Successful slow pathway ablation for atrioventricular nodal re-entrant tachycardia via a hypoplastic inferior vena cava in a patient with an azygos continuation

Catheter ablation of the slow pathway for atrioventricular nodalre-entrant tachycardia (AVNRT) is not always possible due tocongenital or acquired obstruction of the inferior vena cava(IVC). Although a superior access has been proposed as an alternativeapproach, a poor manoeuvrability and a lower stability of theablation catheter may be potential problems. We report a caseof slow pathway ablation for AVNRT in a patient with an azygoscontinuation using a hypoplastic but uninterrupted IVC.     

Cryothermal slow pathway modification for atrioventricular nodal reentrant tachycardia.

AIMS: Predictors of recurrence following transcatheter cryoablation for atrioventricular nodal reentrant tachycardia (AVNRT) are currently unknown. Our objective was to explore predictors of recurrence post-cryoablation for AVNRT, including the impact of procedural endpoints such as complete elimination of slow pathway conduction vs. persistent dual atrioventricular (AV) nodal physiology with or without echo beats. METHODS AND RESULTS: A single center cohort study was performed on patients undergoing a first cryoablation procedure for AVNRT between May 1999 and December 2004. Cryoablation for AVNRT was attempted in 185 consecutive patients (79.2% female), age 43.1 +/- 15.2 years. Acute success was achieved in 170 (91.9%) patients with 4.4 +/- 3.5 cryoapplications and a total procedural duration of 2.8 +/- 0.8 h. Complete elimination of slow pathway conduction was noted in 47.6% of acutely successful interventions, absence of AV nodal echoes despite dual AV nodal physiology in 8.8%, and presence of echoes but no inducible AVNRT on and off isoproterenol in 43.5%. Actuarial recurrence-free survival following acutely successful cryoablation at 1, 3, 6, 12, and 24 months was 94.8, 93.1, 91.7, 90.8, and 90.8%, respectively. Independent predictors of recurrence were younger age (P = 0.0045) and valvular heart disease (P = 0.0186). The achieved procedural endpoint did not modulate recurrence rates. Eight patients (4.3%) experienced transient third degree AV block; none required permanent pacing. CONCLUSIONS: As a cryoablation procedural outcome for AVNRT, persistent dual AV nodal physiology with or without echo beats is not associated with higher recurrence rates than complete elimination of dual AV nodal physiology if AVNRT remains non-inducible on and off isoproterenol.     

经上腔静脉途径行房室结慢径消融24例疗效分析

经股静脉途径行房室结慢径消融(RFCA)术后常需压迫止血、卧床制动等有可能引起下肢静脉血栓等并发症。为此,我院从2007年始开展经上腔静脉途径行房室结慢径消融术,现报道如下。1资料和方法1.1病例选择选择我院2007—2011年临床上有阵发性     

Atrioventricular nodal reentrant tachycardia associated with idiopathic ventricular tachycardia: clinical and electrophysiologic characteristics

Background

Case reports have described the coexistence of ventricular tachycardia (VT) and supraventricular tachycardia in the same patient. This study examines the frequency of dual atrioventricular nodal (AVN) physiology, AVN echo beats, and atrioventricular nodal reentrant tachycardia (AVNRT) in patients with VT.

Methods

Programmed atrial and ventricular stimulation was performed in 132 consecutive patients referred for electrophysiologic study of symptomatic VT. Of the 132, 99 patients had structural heart disease, and 33 patients had idiopathic ventricular tachycardia (IVT).

Results

Among the 33 patients with IVT, 23 had dual AVN physiology. Compared with patients with structural heart disease undergoing VT ablation, dual AVN pathways (70% vs 27%, P < .0001), dual AVN pathways with echo beats (24% vs 8%, P = 0.03), and AVNRT (21% vs 1%, P = .0002) were more common in patients with IVT.

