Comparison between catheter ablation versus permanent pacemaker implantation as an initial treatment for tachycardia-bradycardia syndrome patients: a prospective, randomized trial.

BACKGROUND: Clinical outcomes after catheter ablation (CA) or pacemaker (PM) implantation for the tachycardia-bradycardia syndrome (TBS) has not been evaluated adequately. We tried to compare the efficacy and safety outcomes of CA and PM implantation as an initial treatment option for TBS in paroxysmal atrial fibrillation (AF) patients. METHODS: Sixty-eight patients with paroxysmal AF and TBS (mean 63.7 years, 63.2% male) were randomized, and received CA (n = 35) or PM (n = 33) as initial treatments. The primary outcomes were unexpected emergency room visits or hospitalizations attributed to cardiovascular causes. RESULTS: In the intention-to-treatment analysis, the rates of primary outcomes were not significantly different between the two groups at the 2-year follow-up (19.8% vs. 25.9%; hazard ratio (HR) 0.73, 95% confidence interval (CI) 0.25-2.20, P = 0.584), irrespective of whether the results were adjusted for age (HR 1.12, 95% CI 0.34-3.64, P = 0.852). The 2-year rate of recurrent AF was significantly lower in the CA group compared to the PM group (33.9% vs. 56.8%, P = 0.038). Four patients (11.4%) in the CA group finally received PMs after CA owing to recurrent syncope episodes. The rate of major or minor procedure related complications was not significantly different between the two groups. CONCLUSION: CA had a similar efficacy and safety profile with that of PM and a higher sinus rhythm maintenance rate. CA could be considered as a preferable initial treatment option over PM implantation in patients with paroxysmal AF and TBS. TRIAL REGISTRATION: KCT0000155.

Combination of electrophysiological mapping, radiofrequency catheter ablation, and atrial appendectomy in a 5-year-old girl with tachycardia-induced cardiomyopathy: a case report.

BACKGROUND: Atrial tachycardia (AT) originating from the left atrial appendage (LAA) is uncommon and the most difficult arrhythmia to eliminate. Therefore, we present the case of a 5-year-old girl with tachycardia-induced cardiomyopathy (TIC) caused by AT originating from the LAA and successfully treated with RFCA associated to left atrial appendectomy. With resolution of AT, we observed a progressive improvement of LV function. The effectiveness and safety of this combination therapy were evaluated over a one-month follow-up period. CASE PRESENTATION: A 5 -year-old female was evaluated for three days of incessant cough and a syncopal episode. Surface echocardiography and 24-hour monitoring showed that the infant had persistent atrial tachycardia. Echocardiography revealed an enlarged tele diastolic diameter (46.1 mm) and malfunctioning (EF 28.53%) left ventricle. The location of the lesion at the apex of the LAA was further confirmed by electrophysiological study and RFCA. After RFCA, the infant's ECG monitor showed that sinus rhythm was maintained for up to 22 h. Subsequently, atrial tachycardia recurred and sinus rhythm disappeared. Finally, atrial appendectomy was performed and sinus rhythm returned to normal. CONCLUSIONS: The heart function of the infant improved and sinus rhythm was maintained, further demonstrating the safety and effectiveness of combined treatment with RFCA and atrial appendectomy after electrophysiological localization of AT from LAA to TIC.

[Historical developments in the diagnosis and treatment of pre-excitation syndromes (WPW)]. / Historische Entwicklung in Diagnostik und Therapie bei Präexzitationssyndromen (WPW).

In 1930, Wolff, Parkinson and White described the syndrome that bears their names. The mechanisms of supraventricular tachycardias were analyzed by brilliant electrocardiography interpretation by Pick and Langendorf. Wellens and Durrer using electrophysiologic studies analyzed the tachycardia mechanism invasively. In Germany the group by Seipel and Breithardt as well as Neuss and Schlepper studied the tachycardia mechanisms and response to antiarrhythmic drugs invasively by electrophysiological studies. Following the first successful interruption of an accessory pathway by Sealy in 1967, surgeons and electrophysiologists cooperated in Germany. Two centers, Hannover and Düsseldorf were established. Direct current (DC) ablation of accessory pathways was introduced by Morady and Scheinman. Because of side effects induced by barotrauma of DC, alternative strategies were studied. In 1987, radiofrequency ablation was introduced and thereafter established as curative therapy of accessory pathways in all locations.

Long-term outcomes of the pentaspline pulsed-field ablation catheter for the treatment of paroxysmal atrial fibrillation: results of the prospective, multicentre FARA-Freedom Study.

