多型房室结折返性心动过速的机制和射频导管消融

目的分析多型房室结折返性心动过速（AVNRT）并存的电生理机制和射频导管消融结果。方法18例经电生理检查后行射频导管消融的多型AVNRT患者。慢快型和慢慢型AVNRT的消融方法为首选消融前传慢径（房室结右侧后延伸）,快慢型AVNRT的消融方法为消融最早慢径逆传心房激动部位。消融成功的标准为消除1：1前传慢径,消除快慢型AVNRT的逆传慢径,不能诱发任何类型AVNRT。结果11例在消融前的电生理检查中诱发出2种类型AVNRT,均在三尖瓣环与冠状静脉窦口之间（房室结右侧后延伸）成功消融。7例在电生理检查中诱发出1种类型,消融此型后又诱发出另外1种类型,其中4例在房室结右侧后延伸进一步消融成功,另3例均经左侧后延伸进一步消融成功。消融术后随访6个月至8年,18例均无复发。结论对于大多数多型AVNRT,房室结右侧后延伸可能为其折返环的主要基质,消融可成功治愈多型AVNRT。在少部分多型AVNRT中,左侧后延伸与右侧后延伸可能分别作为不Ⅻ类型AVNRT折返环的主要基质,需要分别消融才能成功治愈。     

多种类型房室结折返性心动过速的机制和经导管射频消融治疗

目的分析多种类型房室结折返性心动过速并存患者的电生理机制和经导管射频消融治疗的结果。方法研究人群为18例经电生理检查后行射频消融治疗的多种类型房室结折返性心动过速(AVNRT)患者。慢快型和慢慢型AVNRT的消融方法为首选消融前传慢径(房室结右侧后延伸),快慢型AVNRT的消融方法为消融最早逆传慢径的心房激动部位。消融成功的标准为消除1:1前传慢径,消除快慢型AVNRT的逆传慢径,不能诱发任何类型AVNRT。结果多种类型AVNRT的发生率为1.8%(18/1000)。18例患者中有11例在消融治疗前的电生理检查中诱发出2种类型AVNRT,有7例在电生理检查中诱发出1种类型AVNRT,消融此型后又诱发出另外1种类型AVNRT。在消融前即诱发出2种类型AVNRT的10例患者,均在三尖瓣环与冠状窦口之间(房室结右侧后延伸)成功消融两种类型AVNRT。在电生理检查中出现1种类型AVNRT,经导管射频消融这种AVNRT后,又出现另外1种类型AVNRT的7例患者中,4例在三尖瓣环与冠状窦口之间(右侧后延伸)成功消融两种类型AVNRT;另3例中的2例在房室结右侧后延伸处消融后,第1种AVNRT不能诱发,但可诱发出另外1种类型AVNRT,经在冠状窦近端及二尖瓣环房侧(房室结左侧后延伸)进一步消融成功;另1例经消融三尖瓣环与冠状窦口之间(右侧后延伸)后,除原诱发的快慢型AVNRT外,还可诱发慢慢型AVN-RT,其逆传心房激动顺序与快慢型时相同,提示2种类型AVNRT均应用同一条逆传慢径,经在冠状静脉窦内和二尖瓣环房侧(房室结左侧后延伸)成功消融2种类型AVN-RT。术后随访18例均无复发。结论对于大多数多种类型AVNRT患者,具有前向和逆向传导功能的传统房室结慢径(房室结右侧后延伸)可能为多型AVNRT的主要基质,因此消融房室结右侧后延伸可成功消融大多数多型AVNRT。对于少部分多型AVNRT患者,左侧后延伸与右侧后延伸可能分别作?     

从慢慢型和慢快型房室结折返性心动过速电生理特性的差异分析折返环的不同

目的从慢慢型房室结折返性心动过速（AVNRT）和慢快型AVNRT的电生理特性的差异分析两型AVNRT间折返环的不同.方法在500例AVNRT患者中的59例慢慢型和60例慢快型之间,比较部分电生理特性的异同;同时在部分慢慢型和慢快型患者中应用2种方法（1）比较起搏时和心动过速时的HA间期的长度;（2）比较心动过速时心室刺激重整心动过速的不同.比较下传共径（LCP）的异同.结果慢慢型的前传慢径和逆传慢径有明显不同的传导时间;慢慢型的逆传慢径与慢快型的逆传快径有明显不同的传导时间和递减特性;和慢快型相比,2种方法均显示慢慢型有较长的LCP.结论 （1）慢慢型AVNRT中前传慢径和逆传慢径的传导时间明显不同;慢慢型较慢快型有较长的下传共径;（2）研究结果支持慢慢型AVNRT可能应用房室结的右侧后延伸和左侧后延伸分别形成心动过速的前传和逆传支而形成折返.     

