Noonan syndrome (NS) is a multisystemic disorder caused by germline mutations in the Ras/MAPK cascade, causing a broad spectrum of phenotypical abnormalities, including abnormal facies, developmental delay, bleeding diathesis, congenital heart disease (mainly pulmonary stenosis and hypertrophic cardiomyopathy), lymphatic disorders, and uro-genital abnormalities. Multifocal atrial tachycardia has been associated with NS, where it may occur independently of hypertrophic cardiomyopathy. Trametinib, a highly selective MEK1/2 inhibitor currently approved for the treatment of cancer, has been shown to reverse left ventricular hypertrophy in two RIT1-mutated newborns with NS and severe hypertrophic cardiomyopathy. Severe lymphatic abnormalities may contribute to decreased pulmonary compliance in NS, and pulmonary lymphangiectasias should be included in the differential diagnosis of a newborn requiring prolonged oxygen administration. Herein we report the case of a pre-term newborn who was admitted to our unit for the occurrence of severe respiratory distress and subentrant MAT treated with trametinib.

Guidelines are important tools to guide the diagnosis and treatment of patients to improve the decision-making process of health professionals. They are periodically updated according to new evidence. Four new Guidelines in 2021, 2022 and 2023 referred to pediatric pacing and defibrillation. There are some relevant changes in permanent pacing. In patients with atrioventricular block, the heart rate limit in which pacemaker implantation is recommended was decreased to reduce too-early device implantation. However, it was underlined that the heart rate criterion is not absolute, as signs or symptoms of hemodynamically not tolerated bradycardia may even occur at higher rates. In sinus node dysfunction, symptomatic bradycardia is the most relevant recommendation for pacing. Physiological pacing is increasingly used and recommended when the amount of ventricular pacing is presumed to be high. New recommendations suggest that loop recorders may guide the management of inherited arrhythmia syndromes and may be useful for severe but not frequent palpitations. Regarding defibrillator implantation, the main changes are in primary prevention recommendations. In hypertrophic cardiomyopathy, pediatric risk calculators have been included in the Guidelines. In dilated cardiomyopathy, due to the rarity of sudden cardiac death in pediatric age, low ejection fraction criteria were demoted to class II. In long QT syndrome, new criteria included severely prolonged QTc with different limits according to genotype, and some specific mutations. In arrhythmogenic cardiomyopathy, hemodynamically tolerated ventricular tachycardia and arrhythmic syncope were downgraded to class II recommendation. In conclusion, these new Guidelines aim to assess all aspects of cardiac implantable electronic devices and improve treatment strategies.

Background/Objectives: Angiotensin receptor neprilysin inhibitor (ARNI) and sodium-glucose co-transporter 2 inhibitors (SGLT2i) are essential medications in heart failure (HF) therapy, and their potential antiarrhythmic effects have been reported. Recently, ARNI and SGLT2i use for HF in adult congenital heart disease (ACHD) has been studied. However, whether any beneficial effects may be achieved on the arrhythmic burden in the complex population of ACHD with a systemic right ventricle (sRV) is still to be determined. Methods: We retrospectively collected all significant arrhythmic events from a cohort of patients with a failing sRV attending our tertiary care center on optimal guideline-directed medical therapy (GDMT) with ARNI and/or SGLT2i. Results: A total of 46 patients (mean age 38.2 ± 10.7 years, 58% male) on sacubitril/valsartan were included. Twenty-three (50%) patients were also started on dapagliflozin. After a median follow-up of 36 [Q1–Q3: 34–38] months, arrhythmic events occurred globally in 13 (28%) patients. Survival analysis showed significant reduction of clinically relevant atrial and ventricular arrhythmia at follow-up (p = 0.027). Conclusions: Our findings suggest that GDMT including sacubitril/valsartan and dapagliflozin may also offer an antiarrhythmic effect in ACHD patients with a failing sRV, by reducing the incidence of arrhythmic events at follow-up.

Background: Pulmonary valve (PV) endocarditis is a frequent complication during follow-up in patients with repaired right ventricular outflow tract (RVOT) obstruction and poses relevant diagnostic and treatment challenges. We aimed to describe in details the possible different clinical presentations of this rare condition and to highlight the role of both transthoracic and transoesophageal echocardiography which, in experienced hands, may provide comprehensive useful information for the clinicians. Case summary: We below describe the clinical presentation and the echo findings of three cases of pulmonary valve endocarditis complicating disease course after different repair modalities of congenital right ventricular outflow tract obstruction. Discussion: The present case series outlines the diagnostic challenges of this increasingly frequent complication during follow-up of patients with congenital RVOT dysfunction after both surgical and percutaneous repair. Despite the diffusion of multimodality imaging, echocardiography with PV-dedicated views play a pivotal role in diagnosing such condition and guiding clinical management. Furthermore, this case series highlight that the suspicion of infective endocarditis should be raised whenever a sudden increase in transvalvular gradient is found during follow-up.

Wearable cardioverter-defibrillators (WCDs) are currently used in patients at temporarily heightened risk for sudden cardiac death (SCD) who are temporarily unable to receive an implantable cardioverter-defibrillator (ICD). WCD can safely record and terminate life-threatening arrhythmias through a non-invasive electrode-based system. The current clinical indications for WCD use are varied and keep evolving as experience with this technology increases. We reviewed and explored the data behind indications for WCD use and discuss its usefulness in congenital heart disease (CHD) patients. We considered 8 consecutive patients (mean age 35.25 years, range 18–51 years, average duration of WCD use 4 months, range 3–6 months) with complex CHD, in which a WCD was used between June 2018 and January 2022. No sustained ventricular arrhythmias requiring shocks were recorded in the observation period. No inappropriate shocks were recorded. All the patients showed a good compliance and a very high mean wear time per day (21.2 ± 1 h a day). Four patients implanted a permanent device (3 CRT-D, 1 ICD), three underwent cardiac surgery at the end of the WCD period and one is still on the waiting list for the operation. Larger trial could confirm the possible conceivable benefit from an extended use of the WCD in certain populations with complex CHD as in our case series, especially in patients with life-treating ventricular arrhythmias waiting for surgery for residual cardiac defects or in the early phases following the surgical/hemodynamic interventions, patients with tachycardiomyopathy expected to improve after the arrhythmias are removed and patients awaiting implantation of an ICD at high risk due to active infection.

Supraventricular tachyarrhythmias pose a significant challenge in neonates and infants, particularly within the first year of life, where prompt and effective management is crucial. By synthesizing available evidence and clinical experience, this review aims to provide a comprehensive overview of antiarrhythmic therapy in this vulnerable population, with a focus on narrow QRS supraventricular tachyarrhythmias. This review examines the current understanding of supraventricular tachyarrhythmia management and discusses the challenges associated with antiarrhythmic therapy in newborns and infants during the critical first year of life, evaluating the efficacy and safety of various antiarrhythmic agents commonly utilized in this population, including dosing considerations, adverse effects, and strategies for acute management and prophylactic long-term antiarrhythmic treatment.