We compared the results of conventional electroanatomic mapping and high-density mapping in ablations of the right ventricular outflow tract.

Between 2014 and 2024, a total of 92 patients underwent ablation using an electroanatomic mapping system. A contact force radiofrequency ablation catheter was used in all patients, except for two who underwent cryoablation.

Our study comprised two groups, with a total of 92 patients. Among them, 45 patients underwent conventional three-dimensional mapping, while 47 patients underwent high-density three-dimensional mapping. In both groups, there were three patients with nonsustained ventricular tachycardia and two patients with sustained ventricular tachycardia, and there was no statistically significant difference in the frequency of ventricular premature contractions between the two groups. There were four patients with systolic dysfunction in the high-density mapping group and four in the conventional mapping group. In the high-density mapping group, the procedure time was significantly shorter. There was a notable difference regarding the reduced fluoroscopy time. The total lesion time and number were also significantly lower in the high-density mapping group. The earliest activation time was significantly longer in this group. The procedure’s success rate was 97.9% for the high-density mapping group and 93.4% for the conventional mapping group. Successful ablation was performed on one ventricular extrasystole in the parahisian localisation in each group, while a cooled type radiofrequency catheter was used for all other cases.

In children with right ventricular outflow tract arrhythmias, high-density mapping can be used with high success rates and safety.

Left bundle branch area pacing is a recent technique gaining rapid acceptance due to its broader target area and excellent electrical parameters. The aim of this study was to demonstrate the feasibility of left bundle branch area pacing in children and share short-term results.

A retrospective study conducted at a single centre between December 2021 and April 2024 involved 19 children who underwent left bundle branch area pacing using Select Secure leads. The study included echocardiographic evaluations, pacing parameters, and follow-up outcomes.

The cohort comprised 10 males and 9 females. Median age was seven years (range 2–18), and median weight was 38 kg (range 13–56). All patients had complete atrioventricular block, with seven having isolated congenital complete atrioventricular block and 12 postoperative complete atrioventricular block. In nine patients, transitioning from epicardial to endocardial pacing resulted in ventricular dysfunction due to chronic right ventricular pacing. The remaining patients received left bundle branch area pacing initially. One patient underwent implantation in a septal position close to the left bundle due to left bundle branch area pacing infeasibility. The median post-procedure QRS duration was 92 msec (range 80–117). Median R wave amplitude, threshold, and impedance values were 14.7 mV (range 13.3–16.8), 0.7 mV (range 0.5–1.1), and 728 ohms (range 640–762), respectively. Atrioventricular (DDD mode) leads were implanted in 10 patients, and ventricular leads (VVIR mode) were implanted in nine patients. Median fluoroscopy dose was 18.7 mGy (13.5–34.52).

Left bundle branch area pacing can be safely conducted in paediatric patients exhibiting a narrow QRS duration and stable pacing parameters.

The left ventricular outflow tract is an important source of ventricular arrhythmias. Up to one-third of all idiopathic ventricular arrhythmias in patients with structurally normal hearts may arise from this region. We would like to share the results of our left ventricular outflow tract ablation using three-dimensional mapping and limited fluoroscopy.

This is a single-centre retrospective cohort study. Forty-six consecutive patients who underwent left ventricular outflow tract ablation procedures between January 2015 and June 2023 were included in the study. The EnSite Precision System (Abbott, St. Paul, MN, USA) was used to facilitate mapping and to reduce or eliminate the need for fluoroscopy.

The study group comprised 29 males and 17 females, with a mean age of 13.4 ± 4.5 years. The most common location for arrhythmias was the left coronary cusp (n : 21). Other locations, in sequence, included the junction of the right and left coronary commissure (n : 10), right coronary cusp (n : 10), left ventricular outflow tract endocardium (n:4), aorto-mitral junction (n : 1), and great cardiac vein (n : 1). Nine of these patients had previously undergone unsuccessful right ventricular outflow tract ablation at another centre. Cryoablation was performed in three patients, irrigated radiofrequency ablation in three patients, and conventional radiofrequency ablation in the remaining patients. The acute success rate was 100%, and no recurrences were observed. The mean follow-up period was 49.6 ± 24.4 months. All patients were asymptomatic and were being followed without antiarrhythmic medication.

Although left ventricular outflow tract ablations pose a risk for coronary artery and heart valve complications, they can be performed successfully and safely with the guidance of three-dimensional mapping.

In this study, we describe our experience utilising Advisor™ High Density (HD) Grid mapping catheter in transcatheter ablation of intraatrial re-entrant and focal atrial tachycardias with or without CHD.

Forty-five consecutive patients with intraatrial re-entrant and focal atrial tachycardia who underwent a transcatheter ablation procedure by using Advisor™ HD Grid mapping catheter and high-density mapping system in our hospital from January 2017 to January 2023 were included into the study.