慢慢型房室结折返性心动过速的电生理机制和射频导管消融治疗

目的　探讨慢慢型房室结折返性心动过速 (AVNRT)的电生理机制和不同射频导管消融方法的治疗效果。方法　812例AVNRT患者分为两组,第 1组 500例,比较慢慢型中前传慢径和逆传慢径的成功消融部位的异同、比较在慢慢型和快慢型中选择性地消融逆传慢径部位的异同。第 2组312例,在设想慢慢型AVNRT折返机制的基础上,前瞻性地对慢慢型仅选择性消融前传慢径而不消融逆传慢径。结果　第 1组 59例慢慢型AVNRT的前传和逆传慢径的传导时间和成功消融的部位明显不同,逆传慢径多在冠状静脉窦(CS)窦口内或CS近端消融成功,而前传慢径多在三尖瓣环和CS窦口之间消融成功;慢慢型与快慢型的逆传慢径有明显不同的传导时间、递减特性和解剖分布。在第 2组前瞻性地仅消融前传慢径治疗 22例慢慢型组中,在三尖瓣环和CS窦口之间成功消融前传慢径并治愈AVN RT后, 21例逆传慢径功能不变,其逆传慢径最早心房插入点部位与前传慢径消融部位不同。所有 812例AVNRT均消融成功,第 1组在 3年以上的随访中, 387例慢快型复发 1例 (0 3% ), 59例慢慢型复发6例(10% ), 54例快慢型无复发。第 2组 312例 3 ~48 ( 23±12 )个月的随访中,慢快型复发 2例(0 5% ),慢慢型和快慢型无复发。结论　(1)慢慢型AVNRT应用电生理特性和解剖分布不同的两条慢径形     

快慢型房室结折返性心动过速的电生理机制和经导管射频消融

目的探讨快慢型房室结折返性心动过速(AVNRT)的电生理机制和经导管射频消融。方法快慢型AVNRT消融患者42例。消融方法为在心室起搏或心动过速时标测最早逆传慢径心房激动部位,然后在窦性心律下或心动过速时消融。消融成功的标准为消除逆传慢径、1:1前传慢径及不能诱发任何类型AVNRT。结果所有42例均消融成功。逆传慢径消融成功部位在三尖瓣环和冠状静脉窦(CS)口之间(传统慢径区域)36例(86%),其最早逆传心房激动也位于上述区域;逆传慢径在CS近端或/和二尖瓣环心房侧消融成功6例(14%),其最早逆传心房激动多位于CS近端1～3cm处。结论多数快慢型AVNRT可在传统慢径区域(房室结右侧后延伸)消融成功,但部分病例需要在CS近端和/或二尖瓣环房侧(左侧后延伸)消融成功。     

射频消融房室结慢径治疗房室结折返性心动过速消融终点的探讨

消融房室结慢径是治疗房室结折返性心动过速（AVNRT）安全而有效的方法.但AVNRT消融终点标准意见不尽一致.本文分析163例AVNRT的射频导管消融术（RFCA）电生理特征及慢径消融时的心电改变,并对其消融的终点标准、消融方法学及并发症预防进行探讨.     

房室结折返性心动过速慢径消融术后复发原因分析

目的探讨房室结折返性心动过速(AVNRT)导管射频电消融(RFCA)术后复发的原因。方法对行导管射频电消融术100例慢快型房室结折返性心动过速患者进行随访,回顾性分析其心电生理和临床资料。结果100例患者中复发10例,复发率为10%。复发病例中7例术后慢径残存,未复发病例中3例慢径残存,慢径残存患者复发率高。未复发病例消融后的快径前传有效不应期(FPERP)较消融前缩短,分别为(277±41)m s和(318±46)m s(P<0.05);而复发病例消融后的快径前传有效不应期(FPERP)较消融前无明显缩短,分别为(298±48)m s和(311±56)m s(P>0.05)。复发病例心内电生理特点复杂多变,多种类型房室结折返性心动过速多见,未复发病例多为单纯典型房室结折返性心动过速。结论房室结折返性心动过速复发的电生理基础仍然是房室结双径路,房室结折返性心动过速复发与慢径残存及复杂的房室结、慢径结构有关。     

