Implantable Cardioverter Defibrillators In Children Research Articles

Indications and management of implantable cardioverter-defibrillator therapy in childhood hypertrophic cardiomyopathy.

Sudden cardiac death is the most common mode of death during childhood and adolescence in hypertrophic cardiomyopathy, and identifying those individuals at highest risk is a major aspect of clinical care. The mainstay of preventative therapy is the implantable cardioverter-defibrillator, which has been shown to be effective at terminating malignant ventricular arrhythmias in children with hypertrophic cardiomyopathy but can be associated with substantial morbidity. Accurate identification of those children at highest risk who would benefit most from implantable cardioverter-defibrillator implantation while minimising the risk of complications is, therefore, essential. This position statement, on behalf of the Association for European Paediatric and Congenital Cardiology (AEPC), reviews the currently available data on established and proposed risk factors for sudden cardiac death in childhood-onset hypertrophic cardiomyopathy and current approaches for risk stratification in this population. It also provides guidance on identification of individuals at risk of sudden cardiac death and optimal management of implantable cardioverter-defibrillators in children and adolescents with hypertrophic cardiomyopathy.

Use of implantable cardioverter-defibrillator in children supported with ventricular assist device: An analysis of data from teh EUROMACS registry.

Data on the use and outcome of children on ventricular assist device (VAD) support provided with an implantable cardioverter-defibrillator (ICD) remains poor. A retrospective analysis of the EUROMACS database on children supported with VAD < 19 years of age from January 1, 2009 to April 1, 2020. Patients with missing data on status of ICD, missing baseline and/or follow up information were excluded. The primary independent variable of interest was the concomitant presence or absence of an ICD at the time of VAD placement. Kaplan-Meier survival analysis was performed to evaluate survival differences between children on VAD with and without an ICD. Out of 303 patients provided with a VAD, 7% (7♀, 15♂) had an ICD implanted and formed the study group. Median age was 14 years, median weight was 43.5kg, and median BSA was 1.39. Median Intermacs stage was 2 (range: 1-7). Seventeen patients (77%) were transplanted, 4 (18%) died while on support, and 1 (5%) was weaned from device after myocardial recovery. Median time on support was 68 days compared to 361 days in the control group (p: 0.01). Three patients underwent device exchange due to thrombus formation in the pump. There was no difference in survival between groups (p= 0.342). The presence of ICD in pediatric patients supported with a VAD is low (7%). Children on VAD support provided with an ICD do not have a survival benefit compared to children without an ICD.

Epicardial vs. transvenous implantable cardioverter defibrillators in children.

The implantable cardioverter defibrillator (ICD) has been increasingly used in children. Both epicardial and transvenous approaches are used, with controversy regarding the best option with no specific recommendations. We aimed to compare outcomes associated with epicardial vs. transvenous ICDs in children. Data were analysed from a retrospective study including all patients <18-year-old implanted with an ICD in a tertiary centre from 2003 to 2021. Outcomes were compared between epicardial and transvenous ICDs. A total of 122 children with an ICD (mean age 11.5 ± 3.8 years, 57.4% males) were enrolled, with 84 (64.1%) epicardial ICDs and 38 (29.0%) transvenous ICDs. Early (<30 days) ICD-related complications were reported in 17 (20.2%) patients with an epicardial ICD vs. 0 (0.0%) with a transvenous ICD (P = 0.002). Over a mean follow-up of 4.8 ± 4.0 years, 25 (29.8%) patients with an epicardial ICD and 9 (23.7%) patients with a transvenous ICD experienced at least one late ICD-related complication [hazard ratio (HR) 1.8, 95% confidence interval (CI) 0.8-4.0]. Implantable cardioverter defibrillator lead dysfunction occurred in 19 (22.6%) patients with an epicardial ICD vs. 3 (7.9%) with a transvenous ICD (HR 5.7, 95% CI 1.3-24.5) and was associated with a higher incidence of ICD-related reintervention (HR 3.0, 95% CI 1.3-7.0). After considering potential confounders, especially age and weight at implantation, this association was no longer significant (P = 0.112). The freedom from ICD lead dysfunction was greater in patients with pleural coils than in those with epicardial coils (HR 0.38, 95% CI 0.15-0.96). In children, after a consideration of patient characteristics at implantation, the burden of complications and ICD lead dysfunction appears to be similar in patients with epicardial and transvenous devices. Pleural coils seem to be associated with better outcomes than epicardial coils in this population. NCT05349162.

