房室结折返性心动过速与房室折返性心动过速临床对比分析

阵发性室上性心动过速(PSVT)是临床常见的心律失常。我院从1993年4月至1997年12月经射频消融治疗PSVT189例,经心内电生理检查证实为房室结折返性心动过逮(AVNRT）(慢一快型)47例,占24盯％;房室折返性心动过逮(AVRT)142例．占75.13％。本就经心内电生理检查明确的AVRT的临床表现、体表心电图等方面做一对比分析。     

房室折返性心动过速合并房室结双径路的射频消融治疗

目的:探讨房室折返性心动过速(AVRT)合并房室结双径路(AVNDP)的电生理特征和射频消融术式的选择。方法:对640例阵发性室上性心动过速(PSVT)进行电生理检查,观察PSVT发作时传导的顺序,然后进行消融治疗。结果:640例PSVT中检出AVRT AVNDP 68例,检出率为10.6%;有8例诱发房室结折返性心动过速,对此类患者进行慢径消融治疗。随访所有经治患者均无复发。结论:AVRT合并AVNDP者阻断房室旁道是消融成功的关键;房室旁道作为"旁观者"时也应作房室旁道消融;如仅有(AH)跳跃但无心动过速者无需接受房室结改良。     

射频消融治疗房室结折返和房室折返性心动过速

目的：总结射频消融(RFCA)治疗房室结折返性心动过速和房窒折返性心动过速的经验。方法：分析67例阵发性室上性心律失常病人的RFCA过程；房室结折返性心动过速(AVNRT)49例，房室折返性心动过速(AVRT)18侧。结果：消融成功率98．5％，复发率1．5％，并发症发生率2．98％。结论：RFCA是治疗AVNRT和AVRT安全有效的方法。     

房室结折返性和房室折返性心动过速的对比研究

【目的】探讨房室结折返和房室折返性心动过速（AVNRT,AVRT）的特点及射频消融（RFCA）的疗效和安全性。【方法】回顾性分析本院近6年行RFCA的823例AVNRT和AVRT患者的临床和电生理特点及手术情况。【结果】AVRT较AVNRT多见．AVNRT女性多于男性,而AVRT男性多见（P〈0．01）。AVRT中左侧较右侧旁路多见。左侧旁路以隐匿性为主．而右侧旁路以显性为主（P〈0．01）;左侧旁路男性多见,而右侧旁路以女性为主（P〈0．01）。右侧显性旁路手术成功率明显低于其他旁路和AVNRT（P〈0．05和P〈0．01）．术后复发率明显高于左侧旁路（P〈0．05和P〈0．01）。2例AVNRT术后出现房室传导阻滞而植入心脏起搏器,发生气胸和血气胸6例。心包填塞1例．假性动脉瘤3例,1例左侧旁路放电时出现心室纤颤。无一例患者死亡。【结论】AVNRT和AVRT消融手术成功率高而复发率低．严重并发症较少．RFCA治疗AVNRT和AVRT是有效和安全的。     

房室结折返性心动过速的基础与临床

广义的室上性心动过速(SVT)指的是异位起搏点或折返环在希氏束分叉以上的心动过速。人类SVT的分类见表1,SVT的机理见表2。房室结折返性心动过速(AVNRT)为SVT的常见类型,占SVT的23.5％～63.5％,本文就其解剖基础、发病机理、电生理特点及治疗作一简述。     

房室结改良术治疗房室结折返性心动过速45例体会

通过采用房室结改良术（主要为下位法）对４５例房室结折返性心动过速患者的射频消融，分析了房室结改良术射频消融中靶点定位，放电功率和时间以及放电过程中要注意的一些经验教训及预防措施。     

房室结折返性心动过速与性别关系探讨

目的房室结折返性心动过速与性别关系研究。方法随机选取在我院住院治疗并经心脏电生理检查确诊的阵发性室上性心动过速患者85例与性别关系进行分析研究。根据发病原因将房室结折返性心动过速作为观察组,将房室折返性心动过速作为对照组。统计分析两组与性别关系。结果观察组差异有统计学意义(P<0.05),不同性别间快径有效不应期与房室跳跃值对比未显著高度差异(P>0.05);女性窦性心律周长、慢径有效不应期及心动过速周长均比男性低(P<0.05)。结论房室结折返性心动过速与性别有明显相关性。     

老年阵发性房室结折返性心动过速射频消融治疗的疗效分析

目的探讨老年阵发性房室结折返性心动过速射频消融治疗的有效性及安全性。方法回顾性分析我科采用射频消融治疗的425例阵发性房室结折返性心动过速患者的临床资料，比较年龄〈65岁组与≥65岁组患者一般情况、术前PR间期、AH间期、射频消融的成功率、操作时间、高度房室传导阻滞的发生率以及复发率。结果术前电生理检查结果≥65岁组的PR间期、AH间期明显长于〈65岁组，差异具有统计学意义。射频消融手术的操作时间、手术成功率、高度房室传导阻滞的发生率以及术后复发率2组差异无统计学意义。结论老年房室结折返性心动过速患者行慢径消融安全有效。     