Conclusion

Dual AVN physiology and AVNRT appear to be associated with IVT. This finding suggests that patients with IVT should undergo a complete electrophysiologic evaluation, and the diagnosis of coexistent AVNRT should be considered in this population.     

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。     

中位法射频消蚀慢径路治疗房室结折返性心动过速

导管射频消蚀术（ＲＦＣＡ）治疗房室结折返性心动过速４３例，采用＂中位法＂选择性阻断慢径路，该技术的关键是：①在Ｘ线右前斜位３０度下，将消蚀电极置于冠状窦口和希氏束连线的中点附近；②消蚀电极双极记录到小Ａ大Ｖ波；③放电时有交界性心律（包括快交界律、慢交界律、交界性早搏）；④以间断放电和时间递增的方法控制消蚀过程；⑤消蚀终点为放电总累积时间达６０～９０秒，重复电生理检查证实慢径阻断或心动过速不能诱发。经１～３个部位的消蚀彻底阻断慢道３６例，遗留慢径传导７例（有心房回波２例）。除１例术后第二天发生一过性Ⅲ°ＡＶＢ，二周恢复正常外，余无并发症发生，随访３～２４个月（平均１４±６），停用任何抗心律失常药，无心动过速发作。消蚀成功率１００％。认为“中位法”是消蚀房室结慢径路治疗房室结折返性心动过速的安全、简便和有效的方法，部分病例保留慢传导并不增加复发率。     

房室折返和房室结折返性心动过速患者的个性分析

目的探讨房室折返性心动过速(AVRT)和房室结折返性心动过速(AVNRT)患者的个性特征。方法采用龚耀先修订的艾森克个性问卷量表,对83例AVRT、105例AVNRT患者射频消融前后和50例对照组正常人的精神质(P)、内外向(E)、情绪稳定性(N)和掩饰倾向(L)值进行测量。结果射频消融前后,各组之间的P、E、N和L值相比较差异无显著性(P>0.05);射频消融前后AVNRT组内女性患者的N分值较男性高(分别为12.93±2.83vs9.88±2.61;12.84±2.87vs9.87±2.64;P均<0.05)。结论AVNRT女性患者具有神经质倾向,这可能是在AVNRT中女性占多数的原因之一。     

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。     

射频消融慢径治疗程控不能诱发且没有跳跃的房室结折返性心动过速

目的:评价射频消融慢径治疗程控不能诱发且没有跳跃的房室结折返性心动过速(AVNRT)患者的远期疗效,探讨其电生理机制.方法:临床证实的AVNRT患者101例,在电生理检查中18例程控不能诱发及没有跳跃(A组),19例程控不能诱发(B组),33例程控没有跳跃(C组),31例程控有跳跃并且能诱发(D组).比较各组电生理的情况及射频消融治疗的远期疗效.结果:术后随访(49.13±30.13)个月,C组1例于术后2个月复发,发生Ⅲ度房室传导阻滞而安装起搏器,D组1例于手术后7个月复发,A、B、C、D组的未复发率均差异无统计学意义(P＞0.05).A、B组与C、D组相比快径逆传功能相对较差,术前B组的快慢径不应期差值较D组小,各组有效消融后交界心律的发生率差异无统计学意义.结论:慢径消融在治疗程控不能诱发及没有跳跃的AVNRT患者是安全有效的.交界性心律可以作为该类患者的射频消融的参考终点.     

Clinical and electrophysiological characteristics in patients with atrioventricular reentrant and atrioventricular nodal reentrant tachycardia.

