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Mehmet Sertac Cekuc,1 Yasemin Sude Ergul,1 Alexa K Pius,1 Makarcyzk Meagan,2 Issei Shinohara,1 Masatoshi Murayama,1 Yosuke Susuki,1 Chao Ma,1 Mayu Morita,1 Simon Kwoon-Ho Chow,1 Bruce A Bunnell,3 Hang Lin,2 Qi Gao,1 Stuart B Goodman1 1Orthopaedic Research Laboratories, Department of Orthopaedic Surgery, Stanford University School of Medicine, Stanford, CA, 94304, USA; 2Center for Cellular and Molecular Engineering, Department of Orthopaedic Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15219, USA; 3Department of Microbiology, Immunology and Genetics, University of North Texas Health Science Center, Fort Worth, TX, 76107, USACorrespondence: Stuart B Goodman; Qi Gao, Email goodbone@stanford.edu; qigao7@stanford.eduBackground: Corticosteroids provide well-established therapeutic benefits; however, they are also accompanied by adverse effects on bone. Metformin is a widely used medication for managing type 2 diabetes mellitus. Recent studies have highlighted additional therapeutic benefits of metformin, particularly concerning bone health and oxidative stress.Objective: This research investigates the effects of prednisolone on cellular metabolic functions and bone formation using a 3D in vitro model. Then, we demonstrate the potential therapeutic effects of metformin on oxidative stress and the formation of calcified matrix due to corticosteroids.Methods: Human mesenchymal stem cells (MSCs) and macrophages were cultured in a 3D GelMA scaffold and stimulated with prednisolone, with and without metformin. The adverse effects of prednisolone and metformin’s therapeutic effect(s) were assessed by analyzing cell viability, osteogenesis markers, bone mineralization, and inflammatory markers. Oxidative stress was measured by evaluating reactive oxygen species (ROS) levels and ATP production.Results: Prednisolone exhibited cytotoxic effects, reducing the viability of MSCs and macrophages. Lower osteogenesis potential was also detected in the MSC group. Metformin positively affected cell functions, including enhanced osteoblast activity and increased bone mineralization. Furthermore, metformin effectively reduced oxidative stress, as evidenced by decreased ROS levels and increased ATP production. These findings indicate that metformin protects against oxidative damage, thus supporting osteogenesis.Conclusion: Metformin exhibits promising therapeutic potential beyond its role in diabetes management. The capacity to alleviate oxidative stress highlights the potential of metformin in supporting bone formation in inflammatory environments.Keywords: corticosteroid, osteogenesis, inflammation, bone, metformin

Hereditary sensory autonomic neuropathy type IV is a rare disorder with an autosomal recessive transmission and characterized by self-mutilation due to a lack in pain and heat sensation. Recurrent hyperpyrexia and anhydrosis are seen in patients as a result of a lack of sweat gland innervation. Self-mutilation and insensitivity to pain result in orthopedic complications and patients undergone recurrent surgical interventions with anesthesia. However, these patients are prone to perioperative complications such as hyperthermia, hypothermia, and cardiac complications like bradycardia and hypotension. We report a 5-year-old boy with hereditary sensory autonomic neuropathy type IV, developing hyperpyrexia and cardiac arrest after anesthesia.

Aim: This study aims to evaluate the clinical characteristics and outcomes of children diagnosed with sinus node dysfunction., Methods: This was a retrospective review of patients diagnosed with sinus node dysfunction in two tertiary paediatric cardiology centres in Turkey from January 2011 to June 2022., Results: In all, 77 patients (50, 64.9% males) were included, with a mean age of 8.2 ± 6.3 years and a mean weight of 28.2 ± 18.8 kg. While age-incompatible bradycardia and pauses were the most common rhythm disturbances, syncope, presyncope, and dizziness (n:33, 43%) were the most frequent initial symptoms. Structural heart disease was present in 58 (75.3%) of the 77 patients, 47 (61%) of whom were congenital. The most commonly associated CHDs were transposition of the great arteries (n:8), atrial septal defect (n:7), and atrioventricular septal defect (n:5). Seven of them also had left atrial isomerism. The remaining 19 patients were isolated. Four patients had SCN5A mutation (two of them were siblings) and two of them had Emery-Dreifuss muscular dystrophy., Conclusion: Although sinus node dysfunction is rare in children, it has been diagnosed with increasing frequency with structural heart disease, especially in patients who have undergone corrective cardiac surgery related to atrial tissue. Since sinus node dysfunction can occur at any time postoperatively, these patients should be kept under constant control. If symptomatic sinus node dysfunction is confirmed, permanent pacing is an effective therapeutic modality.

This review explores the regenerative potential of key progenitor cell types and therapeutic strategies to improve healing of complex fractures and bone defects. We define, summarize, and discuss the differentiation potential of totipotent, pluripotent, and multipotent stem cells, emphasizing the advantages and shortcomings of cell therapy for bone repair and regeneration. The fundamental role of mesenchymal stem cells is highlighted due to their multipotency to differentiate into the key lineage cells including osteoblasts, osteocytes, and chondrocytes, which are crucial for bone formation and remodeling. Hematopoietic stem cells (HSCs) also play a significant role; immune cells such as macrophages and T-cells modulate inflammation and tissue repair. Osteoclasts are multinucleated cells that are important to bone remodeling. Vascular progenitor (VP) cells are critical to oxygen and nutrient supply. The dynamic interplay among these lineages and their microenvironment is essential for effective bone restoration. Therapies involving cells that are more than "minimally manipulated" are controversial and include embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs). ESCs, derived from early-stage embryos, possess pluripotent capabilities and have shown promise in preclinical studies for bone healing. iPSCs, reprogrammed from somatic cells, offer personalized medicine applications and can differentiate into various tissue-specific cell lines. Minimally manipulative cell therapy approaches such as the use of bone marrow aspirate concentrate (BMAC), exosomes, and various biomaterials for local delivery are explored for their effectiveness in bone regeneration. BMAC, which contains mostly immune cells but few mesenchymal and VPs, probably improves bone healing by facilitating paracrine-mediated intercellular communication. Exosome isolation harnesses the biological signals and cellular by-products that are a primary source for cell crosstalk and activation. Safe, efficacious, and cost-effective strategies to enhance bone healing using novel cellular therapies are part of a changing paradigm to modulate the inflammatory, repair, and regenerative pathways to achieve earlier more robust tissue healing and improved physical function. Impact Statement Stem cell therapy holds immense potential for bone healing due to its ability to regenerate damaged tissue. Nonmanipulated bone marrow aspirate contains mesenchymal stem cells that promote bone repair and reduce healing time. Induced pluripotent stem cells offer the advantage of creating patient-specific cells that can differentiate into osteoblasts, aiding in bone regeneration. Other delivery methods, such as scaffold-based techniques, enhance stem cell integration and function. Collectively, these approaches can improve treatment outcomes, reduce recovery periods, and advance our understanding of bone healing mechanisms, making them pivotal in orthopedic research and regenerative medicine.

