多种类型房室结折返性心动过速的电生理特点

目的 探讨多种类型房室结折返性心动过速（AVNRT）的电生理特征及消融体会。方法 回顾性分析成功行射频导管消融的113例AVNRT病人的临床和心内电生理资料。结果 113例AVNRT患者中6例存在多种类型AVNRT,其中存在2种、3种和4种类型AVNRT者各占2例,共有8种类型AVNRT;2例存在MAVNP,其余4例DAVNP阳性;均在慢径路区域行射频消融,放电时出现交界性早搏和/或心律,放电次数,功率、时间和X线曝光时间与同期慢-快型AVNRT相似,术后应用阿托品或异丙基肾上腺素未再诱发室上性心动过速,亦无回波,术中和术后均无房室传导阻滞,随访2.0-25.5月,无1例复发。结论 多种类型AVNRT并不少见,中径路既有逆传功能,也具有前传功能,多种类型AVNRT的射频消融类似于慢-快型AVNRT,安全有效。     

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。     

依赖异丙肾上腺素逆传的房室结折返性心动过速

目的探讨房室结双径路中的室房逆传和对房室结双径路的快径逆传间歇性的认识。方法对401例AVNRT者中,在基础状态下RVAS1S1>500ms为无室房逆传的13例患者进行异丙肾试验,重复电生理检查。结果401例AVNRT为慢快型,其中388例(96.8%)RVAS1S1<300ms,为有室房逆传组,而13例(3.2%)RVAS1S1>500ms,为无室房逆传组。结论AVNRT的病人中行电生理检查示房室结存在双径路而室房分离或室房传导时间长,在不能诱发心动过速时,应使用异丙肾上腺素以明确存在快径间歇性逆传的可能性。     

快慢型房室结折返性心动过速的电生理特点

目的分析快慢型房室结折返性心动过速（AVNRT）患者的临床特征、心电网和电生理检查特点、射频消融治疗特点,旨在为临床长RP。心动过速鉴别提供帮助。方法11例经心内电生理检查证实为慢快型房室结折返性心动过速的患者,回顾性分析其临床特征、心电图特点及电生理检查特点及射频消融治疗。结果心动过速表现为窄QRs波心动过速,RP’〉P’R,P。在Ⅱ、Ⅲ、aVF导联倒置,RP’间期为350±25ms,心率为1664-30bpm。11例患者中有3例出现室房逆传跳跃现象。心房程序刺激无明显跳跃现象,11例均可由心房StS：刺激诱发心动过速发作,且容易诱发,容易终止。心动过速发作时,5例CS9．10A波最早,6例HiS的A波最早,其中1例静推ATP心动过速终止。11例患者中9例经房室结改良消融传统慢径获得成功,2例在冠状静脉窦内消融成功,术后随访3个月以上均未再发作心动过速。结论长RP’心动过速的诊断和鉴别诊断有一定困难,如能排除慢旁道和房速,应考虑快慢型房室结折返性心动过速。     

房室结折返性心动过速伴房室阻滞的心脏电生理特点

目的利用食管法心脏电生理检查探讨房室结折返性心动过速伴房室阻滞的电生理特点。方法回顾分析经食管法电生理检查中房室结折返性心动过速伴房室阻滞18例患者的资料。结果房室结折返性心动过速伴房室阻滞主要表现为2:1房室阻滞,多在诱发开始时出现数秒至数分钟,也可呈持久性存在,2:1传导转为1:1传导时多经过一过性3:2文氏传导并伴一过性束支阻滞。结论P波极向及P波与QRS波群的关系特点是房室结折返性心动过速伴2:1房室阻滞的诊断依据。以此排除房室折返性心动过速,并注意与房速相鉴别。     