阵发性房室结折返性心动过速患者慢径路消融治疗的临床分析

目的探讨射频消融慢径路治疗阵发性房室结折返性心动过速（AVNRT）的临床效果。方法回顾性分析425例采用射频消融治疗的AVNRT患者的临床资料。结果417例手术成功，成功率98．12％。4例（0．94％）出现高度房宣传导阻滞，2例（0．47％）因心室率较慢而安装永久性起搏器。随访6个月内有8例复发，复发率1．9％。结论选择性慢径路消融是成功治愈AVNRT安全有效的方法。     

不同亚型房室结折返性心动过速电生理学特点与射频消融

目的 从不同亚型房室结折返性心动过速电生理学特性及射频消融前后房室结快径前传不应期差异.探讨其电生理学机制.方法 178例慢快型房室结折返性心动过速患者中按消融完成顺序取连续30例,与慢慢型11例和快慢型8例,比较AH跳跃、心动过速时HA、△VA等电生理参数差异,以及射频消融术前后房室结快径前传不应期改变.结果 慢慢型患者AH跳跃明显小于慢快型及快慢型,HA、△VA介于后两型之间;慢快型及快慢型消融术后快径前传不应期显著缩短,慢慢型则有轻度延长趋势.结论 慢慢型房室结折返性心动过速电生理特性明显不同于慢快型及快慢型,消融前传慢径后房室结快径前传不应期未相应缩短,支持其折返环中尚存在逆传慢径.     

Specificity of Retrograde Conduction in Screening for Atrioventricular Nodal Reentrant Tachycardia

Baseline AV conduction properties (antegrade and retrograde) are often used to assess the presence of dual AV nodal physiology or concealed AV accessory pathways. Although retrograde conduction (RET) is assumed to be a prerequisite for AV nodal reentrant tachycardia (AVNRT), its prevalence during baseline measurements has not been evaluated. We reviewed all cases of AVNRT referred for radiofrequency ablation to determine the prevalence of RET at baseline evaluation and after isoproterenol infusion. Results: Seventy-three patients with AVNRT underwent full electrophysiological evaluation. Sixty-six patients had manifest RET and inducible AVNRT during baseline atrial and ventricular stimulation. Seven patients initially demonstrated complete RET block despite antegrade evidence of dual AV nodal physiology. In 3 of these 7 patients AVNRT was inducible at baseline despite the absence of RET. In the other four patients isoproterenol infusion was required for induction of AVNRT, however only 3 of these 4 patients developed RET. One of these remaining patients had persistent VA block after isoproterenol. Conclusions: The induction of AVNRT in the absence of RET suggests that this is not an obligatory feature of this arrhythmia. Therefore, baseline AV conduction properties are unreliable in assessing the presence of AVNRT and isoproterenol infusions should be used routinely to expose RET and reentrant tachycardia.     

Upper and Lower Common Pathways in Atrioventricular Nodal Reentrant Tachycardia:

The concepts of upper and lower common pathways represent long-standing controversies of atrioventricular nodal reentrant tachycardia (AVNRT). Over the last years there has been considerable evidence against the presence of a lower and, especially, an upper common pathway as distinct entities that can be identified in most patients with atrioventricular reentrant tachycardia. The mechanism and relevance of these concepts remain speculative.     

Feasibility and Safety of a Minimally Invasive Approach to Catheter Ablation for Atrioventricular Nodal Reentrant Tachycardia

This study assessed the feasibility and safety of a minimally invasive approach to catheter ablation in 72 consecutive patients with A V nodal reentrant tachycardia. A 3-catheter approach was used in the first 19 patients. In the other 53 patients, a 2-catheter approach was employed. Ablation was successful in all patients after a mean of 3 ± 3 RF applications. Procedure and fluoroscopy times were 62 ± 20 mins and 8 ± 5 mins respectively. Slow pathway was ablated in 43 patients (60%). Transient A V block occurred in 6 patients; there was no permanent AV block. These results suggest that it is feasible to perform ablation for AV nodal reentrant tachycardia safely and with high efficacy using a minimally invasive approach. This has the potential to lessen patient discomfort and to further shorten procedure and radiation exposure times.     

