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ABSTRACT Background Methods Results Conclusions Wolff‐Parkinson‐White (WPW) syndrome and fasciculoventricular pathway (FVP) present electrocardiographic manifestations characterized by delta waves, differentiating these two is challenging. Specifically, WPW type B with QRS width ≤120 ms, resembles typical FVP features. Because of the presence of repolarization abnormalities in WPW syndrome, our hypothesis centered on the potential utility of the QRS‐T angle for distinguishing WPW syndrome from FVP. To determine the discriminative value of the QRS‐T angle for delineating WPW syndrome from FVP.We included cases of WPW syndrome treated with catheter ablation and FVP diagnosed via adenosine triphosphate administration between 2007 and 2023. We excluded cases with WPW type A, QRS width >120 ms, intermittent WPW, congenital heart disease or myocardial damage, ablation history, tachycardia, palpitations within 3 months, and WPW syndrome featuring an accessory pathway on the left lateral wall. Eventually, we identified 40 and 54 patients from the WPW and FVP groups, respectively. The QRS‐T angle was compared between the WPW and FVP cohorts.The QRS‐T angle in the WPW group was significantly larger than in the FVP group (45.7 ± 46.3° vs. 17.8 ± 13.9°, p < 0.001). Receiver operating characteristic curve analysis with a sensitivity and specificity of 65.0% and 72.6%, respectively, demonstrated that the optimal cut‐off value for the QRS‐T angle was 22° for distinguishing WPW from FVP. Remarkably, all cases with a QRS‐T angle >65° were within the WPW group.The QRS‐T angle can offer promising utility in differentiating WPW syndrome from FVP. [ABSTRACT FROM AUTHOR]

Objectives: The goal of this study is to document outcomes of ablation for high-risk accessory pathways in paediatrics using 3D mapping systems with minimal to zero fluoroscopy. Methods: It is a cross-sectional, multicentre study, conducted between 2013 and 2023, and involving four different centres in Hungary, Croatia, Kuwait, and Slovenia. Results: A total of 128 procedures were performed on 111 patients. The cohort included 57.8% anteroseptal (AS) pathways and 42.2% midseptal (MS) pathways. The mean follow-up time was 2.0 ± 2.1 years. Cryoablation was used in 72.7% of the cases, and radiofrequency ablation was used in 27.3%. The EnSite Precision™ Cardiac Mapping System was the predominant system used. The overall acute success rate was 89.1%, with recurrence rates at 17.2% with similar results regardless of the type of energy used. The success rate was not significantly different between AS and MS substrates. The age and weight of the patient had no bearing on the outcomes (median age and weight were 13 years and 52 kg, respectively). The complications rate was at 4.69% and included transient AV block (three patients), hematoma (one patient), right bundle branch block (one patient), and possible permanent complete AV block (one patient). Fluoroscopy was utilized in 18 cases, with a fluoroscopy time mean of 3 min and 45 s. Conclusions: MS and AS AP in paediatric patients can be treated effectively with either RF or cryoablation and with a low dose of radiation using 3D mapping systems, with excellent acute success rates and low complication rates. [ABSTRACT FROM AUTHOR]

We report a case of a 44‐year‐old male who underwent an electrophysiological study for symptomatic supraventricular tachycardia (SVT) with wide QRS complex. The SVT was diagnosed as an antidromic atrioventricular reentrant tachycardia (AVRT) via antegrade conduction of left‐sided accessory pathway (AP). However, the QRS morphology changed during the SVT, and then the SVT was terminated spontaneously. The mapping of AP was performed during sinus rhythm, and the radiofrequency application successfully eliminated the AP, which rendered tachycardias non‐inducible. This was a rare case of antidromic AVRT during which the QRS morphology changed. [ABSTRACT FROM AUTHOR]

Background: Cryoablation of APs localized near the atrioventricular (AV) junction is a well-established ablation strategy in children, and it has proved to be very safe. However, recurrence rates remain considerable for specific accessory pathway (AP) localizations. The aim of this retrospective study was to evaluate the efficacy and safety of a trans-jugular approach for cryoablation of right anterior, anterior-lateral, and anterior-septal APs in children, as compared to the conventional femoral approach. Methods: From June 2019 to November 2023, 24 consecutive patients (mean age 13.2 ± 4.6, 12 males (50% of total cohort)) with right anterior-lateral, anterior, and anterior-septal/para-Hisian APs underwent 3D non-fluoroscopic transcatheter cryoablation through the right jugular vein at our Institution. Ablation results were compared with 24 patients for whom a conventional trans-femoral approach was used. Results: Acute procedural success rate was 100% (n = 24/24), with a non-statistically significant difference as compared to the control group (100% vs. 83%, p = 0.1). During follow-up (1.1 years, interquartile range 0.6–1.3), one patient (4%) had a recurrence in the trans-jugular group, as opposed to eight (38%) in the control group (p = 0.006). No permanent complications occurred. Conclusions: 3D cryoablation of right anterior-lateral, anterior, and anterior-septal/para-Hisian APs in children using a trans-jugular approach is extremely effective and safe, resulting in higher chronic success rate compared to the conventional femoral approach. In children, acute success rate of cryoablation of anterior and para-Hisian accessory pathways via the trans-jugular approach was similar to trans-femoral approach (p = 0.1), but recurrences were significantly lower (p = 0.006). [ABSTRACT FROM AUTHOR]

