Long-Term Follow-Up After Radiofrequency Catheter Ablation of Accessory Atrioventricular Pathways in Children

Outcomes of Focal Pulsed Field Ablation for Paroxysmal Supraventricular Tachycardia

BACKGROUND

Pulsed field ablation (PFA) is primarily used for treatment of atrial fibrillation as it provides better safety and efficacy. However, there are limited data available on the use of PFA for paroxysmal supraventricular tachycardia (PSVT). The study sought to describe the outcomes of PSVT ablation with a novel focal contact force (CF)-sensing PFA.

METHODS

In this first-in-human pilot study, a focal CF-sensing PFA catheter was used for mapping and ablation navigated with an electroanatomic mapping system (EAMS). Pulsed field energy was delivered as biphasic/bipolar electrical pulse trains with 2000 V/delivery. CF was controlled from 2 g to 10 g during PFA.

RESULTS

Procedural acute success was achieved without general anaesthesia or conscious sedation in all 10 patients, including 7 patients diagnosed with typical atrioventricular nodal re-entrant tachycardias and 3 patients with orthodromic reciprocating tachycardias. Successful target ablation time was 2.0 ± 0.5 seconds per patient, and the acute procedural success at the first single site was achieved in 5 patients. The mean skin-to-skin procedure time was 79.4 ± 15 minutes, PFA catheter dwell time was 50.1 ± 14 minutes, and fluoroscopy time was 6.2 ± 7 minutes. Maintenance of sinus rhythm was observed in all patients within 6-month follow-up. No serious adverse events occurred in any subjects during PFA or during the 6-month follow-up.

CONCLUSIONS

A focal CF-sensing PFA catheter could effectively, rapidly, and safely ablate PSVT in conscious patients.

CLINICAL TRIAL REGISTRATION

NCT05770921.

The High-Density Grid Catheter: a Safe Adjunctive Tool in Pediatric and Complex Congenital Heart Disease Patients

INTRODUCTION

The safety and utility of the Advisor™ High Density Grid mapping catheter (HDGC) in children and congenital heart disease (CHD) patients are not well described.

METHODS

Single-center retrospective cohort study of pediatric and CHD patients undergoing electrophysiology study and ablation to determine the effect of HDGC use on outcomes including: acute ablation success, complications, arrhythmia recurrence, fluoroscopy use, and procedure duration.

RESULTS

HDGC was used in 74/261 (28.3%) cases. HDGC subjects differed by median age (17 vs. 13 years; p < 0.001), weight (68 vs. 50 kg; p < 0.001), and prevalence of significant CHD (42% vs. 3%; p < 0.001). Arrhythmia substrates were dissimilar: HGDC cases had higher frequencies of intra-atrial re-entrant tachycardia (25.7% vs. 0.5%), atrial flutter (8.1% vs. 1.1%), ectopic atrial tachycardia (13.5% vs. 3.7%), and premature ventricular contractions (9.5% vs. 0.5%), and lower incidences of atrioventricular re-entrant tachycardia (16.2% vs. 46.1%). Complications were rare (n=5, 1.9%) with no significant difference between groups (p = 1.00). Procedure duration - but not fluoroscopy exposure - was significantly longer in HDGC cases (median 256 vs. 216 min, p < 0.001). Acute success was lower (93.2% vs. 99.4%; p = 0.01) and recurrences higher (13.2% vs. 3.8%; p = 0.016) in HDGC compared to non-HDGC cases.

CONCLUSION

HDGC use in children and CHD patients is safe and not associated with higher complication rates. The lower acute success and higher recurrence rates in HDGC cases likely reflects bias towards HDGC use in more complex arrhythmia substrates rather than less favorable ablation outcomes. This article is protected by copyright. All rights reserved.

Association of age with clinical features and ablation outcomes of paroxysmal supraventricular tachycardias

OBJECTIVE

The role of age in clinical characteristics and catheter ablation outcomes of atrioventricular nodal re-entrant tachycardia (AVNRT) or orthodromic atrioventricular re-entrant tachycardia (AVRT) has been assessed in retrospective studies categorising age by arbitrary cut-offs, but contemporary analyses of age-related trends are lacking. We aimed to study the relationship of age with epidemiological, clinical features and catheter ablation outcomes of AVNRT and AVRT.

METHODS

We recruited 600 patients (median age 56 years, 60% female) with a confirmed diagnosis of AVNRT (n=455) or AVRT (n=145) by means of an electrophysiological study. They were interrogated for arrhythmia-related symptoms with a structured questionnaire and followed up to 1 year. We analysed age as a continuous variable using regression models and adjusting for relevant covariables.

RESULTS

Both typical and atypical forms of AVNRT upraised with age while AVRT decreased (p<0.001 by regression). Female sex predominance in AVNRT was not observed in older patients. Overall, these tachycardias became more symptomatic with ageing despite a longer tachycardia cycle length (p<0.001) and regardless of the presence of structural heart disease, with a higher proportion of dizziness, syncope, chest pain or dyspnoea (p<0.005 for all) and a lower presence of palpitations or neck pounding (p<0.001 for both). Age was not associated with catheter ablation acute success, periprocedural complications or 1-year recurrence rates (p>0.05 for all).

CONCLUSIONS

Age, evaluated as a continuous variable, had a significant association with the clinical profile of patients with AVNRT and AVRT. Nevertheless, catheter ablation outcomes and complications were not significantly related to patients' age.