Subcutaneous versus transvenous implantable cardioverter defibrillators in children and young adults: A meta-analysis.

The implantable cardioverter defibrillator (ICD) has been demonstrated to successfully prevent sudden cardiac death (SCD) in children and young adults. A wide range of device-related complications/malfunctions have been described, which depend on the intrinsic design of the defibrillation system (transvenous-implantable cardioverter defibrillator [TV-ICD] vs. subcutaneous-implantable cardioverter defibrillator [S-ICD]). To compare the device-related complications and inappropriate shocks with TV-ICD versus S-ICD. Electronic databases were queried for studies focusing on the prevention of SCD in children and young adults with TV-ICD or S-ICD. The effect size was estimated using a random-effect model as odds ratio (OR) and relative 95% confidence interval (CI). The primary endpoint was a composite of any device-related complications and inappropriate shocks. We identified a total of five studies including 236 patients (Group S-ICD: 76 patients; Group TV-ICD: 160 patients) with a mean follow-up time of 54.2±24.9months. S-ICD implantation contributed to a significant reduction in the risk of the primary endpoint of any device-related complications and inappropriate shocks (OR: 0.18; 95% CI: 0.05-0.73; p=.02). S-ICD was also associated with a significantly lower incidence of inappropriate shocks (OR: 0.28; 95% CI: 0.11-0.74; p=.01) and lead-related complications (OR: 0.18; 95% CI: 0.05-0.66; p=.01). A trend toward a higher risk of pocket complications (OR: 5.91; 95% CI: 0.98-35.63; p=.05) was recorded in patients with S-ICD. Children and young adults undergoing S-ICD implantation may have a lower risk of a composite of device-related complications and inappropriate shocks, compared to TV-ICD patients.

Subcutaneous implantable cardioverter defibrillator in children and adolescents: results from the S-ICD "Monaldi care" registry.

Implantable cardioverter defibrillators (ICD) are widely accepted therapy in children and adolescents who are survivors of cardiac arrest or for high-risk patients with inheritable channelopathies, cardiomyopathies, or congenital heart disease. Initial experience with subcutaneous ICD (S-ICD) systems has shown a high efficacy in adults. However, the use of S-ICD in children and adolescents implies some specific considerations, as the safety for these patients is unknown and recommendations among physicians may vary widely. We reviewed the data and studied the indications for S-ICD in children and adolescents and discuss the preliminary clinical experience. From a cohort of 297 patients enrolled in the S-ICD "Monaldi care" registry that encompass all the patients implanted in the Monaldi Hospital of Naples, we considered 21 consecutive children and adolescents (mean age 13.9 years, range 8-18 years, mean body weight 59.3 kg, range 38-100 kg) who underwent S-ICD implant from April 2014 to June 2020. Mean follow-up was 41.9±21.9 months. Only one patient presented, 6 weeks after implantation, skin erosion at the inferior parasternal incision that resolved after antibiotic therapy, without the necessity of any system revision. Two patients experienced appropriate shocks and four inappropriate shocks, due to T wave oversensing or atrial arrhythmia. Only one patient, with arrhythmogenic right ventricular dysplasia, required a system revision after 36 months of the first implantation and then a reintervention with a replacement of the S-ICD by a conventional ICD system. Our experience suggests that the S-ICD device can be used in some children over the age of 8 as well as adults, with a similar rate of unwanted side effects, and early evidence of apparent efficacy.

Long-term efficacy and safety of hydroquinidine in patients with Brugada syndrome