后位法消融治疗慢-快型房室结折返性心动过速的报告

目的：探讨后位法射频导管消融（RFCA）治疗慢－快型房室结折返性心动过速9AVNRT）的有效性及安全性。方法：采用后位法RFCA对76例慢－快型AVNRT患进行慢径消融，其中，男24例，女52例。年龄18－62（平均42），岁，先从冠状窗口（Cso)下方的D区开始依次向Cso上方的C及B区寻找理想靶咪，进行试消融及巩固消融。结果：76例AVNRT中74例消融成功，成功率97．4％；并发症少，仅2例出现短时间I或Ⅱ度房室传导阻滞。结论：结果提示后位法射频导管消融是治疗慢－快型室结折返性心动过速安全，有效的方法。     

房室结折返性心动过速射频消融有关问题的探讨

房室结折返性心动过速 (AVNRT)的电生理机制基本明确 ,射频消融方法肯定 ,但仍存在一些问题值得探讨。笔者分析探讨了以下几个方面 :①慢径消融还是快径消融 ;②AVNRT消融中出现交界性心动过速 (JT) ;③AVNRT慢径消融终点与复发率问题 ;④疑难AVNRT的射频消融 ;⑤消融中慢径阻断的判断指标 ;⑥自发而未诱发的AVNRT的射频消融。希望能对AVNRT的射频消融有一个更明确的认识     

在临床实践中进行科研力求接近事物本质

本期刊登了王祖禄、Jackman WM、韩雅玲等两篇文章,“从慢慢型和慢快型房室结折返性心动过速电生理特性的差异分析折返环的不同”、“房室结折返性心动过速的可能折返机制和分型及其在指导慢径消融中的意义”,连同本刊2005年9卷1期17～24页发表的“慢慢型房室结折返性心动过速的电生理机制和射频导管消融治疗”.     

"Left-variant" atypical atrioventricular nodal reentrant tachycardia: electrophysiological characteristics and effect of slow pathway ablation within coronary sinus

Introduction: Recent anatomical and electrophysiological studies have demonstrated the presence of leftward posterior nodal extension (LPNE); however, its role in the genesis of atrioventricular nodal reentrant tachycardia (AVNRT) is poorly understood. This study was performed to characterize successful slow pathway (SP) ablation site and to elucidate the role of LPNE in genesis of atypical AVNRT with eccentric activation patterns within the coronary sinus (CS).
Methods and Results: Among 45 patients with atypical AVNRT (slow-slow/fast-slow/both = 20/22/3 patients) with concentric (n = 37, 82%) or eccentric CS activation (n = 8, 18%), successful ablation site was evaluated. Among 35/37 patients (95%) with concentric CS activation, ablation at the conventional SP region outside CS eliminated both retrograde SP conduction and AVNRT inducibility. Among eight patients with eccentric CS activation, the earliest retrograde atrial activation was found at proximal CS 16 ± 4 mm distal to the ostium during AVNRT. The earliest retrograde activation site was located at inferior to inferoseptal mitral annulus, consistent with the presumed location of LPNE. Ablation at the conventional SP region with electroanatomical approach only rendered AVNRT nonsustained without elimination of retrograde SP conduction in seven of eight patients (88%). Ablation targeted to the earliest retrograde atrial activation site within proximal CS (15 ± 4 mm distal to the ostium); however, eliminated retrograde SP conduction and rendered AVNRT noninducible in six of eight patients (75%).
Conclusion: In 75% of "left-variant" atypical AVNRT, ablation within proximal CS was required to eliminate eccentric retrograde SP conduction and render AVNRT noninducible, suggesting LPNE formed retrograde limb of reentrant circuit.     

Prediction of clinical recurrence of atrioventricular-nodal reentrant tachycardia (AVNRT) after successful slow pathway ablation.

