We report the case of a female neonate admitted to the neonatal ICU with a rapid, narrow-complex tachyarrhythmia determined to be supraventricular tachycardia. Multimodality imaging and genetic testing confirmed a diagnosis of tuberous sclerosis complex with multiple cardiac rhabdomyomas. At 13 days of age, the patient was readmitted, exhibiting recurrent supraventricular tachycardia non-responsive to first-line treatment. Management required triple-drug therapy, whereafter the patient remained stable without recurrences. This is a rare report of supraventricular tachycardia in a functionally normal heart with the occurrence of supraventricular tachycardia due to structural abnormalities, with the possibility of multiple concealed accessory pathways.

Congenital left ventricle to coronary sinus fistula is a rare entity. We report a case of an infant with prenatal finding of left ventricle to right atrial shunt. The anatomy was defined by multi-modality imaging. Baseline electrocardiogram was notable for a Wolff–Parkinson–White pattern. He underwent successful catheter device closure of the left ventricle to coronary sinus fistula. The patient developed supraventricular tachycardia and underwent successful ablation of the accessory pathway.

Diabetic ketoacidosis is one of the most serious and common complications of diabetes, with between 15 and 70% of new-onset type 1 diabetes mellitus worldwide presented with diabetic ketoacidosis. Supraventricular tachycardia, however, is an infrequent complication of diabetic ketoacidosis. We present the case of a child with a new-onset type 1 diabetes mellitus with supraventricular tachycardia as a complication of paediatric diabetic ketoacidosis. The patient received intravenous fluid resuscitation, insulin, and potassium supplementation and subsequently developed stable supraventricular tachycardia initially, confirmed on a 12-lead electrocardiogram despite a structurally normal heart and normal electrolytes. Vagal manoeuvers failed to achieve sinus rhythm. The patient went into respiratory distress and was intubated, for mechanical ventilation. She received one dose of adenosine with successful conversion to sinus rhythm and a heart rate decreased from 200 to 140 beats per minutes. We conclude that supraventricular tachycardia can occur as a complication of diabetic ketoacidosis, including in new-onset type 1 diabetes mellitus. Furthermore, a combination of acidosis, potassium derangement, falling magnesium, and phosphate levels may have precipitated the event. Here, we report a case of supraventricular tachycardia as a complication of paediatric diabetic ketoacidosis.

Although a high percentage of foetuses with supraventricular tachycardia respond to single or dual antiarrhythmic therapy, on occasion when there is no response to these combination regimens, direct intra-foetal therapy remains the only choice, albeit such an approach carries a potential risk to the foetus.

Data with regard to the safety and efficacy of triple antiarrhythmic combination have not been reported before. Here, we present a foetus with intractable tachycardia in whom arrhythmia termination was successfully achieved with triple oral antiarrhythmic therapy.

We report an 11-year-old male with intermittent palpitations episodes, and no other pathological findings were found. With the standard Holter electrocardiogram, there is only the option of 24 to 72 hours monitoring of the patient. A Holter Nuubo ™ Vest was placed for 33 days and a supraventricular tachycardia was found.

There has been great concern with the use of radiofrequency ablation in infants since radiofrequency ablation lesions were shown to have a progressing nature in immature myocardium of animals. In this report, we present a 2-month-old infant with life-threatening medically refractory supraventricular tachycardia. Radiofrequency ablation successfully cured arrhythmia; however, late effects of radiofrequency ablation lesions resulted in a progressive mitral valve perforation requiring surgical repair.

We report on a 14-year-old boy with focal atrial tachycardia. After failure of catheter ablation and medical therapy he received 2 g omega-3 fatty acid supplementation while waiting on repeat ablation. Focal atrial tachycardia disappeared 4 weeks later and antiarrhythmic therapy was terminated. We discuss the antiarrhythmic effect of omega 3-fatty acids on the autonomous nervous system based upon six 24-hour Holter electrocardiographs.

Puncturing the atrial septum is frequently used in adults. In children, the transseptal puncture is less common, technically more demanding, and the rate of complications is not well described. We studied the feasibility and safety of this procedure in a retrospective analysis of 157 consecutive children undergoing transseptal puncture for radiofrequency catheter ablation of left atrial targets in two tertiary-care centres between 2005 and 2013. The median age of the patients at intervention was 12.5 years (1.1–18 years), with median weight of 42 kg (range 9.0–97.0 kg). Pre-excitation was found in 102 procedures, accessory pathway with exclusively retrograde conduction in 41, focal atrial tachycardia in nine, left-sided permanent junctional/reciprocating tachycardia-like accessory pathways in three, and atypical atrioventricular nodal re-entry tachycardia in two. All the procedures were guided by fluoroscopy. Additional imaging by transoesophageal echocardiography was used in three patients. Successful transseptal puncture was possible in 99.4% of the cases, ablation in 97.4%. The median time, including mapping and radiofrequency ablation, was 120 minutes (range 60–450), the median fluoroscopy time 10.8 minutes (range 1.8–75), and the median radiation dose 3 Gy cm2 (range 0.3–35). In total, five patients (3.2%) had a recurrent arrhythmia during the observation period of a median of 40 months (range 1–103). No complications associated with the transseptal puncture were observed. Transseptal puncture is a feasible and safe procedure in children. This access allows successful and efficient radiofrequency ablation of arrhythmia of the left atrium in the vast majority of the patients and might be considered as the first-line approach in this population.

