Junctional ectopic rhythm after AVNRT ablation: An underrecognized complication.

BACKGROUND: Ablation is an effective treatment for atrioventricular nodal reentrant tachycardia (AVNRT). The occurrence of junctional ectopic rhythm (JER), including junctional ectopic tachycardia, following AVNRT ablation has been described as an extremely rare phenomenon, but may be underestimated. We aimed to determine the incidence of JER following AVNRT ablation within our institution, as well as that reported in the literature via an extensive review. METHODS: We reviewed our adult ablation institutional experience for the occurrence of JER after AVNRT ablation from 2009 to 2016. Additionally, we conducted an extensive literature search using different databases looking for AVNRT ablation case series. The individually reported complications of these studies were reviewed, with a primary endpoint defined as the occurrence of JER shortly after AVNRT ablation. The study was approved by our institutional review board. RESULTS: Our institutional data revealed 6/126 patients (prevalence 4.8%) developed non-preexisting JER post-AVNRT ablation. Four patients were asymptomatic. Two patients had persistent symptoms lasting over a year, with one patient requiring repeat ablation. The literature review included 149 adult and pediatric studies. There were three cases of reported JER, out of a total of 37,541 patients (31,768 adults and 5,773 pediatric; prevalence 0.008%). The three JER patients were pediatric, and all required further therapeutic intervention. CONCLUSION: JER might be an underreported complication of AVNRT ablation. It seems most often to be transient and self-limited, occurring days to weeks after ablation, but may also be debilitating, requiring more aggressive management.

Junctional Ectopic Tachycardia Localization and Procedural Approach using Cryoablation.

BACKGROUND: Idiopathic junctional ectopic tachycardia (JET) may still be difficult to control with antiarrhythmic therapy. Transcatheter ablation can be challenging and may be associated with a high risk of unintended atrioventricular block. The objective of this manuscript is to report the procedural technique, the location of the successful ablation, and the procedural characteristics while utilizing 3D mapping for cryoablation of JET. METHODS: A retrospective analysis was performed on all patients who had undergone cryothermal ablation for the treatment of JET at a single center. Patient, arrhythmia, and procedural information and long-term outcomes were evaluated. RESULTS: Thirteen patients with JET were treated by cryothermal ablation. The JET arrhythmia burden varied greatly, generally with inadequate control on medications. Left ventricular dilation was present in three patients, and one patient had dilated cardiomyopathy. The median age at the time of procedure was 13 years, with median weight of 54.1 kg. The ectopic focus was ablated in 11/13 patients within the lower 2/3 of the triangle of Koch (TOK) with cryotherapy. Ablations, which were not successful, low in the TOK were associated with substantially longer procedures, and had a higher risk of recurrence. There was late resolution of the arrhythmia in two of three acutely unsuccessful ablations. There were no complications. CONCLUSION: In the majority of patients JET can be safely ablated with the use of cryotherapy. Foci not identified in the lower 2/3 of the TOK are associated with longer procedures, more lesions, and decreased chance for long-term success.

Paradoxical responses to pacing maneuvers differentiating atrioventricular node reentrant tachycardia and junctional tachycardia.

A 40-year-old female presented at our hospital because of heart palpitations. During an electrophysiological study, atrioventricular (AV) conduction showed dual AV nodal physiology. Three types of supraventricular tachycardia (SVT) were induced. The initiation of SVT was reproducibility dependent on a critical A-H interval prolongation. An early premature atrial contraction during SVT repeatedly advanced the immediate His potential with termination of the tachycardia, indicating AV node reentrant tachycardia (AVNRT). However, after atrial overdrive pacing during SVT without termination of the tachycardia, the first return electrogram resulted in an AHHA response, consistent with junctional tachycardia. The mechanism of paradoxical responses to pacing maneuvers differentiating AVNRT and junctional tachycardia was discussed.

High-amplitude pace mapping increases safety of radiofrequency catheter ablation of parahisian ectopic foci.