Despite the advancements in technology, establishing the optimal implantation technique for pediatric patients with a pacemaker (PM) indication remains challenging. Although the implantation of an epicardial PM is recommended, especially in children weighing less than 10 kg, transventricular placement of endocardial leads can be performed safely, offering a practical substitute for an epicardial pacing system, particularly in situations where a transvenous approach is unfeasible due to patient size, anatomical constraints or epicardial PM leads were not available as in our case., (© 2024 Wiley Periodicals LLC.)

Purpose: Esports players' training takes long periods and they sit for a long time during competitions, which increases their risk of obesity and urges them to develop inappropriate eating behaviors. In this study, we aimed to investigate the night-eating syndrome and food addiction in esports players., Methods: This cross-sectional study was conducted with 248 esports players who were members of a university's esports community. The study data were collected using an online questionnaire consisting of the descriptive information form, Night Eating Questionnaire, and Yale Food Addiction Scale., Results: The mean age of the sports players participating in the study was 22.19 ± 5.97 years. Of them, 55.6% had a normal body weight, 13.4% were obese, 54.4% played esports for 3 years or more, 13.3% experienced night eating syndrome, and 21.4% experienced food addiction. While the weekly duration of playing esports and skipping meals were associated with night eating syndrome, the weekly duration of playing esports and smoking were associated with food addiction (p < 0.05). Additionally, although there was no statistically significant difference, the risk of food addiction was 2.12 times higher in those with poor perceived sleep quality., Conclusion: We observed that night eating syndrome was very common in esports players and that these individuals were at risk in terms of food addiction. Since esports has a more sedentary structure than traditional sports, we suggest that esports players should be evaluated in terms of their unhealthy eating behaviors and risk of eating disorders., (© 2024. The Author(s).)

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., (© 2024 Wiley Periodicals LLC.)

Objectives: Adolescent cases suffering from obesity tend to increase in middle-income countries. This study focused on the relationship between adolescent obesity and parents body mass index (BMI) and the variables of satisfaction, diet implementation and sports promotion., Methods: This cross-sectional study was conducted among adolescents living in the Mediterranean region (n=522, evaluated n=488). Anthropometric measurements were taken by expert researchers and data were collected using face-to-face survey technique., Results: The average BMI of the adolescents and parents' was found to be above normal values. In adolescents, there was a positive and very good correlation with maternal BMI (r=0.711, p<0.01), a positive and moderate correlation with paternal BMI (r=0.512, p<0.01); In girl adolescents, it was positively and very well with maternal BMI (r=0.731, p<0.01), positively and moderately with father BMI (r=0.549, p<0.01); In boy adolescents, a positive and good correlation was found with maternal BMI (r=0.698, p<0.01), and a positive and moderate correlation with paternal BMI (r=0.459, p<0.01). In the analyzes comparing those who thought obesity threatened them (group 1) and those who did not think it threatened them (group 2), there was a statistically significant difference between the groups in terms of BMI distribution, satisfaction with body weight, diet program implementation, diet recommendation by the family and sports encouragement (p<0, 05)., Conclusions: In a cross-sectional perspective paternal obesity is also significant in adolescents and the correlation with maternal obesity is relatively more effective. Also includes evidence of individual efforts and parental contribution in adolescents who see obesity as a threat., (© 2024 Walter de Gruyter GmbH, Berlin/Boston.)

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., (© 2023. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Background: Total abnormal pulmonary venous return anomaly is a CHD characterised by abnormal pulmonary venous flow directed to the right atrium. In this study, we aimed to compare the effects of these techniques on early rhythm problems in total abnormal pulmonary venous return anomaly cases operated with conventional or primary sutureless techniques., Method: Seventy consecutive cases (median age 1 month, median weight 4 kg) who underwent total abnormal pulmonary venous return anomaly repair with conventional or primary sutureless technique between May 1 2020 and May 1 2022 were evaluated. The rate, diagnosis, and possible risk factors of postoperative arrhythmias were investigated. The results were evaluated statistically., Results: When the total abnormal pulmonary venous return anomaly subgroup of 70 cases was evaluated, 40 cases were supracardiac, 18 cases were infracardiac, 7 cases were cardiac, and 5 cases were mixed type. Twenty-eight (40%) cases had a pulmonary venous obstruction. Primary sutureless technique (57%, supracardiac n = 24, mixed = 3, infracardiac = 13) was used in 40 patients. Median cardiopulmonary bypass time (110 versus 95 minutes) and median aortic clamp time (70 versus 60 minutes), median peak lactate (4.7 versus 4.8 mmol/l) in the first 72 hours, and median peak vasoactive inotropic score in the first 72 hours of the primary sutureless and conventional technique used cases value (8 versus 10) were similar. The total incidence of arrhythmias in the conventional group was significantly higher than in the primary sutureless group (46.7% versus 22.5%, p = 0.04). Supraventricular early beat was observed in 3 (7.5%), sinus tachycardia was seen in 6 (15%), junctional ectopic tachycardia was seen in 1 (2.5%), intra-atrial reentry tachycardia was seen in 1 (2.5%), usual supraventricular tachyarrhythmia was seen in 2 cases (5%) in the primary sutureless group. In the conventional group, supraventricular early beat was observed in six of the cases (20%), sinus tachycardia in five (16.7%), junctional ectopic tachycardia in four (13.3%), intra-atrial reentry tachycardia (10%) in three, and supraventricular tachyarrhythmia in seven cases (23.3%). In the first 30 days, there was a similar mortality rate (10% versus 10%), with four patients in the primary sutureless group and three in the conventional group. The median follow-up period of the cases was 8 months (interquartile range (IQR) 6-10 months). In the follow-up, arrhythmias were detected in two cases (one supraventricular tachyarrhythmia and one intra-atrial reentry tachycardia) in the primary sutureless group and three cases (two supraventricular tachyarrhythmia, one intra-atrial reentry tachycardia) in the conventional technique. All cases were converted to normal sinus rhythm with cardioversion and combined antiarrhythmic therapy., Conclusion: Different arrhythmias can be observed in the early period in patients with operated total abnormal pulmonary venous return anomaly. Although a higher rate of rhythm problems was observed in the early period in the conventional method compared to the primary sutureless technique, no significant effect was found on mortality and morbidity between the groups.

