Long-term incidence of arrhythmias in extracardiac conduit Fontan and comparison between systemic left and right ventricle.

AIMS: The extracardiac conduit-Fontan (ECC) has become the preferred technique for univentricular heart palliation, but there are currently no data on the incidence of long-term arrhythmias. This study investigated the incidence of arrhythmias and relation to single ventricle morphology in the long-term follow-up (FU) in ECC. METHODS AND RESULTS: All patients with ECC performed in our Centre between 1987 and 2017 were included (minimum FU 5 years). Of 353 consecutive patients, 303 [57.8% males, aging 8-50 (median 20) years at last FU] were considered and divided into two groups depending on left (194 in Group 1) or right (109 in Group 2) ventricular morphology. Eighty-five (28%) experienced ≥1 arrhythmic complications, with early and late arrhythmias in 17 (5.6%) and 73 (24.1%) patients, respectively. Notably, late bradyarrhythmias occurred after 6 years in 21 (11%) patients in Group 1, and in 15 (13.8%) in Group 2 [P = 0.48]. Late tachyarrhythmias occurred in 55 (18.2%) patients after 12 years: 33 (17%) in Group 1 and 22 (20.2%) patients in Group 2 [P  = 0.5]. Ventricular tachycardias (VT) were documented after 12.5 years in 14 (7.2%) patients of Group 1 and 15 (13.8%) of Group 2 [P = 0.06] with a higher incidence in Group 2 during the FU [P = 0.005]. CONCLUSION: Extracardiac conduit is related to a significant arrhythmic risk in the long-term FU, higher than previously reported. Bradyarrhythmias occur earlier but are less frequent than tachyarrhythmias. Interestingly, patients with systemic right ventricle have a significantly higher incidence of VT, especially in a very long FU.

Corrigendum: Case Report: Epstein-Barr virus and constrictive pericarditis-an unusual combination.

[This corrects the article DOI: 10.3389/fped.2023.1215928.].

Double-Outlet Left Ventricle: Case Series and Systematic Review of the Literature.

Double-outlet left ventricle (DOLV) is an abnormal ventriculo-arterial connection characterized by the origin of both great arteries from the morphological left ventricle. The aim of our paper is to describe the morphological and imaging features of DOLV and to assess the prevalence of the associated malformations and their surgical outcomes. METHODS From 2011 to 2022, we retrospectively reviewed the electronic case records of patients diagnosed with DOLV at the Bambino Gesu Children's Hospital. A systematic search was developed in MEDLINE, Web of Science, and EMBASE databases to identify reports assessing the morphology and outcomes of DOLV between 1975 and 2023. RESULTS: Over a median follow-up of 9.9 years (IQR 7.8-11.7 y), four cases of DOLV were identified at our institution. Two patients were diagnosed with (S,D,D) DOLV subaortic VSD and pulmonary stenosis (PS): one patient had (S,D,D) DOLV with doubly committed VSD and hypoplastic right ventricle, and another patient had (S,D,L) DOLV with subaortic VSD and PS (malposition type). Pulmonary stenosis was the most commonly associated lesion (75%). LITERATURE REVIEW: After systematic evaluation, a total of 12 reports fulfilled the eligibility criteria and were included in our analysis. PS or right ventricular outflow tract obstruction was the most commonly associated lesion (69%, 95% CI 62-76%). The most common locations of VSD were subaortic (pooled prevalence: 75%, 95% CI 68-81), subpulmonary (15%, 95% CI 10-21), and doubly committed (7%, 95% CI 4-12). The position of the great arteries showed that d-transposition of the aorta was present in 128 cases (59% 95% CI 42-74), and l-transposition was present in 77 cases (35%, 95% CI 29-43).

Case report: Epstein-Barr virus and constrictive pericarditis-An unusual combination.