AIMS: Pulmonary vein isolation (PVI) is a well-established strategy for the treatment of paroxysmal atrial fibrillation (PAF). Despite randomized controlled trials and real-world data showing the promise of pulsed-field ablation (PFA) for this treatment, long-term efficacy and safety data demonstrating single-procedure outcomes off antiarrhythmic drugs remain limited. The aim of the FARA-Freedom Study was to evaluate the long-term efficacy and safety of PFA using the pentaspline catheter for PAF. METHODS AND RESULTS: FARA-Freedom, a prospective, non-randomized, multicentre study, enrolled patients with PAF undergoing de novo PVI with PFA, who were followed for 12 months with weekly transtelephonic monitoring and a 72-h Holter ECG at 6 and 12 months. The primary safety endpoint was a composite of device- or procedure-related serious adverse events out to 7 days post-ablation and PV stenosis or atrioesophageal (AE) fistula out to 12 months. Treatment success is a composite of acute PVI and chronic success, which includes freedom from any documented atrial tachyarrhythmia longer than 30 s, use of antiarrhythmic drugs or cardioversion after a 3-month blanking period, or use of amiodarone or repeat ablation at any time. The study enrolled 179 PAF patients (62 ± 10 years, 39% female) at 13 centres. At the index procedure, all PVs were successfully isolated with the pentaspline PFA catheter. Procedure and left atrial dwell times, with a 20-min waiting period, were 71.9 ± 17.6 and 41.0 ± 13.3 min, respectively. Fluoroscopy time was 11.5 ± 7.4 min. Notably, monitoring compliance was high, with 88.4 and 90.3% with weekly events and 72-h Holter monitors, respectively. Freedom from the composite primary effectiveness endpoint was 66.6%, and 41 patients had atrial tachyarrhythmia recurrence, mostly recurrent atrial fibrillation (31 patients). The composite safety endpoint occurred in two patients (1.1%), one tamponade and one transient ischaemic attack. There was no coronary spasm, PV stenosis, or AE fistula. There were four cases of transient phrenic nerve palsy, but all resolved during the index procedure. CONCLUSION: In this prospective, non-randomized, multicentre study, PVI using a pentaspline PFA catheter was effective in treating PAF patients despite rigourous endpoint definitions and high monitoring compliance and demonstrated favourable safety. REGISTRATION: Clinical Trials.gov Identifier: NCT05072964 (sponsor: Boston Scientific Corporation).

Successful high-resolution three-dimensional electroanatomical mapping and radiofrequency catheter ablation of a posteroseptal accessory pathway in a dog using CARTO 3.

A one-year-and-seven-month-old, 28 kg, male castrated crossbreed dog was presented for supraventricular tachycardia causing recurrent episodes of anorexia and lethargy. Sotalol (2.2 mg/kg q12 h) reduced the frequency of symptomatic episodes but did not provide full relief. Three-dimensional electroanatomical mapping was performed at the Ghent University Small Animal Teaching hospital using the CARTO 3. Right atrial activation mapping identified the earliest atrial activation right posteroseptal, near the tricuspid annulus. Fast retrograde ventriculoatrial conduction during tachycardia and extrastimulus testing confirmed the presence of a concealed right posteroseptal accessory pathway. Six radiofrequency catheter ablation applications were delivered, and tachycardia remained uninducible. The dog recovered well from the procedure. Sotalol was stopped three weeks later, and no more clinical signs were noted by the owner. Repeated 24-hour electrocardiography monitoring on day one and at one, three, and 12 months after the procedure showed no recurrence of tachycardia.

Tachycardia and Atrial Fibrillation-Related Cardiomyopathies: Potential Mechanisms and Current Therapies.

Atrial fibrillation (AF) is associated with an increased risk of new-onset ventricular contractile dysfunction, termed arrhythmia-induced cardiomyopathy (AIC). Although cardioembolic stroke remains the most feared and widely studied complication of AF, AIC is also a clinically important consequence of AF that portends significant morbidity and mortality to patients with AF. Current treatments are aimed at restoring sinus rhythm through catheter ablation and rate and rhythm control, but these treatments do not target the underlying molecular mechanisms driving the progression from AF to AIC. Here, we describe the clinical features of the various AIC subtypes, discuss the pathophysiologic mechanisms driving the progression from AF to AIC, and review the evidence surrounding current treatment options. In this review, we aim to identify key knowledge gaps that will enable the development of more effective AIC therapies that target cellular and molecular mechanisms.

