心房不同部位拖带法鉴别不典型房室结折返性心动过速和房性心动过速

目的报道一种鉴别不典型房室结折返性心动过速(AVNRT)和起源点邻近Kock三角的房性心动过速(AT)的新方法。方法 22例室上性心动过速患者,在心房不同部位(右房心耳部、冠状静脉窦近端、远端)起搏拖带心动过速,测定起搏后VA间期(最后一个起搏脉冲前传夺获的心室电图到起搏终止后第一心搏的最早心房电图的距离)。计算各部位起搏后VA间期的差别并取差别绝对数的最大值定义为ΔVA间期。结果 13例AVNRT起搏后ΔVA间期5.8±3.6(0～14)ms,9例AT起搏后ΔVA间期62.8±24.2(21～98)ms。ΔVA间期在所有AVNRT均<15 ms,在所有AT均>15 ms,因此起搏后ΔVA间期>15 ms用于诊断AT的灵敏度和特异度均为100%。结论心房不同部位起搏拖带法可用于准确鉴别不典型AVNRT和起源点邻近Kock三角的AT。     

房室折返性心动过速的拖带现象

1977年,Waldo等在研究心房扑动时发现心房刺激其频率超过心房扑动时,心房扑动增快并跟上刺激频率;随刺激终止,其心房扑动又恢复到刺激前的频率。并将此表现称为拖带现象(Entrainment phenomenon)。随着研究的深入,拖带已不限于心房扑动,它可以出现在各种心动过速中。拖带是折返机制性心动过速的特征性表现这一概念已为多数学者接受。本文以目前业已证实的折返性心动过速——房室折返性心动过速(AVRT)为例,介绍     

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。     

心室融合波伴心房激动提前对间隔旁路逆传的房室折返性心动过速的诊断作用

目的 观察心室融合波伴心房激动提前对间隔旁路逆传的顺向型房室折返性心动过速(OAVRT)的诊断作用。方法 按心内电生理检查标准和射频消融结果，将47例符合人选条件的患者分为两组：房室结折返性心动过速(AVNRT)组和间隔旁路逆传的0AVRT组，分别为24例和23例。心动过速时行心室期前程序刺激(RS2刺激)和心室快速刺激，测量体表心电图上心室融合波之后的心房激动时间是否提前。结果 RS2刺激和心室快速刺激均能形成多个心室融合波。AVNRT组无l例伴有心房激动提前(特异性100％)，而OAVRT组在心室刺激成分明显的心室融合波时，心房激动均被提前(敏感性100％)。两组间的差异十分显著(P＜0．001)。结论 心室融合波伴心房激动时间提前是诊断间隔旁路逆传OAVRT的可靠指标，具有敏感性和特异性高的特点，而且也可用于未能记录到希氏束电图的患者。     

体表心电图特征对典型的房室结折返性心动过速和房室折返性心动过速的鉴别作用

对150例射频消融明确诊断的窄QRS心动过速患者的窦性心律和发作室上性心动过速时的心电图进行分析,从而归纳出典型的房室结折返性心动过速(AVNRT)和房室折返性心动过速(AVRT)心电图特征的差异.结果 5项心电图指标对区分这两种心动过速类型有意义.认为对于AVNRT有预测作用的为伪r′波(V1导联)和伪S波(Ⅱ、Ⅲ、aVF导联).对于AVRT有预测作用的为逆传P波,RP′间期≥70 ms及ST段改变.     

房室结双径路与间隔旁路所致折返性心动过速的鉴别诊断

室上性心动过速(SVT)是临床常见的心律失常，通过心脏电生理检查精确定位是射频导管消融治疗成功的关键。     

常规心电图对典型的房室结折返性心动过速和顺传型房室折返性心动过速的鉴别作用

目的探讨12导联心电图对阵发性窄QRS心动过速中最常见两种类型--典型的房室结折返性心动过速（AVNRT）和顺传型房室折返性心动过速（AVRT）的鉴别作用.方法对206例阵发性窄QRS心动过速（QRS〈0.11 s,心室率〉120次/min）患者的心电图进行了分析.第一部分分析139例患者的心电图,从中归纳出1个12导联心电图算法（algorithm）.第二部分前瞻性分析了67例患者的心电图,以检测这一算法的准确性.心动过速的机制和旁路位置均由成功的射频导管消融术确定.结果 5项心电图指标对区分这两种心动过速类型有意义.对于AVNRT有预测作用的为伪r′波（V1导联,敏感性53%、特异性96%）,伪S波（Ⅱ、Ⅲ、aVF导联,敏感性21%、特异性100%）.对于AVRT有预测作用的为逆传P波（敏感性89%、特异性68%）,RP间期〉70 ms（敏感性90%、特异性91%）,及ST段改变.ST段改变归纳出3个联合指标,分别为：V4、V5导联ST段同时下降≥2 mm（敏感性24%、特异性94%）;V5、V6导联ST段同时下降≥1 mm（敏感性41%、特异性81%）;V6导联ST段同时下降≥1 mm和aVR导联ST段抬高≥1 mm同时出现（敏感性30%、特异性85%）.V1导联逆传P波极性对于旁路的初步定位有帮助,左侧旁路大多为直立、双向或平坦的逆传P波,右侧旁路大多为倒置的逆传P波.12导联心电图算法对心动过速机制的正确诊断率分别为85%和82%.对于AVRT旁路位置的正确判断率为75%～86%.在3个联合指标中,V5、V6导联ST段同时下降≥1 mm的鉴别作用最佳.结论心电图算法有助于更加准确地鉴别阵发性窄QRS心动过速的机制,并且可以对旁路初步定位.     