Constrictive pericarditis is a chronic inflammatory process that can lead to heart failure if not diagnosed and treated correctly. Although Epstein-Barr virus (EBV)-related pericarditis is a very rare condition, it should still be considered for a differential diagnosis. We report the case of an 18-year-old male, who was surgically treated for constrictive pericarditis, in which in situ hybridization to Epstein-Barr virus-encoded RNA (EBER) probe of the excised pericardium led to the subsequent etiological diagnosis of chronic pericarditis caused by EBV.

To go left or right? Driving towards the best direction in paediatric pacing.

BACKGROUND: Permanent pacing in children with isolated congenital complete atrioventricular block may cause left ventricular dysfunction. To prevent it, alternative pacing sites have been proposed: left ventricular epicardial or selective right ventricular endocardial pacing. AIMS: To compare the functional outcome (left ventricular systolic function and synchrony) in paediatric patients with congenital complete atrioventricular block and left ventricular apical epicardial or right ventricular transvenous mid-septal pacing. METHODS: Retrospective study. Epicardial leads were implanted by standard surgical technique, transvenous leads by 3D electroanatomic mapping systems. 3D mapping acquired 3D right ventricular local pacing map and defined the narrowest paced QRS site. 3D mapping guided screw-in bipolar leads on that ventricular site. Electrocardiogram (ECG) (QRS duration) and echocardiographic data (synchrony: interventricular mechanical delay, septal to posterior wall motion delay, systolic dyssynchrony index; contractility: global longitudinal strain, ejection fraction) were recorded. Data are reported as median [interquartile ranges]. p < 0.05 was significant. RESULTS: There were 19 transvenous systems (age 8.8 [6-14] years; right ventricular mid-septum) and 17 epicardial systems (0.04 [0.001-0.6] years; left ventricular apex). Post-implantation QRS significantly widened either in endocardial or in epicardial patients. Most patients reached 4-year follow-up. One-year and 4-year ejection fraction and global longitudinal strain were mostly within normal limits and did not show significant differences between the two groups and between the same endocardial/epicardial group. Synchrony parameters were within normal limits in the two groups. CONCLUSIONS: Left ventricular apical epicardial pacing and 3D mapping-guided right ventricular mid-septal pacing preserved left ventricular contractility and synchrony in children and adolescents with congenital complete atrioventricular block at short-/mid-term follow-up, without relevant significant differences between the two groups.

The SIDECAR project: S-IcD registry in European paediatriC and young Adult patients with congenital heaRt defects.

AIMS: Subcutaneous-implantable cardiac defibrillators (S-ICDs) are used increasingly to prevent sudden cardiac death in young patients. This study was set up to gain insight in the indications for S-ICD, possible complications, and their predictors and follow-up results. METHODS AND RESULTS: A multicentre, observational, retrospective, non-randomized, standard-of-care registry on S-ICD outcome in young patients with congenital heart diseases (CHDs), inherited arrhythmias (IAs), idiopathic ventricular fibrillation (IVF), and cardiomyopathies (CMPs). Anthropometry was registered as well as implantation technique, mid-term device-related complications, and incidence of appropriate/inappropriate shocks (IASs). Data are reported as median (interquartile range) or mean ± standard deviation. Eighty-one patients (47% CMPs, 20% CHD, 21% IVF, and 12% IA), aged 15 (14-17) years, with body mass index (BMI) 21.8 ± 3.8 kg/m2, underwent S-ICD implantation (primary prevention in 59%). This was performed with two-incision technique in 81% and with a subcutaneous pocket in 59%. Shock and conditional zones were programmed at 250 (200-250) and 210 (180-240) b.p.m., respectively. No intraoperative complications occurred. Follow up was 19 (6-35) months: no defibrillation failure occurred, 17% of patients received appropriate shocks, 13% of patients received IAS (supraventricular tachycardias 40%, T-wave oversensing 40%, and non-cardiac oversensing 20%). Reprogramming, proper drug therapy, and surgical revision avoided further IAS. Complications requiring surgical revision occurred in 9% of patients, with higher risks in patients with three-incision procedures [hazard ratio (HR) 4.3, 95% confidence interval (95% CI) 0.5-34, P = 0.038] and BMI < 20 (HR 5.1, 95% CI 1-24, P = 0.031). CONCLUSION: This multicentre European paediatric registry showed good S-ICD efficacy and safety in young patients. Newer implantation techniques and BMI > 20 showed better outcome.

