Local VA index for the differential diagnosis of supraventricular tachycardia.

BACKGROUND: Differentiating between atypical atrioventricular nodal reentrant tachycardia (AVNRT) and orthodromic reciprocating tachycardia utilizing a septal accessory pathway is a complex challenge. OBJECTIVE: The purpose of this study was to describe the "local VA index," a straightforward method based on signals from the coronary sinus catheter, to distinguish between these arrhythmias during tachycardia and entrainment. The ventriculoatrial (VA) interval on the coronary sinus catheter is measured during tachycardia and entrainment, at the site of earliest atrial activity. The difference between these 2 situations defines the "local VA index." We also propose a mechanism to clarify the limitations of historical pacing maneuvers, such as postpacing interval minus tachycardia cycle length (PPI-TCL) and stimulus-atrial interval minus ventriculoatrial interval (SA-VA), by examining nodal decrement and intraventricular conduction delay. METHODS: In a retrospective study of 75 patients referred for supraventricular tachycardia evaluation, 37 were diagnosed with atrioventricular reentrant tachycardia (AVRT) with orthodromic reciprocating tachycardia, and 38 with AVNRT (27 typical, 11 atypical). RESULTS: In comparison to AVRT patients, AVNRT patients exhibited longer PPI-TCL (176 ± 47 ms vs 113 ± 42 ms; P <.01) and SA-VA (138 ± 47 ms vs 64 ± 28 ms; P <.01). The AVRT group had mean local VA index of -1 ± 13 ms, whereas the AVNRT group had a significantly longer index of 91 ± 46 ms (P <.01). An optimal threshold for differentiation was a local VA index of 40 ms. Importantly, there was no significant correlation between pacing cycle length and nodal decrement as well as intraventricular delay related to pathway location. This interindividual variability might explain misleading interpretations of PPI-TCL and SA-VA. CONCLUSION: This novel approach is advantageous because of its simplicity and effectiveness, requiring only 2 diagnostic catheters. A local VA interval difference <40 ms provides a clear distinction for AVRT.

Antidromic and orthodromic reciprocating tachycardias over a novel left-sided accessory pathway involving the vein of Marshall and coronary sinus musculature.

INTRODUCTION: Herein, we present a rare case of the successful ablation of an accessory pathway (AP) involving the Marshall Bundle (MB) and coronary sinus musculature (CSM) in a 40-year-old man with Wolff-Parkinson-White syndrome. METHODS AND RESULTS: An orthodromic reciprocating tachycardia (ORT) was inducible with the earliest atrial activation site located at the posterolateral mitral annulus. The local conduction and the cycle length of ORT was prolonged by peri-mitral ablation; however, it failed to block the AP. The atrial insertion of the AP was identified by remapping during ORT at the left atrial ridge, which was away from the mitral annulus, where ablation was successful. Together with the electrophysiological findings in CSM potentials, we conclude that the epicardial MB-CSM connection functioned as the AP in this patient. CONCLUSION: The novel variant form of AP comprised of MB and CSM should be noted. The atrial insertion of the MB may be the target of catheter ablation.

Fetal permanent junctional reciprocating tachycardia with dilated cardiomyopathy, normal heart rate and transient fetal hydrops; a case report.

Permanent junctional reciprocating tachycardia (PJRT) is a rare form of congenital arrhythmia occurring predominantly in infants and children. Prenatal presentation is frequently characterized by incessant tachycardia leading to dilated cardiomyopathy (DCM). Some patients can have a normal heart rate which leads to a delayed diagnosis. We report a case of a neonate who was presented prenatally with DCM, fetal hydrops, and no signs of fetal arrhythmia. Diagnosis of PJRT was established after delivery with characteristic electrocardiographic patterns. Successful conversion to sinus rhythm with digoxin and amiodarone was achieved three months later. At 16 months of age, both echocardiography and electrocardiography were normal.

Variability of the VA interval at tachycardia induction: a simple method to differentiate orthodromic reciprocating tachycardia from atypical atrioventricular nodal reentrant tachycardia.

