Contact allergy to subcutaneous implantable cardioverter defibrillator in a child with Brugada syndrome.

Allergic reactions to components of cardiac implantable electronic devices are rare and often go undiagnosed, which can lead to a misdiagnosis of device infection. Contact allergy to subcutaneous implantable cardioverter defibrillator (S-ICD) is extremely rare. In this report, we present a case of cobalt-related contact allergy in a pediatric patient with Brugada syndrome who underwent S-ICD implantation.

Exercise-induced type 1 Brugada pattern in a child.

The exercise stress testing may unmask the type 1 Brugada pattern on the surface electrocardiogram in a portion of patients with Brugada syndrome. The occurrence of the type 1 Brugada pattern during an exercise test in pediatric patients is not common. Consequently, the diagnostic yield of the exercise test in this population is still to be explored. We present a case of exercise-induced type 1 Brugada pattern in a 12-year-old child with episodes of palpitations and discuss the available evidence on the role of the exercise stress test in the diagnosis and risk stratification of patients with Brugada syndrome.

Triple Antiarrhythmic Therapy in Newborns with Refractory Atrioventricular Reentrant Tachycardia.

Atrioventricular reentrant tachycardia (AVRT) is the most common form of supraventricular tachycardia in newborns. AVRT is sometimes refractory to conventional antiarrhythmic therapy. We describe our experience about the use of the triple combination of flecainide + propranolol + amiodarone as third-line regimen for refractory and recurrent AVRT in newborns. We considered a series of 14 patients who had failed both first-line and second-line therapy and were treated using the combination of flecainide + propranolol + amiodarone. Transoesophageal electrophysiologic study (TES) was performed to test the effectiveness of medical therapy during hospitalization and to try to reduce the amount of therapy, after amiodarone wash-out, before 1 year of age. TES was repeated at 1 year of age to test the spontaneous resolution of the arrhythmia after treatment discontinuation. Rhythm control was achieved in all 14 patients. At a mean age of 9.3 ± 2 months, AVRT was not inducible by TES in 11/12 amiodarone-free patients. At a mean age of 14.1 ± 3 months, AVRT was still inducible in 7/12 patients after interrupting the entire antiarrhythmic therapy (58.3%). Triple combination was effective as third-line option to suppress AVRT refractory to single and double antiarrhythmic therapy, with no significant adverse events. Our experience suggests that triple therapy could be maintained for a short-term treatment, discontinuing amiodarone before 1 year of age to avoid long-term side effects. Newborns who needed triple therapy appear to have a lower chance of accessory pathway disappearance at 1 year of age. TES could be useful for risk stratification of recurrences at the time of drug discontinuation in infants considered to be at higher risk of recurrent AVRT.

Implantable Loop Recorder with Long Sensing Vector: Safety, Acceptability, and Sensing Performance in Pediatric Patients.

Implantable loop recorders (ILRs) are effective tools for detecting arrhythmias by long-term continuous heart rhythm monitoring. Benefits have been demonstrated even in pediatric patients. ILR with a long sensing vector has recently been designed to improve signal quality in terms of P wave visibility and R wave amplitude. However, there are no data on its use in pediatric patients. We considered a series of pediatric patients implanted with a long sensing vector ILR. Sensing performance, including R wave amplitude and P wave visibility, device-related complications, and diagnostic yield were collected. During follow-up, each patient guided by his/her parents/guardians was also asked to complete a brief questionnaire to assess patient acceptability of the device. Twenty-five consecutive pediatric patients (mean age 11.3 ± 3.5 years, 72% male) were enrolled. The insertion success rate was 100% on the first attempt with no complications. The median amplitude of the R wave was 1.15 mV (interquartile range, 1.01-1.42) with no significant differences between patients aged ≤ or > 10 years (p = 0.726) and between female and male (p = 0.483). P wave was classified as 'always visible' in 24/25 patients (96%). ILR was generally well accepted and tolerated by all involved patients. During a median follow-up of 297 days (117-317), we achieved in 5 patients a correlation between symptoms and rhythm disorders (20%) and ruled out significant arrhythmias in 6 symptomatic children (24%). Long sensing vector ILR showed to be well accepted, with good signal quality and an excellent safety profile even in pediatric patients.

Clinical, Genetic, and Histological Characterization of Patients with Rare Neuromuscular and Mitochondrial Diseases Presenting with Different Cardiomyopathy Phenotypes.