205例房室结折返性心动过速患者的电生理特点分析

目的　总结 2 0 5例房室结双径路折返性心动过速 (AVNRT)患者的食管电生理特点。方法　收集 2 0 5例经心内电生理检查明确诊断的 AVNRT患者体表心电图、食管心电图、分析检出 DAVNP的刺激方法、SR跃增值、AVNRT诱发与终止方式、诱发带与终止带、AVNRT时的心电特点。结果　 (1)DAVNP的显现及 AVNRT的诱发 :176例 (85 .9% )出现 SR跃增 ,其中增频刺激法 (IP)显现者 173例(98.3% )。以 IP法诱发 AVNRT者 15 7例 (76 .6 % ) ,以 PES法诱发者 140例 (6 8.3) ,两种方法均可诱发者92例 (4 4.9% )。需用阿托品诱发者 31例 (15 .1% ) ,需用异丙肾诱发者 5例 (2 .4% )。 (2 ) AVNRT时的心电特点 :RR间期为 349.5 6± 73.5 5 ms,食管电极上 RP- 间期为 5 1.45± 13.0 6 ms,6例 (2 .9% )有 P波滞后现象。伴房室结连接区远侧端 2 :1阻滞 17例 (8.3% ) ,束支传导阻滞 (BBB) 4 9例 (2 3.9% ) ,其中 L BBB10例(4 .9% ) ,RBBB39例 (19% )。 95例 (4 6 .3% )患者的 V1 导联可见伪 r- 波 ,30例 (14.6 % )患者 、 及 av F导联出现伪 S波。结论　 (1) IP法及 PES法均有助于 DAVNP的诊断。 (2 ) AVNRT时的一些特殊心电现象有利于与其它类型室上性心动过速 (PSVT)鉴别。     

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。     

射频消融房室结慢径对老年人房室结电生理功能的影响

目的　分析和比较应用射频消融房室结慢径治疗房室结折返性心动过速对老年人和青年人房室结电生理功能的影响。方法　 76例仅患有慢 快型房室结折返性心动过速的患者分为两组 ,老年组 (≥ 6 0岁 ) 36例和青年组(14～ 4 5岁 ) 4 0例 ,均为行慢径消融术成功病例 ,对比消融前后和两组间的房室结功能参数 ,分析和比较这两组患者在射频消融前后房室结电生理特点的异同。结果　所有病例均消融成功。两组病例消融后较消融前房室结前传文氏周期及最长A2 H2 间期均缩短 ,而老年组的心动过速周长、消融前后窦性心率周长及消融后房室结前传文氏周期均较青年组延长。结论　老年人的房室结前传电生理特性较青年人为差 ,而对房室结折返性心动过速患者的慢径有效消融后 ,房室结电生理特性的变化规律不受年龄因素影响     

典型与非典型房室结折返性心动过速折返环路的对比研究

背景：既往证据显示典型(慢-快型)与非典型(快-慢型)房室结折返性心动过速(AVNRT)并非经同一快径传导,然而对于同时合并典型与非典型AVNRT患者是否也是如此目前尚无证据。本研究通过对比同时合并典型与非典型AVNRT患者的传导间期,进一步探讨两种类型心动过速时慢、快径的特性,以阐明这一问题。方法：入选568例能够在电生理检查过程中通过程控起膊、自律性刺激或自然发生的AVNRT患者中,筛选出26例同时合并典型与非典型AVNRT的患者。通过直接测量慢-快型及快-慢型AVNRT心动过速时的传导间期,间接推算两种心动过速时快径传导时间,比较二者的差异,验证心动过速时经同一快径传导的假设。结果：患者平均年龄40.7±10.3(28-63)岁 ,其中女性14例(53.8%)。在典型ANVRT及非典型AVNRT时,心动过速周长(CL)分别为368.9±43.1、372.6±41.8 ms;心房最早逆传激动点位于冠状静脉窦口(CSO)比例分别为58%、67%;16例(61.5%)患者为快-慢型;慢-快型及快-慢型AVNRT心动过速时快径逆传与前传时间差别为21.68±10.34 ms,差异有统计学意义(P<0.05)。结论：典型和非典型AVNRT时并不完全通过同一快径逆传或前传。     

房室结折返性心动过速室房传导的规律

通过窄 QRS心动过速的心电图 RP′间期及心内电图VA间期变化 ,探讨房室结折返性心动过速 (atrioventriculanodal reentrant tachycardia,AVNRT)室房传导的规律性。　　资料和方法　选择对象为经心内电生理检查及射频消融治疗证实为房室结双经路慢 -快型折返性心动过速的 46例患者 ,男性 2 0例 ,女性 2 6例 ,平均年龄 (4 4± 15 )岁。 46例患者 ,窦性心律时心电图无异常 ,心动过速时呈窄 QRS波 ,QRS时限 <0 .11s,伴 1∶ 1的室房激动关系 ,心动过速时记录体表心电图及希氏束 (HBE)及冠状静脉窦近端 (CS9～10 )心内电图来观察 RP′间…     