We present two exceptional cases of 14-year-old girls diagnosed with rare cardiomyopathies (left ventricular non-compaction, and arrhythmogenic right ventricular cardiomyopathy), both presenting with the unusual finding of bidirectional ventricular tachycardia.

We report on a 12-month-old boy with an ectopic atrial tachycardia successfully treated with the ivabradine that acts on cardiac pacemaker cells by selectively inhibiting the If channel. The patient was diagnosed with supraventricular tachycardia in another centre, and multi-drug therapy was unsuccessful to restore sinus ryhthm, so he was sent to our hospital for catheter ablation. We stopped the medications the patient was taking and started using ivabradine. Sinus rhythm was restored 2 hours after ivabradine treatment was started.

Twelve-lead ECG of a child with Wolff-Parkinson-White syndrome and systolic dysfunction was consistent with the anteroseptal accessory pathway. The earliest atrial activation during electrophysiological study was found between the right anteroseptal region near the HIS. Multiple femoral tract right-sided cryotest lesions followed by radiofrequency catheter irrigated through the jugular vein route were unsuccessful. Then, non-coronary aortic cusp mapping and cryoablation were successfully performed with a retroartic approach.

Background: Isolated complete atrioventricular block is a rare disease often associated with maternal autoantibodies. This study aimed to present the midterm data of patients at our clinic diagnosed with isolated complete atrioventricular block., Methods: We evaluated 108 patients diagnosed with isolated complete atrioventricular block. Demographic data of the patients, electrocardiography, echocardiography, 24-hour Holter monitoring data, and follow-up and complications of the patients who underwent pacemaker implantation were evaluated retrospectively., Results: The mean age of the patients at diagnosis was 5.51 ± 5.05 years. At the time of diagnosis, 74.8% of the patients had no symptoms associated with complete atrioventricular block. The most common symptom was fatigue. Pacemaker implantation was needed in 88 (81.4%) patients during follow-up. Significant bradycardia was the most common pacemaker implantation indication. The mean battery life was 5.41 ± 2.65 years. The battery replacement-free period of 68 patients who underwent pacemaker implantation and continued their follow-up was 4.18 ± 2.89 (0.1-10) years. Pacemaker-related complications developed in 8 patients during follow-up. Left ventricular dysfunction developed (dyssynchrony induced) in 3 patients at follow-up, and all were paced from the right ventricular anterior wall. Those patients underwent cardiac resynchronization therapy and their left ventricular dysfunction improved., Conclusion: Isolated complete atrioventricular block is a rare disease requiring careful clinical follow-up. Patients are often asymptomatic and significant bradycardia is the most common indication for pacemaker implantation. Left ventricular dysfunction is an important cause of morbidity, especially in patients with right ventricular anterior wall pacing. Physicians should be aware of left ventricular dysfunction during follow-up. Cardiac resynchronization therapy should be considered as a treatment option for left ventricular dysfunction.

Triadin knockout syndrome has been defined as a disease with transient long QT, T wave abnormalities, and extremely severe fatal cardiac arrhythmias in young children. In this report, we wanted to share the characteristics of our two cases who presented with sudden cardiac arrest and were diagnosed with triadin knockout syndrome., Case 1: A 7.5-year-old male patient was referred to our clinic with a history of recurrent syncope and aborted cardiac arrest. There was no family history of sudden death, syncope, or arrhythmia. Physical examination, electrocardiography, echocardiography, and 24-hour rhythm Holter monitoring were normal, and bidirectional ventricular tachycardiaT was detected during the exercise stress test. Genetic analysis revealed a homozygous mutation of c.531&#95;533delinsGG, p.(Lys179Asnfs * 44) frameshift variant in TRDN(NM&#95;006073) gene., Case 2: A 4.5-year-old male was admitted due to syncope during exertion and underwent cardiopulmonary resuscitation due to sudden cardiac arrest. He had family history about sudden cardiac death. Physical examination was normal, and there was borderline QTc prolongation. Bidirectional non-sustained polymorphic ventricular tachycardia was observed at adrenaline provocation test. In genetic analysis, c.568dupA, pII190Asnfs * 2 frameshift variant homozygous mutation was detected in TRDN(NM&#95;006073) gene. Intracardiac defibrillator implantation were performed for both cases. There has not been any event under propranolol and flecainide combination treatment., Conclusion: Triadin knockout syndrome (TCOS) is a rare overlap syndrome characterized by highly malignant arrhythmias, and it is a deadly combination of long QT syndrome and catecholaminergic polymorphic ventricular tachycardia that affects primarily young children. Since lethal arrhythmias are frequently described, genetic testing is very important in these patients. Because, identification of a genetic mutation may be a guide in treatment.