Late outcome of extracardiac Fontan patients: 32 years of follow-up.

OBJECTIVES: We sought to evaluate the long-term survival and risk factors for morbidity and mortality in our cohort of patients after extracardiac (EC) Fontan. METHODS: We collected and analysed follow-up data until September 2020 for all patients who underwent EC Fontan operation at our institution from November 1988 to November 2015. RESULTS: Out of 406 patients treated with EC Fontan at a mean age of 5.4 ± 4.5 years, 372 (91.6%) were discharged home; 15% were lost to follow-up. The median follow-up was 14.6 years (interquartile range 8.7-20.3). Two hundred patients (54%) had a good long-term outcome, with an event-free long-term survival, but late adverse events of any kind needing interventional or surgical reoperations were reported in 128 patients (34%). Forty-four patients (12%) developed late Fontan failure. Thirty-seven survivors (10%) had late arrhythmias, with the need for pacemaker implantation. Obstruction of the cavopulmonary pathway occurred in 49 patients (13%), but just 8 patients needed conduit surgical replacement. At 32 years, the survival probability was 84%. The risk of orthotopic heart transplant, considering death as a competing event (showed as cumulative incidence), was 12.5%. A preoperative diagnosis of hypoplastic left heart syndrome was an independent risk factor for the need for heart transplant. CONCLUSIONS: The EC Fontan shows satisfactory long-term survival and low incidence of adverse events and late failure. Conduit replacement is rare, and its longevity may not represent a substantial issue in these patients. However, as with other technical variants, the need for reoperations during long-term follow-up is a significant challenge.

The Modern Surgical Approach to Pulmonary Atresia with Ventricular Septal Defect and Major Aortopulmonary Collateral Arteries.

Pulmonary atresia with ventricular septal defect and major aortopulmonary collaterals is a complex congenital heart defect that includes a heterogeneous subgroup of patients. Variation in the sources of pulmonary blood flow contributes to the complexity of the lesion and the diversity of approaches to its management. Unifocalization and rehabilitation focus on mobilization of collateral arteries and growth of native pulmonary arteries, respectively, with the ultimate surgical goal of achieving separated systemic and pulmonary circulations with the lowest possible right ventricular pressure. Regardless of the strategy, outcomes have altered the natural history of the disease, with a complete repair rate of approximately 80% and low early and late mortality rates. Given this heterogeneity of pulmonary vasculature, a tailored approach should be adopted for each patient, using all diagnostic methods currently offered by technical developments.

Blood flow characteristics after aortic valve neocuspidization in paediatric patients: a comparison with the Ross procedure.

AIMS: The aortic valve (AV) neocuspidization (Ozaki procedure) is a novel surgical technique for AV disease that preserves the natural motion and cardiodynamics of the aortic root. In this study, we sought to evaluate, by 4D-flow magnetic resonance imaging, the aortic blood flow characteristics after AV neocuspidization in paediatric patients. METHODS AND RESULTS: Aortic root and ascending aorta haemodynamics were evaluated in a population of patients treated with the Ozaki procedure; results were compared with those of a group of patients operated with the Ross technique. Cardiovascular magnetic resonance studies were performed at 1.5 T using a 4D flow-sensitive sequence acquired with retrospective electrocardiogram-gating and respiratory navigator. Post-processing of 4D-flow analysis was performed to calculate flow eccentricity and wall shear stress. Twenty children were included in this study, 10 after Ozaki and 10 after Ross procedure. Median age at surgery was 10.7 years (range 3.9-16.5 years). No significant differences were observed in wall shear stress values measured at the level of the proximal ascending aorta between the two groups. The analysis of flow patterns showed no clear association between eccentric flow and the procedure performed. The Ozaki group showed just a slightly increased transvalvular maximum velocity. CONCLUSION: Proximal aorta flow dynamics of children treated with the Ozaki and the Ross procedure are comparable. Similarly to the Ross, Ozaki technique restores a physiological laminar flow pattern in the short-term follow-up, with the advantage of not inducing a bivalvular disease, although further studies are warranted to evaluate its long-term results.