Contemporary procedure characteristics and outcomes of accessory atrioventricular pathway ablations in an integrated community-based health care system using a tiered approach

BACKGROUND

Since the early descriptions of large series of accessory atrioventricular pathway ablations in adults and adolescents over 20 years ago, there have been limited published reports based on more recent experiences of large referral centers. We aimed to characterize accessory pathway distribution and features in a large community-based population that influence ablation outcomes using a tiered approach to ablation.

METHODS

Retrospective analysis of 289 patients (age 14-81) who underwent accessory ablation from 2015-2019 was performed. Pathways were categorized into anteroseptal, left freewall, posteroseptal, and right freewall locations. We analyzed patient and pathway features to identify factors associated with prolonged procedure time parameters.

RESULTS

Initial ablation success rate was 94.7% with long-term success rate of 93.4% and median follow-up of 931 days. Accessory pathways were in left freewall (61.6%), posteroseptal (24.6%), right freewall (9.6%), and anteroseptal (4.3%) locations. Procedure outcome was dependent on pathway location. Acute success was highest for left freewall pathways (97.1%) with lowest case times (144 ± 68 min) and fluoroscopy times (15 ± 19 min). Longest procedure time parameters were seen with anteroseptal, left anterolateral, epicardial-coronary sinus, and right anterolateral pathway ablations.

CONCLUSIONS

In this community-based adult and adolescent population, majority of the accessory pathways are in the left freewall and posteroseptal region and tend to be more easily ablated. A tiered approach with initial use of standard ablation equipment before the deployment of more advance tools, such as irrigated tips and 3D mapping, is cost effective without sacrificing overall efficacy.

Long-Term Patient Experience Following Acutely Successful Ablation of Supraventricular Tachycardia Substrate in Children

Definitive treatment of supraventricular tachycardia (SVT) substrate involves catheter ablation. While objective success rates have been well established, long-term subjective patient experiences have not been well described. We quantify a subjective cure rate and characterize long-term patient experience after acutely successful ablation. A cross-sectional survey of pediatric patients with accessory pathways or atrioventricular nodal reentrant tachycardia who underwent acutely successful ablation from 2008 to 2012 was performed. Data were obtained from medical records and patient surveys. Patients with congenital heart disease other than patent ductus arteriosus, patent foramen ovale, or coronary artery abnormalities were excluded. Statistical analyses included Student's t-test and χ² analysis for continuous and categorical variables, respectively. Surveys were sent to 153 patients of which 147 responded with median follow-up of 7.2 (IQR 6.1-8.5) years. Of the 147 responders, 124 (84%) patients reported cure with a male predominance. Symptoms were present in 130/147 (88%) patients pre-ablation and in 53/147 (36%) post-ablation. Among those with post-ablation symptoms, 50/53 (94%) reported symptomatic improvement. Recurrence occurred in 23/147 (16%) patients and was more prevalent following cryoablation. Ablation of SVT substrate can be curative with excellent long-term results and patient satisfaction. Long-term subjective cure rate is high and there is a substantial decrease in symptoms post-ablation. Many patients continue to have symptoms following ablation; however, the majority of these patients consider themselves cured and symptoms can be attributed to other etiologies. Recurrence is uncommon and occurs more frequently following cryoablation.

Ablation in Pediatric Patients and in Association with Congenital Heart Disease

Transcatheter ablation (TA) for treatment of pediatric tachyarrhythmias was first introduced in the early 1990s. Since then, its use as an alternative to antiarrhythmic drugs to treat supraventricular tachycardias caused by accessory pathway has been increasing. Nowadays, TA can be performed with high success rates and low complication rates even in very young children. Recently, the use of different types of energy (radiofrequency and cryoenergy), special ablation catheters, and 3D nonfluoroscopic mapping systems equipped with high technological tools has further improved safety and efficacy of TA, especially in difficult substrates and in patients with congenital heart disease.

Risk Factors for Early Recurrence Following Ablation for Accessory Pathways: The Role of Consolidation Lesions

BACKGROUND

Atrioventricular reentrant tachycardia is common in children. Catheter ablation is increasingly used as a first-line therapy with a high acute success rate, but recurrence during follow-up remains a concern. The aim of this study was to identify risk factors for recurrence after accessory pathway (AP) ablation.

METHODS

Retrospective cohort study including patients who underwent AP ablation between 2013 and 2018. Cox proportional hazards model was used to examine the association between patient and procedural characteristics and recurrence during follow-up.

RESULTS

From 558 AP ablation procedure, 542 (97%) were acutely successful. During a median follow-up of 0.4 (interquartile range, 0.1-1.4) years, there were 42 (8%) patients with documented recurrence. On univariate analysis, early recurrence was associated with younger age, congenital heart disease, multiple AP, AP location (right sided and posteroseptal versus left sided), cryoablation (versus radiofrequency), empirical ablation, the lack of full power radiofrequency lesions (<50 W), radiofrequency consolidation time <90 seconds and the use of fluoroscopy without a 3-dimensional electroanatomic mapping system. On multivariable analysis, only multiple AP (hazard ratio, 2.78 [95% CI, 1.063-4.74]) and radiofrequency consolidation time < 90 seconds (hazard ratio, 4.38 [95% CI, 1.92-9.51]) remained significantly associated with early recurrence; this association remained true when analyzed in subgroups by pathway location for right and left free wall AP.

CONCLUSIONS

In our institutional experience, radiofrequency consolidation time <90 seconds after ablation of AP was associated with an increased risk of early recurrence.