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.

Objectives: Fasciculoventricular fiber (FVF) that does not cause tachyarrhythmia is a rare form of ventricular preexcitation, which is important to distinguish from Kent fibers. Although, adenosine and some electrocardiographic features are important in the differentiation of Wolff Parkinson White (WPW) than FVF, a clear distinction may not always be possible without an electrophysiological study (EPS). In this study, we aimed to present the clinical and electrophysiological features of our pediatric patients with fasciculoventricular fiber., Patients and Method: Between October 2013 and September 2021, 565 patients who underwent electrophysiological studies due to ventricular preexcitation in our clinic were screened in the study, and 27 (4.7%) patients with fasciculoventricular fiber were included. The data of the patients were obtained from the file records using the electronic internet database system Filemaker ® . Electrophysiological study age, weight, gender, symptom, and presence of congenital heart disease of the patients were obtained from the file records. Accessory pathway localization was evaluated according to the modified Arruda algorithm in pre-procedural electrocardiography. In addition, delta wave amplitudes were measured in the first 40 ms from the surface ECG. PR interval, QRS interval, and delta wave amplitude were recorded before and after ablation in patients with additional accessory pathways. Post-procedure values were included in the FVF group., Results: The mean age of the patients was 11.47 ± 4.25 years. All 70.4% of the reasons for admission were symptoms such as palpitations and syncope. Two patients had hypertrophic cardiomyopathy and 1 patient had ccTGA. In the electrophysiological study, additional manifest WPW was found in 9 (33%) patients (3 patients with high risk, 6 patients with orthodromic supraventricular tachycardia), focal atrial tachycardia in a patient, and atrioventricular nodal reentry tachycardia in a patient. While the delta wave amplitude was found to be 2.56 ± 1.38(1-5.5) mm in the first 40 ms in surface electrocardiography in 9 patients with additional accessory pathway, it was found to be 1.64 ± 0.67(0.5-3) mm in the FVF group. There was no statistically significant difference between the 2 groups (p = .398). Delta wave amplitude > 3.5 mm was not detected in any patient with isolated FVF. Interestingly, delta wave amplitude was < 3.5 mm in 7 (78%) of 9 patients who were identified and ablated with an additional accessory pathway. Total 19 of the patients (59.3%) were adenosine-responsive (18 isolated FVF, 1 manifest AP+FVF adenosine-responsive. 8 patients with other manifest AP + FVF had no pre-procedural adenosine-asystole response, and all of them QRS were expanded)., Conclusion: Although, the fasciculoventricular fibers themselves are not the cause of tachyarrhythmia, the accessory pathway and other tachyarrhythmia substrate frequency accompanying these cases are quite high (approximately 40%) in EPS. The delta wave characteristics of ablated patients are very similar to FVF patients. While all patients with isolated FVF were adenosine responsive, most of those with additional manifest WPW were unresponsive. Therefore, performing EPS in patients with suspected FVF based on surface ECG features seems to be important for the detection of additional tachyarrhythmias and risky accessory pathways., (© 2022 Wiley Periodicals LLC.)

A young child presented with hepatomegaly, ascites and bradycardia in the setting of COVID-19. Permanent complete atrioventricular block and severe right heart failure were diagnosed. He was treated with surgical epicardial pacemaker implantation. This report is the first description of COVID-19-induced permanent complete atrioventricular block in a child.

Background: Mitochondrial fatty acid oxidation disorders (FAODs) cause impairment in energy metabolism and can lead to a spectrum of cardiac pathologies including cardiomyopathy and arrhythmias. The frequency of underlying cardiac pathologies and the response to recommended treatment in FAODs was investigated., Methods: Sixty-eight children (35 males, 33 females) with the diagnosis of a FAOD were included in the study. Cardiac function was evaluated with 12-lead standard electrocardiography, echocardiography, and 24 h Holter monitoring., Results: Forty-five patients (66%) were diagnosed after disease symptoms developed and 23 patients (34%) were diagnosed in the pre-symptomatic period. Among symptomatic patients (n: 45), cardiovascular findings were detected in 18 (40%) patients, including cardiomyopathy in 14 (31.1%) and conduction abnormalities in 4 (8.8%) patients. Cardiac symptoms were more frequently detected in primary systemic carnitine deficiency (57.1%). Patients with multiple acyl-CoA dehydrogenase, long-chain 3-hydroxyacyl-CoA dehydrogenase, and mitochondrial trifunctional protein deficiencies also had an increased frequency of cardiac symptoms. Patients with medium-chain acyl-CoA dehydrogenase, very long-chain acyl-CoA dehydrogenase, and carnitine palmitoyltransferase I deficiencies had a lower prevalence of cardiac symptoms both during admission and during clinical follow up. Cardiomyopathy resolved completely in 8/14 (57%) patients and partially in 2/14 (14.3%) patients with treatment. Two patients with cardiomyopathy died in the newborn period; cardiomyopathy persisted in 1 (7.1%) patient with very long-chain acyl-CoA dehydrogenase deficiency., Conclusion: Early diagnosis, treatment and follow up made a significant contribution to the improvement of cardiac symptoms of patients with FAODs., (© 2022 Japan Pediatric Society.)

We report a patient with long QT syndrome who received an inappropriate implantable cardioverter-defibrillator shock due to electrical interference from a refrigerator. This electrical interference was mistakenly detected as an episode of ventricular fibrillation and ended with an inappropriate delivery of shock without any warning symptoms before.