The mean age of the patients was 14.2 ± 7.3 years (6–32 years), and the mean weight was 48.3 ± 16.2 kg (22–83 kg). Of the total 45 patients, 21 were intraatrial re-entrant tachycardia and 25 were focal atrial tachycardia. Of the 21 re-entrant circuits, 15 were classified as cavotricuspid isthmus-dependent and 5 were non-cavotricuspid isthmus-dependent. In one patient, two re-entrant circuits were identified. A transbaffle ablation was successfully performed from the left atrium in one patient. Of the 25 focal atrial tachycardia, 19 were from right atrium and 6 were from left atrium. A cryoablation was performed in only one patient and radiofrequency ablation in others. The mean procedure time was 180 ± 64 minutes. The mean follow-up period was 69.3 ± 35.3 months. Acute success was 95.5%. Recurrence was noted in two patients (4.4%).

Advisor™ HD Grid mapping catheter was found to be safe and achieved an acceptable success in transcatheter ablation of patients with intraatrial re-entrant tachycardia and focal atrial tachycardias.

This study aimed to evaluate the early outcomes of patients who underwent a concomitant therapeutic maze procedure for congenital heart surgery.

Between 2019 and 2020, eight patients underwent surgical cryoablation by using the same type of cryoablation probe.

Three patients had atrial flutter, two had Wolf–Parkinson–White syndrome, two intra-atrial reentrant tachycardia, and one had atrial fibrillation. Four patients underwent electrophysiological study. Preoperatively, one patient was on 3, two were on 2, five were on 1 antiarrhythmic drug. Six patients underwent right atrial maze and two underwent bilateral atrial maze. Five out of six right atrial maze patients underwent right atrial reduction. Nine different lesion sets were used. Some of the lesions were combined and applied as one lesion. In Ebstein’s anomaly patients, the lesion from coronary sinus to displaced tricuspid annulus was delicately performed. The single ventricle patient with heterotaxy had junctional rhythm at the time of discharge and was the only patient who experienced atrial extrasystoles 2 months after discharge. Seven of the eight patients were on sinus rhythm. No patient needed permanent pacemaker placement.

Cryomaze procedure can be applied in congenital heart diseases with acceptable arrhythmia-free rates by selecting the appropriate materials and suitable lesion sets. The application of cryomaze in heterotaxy patients can be challenging due to differences in the conduction system and complex anatomy. Consensus with the electrophysiology team about the choice of the right–left or biatrial maze procedure is mandatory for operational success.

Focal atrial tachycardia accounts for up to 10–15% of supraventricular tachycardiasubstrates in patients < 30 years. In this study, we aimed to demonstrate the outcome of transcatheter ablation procedures performed through three-dimensional electroanatomic mapping systems using minimal fluoroscopy in a paediatric cohort with focal atrial tachycardia.

Forty-nine consecutive patients with focal atrial tachycardia who underwent an electrophysiologic study and a transcatheter ablation procedure in our hospital from September 2014 to February 2020 were included into the study.

The mean weight of the patients was 48.63 ± 15.4 kg, and the mean age was 14.56 ± 3.5 (5.5–18.4) years. The tachycardia was defined as incessant in 26 patients. Thirteen patients had left ventricular systolic dysfunction with a mean left ventricular ejection fraction of 38.47 ± 12.4% on echocardiography. The mean procedure time was 148.7 ± 94.5 minutes. Transseptal puncture and thus fluoroscopy were required in nine patients. The mean fluoroscopy time was 4.51 ± 5.9 minutes. No fluoroscopy was needed in ablations performed in the right atrium. The acute success rate of the ablation procedures was 97.9%. The mean follow-up period was 50.71 ± 23.5 months. Recurrence was noted in two patients (4.2%).

The outcomes of three-dimensional electroanatomic mapping-guided transcatheter ablation procedures are promising with high acute success, low recurrence and complication rates in children with focal atrial tachycardia. The use of fluoroscopy can be significantly decreased with three-dimensional mapping systems in this group of patients.

Fascicular tachycardia is a common form of sustained idiopathic left ventricular tachycardia. This study aimed to achieve successful results with catheter ablation procedures performed through three-dimensional electroanatomic mapping using near-zero fluoroscopy in fascicular tachycardia patients.

In this study, we included 33 consecutive children with fascicular tachycardia, for whom we performed a transcatheter radiofrequency ablation procedure using the EnSite® system. Activation mapping was performed in all patients during tachycardia, and the earliest presystolic purkinje potentials were the target site for radiofrequency lesions.

Twenty-five patients were male, and eight were female. The mean weight of the patients was 39.6 ± 10.4 kg, and the mean age was 13.6 ± 2.5 years. The mean procedure time was 121.3 ± 44.3 minutes. The mean follow-up period was 18.4 ± 6.5 months. No fluoroscopy was needed in 30 patients. The mean fluoroscopy time in the remaining patients was 166.6 ± 80 seconds. All of the patients had left posterior fascicular tachycardia except for one who had left anterior fascicular tachycardia. The acute success rate was perfect (100%). No patients developed left bundle branch block or complete atrioventricular block. Recurrence developed in one patient.

We suggest that radiofrequency ablations via an electroanatomic mapping system are quite safe and effective, with high success rates in paediatric patients with fascicular tachycardia. This method has the advantage of avoiding ionising radiation exposure for both the patient and operator, thus reducing the lifetime risk of malignancy in the paediatric population.