BACKGROUND: The differential diagnosis between orthodromic atrioventricular reentry tachycardia (AVRT) and atypical AV nodal reentrant tachycardia (aAVNRT) is sometimes challenging. We hypothesize that aAVNRTs have more variability in the retrograde conduction time at tachycardia onset than AVRTs. METHODS: We aimed to assess the variability in retrograde conduction time at tachycardia onset in AVRT and aAVNRT and to propose a new diagnostic tool to differentiate these two arrhythmia mechanisms. We measured the VA interval of the first beats after tachycardia induction until it stabilized. The difference between the maximum and minimum VA intervals (∆VA) and the number of beats needed for the VA interval to stabilize was analyzed. Atrial tachycardias were excluded. RESULTS: A total of 107 patients with aAVNRT (n = 37) or AVRT (n = 64) were included. Six additional patients with decremental accessory pathway-mediated tachycardia (DAPT) were analyzed separately. All aAVNRTs had VA interval variability. The median ∆VA was 0 (0 - 5) ms in AVRTs vs 40 (21 - 55) ms in aAVNRTs (p < 0.001). The VA interval stabilized significantly earlier in AVRTs (median 1.5 [1 - 3] beats) than in aAVNRTs (5 [4 - 7] beats; p < 0.001). A ∆VA < 10 ms accurately differentiated AVRT from aAVNRT with 100% of sensitivity, specificity, and positive and negative predictive values. The stabilization of the VA interval at < 3 beats of the tachycardia onset identified AVRT with sensitivity, specificity, and positive and negative predictive values of 64.1%, 94.6%, 95.3%, and 60.3%, respectively. A ∆VA < 20 ms yielded good diagnostic accuracy for DAPT. CONCLUSIONS: A ∆VA < 10 ms is a simple and useful criterion that accurately distinguished AVRT from atypical AVNRT. Central panel: Scatter plot showing individual values of ∆VA in atypical AVNRT and AVRT. Left panel: induction of atypical AVNRT. The VA interval stabilizes at the 5th beat and the ∆VA is 62 ms (maximum VA interval: 172 ms - minimum VA interval: 110 ms). Right panel: induction of AVRT. The tachycardia has a fixed VA interval from the first beat. ∆VA is 0 ms.

Clinical Course and Electrophysiological Characteristics of Permanent Junctional Reciprocating Tachycardia in Children.

BACKGROUND: In this study, we aimed to evaluate the clinical aspects, electrophysiological studies, and ablation results of permanent junctional reciprocating tachycardia in children. METHODS: The study comprised 29 pediatric patients diagnosed with permanent junctional reciprocating tachycardia between 2011 and 2021 in 2 pediatric electrophysiology centers. From the file records, the basic demographic characteristics of the patients, as well as electrocardiographic and echocardiographic findings, were acquired retrospectively. The medical treatment and responses of the patients throughout follow-up, as well as the electrophysiological study and ablation data of the patients who had electrophysiological study, were assessed. RESULTS: The mean age at diagnosis of the patients was 3.13 ± 4.43 (0-18) years and the mean weight was 18.22 ± 19.68 (3.8-94) kg. Eighteen patients (62.1%) were girls. Eleven patients (38%) developed tachycardia-induced cardiomyopathy. Tachycardia was incessant in 15 patients (51.7%). In total, 22 patients required 26 ablation procedures. Tachycardia-induced cardiomyopathy and multidrug-resistant tachycardia were the most prevalent indications for ablation. The right posteroseptal pathway was detected in 18 patients (81.8%). The acute procedure success rate was 100% (22/22). The recurrence rate was 18% (4/22) and 3 of them underwent successful ablation again. The overall success percentage was 95.4% (21/22). None of the patients had any complications. The mean follow-up period was 4.39 ± 3.05 years. CONCLUSION: Although permanent junctional reciprocating tachycardia is uncommon, it is often persistent, resistant to medical treatment, and associated with a substantial risk of tachycardia-induced cardiomyopathy. Catheter ablation can be performed on these patients at any age, with minimal risk of complications and a high success rate. It is crucial to keep monitor of the patients' recurrence.

Limitations of ventricular pacing maneuvers to differentiate orthodromic reciprocating tachycardia from atrioventricular nodal reentry tachycardia.