BACKGROUND: Even after successful slow pathway (SP) ablation for atrioventricular-nodal reentrant tachycardia (AVNRT), there may be clinical recurrence in certain patients and it is clinically important to be able to predict that. METHODS AND RESULTS: In 97 patients with common type AVNRT, the effective refractory period (ERP) of the fast pathway (FP), SP-ERP, and prolongation of the atrio-His (AH) interval (AH) at the time of jump-up phenomenon were investigated. In patients with residual SP, parameters were re-evaluated in a similar manner. SP was successfully ablated and AVNRT was not inducible in all the patients, but residual SP was observed in 54 of the 97 patients, and there was late clinical recurrence in 10 patients (10/54 patients with residual SP and 0/43 without residual SP, p=0.002). The changes in FP-ERP before and after ablation (DeltaFP-ERP) did not differ between recurrent and non-recurrent patients. Among the patients with residual SP, DeltaSP-ERP did not differ between the groups. However, the changes in DeltaAH before and after ablation (DeltaDeltaAH) were larger in non-recurrent (24+/-30 ms) than in the recurrent patients (4+/-7 ms, p=0.042). CONCLUSIONS: In patients with AVNRT, the residual SP and changes in DeltaAH after successful SP ablation might be useful indices of clinical recurrence.     

Left-septal ablation of the fast pathway in AV nodal reentrant tachycardia refractory to right septal ablation.

In more than 95% of patients with atrioventricular nodal reentrant tachycardia (AVNRT), curative treatment can be achieved with selective ablation of the slow pathway in the right-sided septum. We report a patient with typical AVNRT who had failed attempts to perform conventional right septal ablation of the slow as well as of the fast pathway and finally underwent successful ablation of the fast pathway on the left side of the interatrial septum using a transseptal approach.     

Left atrionodal connections in typical and atypical atrioventricular nodal reentrant tachycardias: activation sequence in the coronary sinus and results of radiofrequency catheter ablation

INTRODUCTION: The presence of atrionodal connections and coronary sinus (CS) breakthrough in atrioventricular nodal reentrant tachycardia (AVNRT) has been suggested. However, the incidence, anatomic relationship with reentrant circuit, and results of catheter ablation are unknown. METHODS AND RESULTS: Fifty-two patients with typical slow/fast AVNRT and 10 patients with atypical slow/intermediate or fast/slow AVNRT were included. Eccentric activation of the CS (EACS) was observed in 3 of 52 patients with typical and 8 of 10 patients with atypical AVNRT. The earliest CS activation in patients with an EACS was recorded at a site 10-20 mm inside the CS ostium. The postpacing interval after transient entrainment at the proximal CS in patients with EACS was 23 +/- 21 msec longer than the pacing cycle length. Modification or ablation of the slow pathway was successful in all patients with typical slow/fast AVNRT and in 7 of 9 patients with atypical AVNRT by RF energy delivered at the right septal tricuspid annulus (TA). In 2 patients with atypical AVNRT and an EACS, RF delivery inside the CS targeting the earliest CS activation eliminated the sustained AVNRT. CONCLUSION: Eccentric coronary sinus activation is observed in some rare cases of typical AVNRT, and in a majority of atypical AVNRT. Entrainment results suggest that the proximal coronary sinus may be part of the reentrant circuit. RF ablation of atypical AVNRT, if it fails from the standard right-side approach, can be targeted at the site of earliest retrograde atrial activation inside the CS.     

Inducibility of atrial flutter in patients with atrioventricular nodal reentrant tachycardia.

BACKGROUND: Previous studies have shown that both atrioventricular nodal reentrant tachycardia (AVNRT) and atrial flutter (AFL) have an area of slow conduction located in the low posterior right atrium near the ostium of the coronary sinus. The aim of this study was to evaluate the inducibility of AFL in patients with AVNRT. METHODS AND RESULTS: One hundred and seventy patients were prospectively evaluated for inducibility of tricuspid valve - inferior vena cava isthmus-dependent AFL. Two groups of patients were analyzed: 71 patients with inducible AVNRT and 99 control patients without a history of AFL. AFL was induced in a greater percentage of patients with AVNRT (53%) than of control patients (27%, p<0.02). In all 21 patients with AVNRT and inducible AFL before slow pathway ablation, AFL was also inducible after slow pathway ablation. There was no difference in the cycle length of induced AFL before and after ablation. CONCLUSIONS: AFL was induced in a greater percentage of patients with AVNRT, suggesting that there may be a common area of posteroseptal perinodal atrium participating in the two-tachycardia circuits. However, radiofrequency ablation of the slow pathway of the AVNRT circuit does not influence the inducibility of AFL.     