AIM: To compare clinical, electrophysiological characteristics and transcatheter ablation results between two groups of patients, one with atrioventricular reentrant tachycardia (AVRT) and the other with atrioventricular nodal reentrant tachycardia (AVNRT). METHODS: The study population consisted of 94 consecutive patients who underwent endocavitary electrophysiological study and radiofrequency (RF) ablation: 46 patients had AVRT due to an accessory pathway with only retrograde conduction while 48 patients had AVNRT. RESULTS: In relation to general and clinical characteristics, differences between the two groups emerged regarding the age of symptom onset (25+/-16 vs 37+/-17 years, p=0.001), the prevalence of heart disease (8 vs 31%, p=0.001) and the correct diagnosis on surface ECG (50 vs 79%, p=0.001). Clinical presentation was quite similar apart from a higher prevalence of fatigue and sweating in the AVNRT group. Transcatheter RF ablation therapy results were similar. CONCLUSIONS: Patients with AVRT have a lower mean age at arrhythmia symptom onset compared with those with AVNRT and have fewer associated cardiac abnormalities. Clinical presentation is quite similar as well as their outcome after ablation. A correct diagnosis by standard ECG is more frequent in AVNRT.     

Shift in the earliest retrograde atrial activation site during the fast–slow form of atrioventricular nodal reentrant tachycardia after the radiofrequency modification of the atrioventricular node: is the atrium a necessary link?

Whether or not the perinodal atrium forms an upper link in the tachycardia circuit of the atypical form of AV nodal reentrant tachycardia (AVNRT) is controversial. We report a case with the fast-slow form of AVNRT in whom the earliest retrograde atrial activation site during the tachycardia changed from the right inferoseptum to the right superoseptum close to the His bundle without a change in the tachycardia cycle length following the radiofrequency energy applications to the earliest retrograde atrial activation site. It was speculated that a sub-atrial reentry with multiple atrial breakthroughs was the possible tachycardia mechanism in the present case.     

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。     

Cryoablation outcomes for AV nodal reentrant tachycardia comparing 4-mm versus 6-mm electrode-tip catheters

BACKGROUND: Cryoablation is increasingly used to treat atrioventricular nodal reentrant tachycardia (AVNRT). It is unknown whether larger electrode-tip cryocatheters improve outcomes without compromising safety. OBJECTIVE: This study sought to compare acute and long-term success with 4-mm versus 6-mm electrode-tip cryocatheters for AVNRT. METHODS: We conducted a 2-group cohort study on 289 patients, age 45.5 +/- 15.9 years (76.8% female), who underwent transcatheter cryoablation as a first-time procedure for AVNRT with 4-mm (N = 152) or 6-mm (N = 137) electrode-tip catheters. RESULTS: Acute procedural success was achieved in 90.7% (95% confidence interval 86.9% to 93.7%) with no difference between the 2 electrode-tip sizes. A shorter fluoroscopy time (16.1 +/- 11.3 versus 20.3 +/- 14.9 minutes, P = .0096) and trend toward briefer procedural duration (166.6 +/- 49.1 versus 173.5 +/- 53.0 minutes, P = NS) were noted with 6-mm electrode tips. Transient AV block occurred in 5.2%, with complete recovery in 4.4 +/- 2.6 seconds. Over a median follow-up of 155 days, recurrences were less common with 6-mm electrode tips. Actuarial event-free survival rates at 1, 3, 6, and 12 months with 6-mm versus 4-mm electrode-tip cryocatheters were 96.7%, 93.4%, 91.9%, and 88.5% versus 89.9%, 87.0%, 84.1%, and 77.1%, respectively, with no recurrence thereafter (P = .0457). In multivariate analyses adjusting for baseline imbalances and medical therapy postablation, cryoablation with a 4-mm-tip catheter incurred a 2.5-fold increased risk of recurrence (hazard ratio 2.5, 95% confidence interval 1.0 to 6.1, P = .0420). CONCLUSION: In patients with AVNRT, cryoablation with 6-mm electrode-tip catheters is safe and is associated with fewer recurrences on long-term follow-up compared with 4-mm electrode-tip cryocatheters.     