Abstract Background Brugada syndrome (BrS) is an inherited channelopathy with an increased risk of supraventricular, ventricular arrhythmias (VAs) and sudden cardiac death (SCD). Implantable cardioverter-defibrillator (ICD) is a cornerstone of SCD prevention, but it does not reduce the incidence of life-threatening VAs and it can carry substantial complications. Hydroquinidine (HQ) is a class IA antiarrhythmic drug used for electrical storms, to reduce ICD's appropriate discharges and as an alternative to ICD in children with BrS or in patients with a contraindication to ICD. Nevertheless, HQ's side effects may undermine treatment compliance. Purpose The aim of this study was to evaluate the efficacy and safety of HQ in reducing VAs (ventricular fibrillation, sustained and non-sustained ventricular tachycardia) inducibility at electrophysiology study (EPS) and atrial fibrillation/flutter (AF/AFL) or VAs recurrence in patients with BrS. Methods From the prospective Piedmont Brugada Registry, patients treated with HQ were selected and divided into three groups according to the indication for HQ initiation: index EPS positive for VAs induction (group 1), secondary prevention of AF/AFl (group 2), secondary prevention of VAs (group 3). In group 3 recurrence of VAs was monitored by implantable devices or by periodic 24-hour ECG Holter monitoring. In 5 patients HQ was started for reasons different from the above mentioned, so they were considered only for safety outcomes. Safety was assessed considering the occurrence of HQ side effects and their impact on treatment discontinuation. Results A total of 98 patients (79 males, 80,6%) were included. Median follow-up was 61 months (IQR 31–89 months). None of the baseline clinical characteristics was associated with arrhythmic recurrences. Among 46 patients in group 1 HQ was effective in reducing EPS inducibility in 91.9% of patients (p&amp;lt;0.0001); in group 2 (31 patients) HQ reduced palpitations [before HQ 83,8%, with HQ 27,6%, RRR 67.1%, NNT 1.8; p&amp;lt;0.0001] and no AF/AFL recurrence was recorded during follow-up (p&amp;lt;0.0001); in group 3 (17 patients; 70.6% with ICD/LR implanted) VAs recurrences were significantly reduced in patients with HQ (5.9% recurrence rate, p&amp;lt;0.0001). Overall, no cardiac arrest occurred during follow-up. At ECG, HQ determined a significant increase in QTc duration (V5-lead mean QTc duration pre-HQ 406 ms vs with HQ 428 ms; p=0.001). Overall, 28.6% of patients presented HQ-related side effects, mainly due to gastrointestinal intolerance (18.3%). Treatment discontinuation rate was 25% but only about half of these patients discontinued HQ for adverse events (29.2% for GI intolerance, 16.7% for drug-induced QTc prolongation, 8.3% for elevated liver enzymes; 45.8% self-discontinuation). Conclusions In patients with BrS, HQ was effective in reducing VAs inducibility at EPS, AF/AFL and VAs recurrences; moreover, it was effective in reducing symptoms. Overall, HQ proved to be safe and well-tolerated. Funding Acknowledgement Type of funding source: None

Cost-Effectiveness of Implantable Cardioverter-Defibrillators in Children with Cardiac Conditions Associated with Risk for Sudden Cardiac Death.

Children at high risk for sudden cardiac death (SCD) receive implantable cardioverter-defibrillators (ICD) for prevention, but the cost effectiveness of ICDs in children at intermediate risk is unclear. Our objective was to create a cost-effectiveness model to compare costs and outcomes in children at risk of SCD, with and without ICD. Utilizing hypertrophic cardiomyopathy as the proxy disease, a theoretical cohort of 8150 children was followed for 69years. Model inputs were derived from the literature, with an incremental cost-effectiveness ratio (ICER) willingness-to-pay threshold of $100,000/quality-adjusted life year (QALY) used to delineate cost effectiveness. Outcomes included prevalence of severe neurological morbidity (SNM), SCD, cost, and QALYs. In children at intermediate risk of SCD (4-6% over 5years), ICD resulted in 56 fewer cases of SNM, 2686 fewer deaths. In children at high risk (> 6% over 5years), ICD placement resulted in 74 fewer cases of SNM and 3663 fewer deaths from cardiac causes. The costs of ICD were higher, but placement was cost effective with an ICER of $3009 per QALY in intermediate risk children, but ICD therapy was a dominant strategy in high-risk children. Sensitivity analysis demonstrated ICD placement was cost-effective until the annual probability of SCD was < 0.22%. The model was robust over a wide range of values. For children at risk of SCD, prophylactic ICD implantation is cost effective, resulting in improved outcomes and increased QALYs, despite increased costs. These findings highlight the economic benefits of ICD utilization in this population.

Progress in application of implantable cardioverter defibrillators in children

Implantable cardioverter defibrillator (ICD) plays an irreplaceable role in preventing sudden cardiac death.There has been a continuous increase in the implantation rate of ICD in children along with technologic improvement.However, the choice of indication, device and implantation approaches of ICD still faces great challenges due to the particularity of children.Related issues on the clinical application of ICD in children, including common diseases, indications and the clinical application of ICD, are reviewed in this paper. Key words: Cardiology; Sudden cardiac death; Implantable cardioverter defibrillator; Child

Long-term follow-up of implantable cardioverter-defibrillators in children: Indications and outcomes.

