Antiarrhythmic therapy for narrow QRS supraventricular tachyarrhythmias in newborns and infants in the first year of life: Potent tools to be handled with care.

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.

Clinical presentation and genetic characterization of early-onset atrial fibrillation in patients affected by long QT syndrome: A single-center experience.

INTRODUCTION: Early-onset atrial fibrillation (AF) has already been observed in approximately 2% of patients with genetically proven long QT syndrome (LQTS). This frequency is higher than population-based estimates of early-onset AF. However, the concomitant expression of AF in LQTS is likely underestimated. The purpose of this study was to examine the clinical presentation, genetic background, and outcomes of a cohort of patients with LQTS and early-onset AF referred to a single tertiary center. METHODS: Twenty-seven patients diagnosed with congenital LQTS were included in the study based on the documentation of early-onset (age ≤50 years) clinical or subclinical AF episodes in all available medical records, including standard electrocardiograms, wearable monitor or cardiac implantable electronic devices. RESULTS: Seventeen patients experienced clinical AF during the follow-up period. Subclinical AF was detected in 10 patients through insertable or wearable cardiac monitors. In our series, the mean heart rate during AF episodes was found to be relatively low despite the patients' young age and the low or minimal effective doses of beta-blockers used for QTc interval control. All patients exhibiting LQTS and early-onset AF were genotype positive, carrying mutations in the KCNQ1 (66%), KCNH2, KCNE1, and SCN5A genes. Notably, most of these patients carried the same p.(R231C) mutation in the KCNQ1 gene (59%) and were from the same families, suggesting concurrent expression of familial AF and LQTS. CONCLUSION: LQTS patients are prone to developing clinical and subclinical AF, even at a younger age. The occurrence of early-onset AF in the LQTS population could be more frequent than previously assumed. AF should be considered as a potential dysrhythmia related to LQTS. Our study emphasizes the importance of carefully researching clinical and/or subclinical episodes of AF through strict heart rhythm monitoring in the LQTS population.

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.

Against all odds: successful pregnancy in an adult patient with unrepaired coarctation of the aorta.

According to the modified World Health Organization classification, pregnant women with unrepaired aortic coarctation are at very high risk for both maternal and fetal complications and should, therefore, be counselled against pregnancy. The most frequent maternal complications include systemic hypertension, renal failure, preeclampsia, and aortic dissection. Herein, we describe a successful pregnancy in an adult patient with unrepaired aortic coarctation.

External Validation of a Risk Score Model for Predicting Major Clinical Events in Adults After Atrial Switch.

BACKGROUND: A risk model has been proposed to provide a patient individualized estimation of risk for major clinical events (heart failure events, ventricular arrhythmia, all-cause mortality) in patients with transposition of the great arteries and atrial switch surgery. We aimed to externally validate the model. METHODS AND RESULTS: A retrospective, multicentric, longitudinal cohort of 417 patients with transposition of the great arteries (median age, 24 years at baseline [interquartile range, 18-30]; 63% men) independent of the model development and internal validation cohort was studied. The performance of the prediction model in predicting risk at 5 years was assessed, and additional predictors of major clinical events were evaluated separately in our cohort. Twenty-five patients (5.9%) met the major clinical events end point within 5 years. Model validation showed good discrimination between high and low 5-year risk patients (Harrell C index of 0.73 [95% CI, 0.65-0.81]) but tended to overestimate this risk (calibration slope of 0.20 [95% CI, 0.03-0.36]). In our population, the strongest independent predictors of major clinical events were a history of heart failure and at least mild impairment of the subpulmonary left ventricle function. CONCLUSIONS: We reported the first external validation of a major clinical events risk model in a large cohort of adults with transposition of the great arteries. The model allows for distinguishing patients at low risk from those at intermediate to high risk. Previous episode of heart failure and subpulmonary left ventricle dysfunction appear to be key markers in the prognosis of patients. Further optimizing risk models are needed to individualize risk predictions in patients with transposition of the great arteries.

Prevalence and Clinical Significance of Intraventricular Conduction Disturbances in Hospitalized Children.

