Electrophysiological Characteristics of Intra-Atrial Reentrant Tachycardia in Adult Congenital Heart Disease: Implications for Catheter Ablation

Catheter ablation in congenital heart diseases: a French nationwide study

BACKGROUND AND AIMS

Current evidence on catheter ablation for patients with congenital heart disease (CHD) is derived from small, retrospective studies. This study aims to provide insights from a nationwide contemporary registry.

METHODS

This prospective study included all CHD patients referred for catheter ablation from 2020 to July 2024 across 28 French centres. The primary outcome was the rate of per-procedural acute success. Secondary outcomes included complications as well as freedom from arrhythmia recurrence.

RESULTS

A total of 1135 consecutive catheter ablation procedures were performed in 998 patients (mean age 46.1 ± 16 years, 55.5% male). The main primary clinical arrhythmias targeted were atrial flutter/tachycardia in 677 (59.6%), atrial fibrillation in 195 (17.2%), ventricular arrhythmia in 188 (16.6%), and atrioventricular reentrant tachycardia in 38 (3.3%), with significant variations in patterns observed based on the underlying substrate. Clinical arrhythmia was successfully ablated in 1071 patients (94.4%). The mean number of arrhythmias targeted per procedure was 1.5 ± 0.7, with overall acute success rates exceeding 90% for all arrhythmias except for ventricular arrhythmias (86.7%). Acute complication occurred in 43 procedures (3.8%), including 1 (0.1%) death. The overall 1- and 2-year recurrence-free rates were 77.3% (95% confidence interval 74.2%-80.4%) and 68.4% (95% confidence interval 64.7%-72.3%), respectively. Significant variations in recurrence rates were noted based on the type of arrhythmia and the underlying CHD.

CONCLUSIONS

Catheter ablation in patients with CHD demonstrates highly favourable acute outcomes and a low complication rate. Recurrence rates during follow-up vary depending on the targeted arrhythmia and the underlying CHD. These findings should be considered in the benefit-risk assessment.

Safety and Outcomes of Catheter Ablation for Consecutive Atrial Tachycardia in Elderly Patients After Previous Cardiac Interventions

Background: Age is a relevant risk factor for the development of atrial arrhythmias and an independent predictor of adverse cardiovascular outcomes. The incidence of atrial tachycardia (AT) is known to increase with aging, but so far, there are no data on elderly patients with AT. Therefore, we sought to assess the safety and outcomes of AT ablation in patients ≥75 years compared to those <75 years. Methods: A total of 420 consecutive patients undergoing AT ablation after previous cardiac interventions (mean 2.1 ± 0.1 prior ablation procedures) were analyzed. Safety, as well as acute and mid-term outcomes of AT ablation were compared between 140 patients ≥75 years (mean age 78.1 ± 0.2 years, 22.9% aged ≥80 years (range 80-86 years)) and 280 patients <75 years (mean age 62.2 ± 0.6 years). Results: Patients ≥75 years were more often female (54.3% vs. 38.2%; p = 0.0024) and presented with more cardiac comorbidities, including arterial hypertension (85.0% vs. 64.3%; p < 0.0001) and coronary artery disease (33.6% vs. 18.2%; p = 0.0006). Acute success of AT ablation was reached in 96.4% vs. 97.9% of patients (p = 0.5173). Major complications (1.4% vs. 0.7%; p = 0.6035) and duration of hospital stay (2 (IQR 2-4) days vs. 2 (IQR 2-3) days; p = 0.9125) did not differ significantly between groups. During a follow-up of 364 (IQR 183-729.5) days, arrhythmia recurrences occurred in 45.0% vs. 49.3% (p = 0.4684), whereas repeat ablation was less frequently performed in patients ≥75 years (25.7% vs. 36.1%; p = 0.0361). Conclusions: AT ablation in patients ≥75 years after previous cardiac interventions in tertiary arrhythmia centers is safe and effective. Therefore, AT ablation should not be ruled out in elderly patients due to age alone, but should be considered based on arrhythmia burden, symptom severity and concomitant clinical and procedural risk factors.