Cardiomyopathies are mostly determined by genetic mutations affecting either cardiac muscle cell structure or function. Nevertheless, cardiomyopathies may also be part of complex clinical phenotypes in the spectrum of neuromuscular (NMD) or mitochondrial diseases (MD). The aim of this study is to describe the clinical, molecular, and histological characteristics of a consecutive cohort of patients with cardiomyopathy associated with NMDs or MDs referred to a tertiary cardiomyopathy clinic. Consecutive patients with a definitive diagnosis of NMDs and MDs presenting with a cardiomyopathy phenotype were described. Seven patients were identified: two patients with ACAD9 deficiency (Patient 1 carried the c.1240C>T (p.Arg414Cys) homozygous variant in ACAD9; Patient 2 carried the c.1240C>T (p.Arg414Cys) and the c.1646G>A (p.Ar549Gln) variants in ACAD9); two patients with MYH7-related myopathy (Patient 3 carried the c.1325G>A (p.Arg442His) variant in MYH7; Patient 4 carried the c.1357C>T (p.Arg453Cys) variant in MYH7); one patient with desminopathy (Patient 5 carried the c.46C>T (p.Arg16Cys) variant in DES); two patients with mitochondrial myopathy (Patient 6 carried the m.3243A>G variant in MT-TL1; Patient 7 carried the c.253G>A (p.Gly85Arg) and the c.1055C>T (p.Thr352Met) variants in MTO1). All patients underwent a comprehensive cardiovascular and neuromuscular evaluation, including muscle biopsy and genetic testing. This study described the clinical phenotype of rare NMDs and MDs presenting as cardiomyopathies. A multidisciplinary evaluation, combined with genetic testing, plays a main role in the diagnosis of these rare diseases, and provides information about clinical expectations, and guides management.

Transcatheter closure of fenestrated atrial septal aneurysm in children: Feasibility and long-term results.

BACKGROUND: To date, extensive experience in transcatheter closure of fenestrated atrial septal aneurysm (ASA) in the pediatric population is limited. METHODS: To report on procedural feasibility, efficacy, and long-term outcome, we enrolled all children submitted to an attempt of transcatheter closure of fenestrated ASA at two, large volume, pediatric cardiology units (Naples and Massa, Italy) between April 2000 to May 2020. RESULTS: This retrospective study included 139 patients (median age 9 years [range 2-18] and weight 36 kg [range 10-102]); 19 (13.7%) children were ≤20 kg (range 10-20) and 14 (10.1%) were ≤5 years old. Single perforation was observed in 28 patients (20.1%), while 111 patients (79.9%) had multifenestrated ASA. The median size of the main defect was 15 mm (range 6-34) and 25 patients (18%) had a defect ≥20 mm. The procedural success rate was 99% (95% confidence interval [CI]: 94.9-99.8) using a single device in 75 (69%), two devices in 31 (28%), and three devices in 3 (3%) cases. Early minor adverse events (AEs) occurred in four patients (2.8%). Late minor AEs were recorded in one patient (0.7%) over a median follow-up of 5 years ([range 0-18 years; total 890.2 person-years, and with 30 patients (22%) followed ≥10 years). Neither mortality nor major AEs were recorded. Freedom from AEs was 99.1% at 10-15 years (95% CI: 93.5-99.8%), without any difference according to atrial septum anatomy or patient age and weight. CONCLUSION: Transcatheter closure of fenestrated ASA is technically feasible and effective in children with excellent long-term outcomes.

Novel echocardiographic score to predict duct-dependency after percutaneous relief of critical pulmonary valve stenosis/atresia.

OBJECTIVES: This study aimed to identify clinical, hemodynamic, or echocardiographic predictive features of persistent duct-dependency of pulmonary circulation (PDDPC) after effective percutaneous relief of pulmonary atresia with the intact ventricular septum (PA-IVS) or critical pulmonary stenosis (CPS). METHODS: From 2010 to 2021, 55 neonates with PA-IVS or CPS underwent percutaneous right ventricle (RV) decompression at our Institution. After successfully relief of critical obstruction, 27 patients (group I) showed PDDPC, whereas RV was able to support the pulmonary circulation in the remaining 28 patients (group II). Clinical, hemodynamic, and echocardiographic features of these two groups were compared. RESULTS: No significant difference in clinical and hemodynamic data was found between the groups, although the group I had a lower oxygen saturation at hospital admission. However, tricuspid valve (TV) diameter <8.8 mm, TV z-score ←2.12, tricuspid/mitral valve annular ratio <.78, pulmonary valve diameter <6.7 mm, pulmonary valve z-score ←1.17, end-diastolic RV area <1.35 cm2 , end-systolic right atrium area >2.45 cm2 , percentage amount of interatrial right-to-left shunt >69.5%, moderate/severe tricuspid regurgitation, RV systolic pressure >42.5 mmHg, tricuspid E/E' ratio >6.6 showed each significant predictive value of PDDPC. These parameters were used to build a composite echocardiographic score (PDDPC-score), assigning one point each above the respective cut-off value. A score ≥4.00 showed high sensitivity (100%) and specificity (86%) in predicting PDDPC. CONCLUSION: Clinical and hemodynamic features fail to predict the short-term fate of the pulmonary circulation after successful treatment of PA-IVS/CPS. However, a simple, composite echocardiographic score is useful to predict PDDPC and could be crucial in the management of this frail subset of patients.