PURPOSE: Various ventricular pacing maneuvers have been developed to differentiate orthodromic reciprocating tachycardia (ORT) from atrioventricular nodal reentry tachycardia (AVNRT). We aimed to evaluate the diagnostic value of ventricular pacing maneuvers in patients undergoing catheter ablation for AVNRT/ORT. METHODS: Sixty patients with supraventricular tachycardia (SVT) undergoing invasive EP study were included (ORT: 31, typical AVNRT: 18, atypical AVNRT: 11). Ventricular overdrive pacing (VOP) and resetting by premature ventricular stimulation (PVS) during SVT were analyzed by 3 independent observers blinded to the ultimate diagnosis. We determined intraclass correlation coefficient (ICC) for interobserver agreement and the diagnostic accuracy of consensual results. RESULTS: Although specificity of all parameters was high (96-100%) for ORT, semi-quantitative parameters of VOP (requiring the recognition of specific ECG patterns) had lower interobserver reliability (ICC: 0.32-0.66) and sensitivity (16.1-77.4%). In contrast, most quantitative measurements of VOP and PVS showed good reproducibility (ICC: 0.93-0.95) and sensitivity (74.2-89.3%), but post-pacing interval after VOP needed correction with AV nodal conduction slowing. False negative results for diagnosing ORT were more common with left free wall vs. right free wall or septal, and slowly vs. fast-conducting septal APs. False positivity was only seen with a bystander, concealed nodo-fascicular/nodo-ventricular (NF/NV) AP in a case of AVNRT. CONCLUSIONS: No single maneuver is 100% sensitive for ORT. Semi-quantitative features have limited reproducibility and all parameters can be misleading in the case of rate-dependent delay during VOP/PVS, ORT circuits remote from the pacing site, or a bystander, concealed NF/NV AP.

Electrophysiologic approach to diagnosis and ablation of patients with permanent junctional reciprocating tachycardia associated with complex anatomy and/or physiology.

INTRODUCTION: Permanent junctional reciprocating tachycardia (PJRT) is a rare supraventricular tachycardia (SVT), typically involving a single decremental posteroseptal accessory pathway (AP). METHODS: Four patients with long RP SVT underwent electrophysiology (EP) study and ablation. The cases were reviewed. RESULTS: Case 1 recurred despite 3 prior ablations at the site of earliest retrograde atrial activation during orthodromic reciprocating tachycardia (ORT). Mapping during a repeat EP study demonstrated a prepotential in the coronary sinus (CS). Ablation over the earliest atrial activation in the CS resulted in dissociation of the potential from the atrium during sinus rhythm. The potential was traced back to the CS os and ablated. Case 2 underwent successful ablation at 6 o'clock on the mitral annulus (MA). ORT recurred and successful ablation was performed at 1 o'clock on the MA. Case 3 had tachycardia with variation in both V-A and A-H intervals which precluded the use of usual maneuvers so we used simultaneous atrial and ventricular pacing and introduced a premature atrial contraction with a closely coupled premature ventricular contraction. Case 4 had had two prior atrial fibrillation ablations with continued SVT over a decremental atrioventricular bypass tract that was successfully ablated at 5 o'clock on the tricuspid annulus. A second SVT consistent with a concealed nodoventricular pathway was successfully ablated at the right inferior extension of the AV nodal slow pathway. CONCLUSION: We describe challenging cases of PJRT by virtue of complex anatomy, diagnostic features, and multiple arrhythmia mechanisms.

Catheter ablation of orthodromic reciprocating tachycardia and atrioventricular nodal reentrant tachycardia in children with hypoplastic left heart syndrome.

INTRODUCTION: Experience with catheter ablation of orthodromic reciprocating tachycardia (ORT) and atrioventricular nodal reentrant tachycardia (AVNRT) in young children with hypoplastic left heart syndrome (HLHS) is limited. We report the feasibility, safety, and outcomes of catheter ablation of ORT and AVNRT in children with HLHS. METHODS AND RESULTS: This was a retrospective review of patients with HLHS who underwent catheter ablation for reentrant supraventricular tachycardias (excluding atrial tachycardias) between 2005 and 2017 at a single center. Descriptive data including demographics, clinical history, procedural data, and outcomes were recorded. Ten children with HLHS underwent eleven catheter ablation procedures. Median age and weight at ablation were 2.7 years (range: 0.1-10.5) and 11.4 kg (range: 3.6-30.4), respectively. Tachycardia mechanism was AVNRT in four, ORT in five (two with preexcitation), and both in one. Acute procedural success was 100% and there was no spontaneous recurrence of tachycardia orpreexcitationin median 92 months (range: 21-175 months) follow-up. Five patients underwent subsequent EP studies at catheterization (intracardiac) or after surgery (via epicardial wires): three were noninducible, one after AVNRT ablation had inducible atrial tachycardia, and one after initial ORT ablation had inducible ORT at fenestration closure and underwent successful repeat ablation. Thus, long-term freedom from clinical tachycardia was 100% and from inducible AVNRT or ORT was 80%. CONCLUSION: Transcatheter ablation for ORT and AVNRT in children with HLHS can be performed with excellent acute and long-term success without major complications.