Electrophysiological evaluation of the sinus node in patients with atrioventricular and/or intraventricular conduction defects

The authors evaluated retrospectively sinoatrial conduction time (SACT), sinus node recovery time (SNRT), and corrected sinus node recovery time (CSNRT) in 272 patients with atrioventricular and/or intraventricular conduction defects without evidence of overt sinus node dysfunction. The study was designed to determine the prevalence of electrophysiologic sinus node abnormalities in patients with overt atrioventricular and/or intraventricular conduction defects. One or more sinus node electrophysiological abnormalities were observed in 133 cases (48.9%). There was a significant prevalence of electrophysiologic sinus node abnormalities only in patients older than 71 years of age. The data suggest that the involvement of the specialized conduction system is much more diffuse than one might expect simply observing the single recorded ECG defect and that the prevalence of associated defects of the conduction system increases with increasing age of patients.     

Coronary sinus recordings of double potentials associated with retrograde conduction through left atrioventricular accessory pathways

INTRODUCTION: In some patients with left AV accessory pathway (AP), double potentials are recorded along the coronary sinus (CS) during retrograde AP conduction only. This electrophysiologic study was performed to clarify the origin and clinical significance of double potentials in 11 patients. METHODS AND RESULTS: The direction of activation of the first, relatively blunt component (DP1) was lateral to septal in 5 patients with anterior or anterolateral AP, centrifugal in 2 patients with posterior or posterolateral AP, and septal to lateral in 4 patients with posteroseptal AP, suggesting the earliest activation of DP1 was near the AP. The direction of activation of the second, sharper potentials (DP2) were septal to lateral in all patients. The double potentials were fused in the paraseptal CS region. Pacing from the lateral CS musculature or lateral left atrium reproduced the double potentials. The effective refractory period of the double potentials was reached by ventricular extrastimulation, and the left atrial deflection preceded the double potentials, excluding a ventricular or AP origin. CONCLUSION: In patients with connections between the paraseptal CS musculature and left atrium but no connections more laterally, retrograde left AP conduction is associated with double potentials in the CS recordings. The double potentials represent activation of the left atrial insertion of the AP (DP1) and later activation of the CS musculature (DP2) via connections between the paraseptal CS musculature and left atrium, respectively. The activation pattern of DP1 depends on AP location, thus providing important information for AP localization during CS mapping.     

Anterograde sinuatrial conduction evaluated by sinus node electrogram in atropine blocked retrograde atrial conduction

Two cases are described where atropine induced the disappearance of reset zone as response to premature atrial stimulation for blocked retrograde atrial conduction. Because of this, sinuatrial conduction time could not be estimated. The sinus node electrogram allowed the direct measurement of sinuatrial conduction and showed a facilitated anterograde conduction through the perinodal fibers after administration of the drug.     

Concealed conduction and dual pathway physiology of the atrioventricular node

INTRODUCTION: Both concealed conduction and dual pathway physiology are important electrophysiologic characteristics of the AV node. The interaction of AV nodal concealment and duality, however, is not clearly understood. METHODS AND RESULTS: The properties of AV conduction curves in the presence and absence of a conditioning blocked impulse were prospectively studied during premature atrial stimulation in 20 patients with AV nodal reentrant tachycardia before and after slow pathway ablation and in 14 control patients. AV nodal duality in the control conduction curve in the absence of a conditioning impulse was observed in 19 (95%) of 20 patients with AV nodal reentrant tachycardia. However, AV nodal duality in the modulated conduction curve in the presence of a blocked impulse was only identified in 2 (10%) of 20 patients (2/20 vs 19/20, P < 0.0001). The modulated curve was characterized by a significantly longer AV nodal effective and functional refractory periods compared to the control curve (P < 0.0001) in both patients with and without AV nodal reentry and in AV nodal reentry patients after successful slow pathway ablation. The maximum AH interval (AH(max)) of the modulated curve was significantly shorter than the control curve in both patients with (217 +/- 74 ms vs 347 +/- 55 ms, P < 0.0001) and without AV nodal reentry (178 +/- 50 ms vs 214 +/- 54 ms, P = 0.02). AH(max) of the control curve was significantly longer in AV nodal reentry patients than in controls (P < 0.0001). AH(max) of the modulated curve, however, was not significantly different between the two groups. After slow pathway ablation, AH(max) of the control curve was significantly reduced (347 +/- 55 ms vs 191 +/- 40 ms, P < 0.0001). Significant reduction in AH(max) of the modulated curve was not observed. CONCLUSION: An interaction of AV nodal concealed conduction and dual pathway physiology was demonstrated by our data. Slow pathway conduction of the AV node was prevented by the concealed beat in both patients with and without AV nodal reentry.     