A 51‐year‐old woman presented with recurring palpitations. Electrocardiography revealed narrow QRS tachycardia with short RP configuration. Computed tomography showed coronary sinus (CS) ostial atresia along with a small persistent left superior vena cava (PLSVC). Electrophysiological study identified the retrograde earliest atrial activation site (EAAS) at the CS ostium without decremental properties, and para‐Hisian pacing suggested retrograde atrioventricular nodal conduction. Using a 1.6‐Fr microelectrode catheter distally placed in the CS via the PLSVC, EAAS was confirmed within the left atrium, not the CS ostium. Transseptal approach revealed a left lateral accessory pathway, which was successfully eliminated. [ABSTRACT FROM AUTHOR]

An 18-year-old female neutered Domestic Shorthair cat was referred for investigation of seizure-like episodes. Physical and neurological examination were unremarkable, as were systemic arterial blood pressure, cardiac troponin I, complete blood count and biochemistry profile. Diagnostic tests included transthoracic echocardiography which ruled out any structural cardiomyopathy, and electrocardiography which showed an underlying regular wide QRS-complex rhythm with pronounced shortening of the PR interval. Considering the findings, a diagnosis of suspected ventricular pre-excitation secondary to an accessory pathway was made. Further investigations were declined and, as no periods of tachycardia were seen on the five-minute electrocardiogram, no antiarrhythmic treatment was started. [ABSTRACT FROM AUTHOR]

Introduction: Detection of accessory pathway (AP) on surface ECG in sinus rhythm helps in the diagnosis of Wolff-Parkinson-White Syndrome (WPW Syndrome), Catheter ablation of AP was indicated in symptomatic patients with preexcitation. Pre-ablation AP localization inferred from the 12-lead surface electrocardiogram (ECG) facilitates a tailored ablation strategy; there by specific risk can be properly assessed. As they are based on pre-excitation in the basal state, available algorithms can lead to complex and ambiguous analysis, mostly due to the variable influence of the AP over QRS morphology. Though various algorithms on surface ECG are available to predict the site of AP on surface ECG, but none of them are accurate. So, we have compared the accuracy of different algorithms in predicting the AP localization in comparison to electrophysiological study (EPS) diagnosis. Methodology: This retrospective observational study cohort consisted of 100 consecutive patients above 15 years of age presented to the tertiary care center with the history of palpitations or for assessment of a manifest AP. Accessory pathways were identified according to the site where successful radiofrequency energy was applied. Arruda algorithm, Milstein algorithm, Fitzpatrick algorithm and Pambrun algorithm were applied on a sinus rhythm manifest preexcited ECG to predict the AP localization by two independent investigators who are unaware of site of successful catheter ablation. Then those were compared with the EPS localization to test the accuracy of individual algorithm. Then Cohen’s Kappa was run to determine if there was agreement between any of the four different algorithms with EPS using SPSS version 20.0. Results: In the study population of 100 patients, male to female ratio of study population was 1.6:1, with a mean age of presentation 43.86 ± 11.4 years with the most common age group of 31 to 45 year. when the AP locations were categorized based on EP Study 56 percent of the AP were found on the left side while 43 percent of the AP were found on right side, 77 percent of the AP were septal pathways. Among the leftsided pathways, left anteroseptal constitutes majority followed by left posteroseptal pathway. On right side majority were in right posteroseptal location in our study. Based on 4 surface ECG algorithms AP was localized and each algorithm was compared with invasive EPS localization for accuracy using Cohen’s Kappa agreement analysis. As per agreement analysis the kappa value for Milstein, Pambrun algorithm, Fitzpatrik and Arruda were 0.188, 0.343, 0.441, and 0.645 respectively. It was found that Arruda algorithm had moderate strength of agreement with the findings of EPS (κ = 0.645). This is the proportion of agreement over and above chance agreement and which was statistically significant and the strongest among all the four algorithms. Conclusion: Our study has compared the accuracy of 4 surface ECG algorithms in predicting the accessory pathway localization with the EPS; it has demonstrated that the Arruda algorithm is more precise and accurate among the available algorithms followed by Fitzpatrik, Pambrun algorithm and Milstein algorithm, Knowing the pathway prior to ablation allows for optimal procedure preparation, mapping pathways that are difficult to find and finally may lessen the catheter-related injury and shortens the procedural time.