Paediatric and adult congenital cardiology education and training in Europe.

BACKGROUND: Limited data exist on training of European paediatric and adult congenital cardiologists. METHODS: A structured and approved questionnaire was circulated to national delegates of Association for European Paediatric and Congenital Cardiology in 33 European countries. RESULTS: Delegates from 30 countries (91%) responded. Paediatric cardiology was not recognised as a distinct speciality by the respective ministry of Health in seven countries (23%). Twenty countries (67%) have formally accredited paediatric cardiology training programmes, seven (23%) have substantial informal (not accredited or certified) training, and three (10%) have very limited or no programme. Twenty-two countries have a curriculum. Twelve countries have a national training director. There was one paediatric cardiology centre per 2.66 million population (range 0.87-9.64 million), one cardiac surgical centre per 4.73 million population (range 1.63-10.72 million), and one training centre per 4.29 million population (range 1.63-10.72 million population). The median number of paediatric cardiology fellows per training programme was 4 (range 1-17), and duration of training was 3 years (range 2-5 years). An exit examination in paediatric cardiology was conducted in 16 countries (53%) and certification provided by 20 countries (67%). Paediatric cardiologist number is affected by gross domestic product (R2 = 0.41). CONCLUSION: Training varies markedly across European countries. Although formal fellowship programmes exist in many countries, several countries have informal training or no training. Only a minority of countries provide both exit examination and certification. Harmonisation of training and standardisation of exit examination and certification could reduce variation in training thereby promoting high-quality care by European congenital cardiologists.

Subcutaneous finger cardioverter-defibrillator in low weight paediatric patients: a case series.

Placement of traditional transvenous implantable cardioverter defibrillator (ICD) system in low-weight children is often difficult because of their vessel size, the elevated risk of lead malfunction and failure, children's growth and various anatomic constraints, creating the need for alternative solutions. Subcutaneous array leads combined with an abdominally placed ICD device can minimize the surgical approach. In this case series, we analyse the data behind indications for subcutaneous finger cardioverter defibrillator (SFCD) and discuss the preliminary clinical experience in low-weight children. We considered 4 consecutive children (mean age 3.9 years, range 3-5.5 years, mean body weight 17.6 Kg, range 14-23 Kg) who underwent SFCD implant from April 2016 to August 2020. All patients showed a good compliance to the device system with no complications (infections or skin erosions). No patients experienced in the observation period (mean time 44.5±21.5 months) sustained ventricular arrhythmias requiring shocks. No inappropriate shocks released by the device occurred. No significant changes were observed in LET (lowest energy tested) performed around 24 months of follow-up. All patients showed a good compliance and stable atrio-ventricular sensing and pacing thresholds. In smaller children in whom a transvenous approach is not feasible or not possible for anatomic reasons, the SFCD appears to be a safe method to prevent SCD with little surgical trauma and preservation of an intact vascular system, providing an adequate bridge to transvenous ICD or subcutaneous ICD implant late in the life.

Aberrant right subclavian artery: the association with chromosomal defects and the related post-natal outcomes in a third level referral centre.