Anatomic assessment of variations in myocardial approaches to the atrioventricular node

Atrial Septum, Coronary Sinus, and Atrioventricular Node. Introduction: The tissues in the posteroinferior atrioventricular (AV) junction around the AV node are important in procedures for ablating and manipulation of catheters in and around the coronary sinus (CS). However, information with regard to the histological arrangement of perinodal myocardium relative to the CS is lacking. Methods and Results: We examined 21 postmortem human hearts without any abnormalities (9 women; mean age 68.8 ± 14.3 years). After making measurements, the posteroinferior AV junction was removed and processed for histology. Sections were cut parallel to the septum. We assessed the myocardial arrangements from the atrial septum and the CS toward the AV nodal tissue, including the transitional cell zone, and measured the dimensions between the compact AV node and the CS, and the circumference of the CS. We observed 3 patterns of myocardial approaches to the AV node: extension of myocardium from the atrial septum (Group A; n = 6); extension of CS musculature (Group B; n = 6); and both septal and CS musculature (Group C; n = 9). The distance between the AV node and the CS in Group A was significantly longer than in the other groups (mean 11.5 ± 3.1 mm, 1.7 ± 0.6 mm, 3.8 ± 1.5 mm, respectively; P < 0.0001), and the circumference of the CS in Group B was longer than in Group A (mean 31.1 ± 7.9 mm*, 44.4 ± 8.4 mm*, 33.7 ± 6.9 mm, respectively; P < 0.05). Conclusion: The myocardial approaches including the transitional cell zone toward the AV node are variable in normal hearts. The location and size of the CS can affect the myocardial arrangements and the area of transitional cells around the AV node.     

房室结双径路或多径路室房传导及其伴发的特殊心电现象

目的探讨房室结双径路或多径路室房传导及其伴发的特殊心电现象和发生机制。方法通过常规心电图对6例异位心搏中出现的房室结双径路或多径路室房传导现象进行回顾性分析。结果其特征为：①心室搏动后跟随P^-波，R—P^-间期有两种或两种以上，相邻两个R—P^-间期差值60ms。②起搏源性室房文氏现象中，R—P^-间期成倍增长，有时伴心室回波。③室性期前收缩后跟随两次P^-波。形成1：2室房同步传导。结论通过推理性分析可在体表心电图上作出房室结双径路或多径路室房传导的诊断。     

三磷酸腺苷对房室结前向传导的影响与房室结前传功能的相关性研究

目的　评价三磷酸腺苷 (ATP)对房室结前向传导的影响与房室结前传功能的相关性。方法　选择 19例预激综合征行射频消融术后且房室结前传文氏点等于或大于 15 0次/分的患者 ,测量房室结前传功能 (前传文氏点、2 :1点)和有效不应期 ,在心房起搏时静脉推注ATP,直至 0 .3 0mg/kg或出现房室前传阻断。结果　房室结前传文氏点平均为 (3 0 5 .79± 4 5 .0 1)ms,前传 2 :1点平均为(2 62 .63±2 4 .5 5 )ms,房室结前传有效不应期平均为(2 3 5 .78± 5 9.2 4 )ms,阻断房室结前传所需ATP平均剂量为(0 .16±0 .0 5 7)mg/kg,总量平均为 (11.4±4 .5 3 )mg。房室结前传文氏点、2 :1点 (ms)与阻断其前向传导所需ATP剂量呈负相关 (r=- 0 .797,P <0 .0 1;r=- 0 .699,P <0 .0 1)。房室结前传有效不应期与阻断其传导所需ATP剂量呈负相关(r=- 0 .4 65 ,P <0 .0 5 )。结论　阻断房室结前向传导所需ATP与房室结前传功能、房室结前传有效不应期有明显相关性 ,房室结前传功能越好 ,房室结前传有效不应期越短 ,阻断房室结前传所需ATP剂量越大。     