Introduction: Data on the prevalence and clinical significance of interventricular conduction disturbances (IVCDs) in children are scarce. While incomplete right bundle branch blocks (IRBBBs) seem to be the most frequent and benign findings, complete bundle blocks and fascicular blocks are often seen in children with congenital/acquired cardiac conditions. This study aims to delineate the prevalence and the diagnostic accuracy of IVCD in children admitted to a paediatric cardiology unit. Methods: Children admitted to the paediatric cardiology unit between January 2010 and December 2020 who had an ECG were included in the study. IVCDs were diagnosed according to standard criteria adjusted for age. Results: Three thousand nine hundred and ninety-three patients were enrolled. The median age was 3.1 years (IQR: 0.0-9.2 years), and 52.7% were males. IVCDs were present in 22.5% of the population: 17.4% of the population presented with IRBBBs, 4.8% with a complete right bundle branch block (CRBBB), 0.1% with a complete left bundle branch block (CLBBB), 0.2% with a left anterior fascicular block (LAFB) and 0.2% with a combination of CRBBB and LAFB. Also, 26% of children with congenital heart disease had an IVCD, and 18% of children with an IVCD had previous cardiac surgery. The overall sensitivity of IVCD in detecting a cardiac abnormality was 22.2%, with a specificity of 75.5%, a PPV of 83.1% and an NPV of 15.1%, but the values were higher for CLBBB and LAFB. Conclusions: IVCDs were present in one-fifth of children admitted to the cardiology unit. IRBBB was the most frequent disturbance, while CRBBB, CLBBB and fascicular blocks were much rarer, though they had a higher predictive value for cardiac abnormalities.

Biventricular performance in adults with a systemic right ventricle: new insights from myocardial work analysis.

To evaluate biventricular mechanics by means of echo-derived myocardial work (MW) analysis in patients with a systemic right ventricle (sRV). Comprehensive echo data were collected in all patients with a sRV who underwent transthoracic echocardiography at our tertiary centre between 2020 and 2021 including sRV function indices, global longitudinal strain (GLS) of right and left ventricle (RV/LV), biventricular MW, and atrial strain in those with congenitally corrected transposition of the great arteries (ccTGA). Fifty-six patients (37 [30.97-45.87]years, 59% male) and 49 healthy individuals matched per age and sex were included for comparison. Global work index (GWI:1106 [869.80-1293.10] Vs 314.2 [281.5-358.2]mmHg%, p < 0.0001) and global constructive work(GCW: 1542.50 [1338.9-1718.50] Vs 416.4 [365.70-464]mmHg%, p < 0.0001) were both increased for sRV compared to normal RV, reflecting exposition to a systemic afterload, with a contemporary raise in wasted work (GWW:197 [138.50-322.20] Vs 26.09 [17.80-43.48]mmHg%, p < 0.0001) and impaired efficiency (GWE:89 [83-93.54] Vs 93.67 [91.67-96] %, p < 0.0001). Conversely, sRV showed reduced MW indices in comparison to normal LV(p < 0.0001 for all). Non-systemic LV demonstrated normal GLS values (19.51 ± 3.9%), but reduced GWI (479 [368-665] Vs 2172 [1978-2386]mmHg%, p < 0.0001) and GCW (708 [490-815]mmHg% Vs 86.5 [59.25-118], p < 0.0001). Nevertherless, non-systemic LV showed also impaired efficiency (91 [88-94] Vs 95 [94-97]%, p < 0.0001). LVGLS values were related to RVGLS (R = 0.5, p = 0.00019), suggesting a consistent interventricular dependency. Atrial strain could be assessed in 16 out of 20 (80%) patients with ccTGA: both atria had reduced strain values compared to their normal counterparts. Moreover, pulmonary atrial strain during the reservoir phase was related to LVGWE (R = 0.58, p = 0.047) and inversely related to LVGLS (R = - 0.71, p = 0.0043). MW analysis is feasible in sRV and may provide additional clinical data. In our cohort MW revealed biventricular impairment, in particular for non-systemic LV, in spite of normal GLS values.

Single-Chamber and Dual-Chamber Pacemaker Devices in Adults with Moderate and Complex Congenital Heart Disease: A Single Tertiary Referral Center Experience.