Purpose: Aortic cusps might be the source of supraventricular or ventricular arrhythmias. For many years, aortic cusp ablation has been widely used to treat premature ventricular contractions (PVCs) and ventricular tachycardia (VT). However, the data on the outcomes of this procedure in children are limited. The study aimed to convey or describe our own aortic cusp ablation experiences in children and, thus, contribute to the literature., Methods: The focus was pediatric cases of ventricular arrhythmia in which the origin of the PVCs was ablated above the Valsalva. The sample comprised patients who underwent aortic cusp ablation between 2013 and 2018. The demographic characteristics, noninvasive test results, procedure details, and follow-up results for the patients were noted., Results: The 3D EnSite Precision cardiac mapping system and limited fluoroscopy were used. A total of 26 procedures were performed on 22 patients. The mean age was 14.4 ± 3.0 (9-19) years, and the mean weight was 57.3 ± 17.5 (27-99) kg. The mean follow-up period after the first presentation was 38.6 ± 22.9 (3-72) months. There were significant differences in the values of the transition index, V2S/V3R, IIR/IIIR, aVRS/aVLS ratio, and QRS polarity in I at various locations. The most common ablation site was the left coronary cusp (LCC). Radio frequency (RF) ablation, cryoablation, and irrigated RF ablation were found to be effective energy sources in 15, 4, and 3 patients, respectively. Patients who underwent ablation at the LCC-right coronary cusp (RCC) commissure were more likely to present with only VT and to experience worsening symptoms. Twelve patients had previously undergone ablation of the right ventricular outflow tract (RVOT). Ablation in the RVOT had been previously performed in all the patients who eventually underwent ablation at the RCC and the LCC-RCC commissure., Conclusion: Aortic cusp ablation can be safely performed in children. The careful evaluation of previous noninvasive tests provides important data for determining the location. There might be significant differences in the signs and requirements on the basis of the locations during mapping and ablation., (© 2020. Springer Science+Business Media, LLC, part of Springer Nature.)

Objective: Cardiac catheterization remains a major source of radiation exposure for patients with congenital heart disease. This study reports the magnitude of radiation with a 3.75 frame per second (fps) pulse fluoroscopy rate and compares the reduction with the previous 15 fps protocol during cardiac catheterization for pediatric and adult congenital heart disease., Material and Methods: All diagnostic and interventional cardiac catheterization procedures from a single tertiary center were analyzed from January 1, 2014 to December 31, 2015, one year before and after implementing lower starting pulse fluoroscopy rates. The radiation dose was quantified as air kerma dose (mGy) and dose-area product (DAP; µGy/m 2 ). Radiation exposure was analyzed for diagnostic and interventional procedures; the diagnostic group was subdivided into cyanotic and acyanotic patients, whereas the interventional group was subdivided according to the most common indications., Results: A total of 786 procedures were analyzed. The median fluoroscopy times and contrast amounts did not show a statistically significant difference between both periods (487 vs. 456 seconds and 42.5 vs. 45.3 cm 3 ). The median air kerma for all procedures showed an 88% reduction after implementing lower pulse fluoroscopy rates (340-41 mGy). The doses were reduced significantly for diagnostic and interventional angiograms from 470 mGy and 162 mGy to 40 mGy and154 mGy. Among all patient groups, the most striking decrease was observed in the diagnostic procedures we use, of which fluoroscopy is more prominent than cine angiography., Conclusion: We claim that novel radiation dose reduction protocols could be easily applied without increasing fluoroscopy time or losing image quality., Competing Interests: Conflict of Interest: The authors have no conflict of interest to declare., (© Copyright 2021 by The Turkish Archives of Pediatrics.)

Objectives: In recent years, cardiac resynchronization therapy (CRT) has also started to be performed in the paediatric and CHD population. This study aimed to evaluate the efficacy of CRT in children with CHD., Patients and Methods: Patients with CHD who underwent CRT treatment in our paediatric cardiology clinic between January, 2010 and January, 2020 were included in the study. Demographic findings, 12-lead electrocardiograms, echocardiograms, clinical characteristics, management strategies, and outcomes were reviewed systematically., Results: The study population consisted of 18 CHD patients who had been treated with CRT for 10 years in our institution. The median age was 11 years (2.2-18 years) and the median weight was 39 kg (10-81 kg). Systemic ventricle was left ventricle in 13 patients, right ventricle in 4 patients, and 1 patient had single-ventricle physiology. CRT implantation indications were as follows: dysfunction after permanent pacemaker in 11 patients, dysfunction after left bundle branch block in 4 patients, and systemic ventricular dysfunction in 3 patients. CRT implantation techniques were epicardial (n = 13), hybrid (n = 4), and transvenous (n = 1) methods. QRS duration significantly decreased after CRT implantation (160 versus 124 m/second, p < 0.05). Median systemic ventricle ejection fraction (EF) significantly increased after the procedure (30 versus 50%, p < 0.05). Fourteen patients (78%) were responders, two patients (11%) were superresponders, and two patients (11%) were non-responders after the CRT treatment. One patient deceased during follow-up. Median follow-up duration was 40 months (6-117 months)., Conclusion: When electromechanical dyssynchrony occurs in paediatric cases with CHD and developing heart failure, patients should be evaluated in terms of CRT to improve ventricular function. Alternative CRT therapy will be beneficial in these cases that do not improve clinically despite optimal medical treatment.

Objective: This study demonstrates the clinical and electrophysiological details of catheter ablation conducted in children with focal atrial tachycardia using three-dimensional electroanatomic mapping systems., Patients and Methods: Electrophysiological procedures were performed using the EnSite™ system., Results: Between 2014 and 2020, 60 children (median age 12.01 years [16 days-18 years]; median weight 41.5 kg [3-98 kg]) with focal atrial tachycardia and treated with catheter ablation were evaluated retrospectively. Tachycardia-induced cardiomyopathy was developed in 15 patients (25%). Most of the focal atrial tachycardia foci were right-sided (75%), and more than one focus was found in four patients. Radiofrequency ablation was performed in 47 patients (irrigated radiofrequency ablation in seven cases), cryoablation in 9, and radiofrequency ablation and cryoablation in the same session in 4 patients. The median procedural time was 163.5 minutes (82-473 minutes). Fluoroscopy was used in 29 of (48.3%) patients (especially for left-side substrate) with a mean time of 8.6 ± 6.2 minutes. The acute success rate was 95%. The procedure failed in three patients, and recurrence was observed in 3.5% of patients (2/57) during a median follow-up of 17 months (2-69 months). The second ablation was performed in four cases, of which three were successful. Overall success rate was 96.6% with no major complications observed, except in one patient with minimal pericardial effusion., Conclusion: Catheter ablation seems to be an effective and safe treatment in focal atrial tachycardia. Electroanatomic mapping system can facilitate the ablation procedure and minimise radiation exposure.