The coexistence of different types of wide QRS complex tachycardias induced by the same trigger has rarely been observed. The electrical instability and incessant nature of tachycardias can cause tachycardiomyopathy and will not allow accurate diagnosis during an electrophysiological study (EPS). In case of an electrical storm, elimination of the trigger may be the first approach to provide patient stability. We report a successfully managed case of repetitive initiation of pleomorphic ventricular tachycardia and Mahaim-type antidromic atrioventricular reentrant tachycardia, induced by a premature ventricular complex in the right ventricular outflow tract.

The non-invasive localization of accessory pathway (AP) in patients with Wolff-Parkinson-White (WPW) syndrome is typically performed upon physicians’ diagnoses based on observing their electrocardiogram (ECG) signals, which are not always the same. Therefore, a high-accuracy automatic method can help minimize this gap regarding AP localization. This study was to develop a novel semi-automatic localization of AP in patients with WPW syndrome, using features selected from the cross-recurrence plot (CRP) of consecutive precordial leads on ECG. The study participants comprised of 31 patients with WPW syndrome (aged 8-69, with the mean age of 31.19±14.69, 32.3% female), receiving successful ablation therapy during the first session. The features extracted from the CRP, including laminarity (LAM), trapping time (TT), determinism (DET), and mean length of diagonal line (L) were then analyzed. The feature reduction, The classification and the cross-validation (CV) methods were sequential forward selection (SFS), the k-nearest neighbors (KNN) and the leave-one-out (LOO) respectively. The proposed method could differentiate the right and left APs in the patients with WPW syndrome with the accuracy value of 87% (sensitivity: 93.33%, specificity: 81.25%). These results were achieved by the LAM and L features from the CRP of (V1, V2) and (V3, V4), respectively.

Ablation of accessory pathways (APs) is the cornerstone for treatment of patients with Wolff-Parkinson-White syndrome and manifestation of atrioventricular reentrant tachycardia. Pulsed field ablation (PFA) is a new type of nonthermal energy source delivered to the underlying tissue via the ablation catheter and used for ablation of arrhythmic substrates. The purpose of this study was to determine the efficiency and long-term outcome of ablation of APs of different localizations using a focal pulsed electrical field. Electrophysiological study was performed in patients with indication for AP ablation. An ablation catheter was used to map the position of AP insertion. Pulsed electric field was delivered through a standard ablation catheter. In left-sided APs, the first ablation attempt was within the coronary sinus (CS). Patient follow-up was scheduled 1–3 months after the ablation. Additional check-up was performed after 6 and 12 months. Fourteen 14 patients (3 pediatric) were treated. Termination of AP conduction was achieved in all procedures. The cohort consisted of 3 right free wall, 3 posteroseptal, and 8 left-sided APs. Ablation through CS was successfully used in 7 of 8 patients with left-sided APs. No complications were reported. Median follow-up was 5.5 months. Conduction recurrence through AP was documented in 1 patient. Focal PFA for AP shows promising results in terms of efficacy and safety. A high rate of successful termination of left-sided APs by ablation within CS may represent a new standard approach. The safety and efficacy profile of PFA seems to be transferable to the pediatric population. [ABSTRACT FROM AUTHOR]

The article present case study of a 52-year-old woman who had been previously diagnosed with type-A Wolff-Parkinson-White (WPW) syndrome. Topics include the diagnostic assessment of a narrow QRS tachycardia; differential diagnosis between orthodromic reciprocating tachycardia (ORT) and atrioventricular nodal reentrant tachycardia (AVNRT); and the complexities in distinguishing a posteroseptal atrioventricular pathway from a rare nodoventricular pathway.

The article presents a case study of a 62-year-old female patient with irregular tachycardia. Topics discussed include the differential diagnoses of narrow QRS tachycardias such as atrial flutter and orthodromic reciprocating tachycardia, the results of the 12-lead electrocardiogram administered to the patient, and the clinical implications of regularly irregular tachycardia.

Wolff-Parkinson-White (WPW) syndrome is defined by specific electrocardiogram (ECG) changes resulting in ventricular pre-excitation (the so-called WPW pattern), related to the presence of an accessory pathway (AP), combined with recurrent tachyarrhythmias. WPW syndrome is characterized by different supraventricular tachyarrhythmias (SVT), including atrioventricular re-entry tachycardia (AVRT) and atrial fibrillation (AF) with rapid ventricular response, with AVRT being the most common arrhythmia associated with WPW, and AF occurring in up to 50% of patients with WPW. Several mechanisms might be responsible for AF development in the WPW syndrome, and a proper electrocardiographic interpretation is of pivotal importance since misdiagnosing pre-excited AF could lead to the administration of incorrect treatment, potentially inducing ventricular fibrillation (VF). Great awareness of pre-excited AF’s common ECG characteristics as well as associated causes and its treatment is needed to increase diagnostic performance and improve patients’ outcomes. In the present review, starting from a paradigmatic case, we discuss the characteristics of pre-excited AF in the emergency department and its management, focusing on the most common ECG abnormalities, pharmacological and invasive treatment of this rhythm disorder. [ABSTRACT FROM AUTHOR]