Validation data of the use of implantable cardioverter-defibrillators (ICD) in the pediatric population is insufficient, with limited follow-up periods. The aim of the study was to report on 17 years of experience with implantable cardioverter-defibrillator (ICD) therapy in children and young adults. This retrospective review included patients below the age of 18 years at the time of ICD implantation between May 2000 and December 2017. For the statistical analysis, the sample was divided into groups by gender and the type of indications for ICD implantation (primary vs secondary prevention). The study group included 20 children (8 female, 12 male) who underwent ICD implantation for primary or secondary prevention of sudden cardiac death (SCD). The average age at the time of the initial procedure was 15.6 years (range: 3.8-17.7 years). Primary electrical disease (PED) was present in 9 patients, cardiomyopathy (CMP) in 9 and 2 others had congenital heart defects (CHDs). The median follow-up time was 6.7 years (range: 0.4-12.5 years). The outcomes of ICD therapy were analyzed. No differences between the sexes were found in terms of treatment strategy effectiveness (p > 0.05). The girls were more often treated as primary prevention (p = 0.009). After implantation, all the patients were on optimal pharmacotherapy. Alltogether there were 126 ICD interventions in 11 patients, including 23 inadequate interventions (IA) in 2 children (18.2%).Three children (15%) died due to electrical storms. In the per-procedure analysis, the overall freedom rate from ICD lead replacement was 90%, 80% and 57% at 1, 5 and 10 years of observation, respectively. Implantable cardioverter-defibrillator implantation indications in children are more heterogeneous in comparison to adult population. In the pediatric population undergoing ICD implantation, the treatment strategy is influenced by gender. The rate of inappropriate ICD discharges (IA) in our group of pediatric patients was low. Rigorous pharmacotherapy and individual ICD programming seemed of paramount importance. Lead malfunctions LF constituted the most prevalent complication observed.

Transvenous and non-transvenous implantable cardioverter-defibrillators in children, adolescents, and adults with congenital heart disease: who is at risk for appropriate and inappropriate shocks?

Non-transvenous implantable cardioverter-defibrillators (ICDs) as used in small patients and in patients with congenital heart disease (CHD) have not been compared with transvenous systems with respect to safety and efficacy yet. Aim of the present study was to describe the prevalence of and to identify contributing factors for appropriate and inappropriate ICD discharges in patients with non-transvenous and transvenous ICD. Single centre analysis of all paediatric and CHD patients who had received an ICD since 1995. One hundred and ninety-five patients were included. A transvenous system had been implanted in 153 (78%) subjects, the remaining 42 (22%) individuals received an extracardiac (EC)-ICD system. During mean follow-up of 4.5 years appropriate ICD shocks were noted in 32 (16%) individuals, whereas inappropriate shocks occurred in 22 (11%) patients. Appropriate shocks were more frequent in patients with an EC-ICD than in individuals with transvenous systems (29% vs. 13%, P = 0.02). Rapidly conducted atrial tachycardia (AT) was the most common reason for inappropriate shocks (76%). Rate of inappropriate shocks was not different between EC and transvenous systems (12% vs. 11%, P = 0.26). Lead failure was more prevalent in subjects with an EC-ICD (29% vs. 7%, P = 0.001). Individuals with EC-ICD systems were particularly prone to experience appropriate shocks. As rapidly conducted AT was the most common reason for inappropriate ICD shocks, rigorous treatment of these arrhythmias and proper ICD programming are mandatory. Though lead failure was of concern in EC-ICD patients, EC-ICD systems were not inferior with respect to inappropriate shocks.

Fifteen years' experience of implantable cardioverter defibrillator in children and young adults: Mortality and complications study.

Young implantable cardioverter defibrillator (ICD) recipients have a high rate of complications, some of which seem to be underestimated. We report our clinical experience with ICD therapy in children and young adults during a 15year follow up. We reviewed the database of ICD recipients at the present institution and chose 73 consecutive patients who underwent implantation at age 6-21years. We analyzed intervention rate, mortality, rate and characteristics of complications and treatment options. A total of 20/73 patients (27.4%) received ≥1 episode of appropriate therapy (AT) for ventricular tachycardia/ventricular fibrillation (anti-tachycardia pacing or shock) and 24/73 patients (32.8%) had one or multiple episodes of inappropriate therapy (IT). Eight patients (11%) had both interventions: AT + IT. A total of 15/73 patients (20.5%) had ventricular lead dysfunction, with 13 re-implantations (17.8%) of a new system. Four of 73 patients (5.5%) had infection: endocarditis or device pocket infection. A total of 2/73 patients (2.7%) died due to ventricular lead dysfunction, while 22/73 patients (30.1%) needed elective device replacement, five of them twice (6.8%). Endocardial ICD implantation in children and young adults is a feasible and life-saving procedure, according to the present 15year follow up. The rate of complications including IT was high: 72.8% in the young ICD recipients. Re-implantation of a new system was often required due to ventricular lead dysfunction or infection in 25% of the patients.