Cardiac pacemakers have improved patient survival and quality of life, although malfunctions can be seen. We present the case of a girl with Seckel syndrome and congenital complete heart block. She had a single chamber permanent pacemaker in the right ventricle. When she referred us with a pulmonary hypertensive crisis (PHC), it was seen that the device was not pacing even in maximum threshold and pulse width values. After new epicardial lead implantation into the left ventricular apex, capture could be established again. For the cases presenting with capture failure, after eliminating lead-related problems and biochemical abnormalities, PHC should be kept in mind as a reason., (© 2020 Wiley Periodicals LLC.)

Background: Hypertrophic cardiomyopathy (HCM) is the second most common pediatric cardiomyopathy. Although there is a large body of literature about HCM in adults, there is limited information on HCM in childhood. We evaluated various aspects of pediatric HCM patients treated at our center., Methods: We identified 152 pediatric patients with HCM between October 2011 and October 2019. Clinical history, invasive (ICD, pacemaker, electrophysiologic study, catheter ablation therapy) and non-invasive (ECG, holter moniterization, echocardiography, cardiac MR, genetic study, medicam treatment) data were collected and evaluated., Results: The mean ± standard deviation age of patients was 8.9 ± 5.7 years (1 month-18 years) and 67.8% were male. The most frequent clinical symptoms were murmur and palpitations. Three cases (2%) had aborted sudden death as the first manifestation of HCM. Of these patients, 120 (78.9%) had non-syndromic HCM and 32 (27.2%) had syndromic HCM. Asymmetric septal hypertrophy was common (48.3%) in the non-syndromic group, whereas concentric hypertrophy was common (56.2%) in syndromic group. Left ventricular outflow tract obstruction (LVOTO) occurred in 39 (25.6%) patients. Nine (5.9%) patients underwent electrophysiologic study and/or ablation and 16 patients underwent surgical intervention. Implantable cardioverter defibrillator (ICD) insertion was performed in 38 patients (26 transvenous, 12 epicardial). ICDs were inserted in three (7.9%) patients for secondary prevention; in the remaining patients (92.1%) the devices were placed for primary prevention. Mean SD follow-up time was 27.1 ± 22 months. Five (3.3%) patients died during the follow-up. No patient had heart transplantation or a long-term assistive device., Conclusion: The etiology of HCM is heterogeneous and present at any age. It is important to determine the timing of surgery and potential risks for sudden cardiac arrest. As most cases of HCM are familial, evaluation of family members at risk should be a routine component of clinical management., (© 2020 Japan Pediatric Society.)

Background: Permanent pacemaker (PM) implantation is performed for various indications and by different techniques in children; however, many problems with lead performance are encountered during follow-up. This study aims to evaluate the possible effects of different lead types and implantation techniques on pacing at early and midterm in children with a permanent PM., Patients and Methods: Pediatric patients who underwent permanent PM system implantation at our tertiary cardiac surgery center between January 1, 2010 and January 1, 2020 were evaluated retrospectively. Patients were categorized in the epicardial pacing lead (EP), transvenous pacing lead (TP), and transvenous bipolar lumenless (Select Secure [SS]) lead groups according to the lead implantation technique and lead type with the same manufacturer. Groups were evaluated statistically for demographic features, pacing type and indication for implantation, lead electrical performance, lead failure, complications, and outcome., Results: Over 10 years, 323 lead implantations were performed on 167 patients (96 males, median age 68 months [5 days-18 years]). Of 323 leads, 213 (66%) were EP, 64 (20%) were TP, and 46 (14%) were SS. Of the total, 136 of the leads were implanted in atria, and 187 were implanted in ventricles. Primary pacing indications were postoperative complete atrioventricular (AV) block (n = 95), congenital AV block (n = 71), sinus node dysfunction (n = 13), and acquired complete AV block (n = 1). Additional cardiac diseases were present in 115 patients (69%). No statistically significant difference was observed in gender, syndrome, or pacing indication (P > .05). Atrial and ventricular capture, threshold, sensing, and lead impedance measurements were not significantly different at the initial and follow-up periods (P > .05). The median follow-up duration was 3.3 years (6 months-10 years). Twenty lead failures were determined in 15 patients (EP: 14 lead failures in 10 patients; TP: two lead failures in two patients; and SS: four lead failures in three patients) during follow-up, and no statistically significant difference was found between groups (P = .466). The 5-year lead survival was 98% for TP, 95% for EP, and 90% for SS; the 10-year lead survival was 90% for TP, 70% for EP, and 70% for SS. There was no mortality related to chronic pacing or due to the procedure of implantation., Conclusions: Despite improvements in technology, lead failure is still one of the most critical problems during these patients' follow-up. Early to midterm lead survival rates of all three lead types were satisfactory., (© 2020 The Authors. Pacing and Clinical Electrophysiology published by Wiley Periodicals LLC.)

Radiofrequency catheter ablation (RFCA) procedure is performed for many tachyarrhythmias. We performed successful RFCA in a 5-year-old child for supraventricular tachyarrhythmia and Wolff-Parkinson-White syndrome. Acute circumflex artery (CxA) occlusion occurred due to RFCA. After percutaneous balloon angioplasty was performed into the CxA, the patient was treated with systemic steroid to resolve myocardial edema. To the best of our knowledge, systemic steroid was used first time for acute coronary artery injury related myocardial ischemia., (© 2020 Wiley Periodicals LLC.)