心室未参与折返的房室结折返性心动过速1例

患者男性,58岁.因“间断心悸6年,再发半小时”人院,每次心悸持续约1h.患者心动过速发作时的心电图提示房室结折返性心动过速(AVNRT).人院后患者完善相关辅助检查,择期行心腔内电生理检查.心腔内电图示心室刺激VA逆传递减,提示无隐性旁道;冠状窦电极程序刺激可见房室结跃增现象并心房回波(图1).静滴异丙肾上腺素后,给...     

房室结双径路参与的房室折返性心动过速

患者男性,38岁。有阵发性室上性心动过速(室上速)史10余年,近2年发作频繁,室上速发作时各种抗心律失常药物均不能直接终止,每次均需食管调搏超速或亚速刺激方可终止。此次因心悸5ｈ就诊。查体:神志清晰,血压12080ｍｍＨｇ(1ｍｍＨｇ=0133ｋＰａ),心率190次ｍｉｎ,律齐,各瓣膜听诊区未闻杂音。心动过速发作时心电图如图1所示。ＱＲＳ波形为室上性,在Ｖ1导联呈ＱＳ型,时限008ｓ,频率190次ｍｉｎ。ＲＲ间期长短交替,分别为320ｍｓ和270ｍｓ。食管导联可见Ｐ′波在ＱＲＳ波群之后,ＲＰ′间期固定,为012ｓ,Ｐ′波形态一致。Ｐ′Ｒ间期则长短交替,…     

隐匿性旁路与房室结折返性心动过速鉴别诊断的临床研究

目的观察经校正的心室起搏拖带起搏后间期（PPI）与心动过速周长（TCL）差值，在隐匿性旁路介导的顺向房室折返性心动过速（O-AVRT）与房室结双径路所致房室结折返性心动过速（AVNRT）鉴别诊断中的价值。方法选择经心内电生理检查和射频消融的65例室上速心动过速患者，窦律时无预激波出现。其中AVNRT37例、O-AVRT28例，以快于心动过速频率5-15次／min的刺激频率进行心动过速拖带，比较校正的心室起搏拖带的PPI与TCL差值等参数在这两组中的差异。结果心内电生理检查发现，28例O-AVRT和37例AVNRT患者，除2例AVNRT患者外均成功拖带，28例O-AVRT患者校正的PPI－TCL差值[（68±20）ms]短于35例AVNRT患者校正的差值[（151±16）ms，P〈0．01]。所有O-AVRT患者校正的PPI-TCL差值均〈110ms，而AVNRT患者的差值均〉110ms。间隔部旁路患者校正的PPI-TCL差值比游离壁旁路患者更短一些。结论经校正的PPI-TCL差值测定是一项快速、有效的鉴别AVNRT和隐匿性O-AVRT的方法，对射频消融具有重要的指导意义；校正的PPI-TCL差值〈110ms对确诊O-AVRT患者能提供更大的判断价值。     

应用改良体表心电图三步法鉴别常见阵发性室上性心动过速临床评价

目的探讨典型房室结折返性心动过速和经隐匿性旁道介导房室折返性心动过速的常用心电图鉴别诊断指标,提出并评价改良的鉴别诊断方案。方法收集2003年1月至2005年11月北京大学人民医院收治的154例患者窦性心律和心动过速发作时的心电图。在分析104例患者的心电图之后提出改良诊断方案,并利用50例患者的心电图进行评价。结果改良方案诊断房室结折返性心动过速及房室折返性心动过速的准确率分别为84%和87%,观察者间的符合率为85%,观察者内的符合率均为89%。结论改良诊断方案可以提高这两种心动过速的心电图鉴别诊断准确率。     