BACKGROUND: The objective of the study is to assess the efficacy of high-amplitude pace mapping in terms of the atrioventricular (AV) block risk after radiofrequency catheter ablation (RCA) of parahisian ectopic foci. METHODS: Twenty patients aged 38 ± 14 years with no structural heart disease underwent RCA of parahisian ectopic foci. All the patients were randomized into two groups: Group I (n = 11) had RCA performed in the region defined as ectopic focus by electrophysiology study and Group II (n = 9) had high-amplitude pacing performed in the region of "perfect" mapping. RCA was done only at the sites where high-amplitude pacing revealed the absence of His bundle capture. RESULTS: In group I, the efficacy of RCA was 54.5% and it was 100% in group II (P = 0.0195). Group II had no complications; in group I there were 27% of AV blocks (P = 0.0893). The late recurrence of ectopic activity was comparable in both groups: 3 (27%) and 2 (22%), respectively (P = 0.7953). In all the cases of recurrent ectopic activity and in all the cases of ineffective primary procedure, group I had effective reablation procedures performed using high-amplitude pace mapping. The overall efficacy in terms of repeated procedures was 90%. CONCLUSION: High-amplitude pace mapping increases primary and secondary efficacy of parahisian ectopic foci RCA and decreases the risk of AV block development. (PACE 2012;35:1458-1463).

Outcomes of junctional ectopic tachycardia ablation in adult population-a multicenter experience.

PURPOSE: Idiopathic junctional ectopic tachycardia (JET) is typically refractory to antiarrhythmic agents. Catheter ablation for JET is feasible but is associated with high risk of unintended atrioventricular (AV) block. There is limited data on the appropriate procedural technique and clinical outcomes with catheter ablation for idiopathic JET in adults. METHODS: This is a multicenter, retrospective study of all adult patients (age ≥ 18 years) who underwent catheter ablation for idiopathic JET. Patient, procedural characteristics, and long-term outcomes were evaluated. RESULTS: Fifteen patients [radiofrequency ablation (RF) = 14 and cryoablation = 1) were treated with catheter ablation. The median age was 58 years with 67% males. All patients underwent mapping of the right atrium and the aortic cusps prior to energy delivery. The location of earliest activation in relation to the atrioventricular (AV) node was postero-superior in 73% (11/15), posterior in 13% (2/15), and superior in 13% (2/15) respectively. Acute success was 100%. Arrhythmia recurrence occurred in 53% (8/15) all of whom underwent a repeat ablation. High-grade AV block requiring permanent pacemaker occurred in 20% (3/15). At 12-month follow-up in the redo-ablation group, 37.5% (3/8) had recurrence of the arrhythmia two of which underwent a third ablation procedure. CONCLUSION: Catheter ablation of idiopathic JET in adults is associated with a high rate of recurrence requiring multiple procedures and high risk of AV block requiring a permanent pacemaker. Mapping and ablation of the non-coronary cusp can be considered as the arrhythmia was controlled in 3 patients with no inadvertent AV block.

Successful catheter ablation of reentrant junctional tachycardia in a patient with asplenia syndrome before total cavo-pulmonary connection.

Asplenia syndrome is commonly associated with complex structural cardiac malformations, and junctional tachycardia (JT), which may compromise hemodynamic status, has been reported in association with asplenia syndrome.(1) We report successful radiofrequency catheter ablation of reentrant JT in a patient with asplenia syndrome.

Remote magnetic catheter mapping and ablation of permanent junctional reciprocating tachycardia in a seven-year-old child.

BACKGROUND: Mapping and catheter ablation of permanent junctional reciprocating tachycardia (PJRT) in children can be challenging. Remote magnetic navigation may improve precise mapping and catheter stability during ablation, as well as reduce fluoroscopy time, especially in conjunction with a non-fluoroscopic mapping system. OBJECTIVE: We report a case of PJRT ablation in a 7-year-old child using remote magnetic navigation. METHODS AND RESULTS: Mapping of the right atrium (RA) and the coronary sinus (CS) and catheter ablation were performed using remote magnetic navigation in conjunction with a non-fluoroscopic mapping system (NavX). We observed excellent catheter steering abilities and constant wall contact during ablation, allowing a short and safe procedure. CONCLUSIONS: Remote magnetic navigation may be used for mapping and ablation of PJRT in children.

Cryoablation of congenital familial ectopic tachycardia with preservation of atrioventricular nodal function in an infant.

A 1-year-old child weighing 8 kg with familial congenital junctional ectopic tachycardia that was difficult to treat with antiarrhythmic medications underwent successful cryoablation with preservation of atrioventricular (AV) nodal function. This report describes a strategy of cryoablation in conjunction with a 3-D mapping system and the use of atrial overdrive pacing during cryothermal application to assess AV nodal function.

[Permanent junctional reciprocating tachycardia (PJRT) and dilated cardiomyopathy]. / Trajna spojna kruzna tahikardija (PJRT) i dilatacijska kardiomiopatija.