Topsy-turvy heart (TTH) is an exceedingly rare cardiovascular malformation characterized by clockwise rotation of the entire heart around its longitudinal axis. There is superoinferior ventricle positioning without the twisting of atrioventricular connections. Electrocardiography (ECG) is a simple noninvasive tool to aid the diagnosis of heart disease. In this case series, we discuss 12-lead ECG findings of three patients with TTH., Competing Interests: Declaration of Competing Interest All authors declare that they have no confict of interest., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Introduction: Congenitally corrected transposition of the great arteries (ccTGA) is a rare congenital heart defect. There are different subgroups according to the location of the heart in the thorax, apical position and situs., Objectives: The purpose of this study was to assess pediatric patients with situs inversus (SI) ccTGA (SI-ccTGA), a rare subgroup of this condition, in detail., Methods: The records of patients with SI-ccTGA followed between January 1, 2010 and January 1, 2019 in our clinic were analyzed retrospectively. Demographic features, associated cardiac defects, arrhythmias and follow-up data were recorded., Results: Twenty-one out of 120 ccTGA patients had SI. The median age was 30 months (4 days-18 years). There were hemodynamically significant associated lesions in 85.7% (n=18) of the patients. A large ventricular septal defect was found in 16 patients (76.2%), severe pulmonary stenosis in 11 (52.4%), pulmonary atresia in six (28.5%), and severe tricuspid regurgitation in two (9.5%). Eleven out of 21 patients had biventricular physiology and eight had single-ventricle physiology. Bidirectional cavopulmonary anastomosis followed by a hemi-Mustard-Rastelli operation were planned for the remaining two patients. Twelve out of 18 patients with associated defects (66.6%) were operated and surgery was planned for three more patients (16.6%). The remaining three patients were scheduled for clinical follow-up. Arrhythmias developed in two (9.5%) patients on follow-up; ablation was performed in one of them and pacemaker implantation followed by cardiac resynchronization therapy was performed in the other. Two patients died during follow-up, one after a central shunt operation and the other preoperatively due to pneumonia and sepsis., Conclusion: SI-ccTGA is not a mirror image of situs solitus ccTGA (SS-ccTGA) due to important anatomic and physiologic differences between them. SI-ccTGA patients have a lower risk of tricuspid valve regurgitation than SS-ccTGA patients. The timing of clinical presentation of these patients mainly depends on the type and severity of the associated lesions, as in all subtypes of ccTGA., (Copyright © 2020 Sociedade Portuguesa de Cardiologia. Publicado por Elsevier España, S.L.U. All rights reserved.)

Known as a benign arrhythmia and normally requiring no specific treatment, accelerated idioventricular rhythm can rarely degenerate to a life-threatening arrhythmia. Here, we present a child with left coronary cusp-originating accelerated idioventricular rhythm, degenerating into torsades de pointes and resulting in cardiac arrest, which was ablated with a cryocatheter. An 11-year-old boy, followed due to asymptomatic accelerated idioventricular rhythm before, was referred to our department because he had experienced an aborted cardiac arrest during sleep. He had been resuscitated for 5 minutes. Twenty-four-hour Holter-ECG revealed incessant accelerated idioventricular rhythm, consisting up to 90% of the whole record and two torsades de pointes attacks, triggered by accelerated idioventricular rhythm-induced "R on T" phenomenon, and resulting in syncope and cardiac arrest. Transthoracic echocardiography revealed no structural cardiac defect but mild left ventricular systolic dysfunction with an ejection fraction of 45% and shortening fraction 23%. An electrophysiologic study was conducted, and accelerated idioventricular rhythm focus was mapped to left aortic coronary cusp. A cryocatheter with an 8-mm tip was preferred for successful ablation of the accelerated idioventricular rhythm focus, due to close neighbourhood to coronary ostium. The patient was discharged in 3 days without any premature ventricular contractions or accelerated idioventricular rhythm and with normalised cardiac functions. After 9 months on follow-up, he was still asymptomatic, without any premature ventricular contractions or accelerated idioventricular rhythm and with normal cardiac functions. Although the clinical course of accelerated idioventricular rhythm is known as benign, accelerated idioventricular rhythm can rarely degenerate to a life-threatening arrhythmia. In such cases, electrophysiologic study and catheter ablation are a good option in such cases with accelerated idioventricular rhythm for an ultimate cure.

The coexistence of long QT syndrome with 2:1 or complete atrioventricular blocks has been reported in the literature, but, to the best of our knowledge, this is the first pediatric case of long QT syndrome coexisting with first-degree atrioventricular blocks( 1 - 3 ).

In Ebstein's anomaly (EA), tachycardia substrates are complex, and accessory pathway (AP) ablations are often challenging. This study demonstrates the utility of the EnSite Velocity system (St. Jude Medical, St Paul, MN) in the catheter ablation of supraventricular tachycardia in children with EA. Twenty patients [Female/Male = 8/12, median age 11.5 years (2.6-18)] with EA who underwent catheter ablation guided by the EnSite Velocity system between December 2011 and December 2016 were retrospectively evaluated. Five patients had severe EA, and two of them were at Fontan palliation pathway. The most common indications for ablations were palpitations/syncope and treatment-resistant arrhythmias. Thirty-one tachycardia substrate foci (21 manifest AP, 2 concealed AP, 4 Mahaim AP, 3 focal atrial tachycardias, and 1 typical atrioventricular nodal reentrant tachycardia) were detected in 20 patients. There were multiple tachycardia substrates in 11 patients (55%). The patient-based acute procedure success rate was 19/20 (95%), and the tachycardia-based success rate was 30/31 (97%). The mean procedure time was 170 ± 43 min (90-265). Fluoroscopy was not used in 15 (75%) patients. The mean fluoroscopy time in the remaining five patients was 3.6 ± 2.9 min (0.7-7.8). During a mean follow-up of 35.1 ± 20.3 months (6-60), tachycardia recurred in four patients (4/19, 21%). No complications were seen. Catheter ablation of arrhythmias can be performed effectively and safely in pediatric EA patients by using a limited fluoroscopic approach with the help of electroanatomical mapping systems. However, the rate of tachycardia recurrence at follow-up remains high.