Predictors of electrocardiographic screening failure for the subcutaneous implantable cardioverter-defibrillator in children: A prospective multicenter study

Subcutaneous implantable cardioverter-defibrillator (SICD) shows promise for select patients at risk of sudden cardiac death. However, patients need to pass an electrocardiographic (ECG) screening (ECG-S) test before they can receive an SICD. Predictors of ECG-S failure in children are unclear. The purpose of this study was to identify the incidence and predictive factors for failure of ECG-S in children. Patients 18 years and younger with a preexisting ICD underwent ECG-S for SICD. ECG and demographic data were analyzed for factors predictive of failure. Seventy-three patients (mean age 14.2 ± 3.3 years; range 5-18 years) with hypertrophic cardiomyopathy (n = 24, 33%), long QT syndrome (n =18, 25%), other inherited arrhythmia syndromes (n= 20, 27%), congenital heart disease (n = 9, 12%), and miscellaneous conditions (n = 2) with an existing transvenous ICD underwent prospective ECG-S. Nineteen (26%) failed ECG-S. Failed patients had a longer corrected QT (QTc) interval (457 ms vs 425 ms; P = .03), a longer QRS duration (120 ms vs 98 ms; P = .04), and a lower ratio of R-wave to T-wave amplitudes (R:T ratio) in lead aVF (4 vs 5; P = .001). Multivariable logistic regression identified QTc interval (odds ratio [OR] 4.31; P = .04), QRS duration (OR 4.93; P = .03), R:T ratio in lead aVF (OR 3.13; P = .08) as predictors of failure. A risk score with 1 point each for QTc interval >440 ms, QRS duration >120 ms, and R:T ratio <6.5 in lead aVF was associated with probability of failure of 15.4% (1 point), 47.4% (2 points), and 88.6% (3 points), respectively. ECG-S failure for SICD occurred in 26% of children, which is higher than the reported incidence in adults. Factors predicting ECG-S failure included longer QTc interval, longer QRS duration, and lower R:T ratio in lead aVF.

Midterm Results of Implantable Cardioverter Defibrillators in Children and Young Adults from a Single Center in Turkey.

Despite concerns about complications with the implantable cardioverter defibrillator (ICD), it is effective for the prevention of sudden cardiac death (SCD). We aimed to analyze our midterm experience with ICD in children and young adults. This retrospective study included patients who were implanted with an ICD between 2001 and 2014. Demographic characteristics, clinical information, shock features, and complications for all patients with ICD were analyzed. The study population was divided into two groups: early-era patients implanted before 2008, and late-era patients implanted after 2008. Sixty-nine patients (median age: 12 years, median follow-up: 52 months) were implanted with an ICD. Diagnostic categories were channelopathy (56.6%), cardiomyopathy (36.2%), congenital heart disease (5.8%), and other (1.4%). We performed implantation for primary prevention in 66.6% (39.3% in early-era patients and 85.4% in late-era patients). Thirty-one (44.9%) received 139 appropriate shocks (66% of total shocks) while 14 (20.2%) received 71 inappropriate shocks. However, there was no statistically significant difference in the use of appropriate shocks in the primary (66.7%) versus the secondary (72.2%) prevention groups. The incidence of appropriate and inappropriate shock was 66.7% and 33.3% in the primary prevention group, and 72.2% and 27.8% in the secondary prevention group, respectively. Two patients died, although only one death was the result of a lead problem. Although lead integrity problems, inappropriate shocks, and infections are significant issues, ICD therapy appears to be a safe, effective, and necessary option for the prevention of SCD in both children and young adults.

Brugada syndrome in the paediatric population: a comprehensive approach to clinical manifestations, diagnosis, and management.