Aberrant right subclavian artery (ARSA) is the most common embryologic abnormality of the aortic arch. The presence of ARSA has been previously associated with an increased risk of Down syndrome. ARSA at birth may be associated with dysphagia, respiratory distress and stridor and there is no clear evidence-based management. The aim of this study was to describe the associations with chromosomal abnormalities and the postnatal outcome of fetuses diagnosed with ARSA. We analysed fetuses diagnosed antenatally with ARSA between January 2013 and September 2019 in the fetal echocardiography unit of the Hospital Monaldi, University 'Vanvitelli' of Naples, Italy. The results showed fifty fetuses diagnosed with ARSA, all confirmed after birth. The ARSA was an isolated finding in 46 fetuses (92%), while in 4 fetuses the ARSA was associated with other cardiac and/or extra-cardiac anomalies. Only one fetus was diagnosed with trisomy 21 (2%). In this fetus the ARSA was the only ultrasound anomaly identified. There were no cases necessitating referral due to the presence of compression symptoms at birth. The presence of ARSA was associated with trisomy 21 in the 2% of cases in our series and there were no neonatal complications due to airway compression at birth.IMPACT STATEMENTWhat is already known on this subject? Aberrant right subclavian artery (ARSA) is the most common embryologic abnormality of the aortich arch. ARSA at birth could be associated with dysphagia, respiratory distress and stridor and no evidence-based management of these fetuses has been described yet. The presence of ARSA has been previously associated with an increased risk of Down syndrome.What do the results of this study add? This study confirms known data on association with chromosomal defects and provides some original data on the absence of symptomatology due to tracheal compression with a postnatal follow-up up to three years of age.What are the implications of these findings for clinical practice and/or further research? Our findings suggest that in cases with adequate prenatal assessment performed by experienced clinicians, delivery can safely take place at local hospitals, with no need of referral soon after birth. The use of transthoracic echocardiography to confirm the diagnoses of ARSA after birth and to plan the next follow-up appointments can be supported.

The Risk of Sudden Unexpected Cardiac Death in Children: Epidemiology, Clinical Causes, and Prevention.

"Sudden unexplained death (SUD) is a tragic event for both the family and community, particularly when it occurs in young individuals. Sudden cardiac death (SCD) represents the leading form of SUD and is defined as an unexpected event without an obvious extracardiac cause, occurring within 1 hour after the onset of symptoms. In children, the main causes of SCD are inherited cardiac disorders, whereas coronary artery diseases (congenital or acquired), congenital heart diseases, and myocarditis are rare. The present review examines the current state of knowledge regarding SCD in children, discussing the epidemiology, clinical causes, and prevention strategies."

Clinical Manifestations of 22q11.2 Deletion Syndrome.

DiGeorge syndrome (DGS), also known as "22q11.2 deletion syndrome" (22q11DS) (MIM # 192430 # 188400), is a genetic disorder caused by hemizygous microdeletion of the long arm of chromosome 22. In the last decades, the introduction of fluorescence in situ hybridization assays, and in selected cases the use of multiplex ligation-dependent probe amplification, has allowed the detection of chromosomal microdeletions that could not be previously identified using standard karyotype analysis. The aim of this review is to address cardiovascular and systemic involvement in children with DGS, provide genotype-phenotype correlations, and discuss their medical management and therapeutic options.

The Heart Muscle and Valve Involvement in Marfan Syndrome, Loeys-Dietz Syndromes, and Collagenopathies.

The inherited connective tissue disorders (Marfan syndrome, Loeys-Dietz syndrome [LDS], and Ehlers-Danlos syndrome [EDS]) involve connective tissue of various organ systems. These pathologies share many common features, nonetheless compared to Marfan syndrome, LDS' cardiovascular manifestations tend to be more severe. In contrast, no association is reported between LDS and the presence of ectopia lentis. The EDS are currently classified into thirteen subtypes. There is substantial symptoms overlap between the EDS subtypes, and they are associated with an increased incidence of cardiovascular abnormalities, such as mitral valve prolapse and aortic dissection.

Cardiovascular Involvement in mtDNA Disease: Diagnosis, Management, and Therapeutic Options.

Mitochondrial diseases (MD) include an heterogenous group of systemic disorders caused by sporadic or inherited mutations in nuclear or mitochondrial DNA (mtDNA), causing impairment of oxidative phosphorylation system. Hypertrophic cardiomyopathy is the dominant pattern of cardiomyopathy in all forms of mtDNA disease, being observed in almost 40% of the patients. Dilated cardiomyopathy, left ventricular noncompaction, and conduction system disturbances have been also reported. In this article, the authors discuss the current clinical knowledge on MD, focusing on diagnosis and management of mitochondrial diseases caused by mtDNA mutations.

Hypertrophic Cardiomyopathy in RASopathies: Diagnosis, Clinical Characteristics, Prognostic Implications, and Management.

