induced after slow pathway ablation for slow-slow AVNRT with 1:1 HA conduction, and earliest atrial activation shifted from right inferoparaseptum to superoparaseptum without change in AVNRT CL. The presence of a lower common pathway was suggested by a longer HA interval during ventricular pacing at AVNRT CL than during AVNRT (n = 5) or Wenckebach HA block during ventricular pacing at AVNRT CL (n = 1). In four patients, HA interval during ventricular pacing at AVNRT CL was unusually long (188 +/- 30 ms). Ablations at the right inferoparaseptum rendered AVNRT noninducible in 5 (83%) of 6 patients. CONCLUSION: Most AVNRTs with different VA block patterns were amenable to classic slow pathway ablation. The reentrant circuit could be contained within a functionally protected region around the AV node and posterior nodal extensions, and different VA block patterns resulted from variable conduction at tissues extrinsic to the reentrant circuit.     

心动过速RR间期交替的发生机制及导管射频消融治疗

目的　分析QRS心动过速伴RR间期长短交替的发生机制及导管射频消融情况。方法　对 6例心动过速伴RR间期长短交替患者 ,常规行动态心电图及食管电生理检查。心内电生理检查提示存在房室旁路或房性心动过速伴房室结双径路 ,先进行旁路或房性心动过速的消融 ,消融成功后再进行心内电生理检查 (包括应用异丙肾上腺素进行心动过速诱发 ) ,如不能诱发心动过速则终止手术。若提示存在房室结多径路 ,则进行慢路径改良术。结果　食管电生理检查提示 :4例患者存在房室旁路伴房室结双径路 ;2例患者存在房室结三径路。心内电生理检查及消融结果显示 :3例患者为房室旁路伴房室折返性心动过速 ,成功消融后不能诱发房室结折返性心动过速 ;1例患者同时存在房室及房室结折返性心动过速 ,成功消融房室旁路后再改良慢路径 ;2例患者为房室结三径路 ,经慢径路改良后房室结传导曲线连续 ,未诱发心动过速。 6例患者无并发症发生 ,随访期间无心动过速发作。结论　室上性心动过速伴RR间期交替发生率较低 ,且均与房室结传导不连续有关。心动过速伴RR间期交替发生机制较为复杂 ,除了与房室结纵向传导的不连续有关外 ,还与其不应期密切相关。食管电生理检查与心内电生理检查相比对揭示RR间期交替的发生机制具有较高的诊断价值。     

Change in the retrograde atrial activation sequence following radiofrequency modification of the atrioventricular node: implications for the electrophysiologic circuit of a variant of atrioventricular nodal reentrant tachycardia

INTRODUCTION: Despite the great success in treating AV nodal reentrant tachycardia (AVNRT) with radiofrequency modification of the AV node, the dimensions of the electrophysiologic circuit of this arrhythmia remain unclear, and simple models fail to explain all tachycardia-related phenomena. METHODS AND RESULTS: We describe three unusual cases of supraventricular tachycardia (SVT). In all three cases, retrograde atrial activation during ventricular pacing or during SVT manifested local left atrial electrograms recorded from the coronary sinus preceding the septal atrial electrograms (eccentric activation), with earliest atrial activity at the lateral or posterolateral mitral annulus. Electrophysiologic maneuvers and observations were consistent with AVNRT as the mechanism in each case. In all cases, radiofrequency modification of the AV node eliminated inducible SVT and abolished dual pathway AV nodal physiology. The retrograde atrial activation sequence during ventricular pacing changed after ablation in each case, with septal atrial electrograms preceding left atrial electrograms recorded from the coronary sinus (concentric activation). CONCLUSION: The observations in these cases cannot be explained by the traditional model of slow, fast, and intermediate AV nodal pathways. A model incorporating a circuit close to the AV node with left atrial and coronary sinus connections is proposed.     

快-慢型房室结折返性心动过速的电生理特征和射频消融治疗

报道８例快－慢型房室结折返性心动过速（ＡＶＮＲＴ）的电生理特征及射频消融治疗。其中３例为慢－快型ＡＶＮ－ＲＴ射频消融改良慢径后出现的快－慢型ＡＶＮＲＴ。８例均经消融慢径而成功终止心动过速。平均放电次数３±１．１次、平均放电时间１２０±３０．４ｓ、平均放电功率３０±１１Ｗ。随访６～２４个月，无复发。快－慢型ＡＶＮＲＴ具有以下临床电生理特征：①快径不应期短、慢径不应期长。②心内电刺激无房室结双径路现象。③心动过速能由心房刺激诱发。④心动过速时ＡＨ间期＜ＨＡ间期，冠状窦近端Ａ波最提前。熟悉快－慢型ＡＶＮＲＴ的电生理特征，对于鉴别房性心动过速及右后间隔旁道参与的房室折返性心动过速十分重要，也是指导快－慢型ＡＶＮＲＴ射频消融成功的关键。     

房室结折返性心动过速射频消融术后复发机制探讨

目的: 探讨房室结折返性心动过速射频消融术后复发原因。方法: 对356 例房室结折返性心动过速患者射频消融术后进行随访,回顾性分析其电生理资料。结果: 356例中10例复发,复发率2.8%,320例患者射频术后无心房回波,无跳跃现象,一直未复发;术后有心房回波无跳跃现象未诱发出室上速17例,其中3例复发;术后有跳跃及心房回波未诱发出室上速11例,其中5例复发;术后有跳跃无心房回波未诱发出室上速8例,2例复发。10例复发患者,第2次射频消融术后房室结不应期均较第1次术后延长,且与术前快径不应期差值明显减小,第2次射频消融术后随访至今（>9个月）,无1例复发。结论: 慢径残存是房室结折返性心动过速射频消融术后复发的主要原因。     