Brugada syndrome is an inherited arrhythmogenic disorder, characterised by coved-type ST-segment elevation in the right precordial leads, and is associated with increased risk of sudden death. It is genetically and clinically heterogeneous, presenting typically in the fourth or fifth decade of life. The prevalence of Brugada syndrome in the paediatric population is low compared with the adult population. Interestingly, over the last several years, there has been growing evidence in the literature of onset of the disease during childhood. Most of the paediatric cases reported in the literature consist of asymptomatic Brugada syndrome; however, some patients manifest the disease at different regions of the cardiac conduction system at a young age. Early expression of the disease can be affected by multiple factors, including genetic substrate, hormonal changes, and still unknown environmental exposures. The initial manifestation of Brugada syndrome in children can include sinus node dysfunction and atrial arrhythmias. Brugada syndrome can also manifest as ventricular arrhythmias leading to sudden death at an early age. In symptomatic children, performance of the ajmaline test by an experienced team can be safely used as a diagnostic tool to unmask latent Brugada syndrome. Defining indications for an implantable cardioverter defibrillator in children with the diagnosis of Brugada syndrome remains challenging. Given the rarity of the syndrome in children, most paediatric cardiologists will only rarely see a young patient with Brugada syndrome and there is still no universal consensus regarding the optimal management approach. Care should be individualised according to the specific clinical presentation, taking into account the family history, genetic data, and the family's specific preferences.

Surgical techniques for implanting implantable cardioverter defibrillators in children and infants

Implantable cardioverter defibrillators (ICDs) are now being used in children. ICDs can be used to prevent sudden cardiac death caused by not only congenital heart defects, but also various non-structural diseases, such as long QT syndrome. However, a standard implantation technique for children, especially infants, has not yet been established. As the surgical implantation in infants is not amenable to transvenous lead placement, it was necessary to choose from epicardial, subcutaneous and pericardial ICD systems. However, many of these systems are associated with high rates of late complications. Lead fracture, insulation breakage, migration, buckling or crinkling of the patch lead and constrictive pericarditis have been reported as the most common lead-related complications. An increase in the defibrillation threshold is another issue that must be considered when using an ICD in a child or infant. Further studies on the outcomes, psychosomatic impact and other specific complications in the pediatric population need to be considered. The clinical use of ICDs in infants is still limited. Therefore, it is important to have many surgical options available so that the treatment can be custom-tailored to suit individual patients.

Clinical Experience of Subcutaneous and Transvenous Implantable Cardioverter Defibrillators in Children and Teenagers

Subcutaneous implantable cardioverter defibrillator (S-ICD) systems have no components in contact with the heart and may avoid complications such as lead fracture, venous obstruction, or endocarditis that occur with transvenous leads. Concerns have been raised regarding inappropriate shocks and pocket erosion with S-ICD systems. We have compared the performance of S-ICD and transvenous ICD systems in children and teenagers. We studied consecutive patients <20 years of age who received an ICD over a 4-year period in two Scottish centers. Baseline characteristics, complications, and ICD therapy were recorded. The primary outcome measure was survival. The secondary outcome measure was survival-free from inappropriate ICD therapy or system revision. Nine S-ICD were implanted in nine patients. Eight transvenous ICD were implanted in six patients; two were redo procedures. Baseline characteristics were well matched. Median duration of follow-up was lower for S-ICD (20 months) than for transvenous ICD (36 months, P = 0.0262). Survival was 100% in both groups. Survival free of inappropriate therapy or system revision was 89% for S-ICD and 25% for transvenous ICD systems (log-rank test, P = 0.0237). No S-ICD were extracted, but three transvenous ICD were extracted due to infection (n = 1) and lead failure (n = 2). In real-world use in children and teenagers, S-ICD may offer similar survival benefit to transvenous ICD, with a lower incidence of complications requiring reoperation. In the absence of randomized trials, S-ICD should be compared prospectively with transvenous ICD in large multicenter registries with comparable periods of follow-up.