Association of left atrial wall thickness with recurrence after cryoballoon ablation of paroxysmal atrial fibrillation.

BACKGROUND: Transmural injury plays a role in successful atrial fibrillation ablation. The effect of left atrial wall thickness (LAWT) on the efficacy of radiofrequency ablation has been identified, but data on the relationship between LAWT and cryoballoon for paroxysmal atrial fibrillation (PAF) are lacking. We aim to explore the relationship between LAWT and recurrence after cryoballoon ablation (CBA). METHODS: We studied 364 patients (mean age 62 years) with PAF who underwent a second-generation CBA and pre-procedure cardiac CTA. LAWT and left atrial volume index (LAVI) were obtained based on pre-procedure cardiac CTA measurements. Follow-up was at least 12 months and predictors of atrial tachyarrhythmia recurrence during follow-up were assessed. RESULTS: Patients were followed up for a median of 19 (12-28) months, with an atrial tachyarrhythmia-free rate of 77.5% after cryoablation. Greater LAVI (50.0 ± 19.6 mL/m2 vs. 44.3 ± 15.4 mL/m2, P = 0.018) and greater LAWT (1.67 ± 0.24 vs. 1.46 ± 0.25 mm, P < 0.001) were associated with atrial tachyarrhythmia recurrence. The mean LAWT of PV antrum correlated with TTI (R = 0.252, P < 0.001). Adding LAWT to the established risk model improved both the discrimination and reclassification effects (IDI: 0.099, 95% CI: 0.065-0.134, P < 0.001; NRI: 0.685, 95% CI: 0.455-0.915, P < 0.001). In a multivariable Cox proportional hazard model, the mean LAWT of PV antrum (hazard ratio [HR]:3.657, 95%CI: 2.319-5.765, P < 0.001) was an independent predictor of atrial tachyarrhythmia recurrence after cryoablation. CONCLUSIONS: The mean LAWT of PV antrum, obtained from preoperative measurements on CT, was associated with atrial tachyarrhythmia recurrence after cryoablation.

Trans-aortic mitral isthmus ablation after surgical patch closure for an atrial septal defect.

INTRODUCTION: In patients with prior atrial septal defect (ASD) closure and atrial tachyarrhythmias, transseptal puncture can be challenging. METHODS AND RESULTS: This case report discusses a 65-year-old man who had previously undergone pulmonary vein isolation (PVI) and cavo-tricuspid isthmus ablation for atrial fibrillation before ASD closure, respectively. He developed atrial tachycardia (AT) and underwent catheter ablation. AT was diagnosed as peri-mitral flutter and the mitral isthmus (MI) linear ablation via a trans-aortic approach successfully terminated it. CONCLUSION: This case demonstrates the feasibility and safety of transaortic MI linear ablation in patients with ASD closure devices or anatomical challenges when transseptal puncture is difficult.

Timing of critical isthmus from end of P wave and usefulness of activation mapping with window of interest from end to end of P wave in reentrant atrial tachycardia.

In activation mapping of reentrant atrial tachycardia (AT), there was no reference for window of interest (WOI). We examined the timing of a successful termination site from end of the P wave and attempted to determine whether the critical isthmus can be identified using activation mapping when WOI was set as end to end of the P wave. Forty patients with 54 reentrant AT who underwent 3D electroanatomic mapping and radiofrequency catheter ablation were evaluated retrospectively. The critical isthmus was defined as a successful termination site. We evaluate critical isthmus timing from end of the P wave and percentage of critical isthmus timing from end of the P wave to tachycardia cycle length. In 54 reentrant AT, Macro-reentry was identified in 46 (85.2%) and micro-reentry was identified in eight (14.8%). The timing of the critical isthmus site from end of the P wave was - 4.0 ± 31.1 ms (Macro-reentry vs. Micro-reentry; - 8.9 ± 29.4 ms vs. 24.0 ± 26.7 ms; P = 0.005). The percentage of critical isthmus timing from end of the P wave/tachycardia cycle length was - 1.4 ± 10.5% (Macro-reentry vs. Micro-reentry; - 3.1 ± 9.8% vs. 8.3 ± 9.3%, P = 0.004) The critical isthmus of reentrant AT is located within 10% backward and forward from end of the P wave to tachycardia cycle length. Setting the WOI from end to end of the P wave is useful for identification of the critical isthmus through activation mapping.

Identification of 2 Distinct Boundaries Distinguishes Critical From Noncritical Isthmuses in Ablating Atypical Atrial Flutter.