Unusual induction of slow-fast atrioventricular nodal reentrant tachycardia. Report of two cases

INTRODUCTION: Generally, the induction of typical atrioventricular nodal reentrant tachycardia (AVNRT) occurs with a premature atrial stimulus that blocks in the fast pathway and proceeds down the slow pathway slowly enough to allow the refractory fast pathway time to recover. We describe two cases in which a typical AVNRT was induced in an unusual fashion. RESULTS: The first case is a 41-year-old man with paroxysmal supraventricular tachycardia. During the electrophysiology study, the atrial extrastimulus inducing the typical AVNRT was conducted simultaneously over the fast (AH) and the slow pathway (AH'). A successful ablation of the slow pathway was performed. During the follow-up no recurrence was noted. The second case is a 52-year-old woman with a Wolff-Parkinson-White syndrome due to a left posterior accessory pathway. After 5 minutes of atrioventricular reentrant tachycardia (AVRT) induced by a ventricular extrastimulus, a variability of the antegrade conduction was noted in presence of the same VA conduction. In fact, a short AH interval (fast pathway) alternated with a more prolonged AH intervals (slow pathway) that progressively lengthened until a typical AVNRT was induced. The ablation of the accessory pathway eliminated both tachycardias. DISCUSSION: A rare manifestation of dual atrioventricular nodal pathways is a double ventricular response to an atrial impulse that may cause a tachycardia with an atrioventricular conduction of 1:2. In our first case, an atrial extrastimulus was simultaneously conducted over the fast and the slow pathway inducing an AVNRT. This nodal reentry implies two different mechanisms: 1) a retrograde block on the slow pathway impeding the activation of the slow pathway from the impulse coming down the fast pathway, and 2) a critical slowing of conduction in the slow pathway to allow the recovery of excitability of the fast pathway. Interestingly, in the second case, during an AVRT the atrial impulse suddenly proceeded alternately over the fast and the slow pathway. The progressive slowing of conduction over the slow pathway until a certain point which allows the recovery of excitability of the fast pathway determines the AVNRT. This is a case of "tachycardia-induced tachycardia" as confirmed by the fact that the ablation of the accessory pathway eliminated both tachycardias.     

Arrhythmias induced during termination of supraventricular tachycardia

Pacing is being used frequently for the treatment of drug-resistant, paroxysmal supraventricular tachycardias (SVT). SVT can usually be terminated by pacing, but arrhythmias may be induced which interfere with the safety of antitachycardia pacing. To quantify these pacing-induced arrhythmias, 453 attempts to terminate SVT in 111 patients were analyzed. The patients were 6 to 73 years old (mean 41); 62 were male. Seventy-six patients had SVT using an accessory atrioventricular bypass, and 35 patients had intranodal SVT. Single and then, if required, multiple ventricular and atrial premature beats and overdrive pacing were delivered from the atrium and ventricle. A pacing-induced arrhythmia occurred in 9% of all attempts (34% of patients). Atrial flutter or fibrillation (AF) was the most frequent arrhythmia (in 8% of all attempts and sustained in 75%). Atrial vs ventricular pacing resulted in a 12% vs 2% incidence of AF. AF was unrelated to age, sex, atrial size and SVT type, and was predominantly induced by multiple premature beats. In 6 patients a different SVT and in 2 patients a nonsustained ventricular tachycardia was induced. In 6 patients SVT could only be terminated by initiating another arrhythmia. Thus, AF is frequently induced during attempted pacing termination of SVT. To limit the risk of AF, a single premature beat should preferentially be used to terminate SVT. In 6% of patients, SVT can only be terminated by inducing another arrhythmia.(ABSTRACT TRUNCATED AT 250 WORDS)     

Comparison of Atrial-His Intervals During Tachycardia and Atrial Pacing in Patients with Long RP Tachycardia

Long RP Tachycardia. Introduction : The purpose of this study is to describe a simple and reliable diagnostic maneuver that allows for the rapid differentiation of atypical AV nodal reentrant tachycardia (AVNRT) from other causes of long KP tachycardia. Long RP tachycardias may he caused by atypical AVNRT, orthodromic reciprocating tachycardia (ORT) involving a slowly conducting retrograde accessory pathway, or atrial tachycardia. The differentiation of atypical AVNRT from ORT or atrial tachycardia may be difficult, especially when the differential diagnosis includes a posteroseptal accessory pathway or an atrial tachycardia arising in the posteroseptal right atrium.
Methods and Results : Twelve patients with atypical AVNRT, 21 with ORT, and 12 with an atrial tachycardia diagnosed using conventional criteria were enrolled In this study. The atrial-His (AH) interval was measured at the His-bundle position during the tachycardia and during atrial pacing from the high right atrium at the tachycardia cycle length in the setting of sinus rhythm. In patients with atypical AVNRT, the mean AH interval was 69 msec ± 50 msec (± SD) longer during high right atrial pacing than during the tachycardia (P < 0.001). In 10 of 12 patients with atypical AVNRT, the AH interval during atrial pacing was more than 40 msec longer than the AH interval measured during the tachycardia. In contrast, in patients with ORT or atrial tachycardia, the differences in AH interval between atrial pacing and tachycardia were never more than 20 and 10 msec, respectively.
Conclusion : The difference in the AH interval between atrial pacing and the tachycardia allows a simple and rapid means of differentiating atypical AVNRT from other types of long RP tachycardias.