The number of device implantation procedures has increased in adult patients with congenital heart disease (ACHD). Despite significant improvements in materials and implantation techniques, these patients are exposed to higher risk of device related complications than general population. Herein, we describe our single tertiary referral center experience on transvenous pacemaker (PM) implantation and follow-up in adult patients with moderate and complex congenital heart disease (CHD) as limited data are available on long-term outcome. We considered all adults with moderate and complex CHD aged more than 16 years who underwent transvenous single-chamber and dual-chamber PM implant for sinus node dysfunction or atrioventricular block between January 2013 to December 2022 at our Unit. Seventy-one ACHD patients were included in the study (mean age 38.6 ± 15.2 years, 64% with moderate CHD, 36% with complex CHD). Among 32 patients implanted with a dual chamber PM (DDD PM), 4 devices were reprogrammed in VDD mode, 3 in VVI and 2 in AAI mode during follow-up because of lead dysfunction or permanent atrial arrhythmia. In addition, 26 patients had a single chamber PM (AAI or VVI PM) and 13 patients had single-lead pacing system with a free-floating atrial electrode pair (VDD PM). Just one of 13 single-lead VDD PM was reprogrammed in VVI mode due to a low atrial sensing. In DDD PM group, 10 re-interventions were needed due to lead dysfunction (8 cases) and lead-related infective endocarditis (2 cases). Only 3 patients in the single-lead PM group developed lead dysfunction with 2 re-interventions needed, but no infective endocarditis was reported. The rate of long-term complications is high in moderate and complex ACHD with transvenous PM devices, and it is mainly lead-related. In our experience, the less leads implanted, the less complications will occur. Considering the heterogeneity of the ACHD population, transvenous single-chamber or dual-chamber PM device implantation should always be tailored on the single patient, balancing risks and benefits in this complex population.

Irrigated contact force sensing catheter for redo ablation of slow-fast atrioventricular nodal reentrant tachycardia in pediatric and adolescent patients: A case series.

Conventional nonirrigated catheters cannot be able to create adequate lesions for effective slow pathway modulation in certain cases of pediatric atrioventricular nodal reentrant tachycardia ablation. Irrigated contact force sensing catheters may be considered in pediatric and adolescent patients to obtain a more extensive slow pathway modulation for redo ablation, avoiding dangerous radiofrequency applications close to the compact atrioventricular node or complex left-sided procedures.

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.

Assessing the feasibility of using the antecubital vein to perform right heart catheterization in children and adults with congenital heart disease: a retrospective, observational single-center study.

BACKGROUND: Right heart catheterization (RHC) usually is performed via the femoral vein or the internal jugular vein. However, the antecubital fossa vein is a valid venous access, and it has become increasingly popular to perform right heart catheterization utilizing this access. METHODS: A retrospective, observational study was conducted to describe use of the antecubital fossa vein for right heart catheterization in adults and children with congenital heart disease (CHD). Patients who had undergone RHC via antecubital fossa vein at the authors' hospital between September 2019 and December 2022 were included. The outcomes studied were procedural failure and procedure-related adverse events. RESULTS: Fifty-two patients with CHD underwent right cardiac catheterization via an upper arm vein. The upper arm vein was unable to perform the RHC in only 2 patients (3.8%). Only 1 patient developed a minor adverse event. No irreversible and/or life-threating adverse events were detected. CONCLUSIONS: The upper arm veins are safe and effective to perform a RHC in children and adults with CHD. This approach demonstrates a high percentage of technical success, and few mild complications.

[Management of postoperative arrhythmias in the tetralogy of Fallot: a literature review]. / Gestione delle aritmie cardiache dopo correzione chirurgica della tetralogia di Fallot: revisione della letteratura.

Tetralogy of Fallot (ToF) occurs in about 4 births/1000/year and represents about one tenth of all congenital heart diseases. Nowadays 86% of patients reach adulthood with corrective surgery. Before the 1980s, these patients were treated only with "surgical palliation", which consisted in the creation of a systemic to pulmonary artery shunt or a pulmonary valvulotomy, whereas after the introduction of extracorporeal circulation, corrective surgery is performed electively between 3 and 6 months of life. After repair patients during their life may develop hemodynamic lesions, including right ventricular outflow tract dysfunction, and arrhythmias which can occur in over 30% of cases. It is estimated that these patients present a risk of sudden death of 0.2%/year. Therefore, for the prevention and treatment of arrhythmic events, a periodic follow-up in specialized centres for adult congenital heart disease is mandatory, because most often arrhythmias are triggered by the presence of hemodynamic lesions, first of all pulmonary regurgitation.

Combined subcutaneous implantable cardioverter defibrillator and pacemaker devices in complex congenital heart disease: a single-center experienced based study.