希氏束旁起搏鉴别间隔部隐匿性AVRT与AVNRT的临床价值

目的：探讨希氏束旁起搏鉴别间隔部隐匿性房室旁道与慢一快型房室结折返性心动过速（AVNRT）的临床价值。方法：采用希氏束逆传不应期心室早搏刺激法将61例患者分别诊断为37例慢一快AVNRT和24例间隔部房室折返性心动过速（AVRT）；再对61例患者采用希氏束旁起搏方法进一步检测。结果：采用希氏束旁起搏法检测37例AVNRT患者中有6例未检测成功，其余31例均为逆传房室结图形；24例AVRT患者中4例未检测成功，15例呈逆传旁道／旁道图形，5例呈非逆传旁道／旁道图形。如以逆传旁道／旁道图形为标准，鉴别间隔快旁路引起的AVRT与慢一快型房室结折返性心动过速，敏感性75％，特异性可达1009／6。结论：希氏束旁刺激法对鉴别诊断AVRT与AVNRT有较高的特异性。     

Differentiation of atypical atrioventricular node re-entrant tachycardia from orthodromic reciprocating tachycardia using a septal accessory pathway by the response to ventricular pacing

OBJECTIVES: The purpose of this study was to determine whether the response to ventricular pacing during tachycardia is useful for differentiating atypical atrioventricular node re-entrant tachycardia (AVNRT) from orthodromic reciprocating tachycardia (ORT) using a septal accessory pathway. BACKGROUND: Although it is usually possible to differentiate atypical AVNRT from ORT using a septal accessory pathway, a definitive diagnosis is occasionally elusive. METHODS: In 30 patients with atypical AVNRT and 44 patients with ORT using a septal accessory pathway, the right ventricle was paced at a cycle length 10 to 40 ms shorter than the tachycardia cycle length (TCL). The ventriculo-atrial (VA) interval and TCL were measured just before pacing. The interval between the last pacing stimulus and the last entrained atrial depolarization (stimulus-atrial [S-A] interval) and the post-pacing interval (PPI) at the right ventricular apex were measured on cessation of ventricular pacing. RESULTS: All 30 patients with atypical AVNRT and none of the 44 patients with ORT using a septal accessory pathway had an S-A-VA interval >85 ms and PPI-TCL >115 ms. CONCLUSIONS: The S-A-VA interval and PPI-TCL are useful in distinguishing atypical AVNRT from ORT using a septal accessory pathway.     

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.     

A new algorithm for concealed accessory pathway localization using T-wave-subtracted retrograde P-wave polarity during orthodromic atrioventricular reentrant tachycardia

INTRODUCTION: AP localization can be predicted by analyzing the polarity of the delta wave, QRS polarity, and R/S ratio in patients with Wolff-Parkinson-White syndrome. However, the estimation of AP location is limited in patients with concealed pathways during atrioventricular reentrant tachycardias (AVRT). Thus, we analyzed retrograde P-wave polarity during orthodromic AVRT and developed an algorithm to predict the localization of concealed accessory pathways (AP). METHODS AND RESULTS: A total number of 131 patients with a single AP and inducible orthodromic AVRT were included. The initial 61 patients were analyzed retrospectively for algorithm development, whereas 70 patients were evaluated prospectively. The retrograde P-wave polarity was analyzed by subtracting the superimposing T-wave during orthodromic AVRT using custom-designed software. Four leads of the surface electrocardiogram (ECG) were identified to accurately distinguish AP locations assigned to four different regions around each AV annulus: I, aVR, aVL, and V(1). Lead V(1) was used to differentiate right (negative or isoelectric) from left (solely positive) APs. Retrograde P-wave in lead I was negative in left posterior APs exclusively and became more positive with an AP location shifting towards right anterior. P-wave polarity in lead aVR demonstrated a shift from a positive polarity from left APs to isoelectric in right APs. The opposite direction (shift from positive to isoelectric) was observed for lead aVL. The subsequently developed algorithm for concealed AP localization using these surface ECG leads demonstrated a high sensitivity, specificity, and positive predictive value particularly for common AP localizations (left posterior and inferior, and right septal) when applied in a prospective fashion. CONCLUSION: Concealed AP localization can be accurately predicted by the analysis of retrograde P-wave polarity during orthodromic AVRT using the algorithm derived from the presented study.     

体表心电图对房室结折返性与房室折返性心动过速的鉴别诊断

为探讨体表心电图对房室结折返性和房室折返性心动过速的鉴别诊断价值,对以射频导管消融、心脏电生理检查、心外膜标测的方法确诊房室结折返性心动过速(AVNRT)和房室折返性心动过速(AVRT)的88例患者的室上性心动过速发作时心电图作对照研究。结果显示:(1)P'波出现率在AVNRT占33％,在AVRT占100％(P<0.01)。(2)R-P'间期<80ms时常见于AVNRT,而≥80ms多见于AVRT(P<0.01)。(3)AVNRT在下壁导联(Ⅱ、Ⅲ、aVF)常见假性S波,而V_1导联常合并假性r波。(4)AVRT无文氏现象,但常出现束支传导阻滞改变且符合Coumel-Slama定律。认为以上特点对两者鉴别诊断有重要价值。