Implantable cardioverter defibrillator therapy in pediatric and congenital heart disease patients: a single tertiary center experience in Korea

PurposeThe use of implantable cardioverter defibrillators (ICDs) to prevent sudden cardiac death is increasing in children and adolescents. This study investigated the use of ICDs in children with congenital heart disease.MethodsThis retrospective study was conducted on the clinical characteristics and effectiveness of ICD implantation at the department of pediatrics of a single tertiary center between 2007 and 2011.ResultsFifteen patients underwent ICD implantation. Their mean age at the time of implantation was 14.5±5.4 years (range, 2 to 22 years). The follow-up duration was 28.9±20.4 months. The cause of ICD implantation was cardiac arrest in 7, sustained ventricular tachycardia in 6, and syncope in 2 patients. The underlying disorders were as follows: ionic channelopathy in 6 patients (long QT type 3 in 4, catecholaminergic polymorphic ventricular tachycardia [CPVT] in 1, and J wave syndrome in 1), cardiomyopathy in 5 patients, and postoperative congenital heart disease in 4 patients. ICD coils were implanted in the pericardial space in 2 children (ages 2 and 6 years). Five patients received appropriate ICD shock therapy, and 2 patients received inappropriate shocks due to supraventricular tachycardia. During follow-up, 2 patients required lead dysfunction-related revision. One patient with CPVT suffered from an ICD storm that was resolved using sympathetic denervation surgery.ConclusionThe overall ICD outcome was acceptable in most pediatric patients. Early diagnosis and timely ICD implantation are recommended for preventing sudden death in high-risk children and patients with congenital heart disease.

Update on pacing and implantable cardioverter defibrillators in children

Pacemakers and implantable cardioverter defibrillators are important therapies in the pediatric and congenital heart disease population. However, these therapies, while potentially life-saving, have major limitations which are particular to the pediatric age group. Lead malfunction, inappropriate discharges, and venous obstruction all complicate device usage in this group. This review will address issues with pacemaker and defibrillator use in the pediatric and congenital heart disease population and discuss potential advances in the area in the next 5 to 10years.

Clinical experience of entirely subcutaneous implantable cardioverter-defibrillators in children and adults: cause for caution

This paper describes our clinical experience of using an entirely subcutaneous implantable cardioverter-defibrillator (S-ICD) in children and adults. Maintaining lead integrity and long-term vascular access are critical challenges of ICD therapy, especially in younger patients. The S-ICD has considerable theoretical advantages in selected patients without pacing indications, particularly children and young adults. Although sensing in an S-ICD may be influenced by age, pathology, and posture, there are currently few published data on clinical sensing performance outside the setting of intra-operative testing or in younger patients. Patients were selected by a multi-disciplinary team on clinical grounds for S-ICD implantation from a broad population at risk of sudden arrhythmic death. Sixteen patients underwent implantation [median age 20 years (range 10-48 years)]. Twelve had primary electrical disease and four had congenital structural heart disease. There were no operative complications, and ventricular fibrillation (VF) induction testing was successful in all cases. During median follow-up of 9 months (range 3-15 months), three children required re-operation. Eighteen clinical shocks were delivered in six patients. Ten shocks in four patients were inappropriate due to T-wave over-sensing. Within the eight shocks for ventricular arrhythmia, three were delivered for VF, among which two had delays in detection with time to therapy of 24 and 27 s. The S-ICD is an important new option for some patients. However, these data give cause for caution in light of the limited published data regarding clinical sensing capabilities, particularly among younger patients.

Feasibility of Implantable Cardioverter Defibrillator Treatment in Five Patients With Familial Friedreich's Ataxia—A Case Series

Friedreich's ataxia (FRA) is an autosomal recessive disease of the central nervous system that is associated with familial cardiomyopathy. Cardiac involvement is seen in more than 90% of the patients and is the most common cause of death in these patients. We present a case series and discuss the indications for implantable cardioverter defibrillator (ICD) implantation in FRA with review of the literature. Five pediatric patients who suffer from FRA (four female and one male, mean age 17.4 years) underwent ICD implantation between 2007 and 2008 in the University Hospital of Goettingen. The diagnosis of FRA was established by standard clinical criteria and proven in each case by genotyping at the frataxin locus. The time from diagnosis to ICD implantation was 10.4±1.73 years (range 8-15 years). All patients received transvenous lead systems. There were no intraoperative and postoperative complications. At the latest follow-up, the neuromuscular symptoms exhibited no further progress and no ICD activations were noticed. Only minor repolarization changes were seen on electrocardiogram. All patients had normal echocardiographic findings and no angina has been reported. Coronary angiographies were normal. It is evident that many FRA patients develop ventricular dysfunction. In the absence of a definitive surgical cure an ICD is generally indicated in young patients with hemodynamically significant sustained ventricular tachyarrhythmias for prevention of sudden cardiac death. Our experience implies the safe use of ICD in children with FRA.