Junctional ectopic tachycardia (JET) is a rare form of arrhythmia that is most commonly seen during infancy. JET is continuous and incessant, characterized by persistently high heart rates that may result in impaired cardiac function and tachycardia-induced cardiomyopathy. Despite the availability of multiple antiarrhythmic treatments, including flecainide and amiodarone, management of JET is generally very difficult. Catheter ablation has a high risk of atrioventricular block and it may require the placement of a pacemaker. Ivabradine, also known as a cardiac pacemaker cell inhibitor, is a new-generation antiarrhythmic used to treat sinus tachycardia and angina pectoris in adult patients. In this article, we present three cases of subjects with infantile congenital JET who were admitted to our clinic with a tachycardia-induced cardiomyopathy. The age of the subjects ranged from 52 days to 10 months. Although the cases of tachycardia could not be controlled by multiple antiarrhythmics, including a combination of amiodarone and flecainide combined with either propranolol or digoxin, they were rapidly converted into sinus rhythm with an ivabradine treatment of 0.1-0.2 mg/kg/day. No cardiac or other side effects were observed during ivabradine treatment, and left ventricular functions and rhythms improved within 24 hours. These three cases therefore provide hope that ivabradine may be a suitable standard initial treatment for congenital JET. However, additional research is needed to confirm the validity of these results in other circumstances., (© 2018 Wiley Periodicals, Inc.)

Aim: Our aim was to evaluate the findings and the role of intraoperative epicardial echocardiography (IEE) in the management of pediatric cardiac surgery patients., Methods: Patients evaluated with IEE between December 2015 and December 2017 were analyzed retrospectively. Demographic data, preoperative transthoracic echocardiography (TTE), and IEE reports were evaluated., Results: A total of 410 patients evaluated by IEE were included in the study. Of these, 52% were women, and 48% were men. The median age was 8.5 months (range: 1 month-7 years), and median body weight was 7.1 kg (range: 3.3-61 kg). The most common diagnoses were tetralogy of Fallot (TOF; n = 148), ventricular septal defect (VSD; n = 117), atrial septal defect (ASD; n = 57), and complete atrioventricular septal defect (AVSD; n = 48). There were minor residual lesions not requiring reestablishment of cardiopulmonary bypass (CPB) in 16.6% (n = 68), while major residual lesions requiring return to CPB were determined in 5.1% (n = 21). Major residual lesions were detected in 7 patients with TOF (4 severe right ventricular outflow tract obstructions, 2 pulmonary artery stenosis, 1 residual VSD shunt), 6 patients with VSD (hemodynamically significant residual shunts), and 5 patients with complete AVSD (3 left atrioventricular valve regurgitations, 1 right atrioventricular valve regurgitation, 1 left ventricular outflow tract obstruction). Transient bradycardia was observed in 5 patients., Conclusion: Intraoperative epicardial echocardiography provides good guidance during congenital heart surgery. IEE helps to clarify the surgical planning and decreases morbidity and mortality due to unnecessary invasive procedures, especially for pathologies involving the pulmonary artery and its branches, as well as for apical ventricular septal defects., (© 2018 Wiley Periodicals, Inc.)

Background: We aimed to evaluate rhythm abnormalities in cases of congenitally corrected transposition of the great arteries (ccTGA) and associated treatment strategies., Patients and Methods: This retrospective cohort study included 65 pediatric patients with ccTGA who were admitted to the clinic between 2009 and 2017. The patients were divided into two groups, and surgical data, Holter electrocardiographic (ECG) recordings, ECG recordings, electrophysiological data, and device implantation data on the two groups were compared., Results: Group I (n = 53, 82%) consisted of patients with significant associated lesions, and Group II (n = 12, 18%) consisted of those with minor or no associated lesions (isolated ccTGA). Rhythm abnormalities were diagnosed in 22 (34%) of the patients based on initial ECG findings and Holter ECG recordings. Eleven (17%) of these patients had atrioventricular (AV) block of different degrees, and the other 11 (17%) had supraventricular arrhythmia (SVA). The median follow-up was 49 months (range, 9-89 months), and the rhythm remained normal in 26 (42%) of the patients. Three patients died on follow-up. Of 40 patients with normal initial findings, nine required pacemaker implantation due to complete heart block, and SVA developed in seven patients on follow-up. No ventricular tachycardia was seen initially or on follow-up. Ablation was performed in four patients. During the follow-up period, pacemakers were implanted in 12 (23%) of patients in Group I and 4 (33%) of patients in Group II due to complete heart block. Cardiac resynchronization therapy (CRT) was performed in four patients due to systemic ventricular dysfunction. Notably, all four of these patients had a pacemaker implanted postoperatively., (© 2018 Wiley Periodicals, Inc.)

Timothy syndrome (TS) is a multisystemic disease that occurs because of a mutation in CACN1C gene and is characterized by prolonged QT interval. Mexiletine is a Class 1B antiarrhythmic drug that causes the disappearance of T-wave alternans by shortening QTc and peak-to-end of the T wave. It may block the development of torsades de pointes in a prolonged QT. This study presented the case of a patient diagnosed with TS and had a cardiac arrest history, prolonged QT, and T-wave alternans. After mexiletine treatment, the QTc interval shortened and T-wave alternans disappeared. Such a case has rarely been seen in the literature, and hence considered rare. This case presentation was of particular importance because it highlighted the use of mexiletine besides an initial beta-blocker treatment in the cases with TS., (© 2017 Wiley Periodicals, Inc.)

An implantable cardioverter defibrillator (ICD) storm involves very frequent arrhythmia episodes and ICD shocks, and it is associated with poor short-term and long-term prognosis. Radiofrequency catheter ablation can be used as an effective rescue treatment for patients with an ICD storm. To our knowledge, this is the first report of an infant with hypertrophic cardiomyopathy presenting with an ICD storm and undergoing successful radiofrequency catheter ablation salvage treatment for the fast left posterior fascicular ventricular tachycardia., (© 2017 Wiley Periodicals, Inc.)