Evaluation of T-wave memory after accessory pathway ablation in pediatric patients with Wolff-Parkinson-White syndrome.

BACKGROUND: T-wave memory (TWM) is a rare cause of T-wave inversion (TWI). Alterations in ventricular activation due to abnormal depolarization may cause repolarization abnormalities on the ECG, even if myocardial conduction returns to normal. These repolarization changes are defined as TWM. In our study, we aimed to determine the frequency of TWM development and the predictors affecting it in the pediatric population who underwent accessory pathway (AP) ablation due to Wolff-Parkinson-White (WPW) syndrome. METHODS: The data of patients with manifest AP who underwent electrophysiological studies and ablation between 2015 and 2021 were retrospectively analyzed. The study included 180 patients who were under 21 years of age and had at least one year of follow-up after ablation. Patients with structural heart disease, intermittent WPWs, recurrent ablation, other arrhythmia substrates, and those with less than one-year follow-up were excluded from the study. The ECG data of the patients before the procedure, in the first 24 h after the procedure, three months, and in the first year were recorded. The standard ablation technique was used in all patients. RESULTS: Postprocedure TWM was observed in 116 (64.4%) patients. Ninety-three patients (51.7%) had a right-sided AP, and 87 patients (48.3%) had a left-sided AP. The presence of posteroseptal AP was found to be significantly higher in the group that developed TWM. Of these patients, 107 (93.1%) patients showed improvement at the end of the first year. Preprocedural absolute QRS-T angle, postprocedural PR interval, and right posteroseptal pathway location were identified as predictors of TWM. CONCLUSION: The development of TWM is particularly associated with the right-sided pathway location, especially the right posteroseptal pathway location. The predictors of TWM are the preprocedural QRS-T angle, the postprocedural PR interval, and the presence of the right posteroseptal AP.

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.

Clinical Course and Electrophysiological Characteristics of Permanent Junctional Reciprocating Tachycardia in Children.

BACKGROUND: In this study, we aimed to evaluate the clinical aspects, electrophysiological studies, and ablation results of permanent junctional reciprocating tachycardia in children. METHODS: The study comprised 29 pediatric patients diagnosed with permanent junctional reciprocating tachycardia between 2011 and 2021 in 2 pediatric electrophysiology centers. From the file records, the basic demographic characteristics of the patients, as well as electrocardiographic and echocardiographic findings, were acquired retrospectively. The medical treatment and responses of the patients throughout follow-up, as well as the electrophysiological study and ablation data of the patients who had electrophysiological study, were assessed. RESULTS: The mean age at diagnosis of the patients was 3.13 ± 4.43 (0-18) years and the mean weight was 18.22 ± 19.68 (3.8-94) kg. Eighteen patients (62.1%) were girls. Eleven patients (38%) developed tachycardia-induced cardiomyopathy. Tachycardia was incessant in 15 patients (51.7%). In total, 22 patients required 26 ablation procedures. Tachycardia-induced cardiomyopathy and multidrug-resistant tachycardia were the most prevalent indications for ablation. The right posteroseptal pathway was detected in 18 patients (81.8%). The acute procedure success rate was 100% (22/22). The recurrence rate was 18% (4/22) and 3 of them underwent successful ablation again. The overall success percentage was 95.4% (21/22). None of the patients had any complications. The mean follow-up period was 4.39 ± 3.05 years. CONCLUSION: Although permanent junctional reciprocating tachycardia is uncommon, it is often persistent, resistant to medical treatment, and associated with a substantial risk of tachycardia-induced cardiomyopathy. Catheter ablation can be performed on these patients at any age, with minimal risk of complications and a high success rate. It is crucial to keep monitor of the patients' recurrence.

Prolonged QT and Torsades de Pointes in a child with late-onset post-operative complete heart block.

A young child presented with syncope attacks. Late-onset post-operative complete atrioventricular block and Torsades de Pointes were diagnosed. She was treated with surgical epicardial pacemaker implantation. This report is the description of Torsades de Pointes due to late-onset post-operative complete atrioventricular block followed by R on T phenomenon in a child.

Glycogen storage disease type 0 due to a novel frameshift mutation in glycogen synthase 2 (GYS2) gene in a child presenting with fasting hypoglycemia and postprandial hyperglycemia.

Hacihamdioglu B, Özgürhan G, Çaran B, Meydan-Aksanli E, Keskin E. Glycogen storage disease type 0 due to a novel frameshift mutation in glycogen synthase 2 (GYS2) gene in a child presenting with fasting hypoglycemia and postprandial hyperglycemia. Turk J Pediatr 2018; 60: 581-583. Glycogen storage disease type 0 (GSD0) has been considered a rare disorder, it is characterized with ketotic hypoglycemia after prolonged fasting and postprandial hyperglycemia. Herein, we report a novel mutation in the glycogen synthase 2 gene in a Turkish child, as well as her clinical characteristics and 12-month follow-up. We evaluated a 5-year-old girl for asymptomatic fasting ketotic hypoglycemia with postprandial hyperglycemia diagnosed with glycogen storage disease type 0. We identified a novel frameshift mutation, c.1081delA (p.Thr361Glnfs*2) in exon 8 on glycogen synthase 2 gene. Children with GSD0 may have a mild phenotype and GSD0 may be underdiagnosed due to subclinical or asymptomatic hypoglycemia. The diagnosis of GSD0 should be considered in a child with ketotic fasting hypoglycemia with postprandial hyperglycemia but without hepatomegaly.