Prognostic implications of baseline rhythm during catheter ablation for atrial tachycardia

BACKGROUND

Atrial tachycardias (AT) occurring in patients after previous atrial fibrillation (AF) ablation are increasingly observed in clinical practice. Catheter ablation is the treatment of choice but an optimal workflow to improve patient outcome has not been defined. The purpose of this study was to assess procedural and clinical outcome depending on baseline rhythm at the beginning of AT ablation.

METHODS

A total of 380 patients (69 (61-75) years, 56.6% male) who underwent catheter ablation for consecutive AT after previous AF ablation were studied.

RESULTS

At the beginning of the procedure, 140 patients (36.8%) presented in sinus rhythm (SR), 208 (54.7%) with AT and 32 (8.4%) with AF. Patients in SR or with AT underwent shorter procedures (173 (132-213) minutes vs. 161 (120-203) minutes vs. 226 (154-249) minutes; p = 0.002) with more frequent termination to SR (87.9% vs. 81.3% vs. 56.3%; p < 0.001) than patients with AF. Acute procedural success did not differ between patients in SR or with AT but was higher compared to those with AF (96.4% vs. 97.1% vs. 87.5%; p = 0.033). During a follow-up of 290 (181-680) days, patients in baseline SR experienced arrhythmia recurrences less often (36.4% vs. 49.5% vs. 68.8%; p = 0.002) than patients with AT or AF.

CONCLUSION

Baseline rhythm during AT ablation predicts procedural and clinical outcome. Whereas acute procedural success does not differ between patients in SR or with AT, patients presenting in SR have a more favorable mid-term success rate.

Long-Term Management of Right Ventricular Outflow Tract Dysfunction in Repaired Tetralogy of Fallot: A Scientific Statement From the American Heart Association

Right ventricular outflow dysfunction, manifesting as stenosis, regurgitation, or both, is nearly universal in patients with repaired tetralogy of Fallot, precipitating a complex pathophysiological cascade that leads to increasing rates of morbidity and mortality with advancing age. As the number of adolescent and adult patients with repaired tetralogy of Fallot continues to grow as a result of excellent survival during infancy, the need to improve late outcomes has become an urgent priority. This American Heart Association scientific statement provides an update on the current state of knowledge of the pathophysiology, methods of surveillance, risk stratification, and latest available therapies, including transcatheter and surgical pulmonary valve replacement strategies, as well as management of life-threatening arrhythmias. It reviews emerging evidence on the roles of comorbidities and patient-reported outcomes and their impact on quality of life. In addition, this scientific statement explores contemporary evidence for clinical choices such as transcatheter or surgical pulmonary valve replacement, discusses criteria and options for intervention for failing implanted bioprosthetic pulmonary valves, and considers a new approach to determining optimal timing and indications for pulmonary valve replacement.

Updates in Arrhythmia Management in Adult Congenital Heart Disease

Arrhythmias are highly prevalent in adults with congenital heart disease. For the clinician caring for this population, an understanding of pathophysiology, diagnosis, and management of arrhythmia is essential. Herein we review the latest updates in diagnostics and treatment of tachyarrhythmias and bradyarrhythmias, all in the context of congenital anatomy, hemodynamics, and standard invasive palliations for congenital heart disease.

High density mapping of complex atrial tachycardia in patients after cardiac surgery

To provide an overview of the current application of high-density mapping (HDM) in the mechanism of complex atrial tachycardias (ATs). Complex ATs are frequently scar-related, after history of previous cardiac surgery and large scars. These scar-related ATs are difficult to manage medically and frequently recur after electrical cardioversion. HDM technologies have enabled rigorous elucidation of AT mechanisms in patients post cardiac surgery. This article showed the application of HDM technology in complex ATs from the mechanisms of complex ATs, the development of HDM technology, and the identification of scars or critical isthmus from HDM. HDM-guided approach is highly effective for identifying the ATs mechanism and critical isthmus.

Efficacy and Safety of Minimally Invasive Transcatheter Closure of Congenital Heart Disease under the Guidance of Transesophageal Ultrasound: A Randomized Controlled Trial

Objective

To investigate the efficacy of minimally invasive transcatheter closure of congenital heart disease (CHD) under the guidance of transesophageal ultrasound.