Risk Factors of Right Ventricular Dysfunction and Adverse Cardiac Events in Patients with Repaired Tetralogy of Fallot.

AIM: This study evaluates the risk factors associated with right ventricular (RV) dilation and dysfunction leading to pulmonary valve replacement (PVR) or adverse cardiac events in repaired Tetralogy of Fallot (rToF) patients. METHODS: Data from all rToF patients who underwent magnetic resonance imaging (MRI) evaluation at our hospital between February 2007 and September 2020 were collected. RESULTS: Three hundred and forty-two patients (60% males, 42% older than 18 years), with a median age of 16 years (IQR 13-24) at the time of MRI, were included. All patients underwent complete repair at a median age of 8 months (IQR 5-16), while palliation was performed in 56 patients (16%). One hundred and forty-four patients (42%) subsequently received pulmonary valve replacement (PVR). At the multivariate analysis, male gender was an independent predictor for significant RV dilation, RV and left ventricular (LV) dysfunction. Transventricular ventricular septal defect (VSD) closure and previous palliation significantly affected LV function and RV size, respectively. Male gender and the transventricular VSD closure were independent predictors for PVR. CONCLUSIONS: Male gender and surgical history (palliation, VSD closure approach) significantly affected the long-term outcomes in rToF patients and should be taken into consideration in the follow-up management and in PVR timing in this patient population.

Idiopathic Ventricular Fibrillation: Look for the Hidden Guilty-A case of aborted cardiac death.

We report a unique case of a 6-year-old male child with aborted sudden cardiac death due to ventricular fibrillation. A rare anomalous aortic origin of the right coronary artery was detected and supposed to be the cause of the malignant arrhythmia. Clinical exome sequencing did not reveal any pathogenic variant related to channelopathies nor other known heart-related genes. The patient underwent cardiac surgery and a cardiac defibrillator was implanted for secondary prevention.

Aortic Valve Neocuspidalization May Be a Viable Alternative to Ross Operation in Pediatric Patients.

The aim of the study was to evaluate the medium-term results of aortic valve neocuspidalization according to Ozaki compared to Ross procedure for treatment of isolated aortic valve disease in pediatric age. Thirty-eight consecutive patients with congenital or acquired aortic valve disease underwent either Ozaki (n = 22) or Ross (n = 16) operation between 01/2015 and 05/2020. The primary outcome was progression of aortic valve disease and aortic ring and root dimension, whereas secondary outcome was freedom from reintervention or death by type of operation. Median age was 12.4 (8.8-15.8) years and the prevailing lesion was stenosis in 20 cases (52%) and incompetence in 18 (48%). One death occurred in the Ross group in the early postoperative period, while there were no deaths in the Ozaki group. Effective treatment of aortic valve stenosis or regurgitation occurred in both groups and remained stable over a median follow-up of 18.2 (5-32) months. In Ozaki group, 3 patients required aortic valve replacement at 4.9, 3.5, and 33 months, respectively. In Ross group, 1 patient required Melody pulmonary valve replacement, whereas none required aortic valve surgery. Finally, significantly higher aortic transvalvular gradient at follow-up was recorded in Ozaki group compared to Ross group. Overall, there was no significant difference in freedom from reoperation or death between the two groups. The medium-term outcome of Ozaki and Ross in pediatric patients is similar, despite an increased tendency of the former to develop aortic transvalvular gradient in the follow-up. Future larger multicenter studies with longer follow-up are warranted to confirm these results.

Aortic valve neocuspidalization in paediatric patients with isolated aortic valve disease: early experience.