Permanent junctional reciprocating tachycardia: a rare, but not to be missed, cause of cardiogenic shock in adults.

We report the case of a 64-year-old woman who was admitted for cardiogenic shock caused by a permanent junctional reciprocating tachycardia. If this incessant and drug-refractory form of tachycardia is a well-known cause of tachycardia-induced cardiomyopathies in infants, its occurrence during adulthood is extremely rare. Catheter ablation is the recommended treatment of this condition.

Electrophysiological features and radiofrequency catheter ablation of accessory pathways associated with atrioventricular discordance.

INTRODUCTION: Although a high prevalence of the presence of an accessory pathway (AP) associated with atrioventricular (AV) discordance has been reported, a case series of its characteristics and the results of catheter ablation (CA) have not been sufficiently documented. METHODS AND RESULTS: We retrospectively examined 11 consecutive patients with atrioventricular discordance who underwent CA for atrioventricular reciprocating tachycardia (AVRT) via an AP and planned cardiac surgery after CA. Orthodromic AVRTs were induced in 10 patients via AP, but no antidromic/duodromic AVRT was induced in any of the cases. A total of 13 APs were identified, and all of them were located around the anatomical tricuspid valve (TV) annulus, including two Ebsteinoid valves. The APs were predominantly located posteriorly, posterolaterally, and posteroseptally on the TV in nine patients (82%). Two patients (18%) had multiple APs or a single broad AP. Four (36%) and three (27%) patients showed twin AVNs and other supraventricular tachycardias (SVTs) except AVRT via the AP. Ten patients (91%) had acute successful CA in the first session, except for one patient with multiple APs who required the third session to eliminate all APs before the planned Fontan surgery. There were no major complications associated with CA. Seven of eight patients who underwent cardiac surgery after CA did not experience peri-/postoperative SVT. CONCLUSION: APs in patients with AV discordance are usually associated with the anatomical TV annulus. CA of an AP in AV discordance is highly effective and recommended to reduce the risk of SVT. The coexistence of twin AVNs and other SVTs should be considered during CA of an AP in AV discordance.

Fetal Persistent junctional reciprocating tachycardia : a diagnostic and a therapeutic challenge.

A mother presented with a fetus at 22±1 weeks of gestation with a sustained supraventricular tachycardia  (SVT) at initially 186 beat per minute (bpm). The fetal M-mode echocardiography showed a 1/1 atrio ventricular ratio (with short atrioventricular (AV) interval and a long ventriculo-atrial (VA) interval, suggesting a Persistent junctional reciprocating tachycardia (PJRT) . Upon  initial present no signs of heart failure or hydrops  were noted and treament was initiated with amiodarone and  digoxin . Fetus heart rate slowed  .Postnatal electrocardiogram  Confirmed  the diagnosis of PJRT New born was put on amiodarone and proparonal). Sinus rhythm was rapidly achieved 9 days later .The patient doing well at  10 months of age with maintain of sinus rhythm. Conclusion: our case report illustrates  a particular  form of  JRT   diagnosed  prenatal PJRT  , characterized  by  a good clinical tolerance, its absence of evolution towards cardiomyopathy  and its rapid and unusual response to antiarrhythmics.

Unusual variants of pre-excitation: From anatomy to ablation: Part III-Clinical presentation, electrophysiologic characteristics, when and how to ablate nodoventricular, nodofascicular, fasciculoventricular pathways, along with considerations of permanent junctional reciprocating tachycardia.