BACKGROUND: Atypical atrial flutters often involve complex circuits. Classic methods of identifying ablation targets, including detailed electroanatomical mapping and entrainment within a well-defined isthmus, may not always be sufficient to allow the critical isthmus to be delineated and ablated, with flutter termination and prevention of reinduction. OBJECTIVES: This study sought a systematic method to classify conduction barriers and isthmuses as critical or noncritical that would improve understanding and ablation success. We also sought a construct unifying single- and dual-loop re-entry. Re-entrant circuits are bounded on 2 sides, although these are not consistently identified. We hypothesized 2 distinct critical boundaries, and a critical isthmus could be consistently defined without requiring entrainment, and ablation connecting these 2 boundaries would terminate tachycardia. METHODS: Activation maps were created electroanatomically. Conduction barriers were classified as noncritical barriers or critical boundaries. Critical boundaries showed sequential activation around the barrier, spanning ≥90% of the cycle length. Noncritical barriers showed nonsequential, parallel, or colliding activation or <90% of the cycle length. Only tissue separating the 2 critical boundaries defined a critical isthmus (CI); all others were considered noncritical. The effect of ablation across a CI was assessed. RESULTS: Complete maps were obtained in 128 cases in 121 patients (28 atypical right atrial, 100 left atrial). In all cases, 2 distinct critical boundaries were identified. Ablation across a CI connecting these critical boundaries terminated tachycardia in 123 of 128 cases (96.1%). Failures were due to inability to achieve block across the isthmus. CONCLUSIONS: Activation mapping of atypical atrial flutter allows consistent identification of 2 critical boundaries. Successful ablation connecting the 2 critical boundaries reliably results in termination of atypical atrial flutter.

Reconsideration of the definition of blanking period and significance of early recurrences after catheter ablation of atrial fibrillation.

PURPOSE OF REVIEW: Early recurrence of atrial tachyarrhythmia (ERAT) during blanking period (BP) is not uncommon after catheter ablation of AF. Current guidelines and consensus statements recommend conservative treatment of ERAT. This review summarized recent studies, underlying mechanism and clinical managements of ERAT, and proposed a reconsideration of the definition and clinical significance of BP. RECENT FINDINGS: Recent studies have shown that the entity of ERAT in the very early phase of BP (i.e., first 4 weeks of the 3-month period) is different from those ERATs occurring late which is strongly associated with the late recurrence of atrial tachyarrhythmia. The optimal BP duration suggested by clinical observation ranges from 21 to 58 days. Using antiarrhythmic drugs and early electrical cardioversion are the effective management for ERAT, whereas re-ablation is a reasonable strategy although remains controversial. SUMMARY: The definition of BP with a shorter duration, that is, 1 month instead of 3 months post AF ablation, is supported by the observations of latest clinical studies. Recurrent atrial tachyarrhythmia beyond the 1-month time frame is associated with higher risk of late recurrence and may warrant repeat ablation. A revisit to the guideline recommendation on management of ERAT is needed to change clinical practice.

Coronary sinus ablations in pediatric patients with supraventricular arrhythmias.

BACKGROUND: Intracoronary sinus ablations have been performed for various arrhythmical substrates. The aim of this study is to report our experience on pediatric patients of the safety and efficacy of ablations in the coronary sinus. METHODS: This is a retrospective study of all patients who underwent ablations in the coronary sinus from October 2013 to October 2021 at a single center. Clinical presentation, type of arrhythmia causing tachycardia, ablation procedure, and outcome were recorded. RESULTS: A total of 27 patients were included in the study. Nineteen (69%) of those followed up received a diagnosis of Wolff-Parkinson-White syndrome (WPW), 4 (15%) were cases of supraventricular tachycardia with concealed accessory pathway (AP), 2 (8%) were cases of focal atrial tachycardia, and 2 (8%) were cases of permanent junctional reciprocating tachycardia. Negative delta wave was noteworthy especially in lead II in 11/19 (58%) cases and coronary sinus diverticulum was detected in the WPW cases. Of those with manifest AP (19 cases), 15 (79%) had a high-risk AP and the AP in all WPW cases was adenosine unresponsive. Radiofrequency (RF) catheter ablation was performed in 25/27 (93%) cases during the procedure, and 16/25 (64%) of these were irrigated RF catheters. No complications were observed in the follow-up, including coronary artery injury. CONCLUSIONS: Catheter ablation of supraventricular tachyarrhythmias can be accomplished effectively and potentially safely within the coronary sinus. Coronary sinus diverticula should be suspected in patients with manifest posteroseptal APs who have a previous failed ablation and typical electrocardiographic signs.