OBJECTIVES: There is growing interest in the aortic valve (AV) neocuspidalization technique for the treatment of aortic valve disease (AVD). We report our medium-term results with this procedure performed in a paediatric patient population. METHODS: Between July 2016 and May 2020, 22 patients with both congenital and acquired isolated AVD were treated with neocuspidalization. The primary outcome was progression of the preoperatively assessed AVD in the immediate postoperative course and at follow-up. Secondary outcome was freedom from reintervention by material used. Potential predictors of failure were analysed in relation to the primary outcome. RESULTS: The median age at operation was 13.9 (interquartile range, 9.8-16.2) years, and the prevailing AV defect was stenosis in 10 cases (45%) and incompetence in 12 (55%). Pre-treated autologous pericardium was used in 13 patients whereas bovine pericardium in 9. Effective treatment of AV stenosis or regurgitation was achieved and remained stable over a median follow-up of 11.3 (4.7-21) months. Three patients required AV replacement at 4.9, 3.5 and 33 months. At follow-up, an upward trend of both median indexed vena contracta jet widths and aortic peak and mean gradients were recorded, the latter associated with a failure to grow the aortic annulus. Predictor of such outcome turned out to be the use of bovine pericardium. A significant inverse linear correlation between AV peak gradient at follow-up and preoperative aortic annular size (P = 0.008) was also demonstrated. CONCLUSIONS: The Ozaki procedure is safe and effective in paediatric patients with AV disease. The use of heterologous pericardium should probably be minimized. Moreover, preoperative small aortic annuli should probably be promptly treated by means of an associated ring enlargement procedure.

Atypical cardiac defects in patients with RASopathies: Updated data on CARNET study.

BACKGROUND: RASopathies are a set of relatively common autosomal dominant clinically and genetically heterogeneous disorders. Cardiac outcomes in terms of mortality and morbidity for common heart defects (such as pulmonary valve stenosis and hypertrophic cardiomyopathy) have been reported. Nevertheless, also Atypical Cardiac Defects (ACDs) are described. The aim of the present study was to report both prevalence and cardiac outcome of ACDs in patients with RASopathies. METHODS: A retrospective, multicentric observational study (CArdiac Rasopathy NETwork-CARNET study) was carried out. Clinical, surgical, and genetic data of the patients who were followed until December 2019 were collected. RESULTS: Forty-five patients out of 440 followed in CARNET centers had ACDs. Noonan Syndrome (NS), NS Multiple Lentigines (NSML) and CardioFacioCutaneous Syndrome (CFCS) were present in 36, 5 and 4 patients, respectively. Median age at last follow-up was 20.1 years (range 6.9-47 years). Different ACDs were reported, including mitral and aortic valve dysfunction, ascending and descending aortic arch anomalies, coronary arteries dilation, enlargement of left atrial appendage and isolated pulmonary branches diseases. Five patients (11%) underwent cardiac surgery and one of them underwent a second intervention for mitral valve replacement and severe pericardial effusion. No patients died in our cohort until December 2019. CONCLUSIONS: Patients with RASopathies present a distinct CHD spectrum. Present data suggest that also ACDs must be carefully investigated for their possible impact on the clinical outcome. A careful longitudinal follow up until the individuals reach an adult age is recommended.

Left ventricular (LV) pacing in newborns and infants: Echo assessment of LV systolic function and synchrony at 5-year follow-up.