The recognition of the presence, location, and properties of unusual accessory pathways for atrioventricular conduction is an exciting, but frequently a difficult, challenge for the clinical cardiac arrhythmologist. In this third part of our series of reviews, we discuss the different steps required to come to the correct diagnosis and management decision in patients with nodofascicular, nodoventricular, and fasciculo-ventricular pathways. We also discuss the concealed accessory atrioventricular pathways with the properties of decremental retrograde conduction that are associated with the so-called permanent form of junctional reciprocating tachycardia. Careful analysis of the 12-lead electrocardiogram during sinus rhythm and tachycardias should always precede the investigation in the catheterization room. When using programmed electrical stimulation of the heart from different intracardiac locations, combined with activation mapping, it should be possible to localize both the proximal and distal ends of the accessory connections. This, in turn, should then permit the determination of their electrophysiologic properties, providing the answer to the question "are they incorporated in a tachycardia circuit?". It is this information that is essential for decision-making with regard to the need for catheter ablation, and if necessary, its appropriate site.

Long-term outcome of neonates and infants with permanent junctional reciprocating tachycardia. When cardiac ablation changes natural history.

Supraventricular tachycardias (SVT) are the most common arrhythmias in the perinatal period. Permanent junctional reciprocating tachycardia (PJRT) is a rare form of SVT, often incessant and refractory to pharmacological treatments. Our goal was to analyze the clinical features and treatment of PJRT in patients younger than 2 months and to describe their long-term outcomes. METHODS: Retrospective descriptive observational study of patients diagnosed between 2000 and 2015 in the NICU of a referral center for the treatment of pediatric arrhythmias. History of pregnancy, neonatal period, pharmacological treatment, electrophysiological study and long-term follow-up were reviewed. RESULTS: 129 of the 10.198 (1.26%) patients admitted to the NICU had SVT, sixteen of them (12.3%) being diagnosed as PJRT. Ten cases had a prenatal diagnosis. For those six patients postnatally diagnosed, the tachycardia was detected either during a routine check-up or because of acute hemodynamic instability. The majority of patients required combinations of drugs, despite that the tachycardia was poorly controlled. Fifteen patients underwent cardiac ablation, nine patients (60%) in the neonatal period and six during childhood. The procedure was completely effective in all cases. One patient had a transient complete AV block that resolved spontaneously 24 hours after the procedure. No other complications were seen. After a mean follow-up of 10.9 years, no patient has presented recurrence, cardiac dysfunction, signs of ischemia or EKG abnormalities, they all have a normal life. CONCLUSIONS: When PJRT is refractory to multiple drugs, cardiac ablation should be taken into account at early stages even in very young patients.

A novel pacing maneuver to verify the postpacing interval minus the tachycardia cycle length while adjusting for decremental conduction: Using "dual-chamber entrainment" for improved supraventricular tachycardia discrimination.

BACKGROUND: The postpacing interval (PPI) minus the tachycardia cycle length (TCL) is frequently used to investigate tachycardias. However, a variety of issues (eg, failure to entrain, decremental conduction, and oscillating TCLs) can make interpretation of the PPI-TCL challenging. OBJECTIVE: The purpose of this study was to investigate a novel maneuver to confirm the PPI-TCL value without using either the ventricular PPI or the TCL interval and to assess the ability of this maneuver to identify decremental conduction and differentiate supraventricular tachycardias. METHODS: We analyzed 77 intracardiac recordings from patients (age 25 ± 20 years; 40 female) who underwent catheter ablation of atrioventricular nodal reentrant tachycardia (AVNRT) or orthodromic reciprocating tachycardia (ORT) with a concealed pathway. We calculated the PPI-TCL, the AH-corrected PPI-TCL, and estimated the PPI-TCL using "dual-chamber entrainment" calculated as [PPIV - TCL = Stim(A→V) + Stim(V→A) - PPIA]. RESULTS: The PPI-TCL calculated by dual-chamber entrainment highly correlated with the observed and AH-corrected PPI-TCL (R2 = 0.79 and 0.96, respectively; P <.001]. A dual-chamber entrainment PPI-TCL value of 80 ms correctly differentiated all AVNRT from septal ORT cases, whereas the standard PPI-TCL and AH-corrected PPI-TCL methods were incorrect in 14% and 6% of cases, respectively. Dual-chamber entrainment identified 3 ± 10 ms of additional decremental conduction beyond AH prolongation, including 4 pathways with significant (>10 ms) decrement. CONCLUSION: Dual-chamber entrainment estimates the PPI-TCL value without using either the ventricular PPI or the TCL interval. This maneuver adjusts for all decremental conduction, including within concealed pathways, where a dual-chamber entrainment PPI-TCL value >80 ms favors AVNRT over ORT. This maneuver can be used to verify the observed PPI-TCL value in challenging cases.