Catheter ablation of atrial tachyarrhythmias in patients with atrioventricular septal defect.

AIMS: The incidence of atrial tachyarrhythmias is high in patients with atrioventricular septal defect (AVSD). No specific data on catheter ablation have been reported so far in this population. We aimed to describe the main mechanisms of atrial tachyarrhythmias in patients with AVSD and to analyse outcomes after catheter ablation. METHODS AND RESULTS: This observational multi-centric cohort study enrolled all patients with AVSD referred for catheter ablation of an atrial tachyarrhythmia at six tertiary centres from 2004 to 2022. The mechanisms of the different tachyarrhythmias targeted were described and outcomes were analysed. Overall, 56 patients (38.1 ± 17.4 years, 55.4% females) were included. A total of 87 atrial tachyarrhythmias were targeted (mean number of 1.6 per patient). Regarding main circuits involved, a cavo-annular isthmus-dependent intra-atrial re-entrant tachycardia (IART) was observed in 41 (73.2%) patients and an IART involving the right lateral atriotomy in 10 (17.9%) patients. Other tachyarrhythmias with heterogeneous circuits were observed in 13 (23.2%) patients including 11 left-sided and 4 right-sided tachyarrhythmias. Overall, an acute success was achieved in 54 (96.4%) patients, and no complication was reported. During a mean follow-up of 2.8 ± 3.8 years, 22 (39.3%) patients had at least one recurrence. Freedom from atrial tachyarrhythmia recurrences was 77.5% at 1 year. Among 15 (26.8%) patients who underwent repeated ablation procedures, heterogeneous circuits including bi-atrial and left-sided tachyarrhythmias were more frequent. CONCLUSION: In patients with AVSD, most circuits involve the cavo-annular isthmus, but complex mechanisms are frequently encountered in patients with repeated procedures. The acute success rate is excellent, although recurrences remain common during follow-up.

[Clinical characteristics of 42 children with focal atrial tachycardia originated from the right atrial appendage].

Objective: To investigate the feature and treatment of atrial tachycardia (AT) originated from right atrial appendage (RAA) in children. Methods: The data of 42 children with AT originated from RAA, who were admitted the First Hospital of Tsinghua University from January 2010 to September 2022 were analyzed retrospectively.The clinical characteristics, treatment and efficacy were analyzed. The children were divided into tachycardia cardiomyopathy group and normal cardiac function group. The differences in the ablation age and the heart rate during AT between two groups were compared by independent sample t-test. Results: Among 42 children, there were 20 males and 22 females. The age of onset was 2.7 (0.6, 5.1) years. Their age at radiofrequency ablation was (6.5±3.6) years, and the weight was (23.4±10.0) kg. Thirty-two children (76%) had sustained AT. The incidence of tachycardia cardiomyopathy was 43% (18/42). Compared to that of the normal cardiac function group, the ablation age and the heart rate at atrial tachycardia of the tachycardia cardiomyopathy group were higher ((8.1±3.8) vs. (5.3±3.1) years, t=-2.63, P=0.012; (173±41) vs. (150±30) beats per minute, t=-2.05, P=0.047. Thirty-eight children (90%) responded poorly to two or more antiarrhythmic drugs. The immediate success rate of radiofrequency ablation (RFCA) was 57% (24/42), and the AT recurrence rate was 17% (4/24). Twenty-two children underwent RAA resection, and their AT were all converted to sinus rhythm after the surgery. During the RAA resection, 10 cases of right atrial appendage aneurysm were found, 9/18 of which failed the RFCA. Conclusions: The AT originated from the RAA in children tend to present with sustained AT, respond poorly to antiarrhythmic drugs, and has a low success rate of RFCA as well as high recurrence rate. Resection of the RAA is a safe and effective complementary treatment.

Coumel tachycardia in children.