BackgroundDespite the high success rate of radiofrequency catheter ablation (RFCA) in Wolff-Parkinson-White Syndrome (WPW), localizing the successful ablation site can be challenging and may require multiple radiofrequency (RF) applications.ObjectiveThis study aims to evaluate the efficacy of a novel workflow for the automatic and precise identification of accessory pathway ablation site, named Delta Wave Automatic Mapping.MethodsPatients undergoing a first procedure for RF ablation of a manifest accessory pathway were included. Electro-Anatomical Mapping (EAM) was performed with the CARTO 3 system (Biosense Webster, Johnson & Johnson Medical S.p.a., Irvine, CA) leveraging auto-acquisition algorithms already present in the CARTO 3 software. Mapping and ablation were performed with an irrigated tip catheter with contact force sensor. Procedure success was defined as loss of pathway function after ablation. The number of RF applications required and time to effect were measured for each patient. Recurrences were evaluated during follow-up visits. Additionally, at the end of each procedure, historical predictors of ablation success were measured offline to evaluate their relationship with the successful ablation site found with the novel workflow.ResultsA total of 50 patients were analysed (62% APs right and 38% APs left). All 50 APs were successfully eliminated in each procedure with a median Time-to-effect (TTE) of 2.0 (IQR 1.2–3.5) seconds. No AP recurrences during a median follow-up of 10 (IQR 6–13) months were recorded. Offline analysis of successful ablation site revealed a pre-ablation delta/ventricular interval of ≤−10 msec in 52% of the patients and in 100% of the patients the signal related to the Kent bundle was identified.ConclusionsThe novel workflow efficiently localizes APs without requiring manual annotations. Historical endocardial parameters predicting success were measured offline for each case and they corresponded to the ablation target automatically annotated by the proposed workflow. This novel mapping workflow holds promise in enhancing the efficacy of RFCA in the presence of manifest APs.

Objective: To investigate the utility of simultaneous multi-catheter cryotherapy for the treatment of APs that were previously resistant to standard radiofrequency (RF) catheter ablation. Background: Catheter ablation is established in the treatment of accessory pathways (AP), with high rates of permanent procedural success with a single attempt. However, there are still instances of acute procedural failure and AP recurrences with standard RF and cryotherapy methods. Methods: Seven consecutive cases of pre-excitation syndromes with prior failed RF catheter ablation had the novel treatment. Cryotherapy was delivered using two 8 mm tip focal cryoablation catheters (Freezor® Max, Medtronic, Minneapolis, Minnesota, USA). Results: Accessory pathway localisation was septal in 5 cases, left posterolateral in 1, right lateral in 1. In all cases, ablation of the AP was acutely successful with no procedural complications. Median procedure and fluoroscopy durations were 199 and 35 min, sequentially. Median Procedure duration fell significantly in the second half of series (174 min) compared to the first half (233 min, P = 0.05). One patient had evidence of a recurring AP conduction with pre-excitation at 5-week follow up. After a median follow up of 66.8+-6.5 months, 6 out of 7 patients remained asymptomatic and free of pre-excitation. Conclusion: Simultaneous multi-catheter cryotherapy is feasible, safe and can provide definitive cure of accessory pathways that were previously resistant to standard radiofrequency ablation. Further study is required in the assessment of this novel form of advanced cryotherapy to treat complex and resistant arrhythmias.

The ECG of a patient during sinus rhythm shows preexcited QRS pattern, with rS pattern in lead V1, transition in lead V2, and positive inferior leads. Following the stepwise algorithms, the location of accessory pathway (AP) was identified at anteroseptal region. However, the precordial transition in lead V2 indicates mid-septal or posteroseptal AP. The mismatch suggested multiple APs and 5 APs were identified by electrophysiologic study. This case highlights the importance of detailed analysis of ECG in order to achieve adequate ablation. [ABSTRACT FROM AUTHOR]

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Wolf–Parkinson–White (WPW) syndrome is a disorder characterized by the presence of at least one accessory pathway (AP) that can predispose people to atrial/ventricular tachyarrhythmias and even sudden cardiac death. It is the second most common cause of paroxysmal supraventricular tachycardia in most parts of the world, affecting about 0.1–0.3% of the general population. Most patients with WPW syndrome have normal anatomy, but it may be associated with concomitant congenital heart disease or systemic diseases. Although many individuals are asymptomatic, during supraventricular arrhythmia episodes, they may experience severe symptoms, including syncope or even sudden cardiac death (mainly due to pre-excited atrial fibrillation over rapidly conducting AP). In addition to arrhythmia-related symptoms, for some specific locations of the APs with overt anterograde conduction, there might be a reduction in exercise capacity mediated by a reduction in LV systolic performance due to anomalous LV depolarization. Although it is typically diagnosed through electrocardiography (ECG), additional tests are necessary for risk assessment. Management of WPW syndrome may be quite challenging and can vary from only acknowledging the presence of the accessory pathway to pharmacological treatment or radiofrequency ablation. Early diagnosis, risk assessment, and appropriate treatment are critical steps in the management of WPW syndrome, aiming to improve the quality of life and reduce the risk of life-threatening arrhythmias. [ABSTRACT FROM AUTHOR]