三磷酸腺苷对室房传导的电生理作用

目的　探讨三磷酸腺苷 (adenosine triphosphate,ATP)对房室结双径路参与的房室交界区折返性心动过速和旁路参与的房室折返性心动过速患者的室房传导的电生理作用。　方法　 39例房室交界区折返性心动过速和 6 7例房室折返性心动过速患者在右心室起搏 (频率 140次 / m in)时 ,经股静脉快速注射 ATP 2 0 mg,连续记录体表心电图和心内电图 ,观察室房传导变化。　结果　房室交界区折返性心动过速组 33例 (84.6 % )在注射 ATP后出现室房阻滞 ,其余 6例无变化。6 7例房室旁路患者在消融前 ,6 1例 (91% )室房传导无变化 ,另 6例出现室房阻滞 ,其中 2例具递减性传导 ;而在消融后 2 4例右心室起搏频率超过 16 0次 / m in,仍为 1∶ 1逆传 ,注射 ATP后 2 3例出现室房阻滞 ,仅 1例不受影响。　结论　 ATP对房室结及旁路的电生理作用不同 ,注射 ATP后出现室房阻滞对鉴别经房室结或旁路逆传有一定价值 ,是旁路消融成功的一个判别指标 ,但并不一定完全可靠     

Effect of site, summation and asynchronism of inputs on atrioventricular nodal conduction and refractoriness

The impulses coming from the sinus node synchronically penetratethe A V node via the crista terminalis and inter-atrial septum.Studies in superfused rabbit AV preparations suggest that thecrista terminalis is a more effective input than the inter-atrialseptum, and that the summation of both inputs facilitates AVnodal conduction. The aim of this study was to verify the hypothesisin a more physiological model, such as the whole rabbit heartperfused by a Langendorff system. Fifteen rabbit hearts were studied in a Langendorff perfusionsystem with six bipolar extracellular electrodes: two for stimulating(crista terminalis and inter-atrial septum) and four for recording(crista terminalis, inter-atrial septum, His bundle electrogramand right ventricle). Seven hearts (Group I) were consecutivelypaced at the crista terminalis, inter-atrial septum and bothsites simultaneously, to determine the AV nodal Wenckebach cyclelength and effective refractory period under basal conditionsand after acetylcholine (0.75 x 10^–6 M). In eight heartsunder 0.75 x 10^–6 M acetylcholine (Group II), the cristaterminalis and inter-atrial septum were simultaneously (delay= 0 ms) or sequentially (delay = 2,4, 6,8,10,12,14,and 16 ms)stimulated to calculate the AV nodal effective refractory periodand the AH interval at an atrial coupling interval 5 ms longerthan the AV nodal effective refractory period, for each delaytested. There were no basal differences in AV nodal parameters duringcrista terminalis pacing, inter-atrial septum pacing or simultaneousstimulation in both sites in Group I; after acetylcholine, theAV nodal Wenckebach cycle length and effective refractory periodtended to be shorter during crista terminalis pacing (cristaterminalis = 188 ±33 and 147±34; inter-atrialseptum = 195±35 and 158±35; both sites = 195±34and 154±36; values expressed in cycle length of pacing-ms),although the differences did not reach statistical significance.In Group II, the AH interval tended to prolong slightly on increasingthe delay between crista terminalis and inter-atrial septumstimulation (delay 0 = 119±31, 2 = 125±29, 4 =129±33,6 = 129±29,8 = 128±30,10 = 134±34,12= 132±35,14 = 129±32,and 16 = 131 ±31 ms),butagain the differences did not reach statistical significance;the A V nodal effective refractory period did not change whenthe delay was varied. Conclusions: (1) Neither the input site nor the synchronoussummation of inputs plays an important role in A V nodal conduction.(2) These results suggest that A Vnodal response during atrialtachyarrythymias depends more on atrial rate than on shiftingsin site and time coupling of inputs.