Effects of Pharmacological Autonomic Blockade on Dual Atrioventricular Nodal Pathways Physiology in Patients with Slow-Fast Atrioventricular Nodal Reentrant Tachycardia

The purpose of this study was to investigate the atrioventricular AV nodal physiology and the inducibility of AV nodal reentrant tachycardia (AVNRT) under pharmacological autonomic blockade (AB). Seventeen consecutive patients (6 men and 11 women, mean age 39 ± 17 years) with clinical recurrent slow-fast AVNRT received electrophysiological study before and after pharmacological AB with atropine (0.04 mg/kg) and propranolol (0.2 mg/kg). In baseline, all 17 patients could be induced with AVNRT, 5 were isoproterenol-dependent. After pharmacological AB, 12 (71 %) of 17 patients still demonstrated AV nodal duality. AVNRT became noninducible in 7 of 12 nonisoproterenol dependent patients and remained noninducible in all 5 isoproterenol dependent patients. The sinus cycle length (801 ± 105 ms vs 630 ± 80 ms, P < 0.005) and AV blocking cycle length (365 ± 64 ms vs 338 ± 61 ms, P < 0.005) became shorter after AB. The antegrade effective refractory period and functional refractory period of the fast pathway (369 ± 67 ms vs 305 ± 73 ms, P < 0.005; 408 ± 56 ms vs 350 ± 62 ms, P < 0.005) and the slow pathway (271 ± 30 ms vs 258 ± 27 ms, P < 0.01; 344 ± 60 ms vs 295 ± 50 ms, P < 0.005) likewise became significantly shortened. However, the ventriculoatrial blocking cycle length (349 ± 94 ms vs 326 ± 89 ms, NS) and effective refractory period of retrograde fast pathway (228 ± 38 ms vs 240 ± 80 ms, NS) remained unchanged after autonomic blockade. Pharmacological AB unveiling the intrinsic AV nodal physiology could result in the masking of AV nodal duality and the decreased inducibility of clinical AVNRT.     

Cryoablation for Presumed Atrioventricular Nodal Reentrant Tachycardia in Pediatric Patients

Background: Little data exist on the outcomes of cryoablation for the treatment of presumptive atrioventricular nodal reentrant tachycardia (AVNRT) in a pediatric population. Methods: We performed a retrospective chart review of patients undergoing cryoablation from January 2006 to October 2010 for presumed AVNRT at the Children's Hospital Colorado. Inclusion criteria were age ≤ 18, normal heart structure, no prior ablation procedures, documented narrow complex tachycardia, and no inducible tachycardia or other tachycardia mechanisms during electrophysiology study. Results: Thirteen patients underwent cryoablation for presumed AVNRT. Cryoablation catheter tip size varied from 4 to 8 mm with a median of eight cryoablation lesions. Isoproterenol was utilized preablation in 54% and none postablation. Procedural endpoints, per written report, were loss of sustained slow pathway, change in Wenckebach cycle length, and no specific endpoint. Procedural endpoints, per measured data, were a decrease in patients exhibiting sustained slow pathway conduction. Maximum atrial‐His (AH) interval with atrial overdrive pacing was reduced from 266 ms preablation to 167 ms postablation, p = 0.006. The number of patients with an AH jump was reduced from 6 to 2. After follow‐up of 13.8 ± 14.3 months, 23% (3/13) had documented tachycardia recurrence. No statistical significance was determined when comparing electrophysiology testing parameters pre‐ and postablation among the group with recurrence versus the group without recurrence. Conclusions: Cryoablation can be considered as a safe alternative to radiofrequency ablation for the treatment of presumed AVNRT among pediatric patients, albeit with a recurrence rate of 23%. (PACE 2012; 35:1319–1325)     

Ablation of Atrioventricular Nodal Reentrant Tachycardia in a Patient with Reversal of Slow and Fast Pathways Inputs into the Atrioventricular Node

We report a case of atrioventricular nodal reentrant tachycardia (AVNRT) coexistent with His bundle anomaly and atrial septal defects. The His‐bundle potential was recorded at the coronary sinus (CS) ostium. Fractionated atrial potentials and an A:V electrogram ratio 1:3 were recorded at the anterior septum of the tricuspid annulus approximately 2 cm from CS ostium. Radiofrequency catheter ablation at the anterior septum of the tricuspid annulus effectively eliminated AVNRT. (PACE 2012; 35:e17–e19)     

A Nodoventricular Fiber Associated with Dual AV Nodal Conduction, AV Nodal Reentrant Tachycardia, and Anterior Location of the Slow AV Nodal Pathway

We present a case of a patient with a nodoventricular tract, associated with dual AV nodal conduction and AV nodal reentrant tachycardia, and an anteroseptal location of the slow AV nodal pathway. The remarkable feature of this case is the site of successful ablation, in the anteroseptum just anterior and superior to the His bundle, where both preexcitation and dual AV nodal physiology were abolished.