BACKGROUND: Coumel tachycardia is an infrequent form of supraventricular tachycardia (SVT) that usually occurs in infants and children. It is a tachycardia mediated by an accessory pathway with retrograde slow conduction that explains the classic ECG pattern with long RP' interval and negative P waves in leads II, III, and aVF. In this study, we describe the clinical course and management of Coumel tachycardia in children. CASE REPORT: We conducted a retrospective review of five consecutive pediatric patients, mean age 11 ± 3 years (range 6 to 14). The first episode of SVT was at a mean age of 10.4 ± 4.8 years (range 2 to 14) with a mean evolution of 7.4 ± 9.4 months (range 1 to 24). Pharmacological therapy was unsuccessful despite the combination of antiarrhythmic drugs. The tachycardia was incessant with a density > 85% by 24-hour Holter monitoring; one patient developed tachycardia-induced cardiomyopathy. All children underwent successful radiofrequency catheter ablation, mean 5 ± 3 applications (range 1 to 8) with a single session and with no complications. After a mean follow-up of 24 ± 16 months, all patients were asymptomatic and recurrence-free without antiarrhythmic treatment. CONCLUSIONS: Coumel tachycardia is clinically persistent and usually refractory to antiarrhythmic treatment with substantial risk of tachycardia-mediated cardiomyopathy. Catheter ablation is effective and safe in children; thus, it should be indicated promptly and based on individual selection.

INTRODUCCIÓN: La taquicardia de Coumel es una forma poco frecuente de taquicardia supraventricular que suele presentarse en lactantes. Es una taquicardia mediada por una vía accesoria de conducción lenta retrógrada que explica el patrón ECG clásico con intervalo RP' largo y ondas P negativas en las derivaciones II, III y aVF. En este trabajo se describe el curso clínico y el manejo de la taquicardia de Coumel en niños. CASO CLÍNICO: Se llevó a cabo una revisión retrospectiva de cinco pacientes pediátricos consecutivos, con una media de edad de 11 ± 3 años (intervalos 6 a 14). El primer episodio de taquicardia 10.4 ± 4.8 años con evolución de 7.4 ± 9.4 meses. El tratamiento farmacológico fue ineficaz a pesar de la combinación de antiarrítmicos. La taquicardia era incesante con una densidad > 85% por Holter-24h; un paciente desarrolló miocardiopatía inducida por taquicardia. Todos los niños fueron sometidos a ablación con catéter y radiofrecuencia con éxito, y un promedio de 5 ± 3 aplicaciones en una sola sesión y sin complicaciones. Después de un seguimiento de 24 ± 16 meses, todos los pacientes fueron asintomáticos y libres de recurrencia sin tratamiento antiarrítmico. CONCLUSIONES: La taquicardia de Coumel es clínicamente persistente y generalmente refractaria al tratamiento antiarrítmico con un riesgo sustancial de miocardiopatía mediada por taquicardia. La ablación con catéter es eficaz y segura en niños, por lo que debe indicarse de forma temprana y en lactantes de una selección individual.

High-density Mapping Catheter (Advisor™ HD Grid) Usage for Intra-atrial Reentrant Tachycardia Ablation in Children and Young Adult Patients with Congenital Heart Disease.

BACKGROUND: We aimed to share our experience of intra-atrial reentrant tachycardia mapping and ablation with a new grid-style multielectrode high-density mapping catheter (Advisor™ HD Grid) in pediatric and young adult patients with operated congenital heart disease. METHODS: All patients with operated congenital heart disease and intra-atrial reentrant tachycardia mapping with the new grid-style catheter between October 2019 and December 2022 were included (group 1), and the results were compared to those patients who operated with conventional catheter methods before this period (group 2). All procedures were performed using the EnSite Precision 3D mapping system (Abbott Laboratories, Abbott Park, Ill, USA) with a limited fluoroscopy approach. Data were evaluated retrospectively. RESULTS: In group 1 (n = 16; 9 male), the median age was 21 years (10-36), compared to 19 years (9-27) in group 2 (n = 10; 5 male). While irrigated radiofrequency ablation was pre-ferred in all patients, the median number of 15 lesions (8-38) in group 1 was significantly less than the median of 30 lesions (8-71) in group 2 (P =.027). The median procedure duration of 159 minutes (110-233) in group 1 was significantly shorter compared to 280 minutes (180-370) in group 2 (P <.05). Acute procedural success was achieved in all patients (16/16; 100%) in group 1 compared to 8/10 patients (80%) in group 2. During the median follow-up of 27 months (11-36), there was only 1 intra-atrial reentrant tachycardia recurrence in group 1 (1/16; 6.2%) and 2 recurrences (2/8; 25%) in group 2 during the median follow-up of 110 months (56-151). No complications related to the mapping catheter itself occurred. CONCLUSION: In the intra-atrial reentrant tachycardia ablation of children with congenital heart disease to increase procedural success and shorten the mapping duration, the utility of Advisor™ HD Grid mapping catheter seems to be a feasible alternative.