Methods

A total of 100 patients with CHD treated in our hospital from February 2019 to April 2020 were enrolled in the group. The patients were randomly divided into control group and research group. The control group received minimally invasive transcatheter closure under the guidance of X-ray, and the research group received minimally invasive transcatheter closure under the guidance of transesophageal ultrasound. The operative results, the intraoperative- and postoperative-related indexes, and the incidence of early postoperative complications and follow-up results were compared.

Results

First of all, we compared the results of the two groups: 48 cases of success, 2 cases of difficulty in the research group, 35 cases of success, 11 cases of difficulty, and 4 cases of failure in the control group. The success rate in the research group was higher than that in the control group (P < 0.05). Secondly, we compare the relevant indicators in the process of operation. The operation time, cardiopulmonary bypass time, upper and lower cavity obstruction time, and blood transfusion volume in the research group were lower than those in the control group (P < 0.05). In terms of postoperative-related indexes, the ventilator-assisted time, 24 h postoperative drainage, ICU time, and postoperative hospital stay in the research group were all lower than those in the control group (P < 0.05). The incidence of early postoperative complications in the research group was significantly lower than that in the control group such as secondary pleural hemostasis, pulmonary infection, pleural effusion, subcutaneous emphysema, poor incision healing, phrenic nerve loss, and right lower limb numbness (P < 0.05). All patients were followed up for 6 months, and the cardiac function of both groups returned to normal. There was no significant difference in the incidence of postoperative residual shunt and new tricuspid regurgitation. There was no significant difference in the data (P > 0.05). Considering abnormal ECG events, the incidence of abnormal ECG events (complete right bundle branch block, incomplete right bundle branch block, second- and third-degree block, left anterior branch block) in the research group was significantly lower than that in the control group (P < 0.05).

Conclusion

Minimally invasive transcatheter closure of CHD under the guidance of transesophageal ultrasound has the advantages of less trauma, less blood loss, short hospital stay, simple operation, less postoperative complications, and remarkable therapeutic effect. Minimally invasive transcatheter closure under the guidance of transesophageal ultrasound has the advantage of adapting to a wide range of syndromes and can be used for the closure of CHD in children. According to different types of CHD, registering the corresponding occlusive pathway can improve the success rate of operation. Through postoperative reexamination and regular follow-up, it is proved that minimally invasive transcatheter closure under the guidance of transesophageal ultrasound is safe, effective, and feasible.

Discrimination of atypical atrioventricular nodal reentrant tachycardia from atrial tachycardia by the V-A-A-V response

INTRODUCTION

The electrophysiological discrimination between fast-slow (F/S-) atrioventricular (AV) nodal reentrant tachycardia (NRT) and atrial tachycardia (AT) originating from the interatrial septum remains challenging. While a V-A-A-V response may occur immediately after ventricular induction or entrainment of either tachycardia, the electrophysiological dissimilarities in that response between the two tachycardias remain unclear. The purpose of this study was to identify a diagnostic indicator discriminating F/S-AVNRT from AT by examining the difference in the V-A-A-V response between the two tachycardias.

METHODS

This retrospective study included 17 patients with F/S-AVNRT [7 with common-form F/S-AVNRT using a typical slow pathway (SP) and 10 with superior type F/S-AVNRT using a superior SP] and 10 patients with reentrant AT. All 27 patients presented with long RP supraventricular tachycardia and an initial V-A-A-V response upon ventricular induction or entrainment. The V-A-A-V response in patients with F/S-AVNRT was due to dual atrial responses. We measured the interval between the first (A1) and second atrial electrogram (A2) of V-A-A-V and calculated ΔAA by subtracting A1-A2 from the tachycardia cycle length.

RESULTS

V-A-A-V responses were observed most often upon ventricular induction of F/S-AVNRT (6±5 times) as well as AT (6±6 times; P = 0.87). The V-A-A-V response upon ventricular entrainment was observed in a single patient with F/S-AVNRT versus 10 all patients with AT (P<0.001). ΔAA ranged between -80 and 228 ms in F/S-AVNRT and between -184 and 26 ms in AT. A ΔAA >26 ms predicted a diagnosis of F/S-AVNRT with a 76% sensitivity and 100% specificity, while a ΔAA ←80 ms predicted a diagnosis of AT with a 50% sensitivity and 100% specificity.

CONCLUSIONS

ΔAA is a useful, confirmatory, diagnostic indicator of F/S-AVNRT versus AT associated with the V-A-A-V response. This article is protected by copyright. All rights reserved.