We described the differential ventricular overdrive pacing during long RP' supraventricular tachycardia and discussed about its response leading to the dianosis. [ABSTRACT FROM AUTHOR]

Background: Radiofrequency (RF) catheter ablation of para‐Hisian accessory pathways (APs) can be challenging due to proximity to the conduction system. Methods: A total of 30 consecutive patients with para‐Hisian AP were enrolled for ablation in three centers, 12 (40%) of whom had previously failed attempted ablation from the inferior vena cava (IVC) approach. Ablation was preferentially performed using a superior approach from the superior vena cava (SVC) in all patients. Results: The para‐Hisian AP was eliminated from the SVC approach in 28 of 30 (93.3%) patients. In the remaining two patients, additional ablation from IVC was required to successfully eliminate the AP. There were two patients experienced reversible complete atrial‐ventricular block and PR prolongation during the first RF application. Long‐term freedom from recurrent arrhythmia was achieved in 29 (96.7%) patients over a mean follow‐up duration of 15.6 ± 4.6 months. Conclusion: Catheter ablation of para‐Hisian AP from above using a direct SVC approach is both safe and effective, and should be considered especially in patients who have failed conventional ablation attempts from IVC approach. [ABSTRACT FROM AUTHOR]

Background: Posteroseptal accessory pathways (APs) associated with coronary sinus (CS) diverticulum present a rare and challenge for ablation. This study aimed to compare the safety and efficacy of conventional approach and three‐dimensional (3D) mapping system in the catheter ablation. Methods and Results: This was a retrospective study of all patients (from January 2013 to July 2022) who underwent catheter ablation of posteroseptal AP associated with CS diverticula in our center. Patients who underwent catheter ablation using the traditional fluoroscopy method were included in the conventional method group (n = 13). Patients who underwent catheter ablation using the 3D mapping method were included in the 3D mapping group (n = 11). Clinical characteristics, ablation procedure, and outcomes were recorded and analyzed between the two groups. Out of 669 patients with posteroseptal APs, 24 of them (3.6%) were associated with CS diverticula. All patients in both groups successfully completed the electrophysiological study. In the conventional method group, two patients experienced complications (one patient with pericardial effusion and the other patient with femoral arterial hematoma), and two patients had recurrence. However, no patients suffered from complications or recurrence during follow‐up. The procedure time and fluoroscopy time in the conventional method group were significantly longer than those in the 3D mapping method group. Conclusions: The utilization of 3D mapping led to reduced fluoroscopy time, shorter procedure duration, enhanced acute success rates, and decreased incidence of complications. [ABSTRACT FROM AUTHOR]

We present a case of a 32-year-old male with a history of palpitations and preexcitation on ECG who underwent altogether four failed catheter ablations using different approaches in the two other electrophysiology centers within two years. ECG showed overt preexcitation with a positive delta wave in lead I and negative in leads V1–V3, suggesting a right free wall accessory pathway. During the electrophysiological study, the accessory pathway was localized on the free lateral wall. However, the electrograms and mapping during atrial and ventricular pacing suggested the presence of true epicardial accessory pathway. Repeated radiofrequency energy delivery with the support of the steerable sheath and excellent contact (as assessed by intracardiac echocardiography) at the earliest ventricular activation was not successful. Therefore, the Farawave catheter (Boston Scientific, Inc) was used, and a flower configuration with the intention to cover the entire atrial attachment of the pathway during ventricular pacing was selected. Application of pulsed field resulted in interruption of accessory pathway conduction. An electrophysiological study one year later confirmed the persistent effect of ablation. This case illustrates the potential utility of pulsed field energy for the ablation of atrial insertion of the accessory pathway with an epicardial course. Such an approach can avoid epicardial mapping and access and may improve the safety of the procedure.

Abstract Introduction During ventricular pacing, a fusion of atrial activation may occur owing to the simultaneous retrograde conduction of the atrioventricular (AV) node and accessory pathway (AP), potentially leading to an inaccurate mapping of the atrial AP insertion site. Objective We tested the hypothesis that landiolol, an ultra‐short‐acting intravenous β1‐blocker, could dissociate a fusion of atrial activation. Methods We conducted a prospective before‐and‐after study to investigate the effect of landiolol on retrograde conduction via the AV node and AP. We enrolled 21 consecutive patients with orthodromic AV reciprocating tachycardia who underwent electrophysiological studies at our hospital between January 1, 2018, and August 31, 2020. Results Six patients exhibited a fusion of atrial activation. After landiolol administration (10 μg/kg/min), the effective refractory period was unchanged in AP (280 [240–290] ms vs. 280 [245–295] ms, p = .91), whereas that of the AV node was prolonged (275 [215–380] ms vs. 332 [278–445] ms, p = .03). The Wenckebach pacing rate via retrograde AV node decreased after landiolol administration (180 [140–200] beats per minute [bpm] vs. 140 [120–180] bpm, p = .02). Thus, landiolol decreased the minimum ventricular pacing rate required to dissociate a fusion of atrial activation (180 [160–200] bpm vs. 140 [128–155] bpm, p = .007). Radiofrequency catheter ablation under landiolol administration successfully eliminated AP in all patients during ventricular pacing without complications or recurrence. Conclusion Landiolol inhibited the AV node without affecting the AP and helped dissociate a fusion of atrial activation at a lower ventricular pacing rate.