RASopathies are multisystemic disorders caused by germline mutations in genes linked to the RAS/mitogen-activated protein kinase pathway. Diagnosis of RASopathy can be triggered by clinical clues ("red flags") which may direct the clinician toward a specific gene test. Compared with sarcomeric hypertrophic cardiomyopathy, hypertrophic cardiomyopathy in RASopathies (R-HCM) is associated with higher prevalence of congestive heart failure and shows increased prevalence and severity of left ventricular outflow tract obstruction. Biventricular involvement and the association with congenital heart disease, mainly pulmonary stenosis, have been commonly described in R-HCM. The aim of this review is to assess the prevalence and unique features of R-HCM and to define the available therapeutic options.

Wearable cardioverter-defibrillator (life-vest): A feasible bridging treatment in adult congenital heart disease.

BACKGROUND: 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. METHODS: We reviewed and explored the data behind indications for WCD use and discuss its usefulness in congenital heart disease (CHD) patients. RESULTS: 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. CONCLUSIONS: 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.

Pathophysiology and clinical presentation of paediatric heart failure related to congenital heart disease.

Congenital heart disease (CHD) and cardiomyopathies represent the two most important causes of paediatric heart failure (HF) in developed countries. We made a review of the literature on pathophysiology and clinical presentation of paediatric HF in children with CHD. Two main pathophysiologic models can be identified: the 'over-circulation failure', characterised by signs and symptoms of congestion or hypoperfusion, due respectively to volume or pressure overload, and the 'pump failure'. CONCLUSIONS: The comprehension of the HF pathophysiology in paediatric patients with CHD is of paramount importance for the optimal management and for addressing the best therapeutic choices.

A frightening giant QRS complex in a 3-months-old infant.

A 3-months-old infant was urgently admitted for drowsiness and lack of appetite started 24 h before. The ECG showed sinus rhythm with a prolonged AV interval (200 ms) and very large QRS complexes (280 ms) due to Flecainide overdosing following incorrectly administration for poor communication between parents resulted in both giving a dose to the infant. Flecainide serum level was 1.2µg/ml, confirming the diagnosis of an accidental drug intoxication. The patient started continue hydration with a close monitoring. Three hours later a significant narrowing of the QRS complex (150 ms) was observed, then over the following 24 h, the QRS almost completely normalized.

Impact of Regular Physical Activity on Aortic Diameter Progression in Paediatric Patients with Bicuspid Aortic Valve.

Patients with bicuspid aortic valve (BAV) have an increased risk of aortic dilation and aortic dissection or rupture. The impact of physical training on the natural course of aortopathy in BAV patients remains unclear. The aim of this study was to evaluate the impact of regular physical activity on aortic diameters in a consecutive cohort of paediatric patients with BAV. Consecutive paediatric BAV patients were evaluated and categorized into two groups: physically active and sedentary subjects. Only the subjects with a complete 2-year follow-up were included in the study. To evaluate the potential impact of physical activity on aortic size, aortic diameters were measured at the sinus of Valsalva and mid-ascending aorta using echocardiography. We defined aortic diameter progression the increase of aortic diameter ≥ 10% from baseline. Among 90 BAV patients (11.5 ± 3.4 years of age, 77% males), 53 (59%) were physically active subjects. Compared to sedentary, physically active subjects were not significantly more likely to have > 10% increase in sinus of Valsalva (13% vs. 8%, p-value = 0.45) or mid-ascending aorta diameter (9% vs. 13%, p-value = 0.55) at 2 years follow-up, both in subjects with sinus of Valsalva diameter progression (3.7 ± 1.0 mm vs. 3.5 ± 0.8 mm, p-value = 0.67) and in those with ascending aorta diameter progression (3.0 ± 0.8 mm vs. 3.2 ± 1.3 mm, p-value = 0.83). In our paediatric cohort of BAV patients, the prevalence and the degree of aortic diameter progression was not significantly different between physically active and sedentary subjects, suggesting that aortic dilation is unrelated to regular physical activity over a 2-year period.

Advanced Heart Failure in Special Population-Pediatric Age.

Heart failure (HF) is an important health care issue in children because of its considerable morbidity and mortality. Advanced HF encompasses patients who remained symptomatic despite optimal medical treatment and includes patients who require special management, such as continuous inotropic therapy, mechanical circulatory support, or heart transplantation (HT). HT is the gold standard for children with advanced HF; nonetheless, the number of suitable donors has not increased for decades, leading to prolonged waitlist times and increased mortality rates. Therefore, the role of pediatric mechanic circulatory support has been assessed as an alternative treatment in patients in whom heart transplant could not be performed. The authors discuss the epidemiology, causes, pathophysiology, clinical manifestation, medical treatment, device therapy, and HT in pediatric HF, and a particular emphasis was posed on patients with advanced HF.