Radiofrequency ablation in a patient with atrioventricular reentrant tachycardia and atrioventricular nodal reentrant tachycardia with 2:1 atrioventricular block.

The authors report the case of 15-year-old girl with a history of palpitations and shortness of breath during exercise. The electrocardiogram showed ventricular preexcitation suggesting a Wolff-Parkinson-White syndrome with a posteroseptal accessory pathway. During the electrophysiological study a left posterospetal accessory pathway was identified and an orthodromic atrioventricular reentry tachycardia was reproducibly induced (cycle length 400 ms). After disappearance of the ventricular pre-excitation with radiofrequency ablation, a dual physiology of atrioventricular node condution was documented and a slow-fast atrioventricular nodal reentrant tachycardia was repeatedly induced. Upon induction, this tachycardia presented a proximal atrioventricular block with 2:1 condution converted to 1:1 condution with overdrive pacing from the proximal coronary sinus (cycle length 270 ms). Radiofrequency ablation of the slow pathway was performed with success. We discuss the need to suspect and seek different arrhythmogenic substracts of tachycardia in a single patient, the electrophysiologic conditions that could explain the inducibility of different arrhythmias in this case, and the controversy regarding ablation of more than one reentry circuit in a single procedure.     

A case of atrioventricular nodal reentrant tachycardia with atresia of the coronary sinus ostium

We report a case of atrioventricular nodal reentrant tachycardia coexistent with atresia of the coronary sinus ostium. Radiofrequency current application between the supposed coronary sinus ostium and the tricuspid valve was effective at eliminating the tachycardia. A coronary venogram obtained by left coronary arteriography was useful for guiding the mapping catheter to the successful ablation site.     

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。     

The atrioventricular nodal reentrant tachycardia circuit: a proposal.

Several models of the atrioventricular nodal reentrant tachycardia circuit have been proposed. Recently, there has been experimental and clinical electrophysiology evidence that the right and left inferior extensions of the human atriventricular node and the atrionodal inputs they facilitate may provide the anatomic substrate of the slow pathway. Inferior nodal extensions appear to constitute a necessary limb of the tachycardia circuit in all forms of atrioventricular nodal reentrant tachycardia and represent the ablation target for all forms of this arrhythmia. Anatomic variations of multiple atrionodal inputs via atrial transitional cells may create the conditions for tachycardia inducibility and differing patterns of retrograde atrial activation. In the present article, we summarize the available evidence and propose a comprehensive model of the tachycardia circuit for all forms of atrioventricular nodal reentrant tachycardia based on the concept of atrionodal inputs.     

Fast-slow and slow-slow form of atrioventricular nodal reentrant tachycardia sustained by the same reentrant circuit: a case report.

It has been suggested that a reentrant circuit confined to the posterior extensions of the atrioventricular node underlies both fast-slow and slow-slow types of atrioventricular nodal reentrant tachycardia (AVNRT). According to this hypothesis the fast-slow reentrant circuit would be formed by two slow pathways, located in the rightward and leftward posterior extension of the atrioventricular node. Thus, the fast pathway would act as a bystander with respect to the reentrant circuit. We describe the case of a 40-year-old woman with several episodes of palpitations unresponsive to antiarrhythmic drugs. The ECG during symptoms showed a narrow QRS tachycardia with a long ventriculo-atrial interval and a negative P wave in the inferior leads. Electrophysiological study showed the inducibility of a slow-slow AVNRT which rapidly shifted to a fast-slow AVNRT without any change in the duration of the tachycardia cycle. Our observation is in agreement with the hypothesis that the fast-slow reentrant circuit consists of two slow pathways with the fast pathway acting as a bystander.     

Unusual variant of atrioventricular nodal reentrant tachycardia.

Electrophysiologic study in a patient with supraventricular tachycardia revealed an unusual activation pattern in the coronary sinus (CS) electrodes. Pacing maneuvers confirmed the tachycardia was a slow-slow AV nodal reentrant tachycardia with double potentials in the distal CS electrodes due to an earlier left atrial signal (50 ms) and later CS musculature activation. The left-sided AV nodal inputs were successfully ablated from within the CS.     

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.     

房室结折返性心动过速患者的室房阻滞现象

目的分析经射频消融术证实的房室结折返性心动过速(AVNRT)患者基础状态下的室房(VA)阻滞和心动过速发作时心房侧传导阻滞现象的电生理特点和鉴别诊断方法。方法对行射频消融术治疗的861例AVNRT患者基础状态下和心动过速时伴有VA阻滞的患者的临床和电生理参数进行分析,并与同期不伴逆传阻滞的AVNRT患者进行对比。结果基础状态下心室起搏频率140次/分以下出现VA阻滞者53例,其中120次/分以下阻滞者37例,与无VA阻滞组相比男性比例增多,52例未能诱发心动过速,应用异丙肾上腺素后50例可诱发心动过速。心动过速发作时2例可见到心房侧的传导阻滞现象。结论部分AVNRT患者中在基础状态下可见VA阻滞现象,此时需要异丙肾上腺素等药物改善室房传导以诱发心动过速。心动过速发作时可见到心房侧传导阻滞现象,需仔细鉴别以明确诊断。     

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.     