We present 14-year-old girl with permanent junctional reciprocating tachycardia which was refractory to medicamentous therapy, who also had dilated cardiomyopathy. She underwent successful radiofrequent catheter ablation of accessory pathway after wich the histologic changes in the myocardium were observed in the form of compensatory hypertrophy of cardiac muscle (cardiac remodelling). The question of cause and consequence appeared: whether the arrhythmia is a consequence of dilated cardiomyopathy, or it is tachycardia- induced cardiomyopathy. This particular issue is discussed in this article. Based on the diagnostic procedure and complete recovery of myocardium after catheter ablation of accessory pathway, it is obvious that the tachycardia was due to tachicardiomyopathy, i.e. cardiomyopathy caused by permanent reciprocating junctional tachycardia.

Transcatheter cryothermal ablation of junctional ectopic tachycardia in the normal heart.

BACKGROUND: Junctional ectopic tachycardia in the normal heart is rare and often is resistant to pharmacologic management. Transcatheter ablation using radiofrequency energy places the AV node at risk. OBJECTIVES: The purpose of this study was to report our experience with transcatheter cryothermal ablation using three-dimensional mapping in six patients with junctional ectopic tachycardia. METHODS: A review of clinical and electrophysiologic data was performed on all patients with structurally normal hearts who underwent cryothermal ablation for treatment of junctional ectopic tachycardia at two institutions. RESULTS: Six patients (age 7.7-36.5 years) underwent attempted transcatheter cryothermal ablation using three-dimensional mapping. Only one patient had achieved arrhythmia suppression on medical management. Cryothermal mapping (-30 degrees C) localized the junctional focus while normal conduction was monitored. The junctional focus was high in the triangle of Koch in four patients and was low in one patient. The sixth patient had only one run of junctional ectopic tachycardia during the procedure and therefore received an empiric cryoablation (-70 degrees C) lesion. Subsequent cryoablation lesions were delivered at and around the junctional focus. In one patient, cryomapping eliminated the junctional focus but resulted in transient complete AV block; therefore, cryoablation was not performed. All patients who received the cryoablation lesions had elimination of their junctional ectopic tachycardia at 6-week follow-up. The patient who did not receive a cryoablation lesion remained in a slower junctional rhythm at follow-up. CONCLUSION: Cryoablation of junctional ectopic tachycardia is safe and effective. Nonetheless, proximity to the His-Purkinje system may preclude success. Empiric cryoablation can be effective; cryotherapy may not yield immediate success, but a delayed salutary effect can follow.

[Permanent junctional reciprocating tachycardia causing cardiomyopathy in an adult woman]. / Permanente junktionale Reentrytachykardie als Kardiomyopathie-Ursache bei einer erwachsenen Frau.

A 35-year-old female was referred with progressive dyspnoea and elevated heart rate. Surface electrocardiography (ECG) showed supraventricular tachycardia (SVT) with long RP interval and inverse P waves. ECG revealed left ventricular dilation and severe systolic dysfunction. An electrophysiological (EP) examination was performed due to incessant SVT despite betablocker medication. Permanent junctional reciprocating tachycardia (PJRT) was diagnosed and successfully ablated. During follow-up, the patient's symptoms abated and ECG parameters normalized. PJRT is usually found in infants and children, but should also be considered as a rare cause of incessant SVT and tachycardiomyopathy in adults.

Junctional tachycardias: anatomic substrate and its significance in ablative procedures.

The conduction system was studied by serial section in three patients with intractable supraventricular tachycardias originating from the atrioventricular (AV) junction who died suddenly. The three patients were a 6 month old girl (Case 1), a 5 month old boy (Case 2) and a 22 year old woman (Case 3). The latter had a pacemaker inserted after surgical ablation of the AV node. The heart was hypertrophied and enlarged in all. In Case 1, the AV node was partly within the central fibrous body and there was a left-sided AV bundle with acute necrosis in the summit of the ventricular septum, adjacent to the AV node and bundle. In Case 2, the coronary sinus was displaced cranially close to the central fibrous body, resulting in abnormality of the latter, with entrapment, distortion and division of the AV node and bundle into two distinct components within the central fibrous body. In Case 3, a left-sided AV node was connected to the atrial septum. The right AV node was completely interrupted by sutures and the penetrating and branching bundle and bundle branches were markedly fibrosed. In addition, the atrial septum and summit of the ventricular septum showed marked inflammatory reaction with fibrosis, which was more marked on the right ventricular side. Histologic examination of the conduction system in all three cases demonstrated congenital abnormalities of the AV junction that may be related to the tachycardia. These findings emphasize the need to carefully evaluate the atrial septum and AV junctional area, including the coronary sinus, before ablative procedures are undertaken.(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical and electrophysiologic features and role of catheter ablation techniques in adult patients with automatic atrioventricular junctional tachycardia.