Result and technique consideration of radiofrequency catheter ablation of tachycardia in patients with dextrocardia

BACKGROUND

Patients with tachycardia, in the context of pre-existing dextrocardia, could benefit from catheter ablation. However, anatomical complexities hinder effective conduct of this procedure. We aimed to retrospectively summarize the clinical characteristics and the safety and efficiency, and recommended the technique considerations.

METHODS

Twenty-one cases from 19 patients with tachycardia and dextrocardia, who underwent catheter ablation between 2009 and 2021, were enrolled. All patients underwent echocardiography and computed tomography (CT) to confirm the anatomical malformations. Transseptal puncture was guided by fluoroscopy or intracardiac echocardiography when left atrial access was necessary and the ablation process was guided by three-dimensional mapping.

RESULTS

Six cases exhibited situs solitus while nine cases exhibited situs inversus. Fourteen cases had atrial fibrillation, seven had atrial flutter, and two had atrioventricular reentrant tachycardia (AVRT); two cases had combined atrial fibrillation and atrial flutter. Acute success was achieved in 18 cases (85.7%, 18/21). The three-dimensional mapping system was not employed in the three cases which failed. During long-term follow-up (20.71 ± 21.86 months), eight cases (72.7%, 8/11) of atrial fibrillation with dextrocardia successfully attained sinus rhythm. None of AVRT cases had recurrence. Half of the atrial flutter cases with dextrocardia, especially those with a history of surgical correction for cardiac malformations, underwent recurrence. One case had cardiac tamponade.

CONCLUSIONS

Catheter ablation for tachycardia patients with dextrocardia, is safe, efficient, and feasible. It is imperative to integrate echocardiography, cardiac computer tomography, and three-dimensional mapping, and apply three-dimensional reconstruction to facilitate the success of catheter ablation. This article is protected by copyright. All rights reserved.

Electrophysiological Characteristics of Intra-Atrial Reentrant Tachycardia in Adult Congenital Heart Disease: Implications for Catheter Ablation

Background

Ultra‐high‐density mapping enables detailed mechanistic analysis of atrial reentrant tachycardia but has yet to be used to assess circuit conduction velocity (CV) patterns in adults with congenital heart disease.

Methods and Results

Circuit pathways and central isthmus CVs were calculated from consecutive ultra‐high‐density isochronal maps at 2 tertiary centers over a 3‐year period. Circuits using anatomic versus surgical obstacles were considered separately and pathway length <50th percentile identified small circuits. CV analysis was used to derive a novel index for prediction of postablation conduction block. A total of 136 supraventricular tachycardias were studied (60% intra‐atrial reentrant, 14% multiple loop). Circuits with anatomic versus surgical obstacles featured longer pathway length (119 mm; interquartile range [IQR], 80–150 versus 78 mm; IQR, 63–95; P<0.001), faster central isthmus CV (0.1 m/s; IQR, 0.06–0.25 versus 0.07 m/s; IQR, 0.05–0.10; P=0.016), faster non‐isthmus CV (0.52 m/s; IQR, 0.33–0.71 versus 0.38 m/s; IQR, 0.27–0.46; P=0.009), and fewer slow isochrones (4; IQR, 2.3–6.8 versus 6; IQR 5–7; P=0.008). Both central isthmus (R²=0.45; P<0.001) and non‐isthmus CV (R²=0.71; P<0.001) correlated with pathway length, whereas central isthmus CV <0.15 m/s was ubiquitous for small circuits. Non‐isthmus CV in tachycardia correlated with CV during block validation (R²=0.94; P<0.001) and a validation map to tachycardia conduction time ratio >85% predicted isthmus block in all cases. Over >1 year of follow‐up, arrhythmia‐free survival was better for homogeneous CV patterns (90% versus 57%; P=0.04).

Conclusions

Ultra‐high‐density mapping‐guided CV analysis distinguishes atrial reentrant patterns in adults with congenital heart disease with surgical obstacles producing slower and smaller circuits. Very slow central isthmus CV may be essential for atrial tachycardia maintenance in small circuits, and non‐isthmus conduction time in tachycardia appears to be useful for rapid assessment of postablation conduction block.