Abstract Background Posteroseptal accessory pathways (APs) associated with coronary sinus (CS) diverticulum present a rare and challenge for ablation. This study aimed to compare the safety and efficacy of conventional approach and three‐dimensional (3D) mapping system in the catheter ablation. Methods and Results This was a retrospective study of all patients (from January 2013 to July 2022) who underwent catheter ablation of posteroseptal AP associated with CS diverticula in our center. Patients who underwent catheter ablation using the traditional fluoroscopy method were included in the conventional method group (n = 13). Patients who underwent catheter ablation using the 3D mapping method were included in the 3D mapping group (n = 11). Clinical characteristics, ablation procedure, and outcomes were recorded and analyzed between the two groups. Out of 669 patients with posteroseptal APs, 24 of them (3.6%) were associated with CS diverticula. All patients in both groups successfully completed the electrophysiological study. In the conventional method group, two patients experienced complications (one patient with pericardial effusion and the other patient with femoral arterial hematoma), and two patients had recurrence. However, no patients suffered from complications or recurrence during follow‐up. The procedure time and fluoroscopy time in the conventional method group were significantly longer than those in the 3D mapping method group. Conclusions The utilization of 3D mapping led to reduced fluoroscopy time, shorter procedure duration, enhanced acute success rates, and decreased incidence of complications.

Introduction: Acquired Wolff–Parkinson–White (WPW) syndrome can occur after congenital heart disease (CHD) surgery. Methods and Results: A 27‐year‐old male with Ebstein's anomaly and manifest WPW syndrome received catheter ablation twice. The first electrophysiology study (EPS) induced orthodromic atrioventricular reentrant tachycardia and successfully eliminated the posteroseptal accessory pathway (AP). Six months after the Cone procedure, the patient suffered from palpitation. The second EPS was performed and abolished the right lateral AP. Conclusion: The appearance of a new AP after the reconstruction of CHD is a rare finding and should raise suspicion of an acquired AP connection. [ABSTRACT FROM AUTHOR]

Background and Aims: Ablation of anteroseptal accessory pathways (AS‐AP) is challenging, with lower success and more complications compared to other APs. AS‐APs can be successfully ablated from the right atrium (RA) or the aortic valve's noncoronary cusp (NCC). We report two patients who required a hybrid ablation approach to achieve successful abolition of both anterograde and retrograde AS‐AP conduction. Methods and Results: A 21‐year‐old female with supraventricular tachycardia (SVT) and pre‐excitation on electrocardiogram (ECG) underwent electrophysiology study (EPS) confirming an AS‐AP with anterograde and retrograde conduction. Ablation in the NCC achieved immediate and persistent anterograde conduction block. Electrophysiological maneuvers showed persistent retrograde AP conduction and orthodromic reciprocating tachycardia (ORT) remained easily inducible. Additional ablation in the NCC did not eliminate retrograde conduction. Further ablation in the RA opposite the NCC at the site of earliest retrograde atrial activation during ORT restored sinus and eliminated retrograde AP conduction. A 52‐year‐old male with SVT and ECG with pre‐excitation underwent EPS that confirmed an AS‐AP with anterograde and retrograde conduction. Ablation was performed in the NCC resulting in immediate elimination of pre‐excitation. Retrograde conduction was still present and confirmed by repeating electrophysiological maneuvers. Ablation was performed in the RA opposite the successful ablation site in the NCC, eliminating retrograde AP conduction. Conclusion: Two cases of AS‐AP with anterograde and retrograde conduction and successful elimination of pathway conduction required a hybrid ablation approach from the NCC and RA. This approach may be helpful in other cases to improve success rates without using excessive ablation near the normal conduction system. [ABSTRACT FROM AUTHOR]