BACKGROUND: Small retrospective studies reported that left ventricular (LV) pacing is likely to preserve LV function in children with isolated congenital complete atrioventricular block (CCAVB). The aim of this study was to prospectively evaluate LV contractility and synchrony in a cohort of neonates/infants at pacemaker implantation and follow-up. METHODS: Patients with CCAVB who underwent LV pacing were evaluated with electrocardiogram and echocardiogram in a single-center, prospective study. Data were collected at implantation, at 1-month and every year of follow-up, up to 5 years. LV ventricular dimensions (diameters and volumes), systolic function (ejection fraction [EF] and global longitudinal strain [GLS]), and synchrony were evaluated. Data are reported as median (25th-75th centiles). RESULTS: Twenty consecutive patients with CCAVB underwent pacemaker implantation (12 single-chamber pacemaker [VVIR] and eight dual-chamber pacemaker [DDD]) with epicardial leads: 17 on the LV apex and three on the free wall. Age at implantation was 0.3 months (1 day-4.5 months). Patients showed good clinical status, normal LV dimensions, preserved systolic function, and synchrony at 60 (30-60) months follow-up. EF increased to normal values in patients with preimplantation EF <50%. Presence of antibodies and pacing mode (DDD vs VVIR) had no impact on the outcome. CONCLUSIONS: LV pacing preserved LV systolic function and synchrony in neonates and infants with CCAVB at 5-year follow-up. LV EF improved in patients with low preimplantation EF. Pacing mode or the presence of autoantibodies did not demonstrated an impact on LV contractility and synchrony.

Outcome for Conservative Surgery for the Correction of Severe Mitral Valve Regurgitation in Children: A Single-Center Experience.

Evolving reconstructive techniques have progressively become the preferred approach for treatment of pediatric mitral valve regurgitation. We present our experience in a cohort of patients undergoing surgical correction for severe mitral regurgitation. Fifty-five patients (age 1 month-18 years; median 5 years) were included in the present analysis. Different surgical techniques were used (posterior leaflet augmentation in 25, isolated cleft closure in 12, Alfieri-type procedure in 10, annuloplasty in 5, with artificial chordae in 2, and quadrangular resection with chordal transposition in 1). Follow-up time ranged from 1 to 192 months (median 38[IQR 12-54] months). Operative and follow-up mortality was 0%. Reintervention in the whole population occurred in 31% of patients. However, when first surgery was performed under 2 years of age (no = 17), reintervention reached nearly 50%. The degree of residual mitral regurgitation at follow-up remained stable after surgery, while a significant increase in mean transmitral gradient was observed over time (paired t test = 0.03). In multivariable Cox-regression analysis, post-surgical transmitral gradient was the only independent predictor for reintervention (p = 0.017; HR 2.4; 95%CI 1.2-5.1), after correcting for differences in age at surgery, type of reintervention, mitral annulus dimension, and BSA at the first surgery. ROC curve demonstrated that a post-surgical transmitral mean gradient value > 5 mmHg, was predictive for reintervention (AUC = 0.89; Youden index = 0.44). Our study suggests that the use of conservative technique strategy achieves satisfactory functional results in infants and children with severe MR, although the rate of reoperation in younger patients remains substantial. Post-operative moderate mitral stenosis was the strongest predictor for reoperation.

Midterm Echocardiographic Assessment of Right Ventricular Function After Midline Unifocalization.

BACKGROUND: Patients with an open ventricular septal defect (VSD) after repair of pulmonary atresia (PA), VSD, and major aortopulmonary collaterals (MAPCAs) are the most vulnerable subgroup. We analyzed the impact of concomitant versus delayed VSD closure on survival and intermediate-term right ventricular (RV) function. METHODS: Between October 1996 and February 2017, 96 patients underwent a pulmonary flow study-aided repair of PA/VSD/MAPCAs. For patients who underwent either concomitant or delayed intracardiac repair, echocardiographic RV systolic function was retrospectively calculated to assess (1) RV fractional area change (RVFAC) and (2) two-dimensional RV longitudinal strain (RVLS) of the free wall of the right ventricle. QLAB cardiac analysis software version 10.3 (Philips Medical Systems, Andover, MA) was used for analysis. RESULTS: A total of 64 patients underwent concomitant VSD closure at the time of unifocalization, and 16 patients underwent delayed VSD closure at a median of 2.3 years (range: 3 days to 7.4 years). At a median follow-up of 8.1 years (range: 0.1 to 19.5 years) for the concomitant repair group versus 7.4 years (range: 0.01 to 15.3 years) for the delayed repair group, no differences in RVFAC and RVLS were observed (RVFAC: 41.0% ± 6.2% versus 41.2% ± 7.6%, p = 0.91; RVLS: -18.7 ± 4.3 versus -18.9 ± 4.0, p = 0.87). CONCLUSIONS: Patients (83%) with PA/VSD/MAPCAs underwent complete repair at intermediate-term follow-up with preserved RV function. Delayed VSD closure was accomplished in 50% of the patients initially deemed unsuitable for repair. Delayed VSD closure did not affect survival and did not portend impaired RV systolic function.