Atrioventricular nodal reentrant tachycardia in children: effect of slow pathway ablation on fast pathway function

INTRODUCTION: Prior studies in adults have shown significant shortening of the fast pathway effective refractory period after successful slow pathway ablation. As differences between adults and children exist in other characteristics of AV nodal reentrant tachycardia (AVNRT), we sought to characterize the effect of slow pathway ablation or modification in a multicenter study of pediatric patients. METHODS AND RESULTS: Data from procedures in pediatric patients were gathered retrospectively from five institutions. Entry criteria were age <21 years, typical AVNRT inducible with/without isoproterenol infusion, and attempted slow pathway ablation or modification. Dual AV nodal pathways were defined as those with > or =50 msec jump in A2-H2 with a 10-msec decrease in A1-A2. Successful ablation was defined as elimination of AVNRT inducibility. A total of 159 patients (age 4.4 to 21 years, mean 13.1) were studied and had attempted slow pathway ablation. AVNRT was inducible in the baseline state in 74 (47%) of 159 patients and with isoproterenol in the remainder. Dual AV nodal pathways were noted in 98 (62%) of 159 patients in the baseline state. Ablation was successful in 154 (97%) of 159 patients. In patients with dual AV nodal pathways and successful slow pathway ablation, the mean fast pathway effective refractory period was 343+/-68 msec before ablation and 263+/-64 msec after ablation. Mean decrease in the fast pathway effective refractory period was 81+/-82 msec (P < 0.0001) and was not explained by changes in autonomic tone, as measured by changes in sinus cycle length during the ablation procedure. Electrophysiologic measurements were correlated with age. Fast pathway effective refractory period was related to age both before (P = 0.0044) and after ablation (P < 0.0001). AV block cycle length was related to age both before (P = 0.0005) and after ablation (P < 0.0001). However, in dual AV nodal pathway patients, the magnitude of change in the fast pathway effective refractory period after ablation was not related to age. CONCLUSION: Lack of clear dual AV node physiology is common in pediatric patients with inducible AVNRT (38%). Fast pathway effective refractory period shortens substantially in response to slow pathway ablation. The magnitude of change is large compared with adult reports and is not completely explained by changes in autonomic tone. Prospective studies in children using autonomic blockade are needed.     

Atypical atrioventricular nodal reentrant tachycardia with eccentric coronary sinus activation: electrophysiological characteristics and essential effects of left-sided ablation inside the coronary sinus.

BACKGROUND: The precise electrophysiological characteristics and essential effects of left-sided ablation in atrioventricular nodal reentrant tachycardia (AVNRT) with eccentric coronary sinus (CS) activation (ECSA) have not been described. OBJECTIVE: The purpose of this study was to elucidate the tachycardia characteristics and essential effects of left-sided ablation in AVNRT with ECSA. METHODS: Electrophysiological and ablation data were reviewed in 340 patients with all forms of AVNRT. RESULTS: Among 360 AVNRTs in the 340 patients, there were 23 atypical AVNRTs (6%; 12 slow-slow and 11 fast-slow) in 18 (5%) patients who exhibited ECSA with the earliest retrograde atrial activation 11 +/- 5 mm inside the CS. The patients with ECSA during the tachycardia were significantly younger than those without (38 +/- 18 vs. 51 +/- 18 years; P<.01). The presence of upper (UCP) and lower common pathways (LCP) was suggested in three (17%) and 18 (100%) patients, respectively. An ablation exclusively targeting the earliest retrograde atrial activation inside the CS eliminated the tachycardias with the elimination (n = 12) or modification of the left-sided slow pathway (SP) conduction (n = 6) without any complications. The entire reentrant circuit was considered to reside on the left side in two patients (11%) because the bidirectional SP conduction was simultaneously eliminated after the ablation inside the CS. CONCLUSIONS: Atypical AVNRT with ECSA involved the left-sided SP as a retrograde limb, and the reentrant circuit was more frequently associated with evidence that suggested a UCP and LCP. Ablation exclusively targeting the earliest retrograde atrial activation inside the CS was highly effective in this entity.