Introduction: During ventricular pacing, a fusion of atrial activation may occur owing to the simultaneous retrograde conduction of the atrioventricular (AV) node and accessory pathway (AP), potentially leading to an inaccurate mapping of the atrial AP insertion site. Objective: We tested the hypothesis that landiolol, an ultra‐short‐acting intravenous β1‐blocker, could dissociate a fusion of atrial activation. Methods: We conducted a prospective before‐and‐after study to investigate the effect of landiolol on retrograde conduction via the AV node and AP. We enrolled 21 consecutive patients with orthodromic AV reciprocating tachycardia who underwent electrophysiological studies at our hospital between January 1, 2018, and August 31, 2020. Results: Six patients exhibited a fusion of atrial activation. After landiolol administration (10 μg/kg/min), the effective refractory period was unchanged in AP (280 [240–290] ms vs. 280 [245–295] ms, p =.91), whereas that of the AV node was prolonged (275 [215–380] ms vs. 332 [278–445] ms, p =.03). The Wenckebach pacing rate via retrograde AV node decreased after landiolol administration (180 [140–200] beats per minute [bpm] vs. 140 [120–180] bpm, p =.02). Thus, landiolol decreased the minimum ventricular pacing rate required to dissociate a fusion of atrial activation (180 [160–200] bpm vs. 140 [128–155] bpm, p =.007). Radiofrequency catheter ablation under landiolol administration successfully eliminated AP in all patients during ventricular pacing without complications or recurrence. Conclusion: Landiolol inhibited the AV node without affecting the AP and helped dissociate a fusion of atrial activation at a lower ventricular pacing rate. [ABSTRACT FROM AUTHOR]

Copyright of Rechtsmedizin is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

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. [ABSTRACT FROM AUTHOR]

Introduction: Accessory atrioventricular pathways (APs) may mediate atrioventricular reciprocating tachycardia and, in some cases, have the potential to conduct atrial tachycardia rapidly, which can be life threatening. While catheter ablation can be curative, ablation of right free wall APs is associated with a high rate of recurrence, likely secondary to reduced catheter stability along the right free wall atrioventricular groove. We sought to identify characteristics associated with a lower rate of recurrence and hypothesized ablation lesions placed on the ventricular side of the atrioventricular groove using a retroflexed catheter approach would decrease rates of recurrence. Methods and Results: Retrospective chart review of patients who underwent catheter ablation of a right free wall AP from January 1, 2008 through June 1, 2021 with >2 months follow up. Cox proportional hazards regression was used to identify relationships between predictor variables and AP recurrence. We identified 95 patients who underwent ablation of 98 right free wall APs. Median age was 13.1 years and median weight at ablation was 52.3 kg. Overall, 23/98 (23%) APs recurred. Use of a retroflexed catheter course approaching the atrioventricular groove from the ventricular aspect was associated with reduced risk of AP recurrence with (univariable hazard ratio of 0.10 [95% confidence interval: 0.01–0.78]), which remained significant in multiple two variable Cox proportional hazards models. Conclusion: Use of a retroflexed catheter course is associated with a reduced likelihood of AP recurrence. This approach results in improved catheter stability and should be considered for ablation of right free wall APs. [ABSTRACT FROM AUTHOR]

Wolff-Parkinson-White Syndrome (WPW) has been associated with reduced local myocardial deformation, and when left ventricular dysfunction is present, catheter ablation of the accessory pathway may be required, even in asymptomatic patients. We aimed to evaluate the diagnostic value of non-invasive myocardial work in predicting subtle abnormalities in myocardial performance in children with WPW.Seventy-five paediatric patients (age 8.7 ± 3.5 years) were retrospectively recruited for the study: 25 cases with manifest WPW and 50 age- and sex- matched controls (CTR). Global myocardial work index (MWI) was measured as the area of the left ventricle (LV) pressure-strain loops. From MWI, global Myocardial Constructive Work (MCW), Wasted Work (MWW), and Work Efficiency (MWE) were estimated. In addition, standard echocardiographic parameters of LV function were evaluated. Despite normal LV ejection fraction (EF) and global longitudinal strain (GLS), children with WPW had worse MWI, MCW, MWW, and MWE. At multivariate analysis, MWI and MCW were associated with GLS and systolic blood pressure, and QRS was the best independent predictor of low MWE and MWW. In particular, a QRS > 110 ms showed good sensitivity and specificity for worse MWE and MWW values. In children with WPW, myocardial work indices were found significantly reduced, even in the presence of normal LV EF and GLS. This study supports the systematic use of myocardial work during the follow-up of paediatric patients with WPW. Myocardial work analysis may represent a sensitive measure of LV performance and aid in decision-making. [ABSTRACT FROM AUTHOR]

Introduction: The aim of the study was to describe the electrocardiographic features of ventricular pre-excitation (VPE) patterns characterized by the presence of delta (δ) wave, short P-δQRS interval, wide δQRS complexes in dogs with right-sided accessory pathways. Animals, materials and methods: Twenty-six dogs with a confirmed accessory pathways (AP) via electrophysiological mapping were included. All dogs underwent a complete physical examination, 12-lead ECG, thoracic radiography, echocardiographic examination and electrophysiologic mapping. The AP were located in the following regions: right anterior, right posteroseptal, right posterior. The following parameters were determined: P-δQRS interval, δQRS duration, δQRS axis, δQRS morphology, δ-wave polarity, Q-wave, R-wave, R'-wave, S-wave amplitude, and R/S ratio. Results: In lead II, the median δQRS complex duration was 82.4 (IQR 7.2) and the median P-δQRS interval duration was 54.6 (IQR 4.2) msec. The median δQRS complex axis in the frontal plane was: + 68° (IQR 52.5) for right anterior APs, − 24 ° (IQR 24) for right postero-septal APs, − 43.5 ° (IQR 27.25) for right posterior APs (P = 0.007). In lead II, the polarity of the δ wave was positive in 5/5 right anterior APs and negative in 7/11 postero-septal APs and 8/10 in right posterior APs. In precordial leads of all dogs, R/S was ≤ 1 in V1 and > 1 in all leads from V2 to V6. Conclusion: Surface electrocardiogram can be used to distinguish right anterior APs from right posterior and right postero-septal ahead of an invasive electrophysiological study. [ABSTRACT FROM AUTHOR]