It has been reported that the presence of intermittent pre-excitation indicates low risk of rapid conduction via the accessory pathway in atrial fibrillation. We report a case of a 10-year-old boy with a history of intermittent pre-excitation who presented with atrial fibrillation with very rapid conduction.

An 8-year-old girl with supraventricular tachycardia and an implanted vagus nerve stimulator underwent radiofrequency ablation of her supraventricular tachycardia substrate. No known literature exists addressing the potential interaction of these two technologies, although there are reported cases of interaction between radiofrequency and other implanted stimulating devices such as pacemakers. The procedure was performed successfully without observed interaction, and the patient’s family reported no significant change in frequency of seizure control.

Introduction: Digoxin or propranolol are used as first-line enteral agents for treatment of infant supraventricular tachycardia. We used a large national database to determine whether enteral digoxin or propranolol was more effciacious as first-line infant supraventricular tachycardia therapy. Materials and Methods: The Pediatric Health Information System database was queried over 10 years for infants with supraventricular tachycardia initiated on enteral digoxin or propranolol monotherapy. Patients were excluded for Wolff–Parkinson–White, intravenous antiarrhythmics (other than adenosine), or death. Success was considered as discharge on the initiated monotherapy. Risk factors for successful monotherapy and risk factors for readmission for supraventricular tachycardia for patients discharged on monotherapy were determined. Results: A total of 374 patients (59.6% male) met the study criteria. Median length of stay was 7 days (interquartile range of 3–16 days). Patients had CHD (n=199, 53.2%) and underwent cardiac surgery (n=123, 32.9%), ICU admission (n=238, 63.6%), mechanical ventilation (n=146, 39.0%), and extracorporeal membrane oxygenation (n=3, 0.8%). Pharmacotherapy initiation was at median 37 days of life (interquartile range of 12–127 days) and 47.3% were initiated on digoxin. Success was similar between digoxin (73.1%) and propranolol (73.5%). Initial therapy with digoxin was not associated with success (odds ratio 1.01, 95% CI 0.64–1.61, p=0.93). Multivariable analysis demonstrated hospital length of stay (odds ratio 0.98, 95% CI 0.98–1.00) and involvement of a paediatric cardiologist (odds ratio 0.46, 95% CI 0.29–0.75) associated with monotherapy failure, and male gender (odds ratio 1.66, 95% CI 1.03–2.67) associated with monotherapy success. No variables were significant for readmission on multivariable analysis. Discussion: Digoxin or propranolol may be equally efficacious for inpatient treatment of infant supraventricular tachycardia.

Background: “ALARA – As Low As Reasonably Achievable” protocols reduce patient radiation dose. Addition of electroanatomical mapping may further reduce dose. Methods: From 6/11 to 4/12, a novel ALARA protocol was utilised for all patients undergoing supraventricular tachycardia ablation, including low frame rates (2–3 frames/second), low fluoro dose/frame (6–18 nGy/frame), and other techniques to reduce fluoroscopy (ALARA). From 6/12 to 3/13, use of CARTO® 3 (C3) with “fast anatomical mapping” (ALARA+C3) was added to the ALARA protocol. Intravascular echo was not utilised. Demographics, procedural, and radiation data were analysed and compared between the two protocols. Results: A total of 75 patients were included: 42 ALARA patients, and 33 ALARA+C3 patients. Patient demographics were similar between the two groups. The acute success rate in ALARA was 95%, and 100% in ALARA+C3; no catheterisation-related complications were observed. Procedural time was 125.7 minutes in the ALARA group versus 131.4 in ALARA+C3 (p=0.36). Radiation doses were significantly lower in the ALARA+C3 group with a mean air Kerma in ALARA+C3 of 13.1±28.3 mGy (SD) compared with 93.8±112 mGy in ALARA (p<0.001). Mean dose area product was 92.2±179 uGym2 in ALARA+C3 compared with 584±687 uGym2 in ALARA (p<0.001). Of the 33 subjects (42%) in the ALARA+C3 group, 14 received ⩽1 mGy exposure. The ALARA+C3 dosages are the lowest reported for a combined electroanatomical–fluoroscopy technique. Conclusions: Addition of CARTO® 3 to ALARA protocols markedly reduced radiation exposure to young people undergoing supraventricular tachycardia ablation while allowing for equivalent procedural efficacy and safety.

A 10-year-old boy with polyvalvular dysplasia and severe involvement of both atrioventricular valves presented with palpitations. Concern was raised for atrial tachyarrhythmia due to biatrial enlargement; however, ambulatory monitoring discovered a reentrant mechanism. Electrophysiology study revealed atypical atrioventricular nodal reentrant tachycardia involving two components of the slow pathway, with inputs in the posterior septum around his dysplastic tricuspid valve. He underwent successful modification of the slow pathway using cryoablation.