非跳跃性房室结功能曲线的房室结折返性心动过速消融成功的电生理特点

目的 :探讨呈非跳跃性房室结功能曲线 (AVNFC)的房室结折返性心动过速 (AVNRT)射频消融成功的电生理特点。方法 :将 75例AVNRT患者分为 3组 :A组 16例 ,心房递增起搏和A1A2 程序刺激均呈非跳跃性AVNFC ;B组 10例 ,仅心房递增起搏呈跳跃性AVNFC ;C组 4 9例 ,心房递增起搏和A1A2 程序刺激均呈跳跃性AVNFC。比较 3组患者射频消融前后组内及组间的电生理参数。结果 :消融后 3组患者心房递增起搏时最大AH间期 (A1H1max)均比消融前显著缩短 (P <0 .0 5 )。A组消融前、后A1H1max的缩短程度均小于B组和C组 (P <0 .0 5 )。A组非典型AVNRT的诱发率明显高于B组和C组。结论 :对于心房递增起搏和A1A2 程序刺激均呈非跳跃性AVNFC的AVNRT患者 ,消融后A1H1max的显著缩短可作为消融成功的指标之一。AVNFC呈非跳跃性的房室结双径路患者易诱发非典型AVNRT。     

Characterizing dual atrioventricular nodal physiology in pediatric patients with atrioventricular nodal reentrant tachycardia

INTRODUCTION: Dual atrioventricular (AV) nodal physiology, defined as an AH jump > or =50 msec with a 10 msec decrease in A1A2, is the substrate for atrioventricular nodal reentrant tachycardia (AVNRT) and yet it is present in a minority of pediatric patients with AVNRT. Our objective was to characterize dual AV nodal physiology as it pertains to a pediatric population. METHODS/RESULTS: We retrospectively reviewed invasive electrophysiology studies in 92 patients with AVNRT (age12.1 +/- 3.7 yrs) and in 46 controls without AVNRT (age 13.3 +/- 3.7 yrs). Diagnoses in controls: syncope (N = 31), palpitations (N = 6), atrial flutter (N = 3), history of atrial tachycardia with no inducible arrhythmia (N = 3), and ventricular tachycardia (N = 3). General anesthesia was used in 49% of AVNRT and 52% of controls, P = 0.86. There were no differences in PR, AH, HV, or AV block cycle length. With A1A2 atrial stimulation, AVNRT patients had a significantly longer maximum AH achieved (324 +/- 104 msec vs 255 +/- 67 msec, P = 0.001), and a shorter AVNERP (276 +/- 49 msec vs 313 +/- 68 msec P = 0.0005). An AH jump > or =50 msec was found in 42% of AVNRT versus 30% of controls (P = 0.2). Using a ROC graph we found that an AH jump of any size is a poor predictor of AVNRT. With atrial overdrive pacing, PR > or = RR was seen more commonly in AVNRT versus controls, (55/91(60%) vs 6/46 (13%) P = 0.000). CONCLUSIONS: Neither the common definition of dual AV nodes or redefining an AH jump as some value <50 msec are reliable methods to define dual AV nodes or to predict AVNRT in pediatric patients. PR > or = RR is a relatively good predictor of AVNRT.     

Development of multiform ventricular tachycardia during atrioventricular nodal reentrant tachycardia.

A woman of 18 presented with a supraventricular tachycardia, subsequently shown to be caused by atrioventricular nodal reentry, which abruptly deteriorated to a multiform ventricular tachycardia. She had not received any antiarrhythmic drugs nor did she have any of the disorders that are usually associated with this atypical ventricular tachycardia.     

Quadruple atrioventricular nodal pathways: involved in orthodromic atrioventricular reentrant tachycardia

Supraventricular tachycardia can be caused by multiple atrioventricular nodal pathways or atrioventricular accessory pathways. Herein, we report the case of a patient who was diagnosed with an orthodromic atrioventricular reentrant tachycardia that was caused by an unusual combination of quadruple atrioventricular nodal pathways and an atrioventricular accessory pathway. Radiofrequency catheter ablation of the accessory pathway successfully eliminated the arrhythmias and the patient's symptoms. Careful analysis of complete electrophysiologic studies can help in the diagnosis of such rare clinical presentations.     

冷冻消融治疗房室结折返性心动过速中的房室阻滞现象

消融术中房室阻滞(AVB)是临床上常见且较严重的并发症.本文就冷冻消融治疗房室结折返性心动过速(AVNRT)中出现的一过性AVB现象进行探讨.     

Clinical management of patients with atrioventricular nodal reentrant tachycardia

A broad array of therapeutic options is currently available for the management of patients with AV nodal reentrant tachycardia. While acute termination of tachycardias is readily achieved, either by vagal maneuvers or intravenous medication, the decision to embark on a long-term therapeutic plan to prevent recurrences must be clinically individualized. When a chronic pharmacologic approach is desired, electrophysiologic testing is invaluable for confirming the diagnosis and selecting appropriate medication. However, the growing awareness of potential proarrhythmic effects and the inconvenience and expense of lifelong drug therapy, coupled with other advances in the field, have made nonpharmacologic approaches more attractive. This is especially so for symptomatic younger patients. The definitive cure rates achievable with surgery are now being approached by transcatheter AV nodal modification procedures that ablate AV nodal reentrant tachycardia while preserving anterograde AV nodal conduction. Over the next decade, it is likely that the latter technique will become widely used for the long-term management of symptomatic AV nodal reentrant tachycardia.