A new criterion to differentiate atrioventricular nodal reentrant tachycardia from atrioventricular reciprocating tachycardia: Combined AVR criterion.

AIM: A combined aVR criterion is described as the presence of a pseudo r' wave in aVR during tachycardia in patients without r' wave in aVR in sinus rhythm and/or a ≥50% increase in r' wave amplitude compared to sinus rhythm in patients with r' wave in the basal aVR lead. We aimed to investigate the use of combined aVR criterion in differential diagnosis of atrioventricular nodal reentrant tachycardia (AVNRT) and atrioventricular reciprocating tachycardia (AVRT). METHODS: In this prospective study, 480 patients with inducible narrow QRS supraventricular tachycardia (SVT) were included. Twelve-lead electrocardiogram (ECG) was conducted during tachycardia and sinus rhythm. The patients were divided into two groups according to the arrhythmia mechanism that determined via EPS, AVNRT, and AVRT. Criteria of narrow QRS complex tachycardia were compared between the two groups. RESULTS: AVNRT was present in 370 (77%) patients and AVRT in 110 (23%) patients. Combined aVR criterion was found to be more frequent in patients with AVNRT (84.1% and 9.1%, p < 0.001). In logistic regression analysis, combined aVR criterion and classical ECG criterion were found to be the most important predictors of AVNRT (p < 0.001). The sensitivity, specificity, positive predictive value, and negative predictive value of the combined aVR criterion for AVNRT were 84.1%, 90.9%, 96.9%, and 62.9%, respectively. CONCLUSION: In the differential diagnosis of patients with SVT, the combined aVR criterion identifies the presence of AVNRT with an independent and acceptable diagnostic value. In addition to classical ECG criteria for AVNRT, it is necessary to evaluate the combined aVR criterion in daily practice.

Yield of 48-hour Holter monitoring in children with unexplained palpitations and significance of associated symptoms.

OBJECTIVE: To determine the yield of 48-hour Holter monitoring in children with unexplained palpitations and the significance of associated symptoms. METHODS: This descriptive study was conducted at the Children's Hospital and Institute of Child Health, Lahore, Pakistan, from January 1 to December 31, 2015. All children above 5 years of age with history of intermittent palpitations and normal basic cardiovascular workup were enrolled. A 48-hour Holter study was performed using Motara Holter Monitoring System. Frequency of various symptoms and abnormal Holter findings were analysed. SPSS 21 was used for data analysis. RESULTS: Of the 107 patients, 69(64.5%) were males and 38(34.5%) females. The median age was 10 years (interquartile range: 5-18 years). Most common concomitant symptoms with palpitation included syncope/pre-syncope in 35(32.7%) patients, chest pain 22(20.5%), shortness of breath 21(19.6%) and colour change/pallor 11(10.3%). Holter recording was positive in 40(37%) patients. Frequent premature ventricular contractions 12(11.2%) and atrial ectopic beats 9(8.4%) were the most common findings. Holter findings were significantly more common in patients with history of shortness of breath and colour change/pallor during palpitations (p=0.002). CONCLUSIONS: Extended 24-hour Holter monitoring in children with palpitations was an inexpensive, non-invasive investigation with a reasonably high diagnostic yield in detecting arrhythmias.

Coexistence of a permanent form of a junctional reciprocating tachycardia and coronary sinus aneurysm: A case report.

A 58-year-old man with a long R-P' narrow QRS tachycardia underwent an electrophysiological study. The tachycardia was diagnosed as a permanent form of junctional reciprocating tachycardia (PJRT), and the earliest atrial activation site during tachycardia was coronary sinus (CS) ostium. Radiofrequency ablation at the site was initially not successful because the tip impedance and temperature were unstable. After changing of the ablation catheter to that with contact force sensor, the accessory pathway was immediately ablated and the PJRT was no longer induced. A retrograde CS angiogram revealed a fusiform aneurysm, which was located at the earliest activation site during the tachycardia.