AV nodal reentrant tachycardia using three different AV nodal pathways

In a patient with frequent paroxysmal supraventricular tachycardia, an electrophysiologic study was performed. Although by programmed atrial stimulation only double AV nodal pathways could be documented, three distinct forms of AV nodal reentrant tachycardia could be induced. By programmed atrial stimulation a typical AV nodal reentrant tachycardia was initiated, by programmed ventricular stimulation, an AV nodal reentrant tachycardia was induced with an antegrade conduction time of 215 ms and a retrograde conduction time of 160 ms. Furthermore, a third form of tachycardia was induced with alternating cycle length due to two different antegrade conduction times, whereas retrograde conduction time was almost identical, irrespective of the antegrade conduction time. The patient received betaxolol (20 mg day-1); during a second electrophysiologic study, the tachycardia could not be induced, and it did not occur spontaneously during a follow-up period of 14 months.     

Slow pathway ablation in a patient with common AV nodal reentrant tachycardia and complete situs inversus.

A 72-year-old woman with complete situs inversus underwent successful slow pathway ablation of typical AV nodal reentrant tachycardia. Catheter ablation of AV nodal reentrant tachycardia in dextrocardia required a lengthy procedure but was safe and without complications.     

射频消融治疗儿童房室结折返性心动过速的体会

目的　讨论射频消融术 (RFCA)治疗儿童房室经折返性心动过速的体会。方法　 1992年 3月至 2 0 0 1年 12月 ,应用射频消融术 (RFCA)治疗儿童房室结折返性心动过速共 5 2例 ,男 3 0例 ,女 2 2例 ,平均年龄 (8 4± 3 2 )岁 (3 5～15岁 )。全部病例均行食道心房调搏术及心内电生理检查 ,选择消融慢径路。结果　食道心房调搏术S2 R跳跃延长(63 1± 10 3 )ms(5 0～ 110ms) ,心内电生理检查AH跳跃延长 (5 2 4± 15 8)ms(3 0～ 10 5ms)。总消融成功率 97 6% ,输出功率 (18 2± 3 2 )W ,放电次数 (12 1± 4 2 )次 ,手术时间(1 5± 0 5 )h ,X线曝光时间 (18 5± 5 4)min。结论　射频消融术治疗儿童房室结折返性心动过速是安全、有效的 ,但应严格掌握适应证     

Cryoablation versus radiofrequency ablation for treatment of pediatric atrioventricular nodal reentrant tachycardia: Initial experience with 4-mm cryocatheter

BACKGROUND: Initial reports have shown cryoablation to be safe and efficacious for treatment of atrioventricular nodal reentrant tachycardia (AVNRT). No direct comparisons of cryoablation vs radiofrequency (RF) catheter ablation in pediatric patients have been made. OBJECTIVES: The purpose of this study was to compare the outcomes of cryothermal vs RF catheter ablation for treatment of AVNRT in pediatric patients. METHODS: We retrospectively reviewed consecutive ablation procedures for treatment of AVNRT at a single arrhythmia center. The RF group consisted of patients who underwent RF ablation from 2002 until cryothermy became available. The cryoablation group consisted of patients who underwent cryothermal ablation from 2004 to 2005. The groups were compared for procedural and electrophysiologic outcomes. RESULTS: RF (n = 60, age 14 +/- 4 years) and cryoablation (n = 57, age 14 +/- 4 years) groups had similar demographic and baseline parameters. Procedural times were shorter in the RF group (RF ablation 112 +/- 31 minutes vs cryoablation 148 +/- 46 minutes, P < .001). Fluoroscopy times were comparable (RF ablation 21 +/- 15 minutes vs cryoablation 20 +/- 13 minutes, P = .77). In an intention-to-treat analysis, success of the procedure was 100% for RF ablation and 95% for cryoablation (P = .11). No permanent AV block occurred in either group. Recurrence rates were higher for the cryoablation group, but this did not reach statistical significance (RF ablation 2% vs cryoablation 8%, P = .19). CONCLUSION: Cryoablation appears to be similar to RF for ablation of AVNRT with respect to short-term efficacy and safety of the procedure in a pediatric population. Recurrence rates are higher with cryoablation.