BACKGROUND: Subcutaneous implantable cardioverter defibrillators (S-ICD) are widely accepted therapy in congenital heart disease (CHD) patients at risk of life-threatening ventricular arrhythmias or sudden cardiac death (SCD) when pacing is not required. Occasionally, pacemaker (PM)-dependent CHD patients will subsequently develop an indication for a cardioverter defibrillator. The use of S-ICD in complex CHD patients who have had already PM devices implanted implies some specific considerations, as the safety for these patients in unknown and recommendations among physicians may vary widely. METHODS: We review the data and studied the indications for S-ICD in complex CHD with previous PM and discuss its usefulness in clinical practice. RESULTS: From a large cohort of 345 patients enrolled in the S-ICD Monaldi care registry, which encompass all the patients implanted in the Monaldi Hospital of Naples, we considered 11 consecutive complex CHD patients (10M/1F aged 40.4 ±18.4 years) who underwent S-ICD implant after a previous PM implant, from February 2015 to October 2022. Mean follow-up was 25.5 ± 22 months. All the patients showed a good compliance to the device system with no complications (infections or skin erosions). CONCLUSIONS: In complex CHD with already implanted PM devices, S-ICD implant appears to be a safe alternative to PM upgrading to transvenous ICD system, avoiding abandoned leads or life-threatening lead extraction. However, there are important issues with regard to testing and programming that need to be addressed at the time of implantation.

End-stage heart failure in congenitally corrected transposition of the great arteries: a multicentre study.

BACKGROUND AND AIMS: For patients with congenitally corrected transposition of the great arteries (ccTGA), factors associated with progression to end-stage congestive heart failure (CHF) remain largely unclear. METHODS: This multicentre, retrospective cohort study included adults with ccTGA seen at a congenital heart disease centre. Clinical data from initial and most recent visits were obtained. The composite primary outcome was mechanical circulatory support, heart transplantation, or death. RESULTS: From 558 patients (48% female, age at first visit 36 ± 14.2 years, median follow-up 8.7 years), the event rate of the primary outcome was 15.4 per 1000 person-years (11 mechanical circulatory support implantations, 12 transplantations, and 52 deaths). Patients experiencing the primary outcome were older and more likely to have a history of atrial arrhythmia. The primary outcome was highest in those with both moderate/severe right ventricular (RV) dysfunction and tricuspid regurgitation (n = 110, 31 events) and uncommon in those with mild/less RV dysfunction and tricuspid regurgitation (n = 181, 13 events, P < .001). Outcomes were not different based on anatomic complexity and history of tricuspid valve surgery or of subpulmonic obstruction. New CHF admission or ventricular arrhythmia was associated with the primary outcome. Individuals who underwent childhood surgery had more adverse outcomes than age- and sex-matched controls. Multivariable Cox regression analysis identified older age, prior CHF admission, and severe RV dysfunction as independent predictors for the primary outcome. CONCLUSIONS: Patients with ccTGA have variable deterioration to end-stage heart failure or death over time, commonly between their fifth and sixth decades. Predictors include arrhythmic and CHF events and severe RV dysfunction but not anatomy or need for tricuspid valve surgery.

Contact force sensing radiofrequency catheter ablation guided by electroanatomic mapping in pediatric patients with permanent junctional reciprocating tachycardia: A case series.

Limited data are available on the use of irrigated contact force (CF) catheters for radiofrequency (RF) ablation of permanent junctional reciprocating tachycardia (PJRT) in children. We considered five consecutive pediatric patients with diagnosis of PJRT who underwent RF ablation with irrigated CF catheter guided by electroanatomic mapping, obtaining a low number of RF pulses and minimal fluoroscopy exposure. High CF values are not necessary to obtain effective RF lesions and successful ablation.

Remote monitoring of implantable loop recorders reduces time to diagnosis in patients with unexplained syncope: a multicenter propensity score-matched study.

Background: There are little data on remote monitoring (RM) of implantable loop recorders (ILRs) in patients with unexplained syncope and whether it confers enhanced diagnostic power. Objective: To evaluate the effect of RM in ILR recipients for unexplained syncope for early detection of clinically relevant arrhythmias by comparison with a historical cohort with no RM. Methods: SyncRM is a propensity score (PS)-matched study prospectively including 133 consecutive patients with unexplained syncope and ILR followed up by RM (RM-ON group). A historical cohort of 108 consecutive ILR patients with biannual in-hospital follow-up visits was used as control group (RM-OFF group). The primary endpoint was the time to the clinician's evaluation of clinically relevant arrhythmias (types 1, 2, and 4 of the ISSUE classification). Results: The primary endpoint of arrhythmia evaluation was reached in 38 patients (28.6%) of the RM-ON group after a median time of 46 days (interquartile range, 13-106) and in 22 patients (20.4%) of the RM-OFF group after 92 days (25-368). The PS-matched adjusted ratio of rates of arrhythmia evaluation was 2.53 (95% confidence interval, 1.32-4.86) in the RM-ON vs. RM-OFF group (p = 0.005). Conclusion: In our PS-matched comparison with a historical cohort, RM of ILR patients with unexplained syncope was associated with a 2.5-fold higher chance of evaluations of clinically relevant arrhythmias as compared with biannual in-office follow-up visits.