Wolf-Parkinson-White (WPW) accessory pathway (AP) may be associated with reentry supraventricular tachycardia (SVT) in addition to ventricular dyssynchrony and cardiac dysfunction. Electrophysiological studies (EPS) are the gold standard for the localization of the AP; however, 2D speckle-tracking echocardiography (2D-STE) may help in the localization of the AP noninvasively. Our study aims to evaluate the capability of 2D-STE for AP localization and the identification of AP-related contractile abnormalities and dyssynchrony in pediatric patients with WPW syndrome. This prospective multicenter cohort study involved 18 pediatric patients with ventricular preexcitation from January 2021 to January 2023. Tissue Doppler imaging (TDI), conventional echocardiography, and 2D-STE were done. Myocardial velocities, myocardial performance index (MPI), the global and segmental longitudinal strain of the left ventricle (LV), and time-to-peak longitudinal strain (TPLS) were measured before and after ablation. The longitudinal strain of the LV segments supplied by the AP, or the nearby segments close to the AP, was significantly impaired and improved after ablation (P = 0.0001). The abnormal strain pattern in the affected segments could predict the location of the AP. The TPLS of the affected segments significantly increased after ablation (P = 0.0001), denoting improved dyssynchrony. The ejection time and the LV MPI measured at the basal septum improved significantly after ablation. Conclusions: 2D STE may be used for noninvasive localization of the AP and to evaluate cardiac function and dyssynchrony in patients with WPW. Further research on more patients is necessary to validate this method for AP localization. What is Known: • Accessory pathways (AP) associated with the Wolf-Parkinson-White (WPW) syndrome have been linked to supraventricular tachycardia (SVT). Even without SVT, WPW can cause left ventricular dyssynchrony, contractile dysfunction, and cardiomyopathy. • Electrophysiology study is the gold standard for the localization of the AP in WPW syndrome. What is New: • The combination of 2D-speckle-tracking echocardiography (2D-STE) and the modified Arruda algorithm can precisely localize the AP associated with WPW syndrome. • 2D-STE can potentially assess cardiac function and dyssynchrony related to WPW syndrome. Additionally, 2D-STE can be utilized to evaluate the effectiveness of ablation in restoring cardiac function and dyssynchrony. [ABSTRACT FROM AUTHOR]

Background: Open‐window mapping (OWM) is a novel automated mapping method for catheter ablation of an accessory pathway (AP), in which the local signal is annotated with window‐of‐interest parameters to analyze both atrial and ventricular signals. This study aimed to determine the utility of OWM in visualizing the location and width of APs in patients with Wolff‐Parkinson‐White syndrome. Methods: This two‐center study enrolled 30 patients (20 males; mean age: 56 years, interquartile range [IQR]: 22–69 years) who underwent high‐density OWM with the extended early‐meets‐late (EEML) algorithm using a 20‐electrode, 5‐spline catheter (PENTARAY, Biosense Webster). The lower threshold of the EEML was set to adjust the EEML gap to match the propagation mapping, and broad APs were defined as an EEML gap > 1 cm. Results: The median mapping points, mapping time, and lower threshold of the EEML were 2482 (IQR: 1755–4000) points, 23 (IQR: 15–30) min, and 23 (IQR: 18–25), respectively. All 30 APs (24 in the mitral annulus and 6 in the tricuspid annulus) were successfully eliminated. Of these APs, 21 (70%) were eliminated by the first radio frequency (RF) application. OWM revealed broad APs in 11 patients (37%), in four of whom (36%) the first RF application achieved a loss of AP conduction (vs. 90% of patients without broad APs; p =.004). Conclusion: OWM facilitates the visualization of the location and width of APs, which may be particularly useful for predicting whether multiple RF applications are required for broad APs. [ABSTRACT FROM AUTHOR]

This is a challenging case of Wolff-Parkinson-White syndrome which was located in the right posteroseptum region. Patient had a previous unsuccessful attempt at ablation. It is often difficult to precisely locate this type of accessory pathway. A repeat procedure using 3D electroanatomic mapping, the electroanatomic geometry of the heart was created. The accessory pathway potential was identified and the accessory pathway was successfully ablated in minimum amount of time. In this case report showed that the advanced three-dimensional cardiac mapping system plays a very important role in guiding clinicians in order to precisely locate and safely ablate this type of challenging accessory pathway. [ABSTRACT FROM AUTHOR]