Subcutaneous implantable cardioverter-defibrillator: is it ready for use in children and young adults? A single-centre study.

Aims: Use of the subcutaneous implantable cardioverter-defibrillator (S-ICD) to prevent sudden cardiac death is increasing. Few data exist on S-ICD in young patients. We reviewed our single-centre experience in order to assess the effectiveness and safety of S-ICD implantation, and to identify potential factors associated with complications. Methods and results: Observational, non-randomized, standard-of-care study on S-ICD implantation/follow-up in young patients with inherited arrhythmias (IA), cardiomyopathies, and congenital heart defects (CHD). Fifteen patients (6 CHD, 8 cardiomyopathies, and 1 IA), median age 15 years (25th-75th centiles, 14-28), 10 of them <18 years, with body mass index (BMI) 22.6 ± 3.4, underwent S-ICD implantation (primary prevention 93%). The first six patients underwent a standard implantation procedure (three surgical incisions), the following nine a two-incision procedure. No intraoperative complications occurred. Over 12 (7-24) months follow-up, two patients received appropriate shocks and one (7%) inappropriate shock. Four patients had device-related complications requiring surgical intervention: three skin erosions at the superior parasternal incision, one pocket infection. A higher risk of complications was seen in patients who underwent standard procedures [hazard ratio (HR) 4.98, 95% confidence interval (CI) 1.53-47.36; P = 0.0482] and those with BMI <20 (HR 9.44, 95% CI 0.95-93.23; P = 0.0169). Conclusion: S-ICD implantation was safe and effective in young patients with low rates of inappropriate shock. However, the risk of device-related complications during follow-up remains substantial in patients with low BMI. To prevent possible complications, a two-incision technique should be preferred.

Bradyarrhythmias in Repaired Atrioventricular Septal Defects: Single-Center Experience Based on 34 Years of Follow-Up of 522 Patients.

Atrioventricular Septal Defect (AVSD) is a rare congenital heart defect (CHD) often associated with genetic syndromes, most commonly Down syndrome (DS). Over the last four decades, surgical repair has increased survival and improved quality of life in these patients. The prevalence of bradyarrhythmias namely, atrioventricular block (AVB) and sinus node dysfunction (SND) in AVSD is partially known. 522 cases with both partial and complete AVSD (38.7% with DS), undergoing intracardiac repair from 1982 to 2016 at our institution, were reviewed from our system database. 38 (7.3%) patients received permanent PM implantation for AVB (early or late) or SND. On one hand, AVB requiring PM was found in 26 (4.98%). This was further subdivided into early-onset 14 (2.6%) and late-onset AVB 12 (2.2%) (median 4 [IQR 1-7] years). On the other hand, 12 (2.3%) experienced late SND requiring PM (median 11 [IQR 3.5-15.2] years). Early and late AVB were independent from the type of AVSD (partial or complete), whereas the late SND was remarkably observed in complete AVSD compared to partial AVSD (p = 0.017). We classified the cohort into two main categories: DS (202, 38.7%) and non-DS (320, 61.3%). At Kaplan-Meier survival analysis, DS was significantly associated with late-onset bradyarrhythmias (p = 0.024). At Cox regression analysis, we identified DS as an independent predictor of PM implantation (HR 2.17). In conclusion, about 7% of repaired AVSD patients need PM implantation during follow-up. There are no differences in early and late AVB occurrence according to the type of AVSD. There is a higher incidence of late SND in repaired complete AVSD, with a later timing onset in patients with associated DS. Moreover, DS seems to be an independent predictor of PM implantation.