A total of 8 patients with junctional tachycardia (JT) were included for study. Patients with JT had a supraventricular arrhythmia that was initiated by a junctional complex without PR prolongation and episodes of atrioventricular (AV) dissociation. JT could not be initiated by pacing and occurred either spontaneously (3 patients) or with isoproterenol (5 patients). Tachycardia could be consistently terminated by either carotid sinus massage (1 patient), intravenous adenosine (2 patients), or critically timed ventricular premature complexes (3 patients). In 6 of the 8 other patients, tachycardia foci (atrial or ventricular) or mechanisms (AV node reentry) were found. Two patients underwent complete AV junctional ablation and 2 had termination of tachycardia without change in the AV conduction by perinodal application of radiofrequency lesions. AVJT appears to be due to abnormal automaticity and may be successfully ablated by application of radiofrequency energy to perinodal areas.

Selective catheter ablation of the tachycardia focus in patients with nonreentrant junctional tachycardia.

We describe a technique for ablation of junctional tachycardia focus by means of examining the earliest atrial activation sequence during tachycardia. The procedure was successful in 7 of 9 patients, and 1 developed complete atrioventricular block.

Life-threatening postoperative junctional ectopic tachycardia.

Junctional ectopic tachycardia developed in an infant after intraatrial repair of transposition of the great arteries. He failed to respond to medical management and, in moribund condition, underwent His bundle cryoablation. He survived and ultimately did well. Junctional ectopic tachycardia is not uncommon after open heart operations in children and may be lethal. Its genesis, diagnosis, and treatment are now well enough understood to allow successful treatment of nearly all patients.

Treatment of incessant reciprocating atrioventricular tachycardia by a closed heart surgical technique.

The case of a 40-year-old woman having disabling symptoms of incessant atrioventricular reciprocating tachycardia is reported. She underwent surgical therapy by a closed heart technique. Operative technique and the advantages of the epicardial approach in the present case are detailed.

Junctional ectopic tachycardia in six paediatric patients.

The presenting features and treatment responses of six children with junctional ectopic tachycardia are evaluated. Two of the patients were siblings and both presented in early childhood with cardiopulmonary failure. The elder sibling died, the surviving sibling was controlled on a combination of amiodarone, digoxin, and sotalol. The remaining four patients presented in later childhood with tachycardia induced cardiomyopathy. Two of the patients were diagnosed incidentally and have normalised their myocardial function on sotalol therapy. The other two presented in congestive cardiac failure. Radiofrequency His bundle ablation and insertion of a permanent pacemaker to control the arrhythmia was undertaken in the elder of the two patients. The remaining patient has had marginal recovery of myocardial function on a combination of amiodarone and sotalol treatment. Improvement in myocardial function may take several months and is dependent on control of the tachycardia in some patients. Sotalol, when used as single or combination treatment, was partially successful in four cases in reducing heart rate. None of the patients reverted to sinus rhythm.

Neonatal radiofrequency catheter ablation of junctional tachycardias.

Junctional tachycardias comprise several arrhythmia types with differing mechanisms, principally involving the region of the atrioventricular (A-V) junction. Neonatal radiofrequency catheter ablation has typically been reserved for life-threatening, drug-refractory cases due to the unique concerns regarding patient size and development. We performed radiofrequency catheter ablation on two neonates with incessant, rapid junctional tachycardias and hemodynamic compromise after failing conventional medical therapy. This report describes 2 neonates who underwent emergent radiofrequency catheter ablation, and compares these two patients to a larger pediatric catheter ablation patient cohort. Both neonates had an acutely successful outcome and were able to be discharged within a week of the ablation procedure. Fluoroscopy time and total procedure time were shorter in these two patients than in the course of the average pediatric catheter ablation. Though long-term developmental consequences of neonatal catheter ablation are yet unknown, in unique extreme situations, radiofrequency catheter ablation can be performed in neonates, as in older children and adults, without excessive acute morbidity.

Antegrade conduction over a concealed accessory pathway after His bundle catheter ablation.

The existence of unidirectional retrograde preexcitation or concealed bypass fibers and their role in paroxysmal supraventricular tachycardia have been known for a long time. However, the exact anatomic and physiological nature of this retrograde limb remains unclear. We report here on a patient who had a concealed accessory pathway (AP) with circus movement tachycardia. After His bundle catheter ablation the AP had the property to conduct in the antegrade direction. The absence of antegrade conduction over the AP before ablation is likely due to its decremental properties of conduction and to repetitive retrograde concealed conduction from the normal pathway.