Subcutaneous Implantable Cardioverter-Defibrillators in Pediatrics and Congenital Heart Disease

Low Risk of Inappropriate Shock Among Pediatric Patients With an Implantable Cardioverter Defibrillator: A Single Center Experience

Implantable cardioverter-defibrillators (ICD) are increasingly being used among the pediatric population for indications of both primary and secondary prevention. There is limited long-term data on the outcomes of pediatric patients following ICD implantation. The aim of this study was to investigate the characteristics of this population, burden of appropriate and inappropriate shock and complication rate in a large tertiary pediatric medical center. Included were children under the age of 18 years who underwent ICD implantation and had clinical follow up at our center. Data were retrospectively collected between study period 2005-2020. Primary outcome was the incidence of ICD shock appropriate and inappropriate. Secondary outcome was defining our patient population characteristics. Our cohort included 51 patients who underwent ICD implantation. Mean age at implantation was 10.9 ± 4.7 years and average follow-up time was 67 months. Diagnoses of implanted patients were: 28 (55%) patients with syndromes with risk for sudden death, cardiomyopathy in 14 patients (27%) and congenital heart disease (CHD) in 9 patients (18%). Forty-two (82%) patients had an ICD implanted for secondary prevention after experiencing a life-threatening arrhythmia and 9 (18%) for primary prevention. An endocardial system was implanted in 39 (76%) patients and an epicardial systems in 12 (24%) patients. A total of 20 (39%) patients received appropriate shocks for ventricular fibrillation(VF). 5 patients received inappropriate shocks, 4 due to sinus tachycardia and 1 due to rapidly conducted atrial fibrillation. Those who received an inappropriate shock had a significantly shorter ICD-programmed VF detection cycle length compared to those who did not receive an inappropriate shock (320 ms versus 270 ms, p = 0.062). This single center study demonstrates a high rate of appropriate ICD shocks (39%) and a low rate of inappropriate ICD shocks. Accurate programming of ICD devices in the pediatric population is paramount to avoid inappropriate ICD shocks.

Complications and inappropriate shocks in pediatric patients receiving a subcutaneous implantable cardioverter defibrilator

INTRODUCTION AND OBJECTIVES

There is limited evidence regarding the use of subcutaneous implantable cardioverter-defibrillators (S-ICD) in pediatric patients. The aim of this study was to determine the incidence of complications in these patients at our center, according to the type of ICD and patient size.

METHODS

We included all patients aged<18 years who received an S-ICD since 2016 at our center. As a control group, we also included contemporary patients (since 2014) who received a transvenous ICD (TV-ICD). The primary endpoint was a composite of complications and inappropriate shocks.

RESULTS

A total of 26 patients received an S-ICD (median age, 14 [5-17] years; body mass index [BMI], 20.2 kg/m2). Implantation was intermuscular in 23 patients (88%) and subserratus in the remainder. Two incisions were used in 24 patients (92%). In all patients, 2 zones were programmed: a conditional zone set at 230 (220-230) bpm, and a shock zone set at 250 bpm. Nineteen patients received a TV-ICD (median age, 11 [range, 5-16] years; BMI, 19.2 kg/m2, 79% single-chamber). Survival free from the primary endpoint at 5 years was 80% in the S-ICD group and 63% in the TV-ICD group (P=.54). Survival free from inappropriate shocks was similar (85% vs 89%, P=.86), while survival free from complications was higher in the S-ICD group (96% vs 57%, cloglog P=.016). There were no therapy failures in the S-ICD group, and no increased complication rates were observed in patients with BMI ≤20 kg/m2.

CONCLUSIONS

With contemporary implantation techniques and programming, S-ICD is a safe and effective therapy in pediatric patients. The number of inappropriate shocks is similar to TV-ICD, with fewer short- and mid-term complications.

Subcutaneous Implantable Cardioverter Defibrillators in Pediatrics and Congenital Heart Disease

Subcutaneous implantable cardioverter defibrillators (S-ICDs) are being used with increased frequency in children and patients with congenital heart disease. Vascular access complexities, intracardiac shunts, and specific anatomies make these devices particularly appealing for some of these patients. Alternative screening, implantation, and programming techniques should be considered based on patient size, body habitus, anatomy, procedural history, and preference. Appropriate and inappropriate shock rates are generally comparable to those seen with transvenous devices. Complications such as infection can occur, although their severity is likely to be less than that seen with transvenous devices. Technical advances are likely to further broaden S-ICD applicability.

Emerging Technologies for the Smallest Patients

Pediatric and congenital heart disease patients may require cardiac implantable electronic device implantation, inclusive of pacemaker, ICD, and implantable cardiac monitor, for a variety of etiologies. While leads, generators, and monitors have decreased in size over the years, they remain less ideal for the smallest patients. The potential for a miniature pacemaker, fetal micropacemaker, improving leadless technology, and rechargeable devices creates hope that the development of pediatric-focused devices will increase. Further, alternative approaches that avoid the need for a transvenous or surgical approach may add more options to the toolbox for the pediatric and congenital electrophysiologist.

Advancing the science of management of arrhythmic disease in children and adult congenital heart disease patients within the last 25 years

This review article reflects how publications in EP Europace have contributed to advancing the science of management of arrhythmic disease in children and adult patients with congenital heart disease within the last 25 years. A special focus is directed to congenital atrioventricular (AV) block, the use of pacemakers, cardiac resynchronization therapy devices, and implantable cardioverter defibrillators in the young with and without congenital heart disease, Wolff-Parkinson-White syndrome, mapping and ablation technology, and understanding of cardiac genomics to untangle arrhythmic sudden death in the young.

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.

Opportunities and drawbacks of the subcutaneous defibrillator across different clinical settings

INTRODUCTION

The subcutaneous implantable cardioverter-defibrillator (S-ICD) is an established therapy for the prevention of sudden cardiac death (SCD) and an alternative to a transvenous implantable cardioverter-defibrillator system in selected patients. Beyond randomized clinical trials, many observational studies have described the clinical performance of S-ICD across different subgroups of patients.

AREAS COVERED

Our review aimed to describe the opportunities and drawbacks of the S-ICD, focusing on their use in special populations and across different clinical settings.

EXPERT OPINION

The choice to implant S-ICD should be based on the patient's tailored approach, which takes into account the adequate S-ICD screening at rest or during stress, the infective risk, the ventricular arrhythmia susceptibility, the progressive nature of the underlying disease, the work or sports activity, and the risk of lead-related complications.

Efficacy of SubcutAneous implantable cardioVErter-defibrillators in ≤18 year-old CHILDREN: SAVE-CHILDREN registry

BACKGROUND

In adult patients, subcutaneous implantable cardioverter defibrillators (S-ICDs) have been reported to be non-inferior to transvenous ICDs with respect to the incidence of device-related complications and inappropriate shocks. Only a few reports have investigated the efficacy of S-ICDs in the pediatric field. This study aimed to investigate the utility and safety of S-ICDs in patients ≤18 years old.

METHODS

This study was a multicenter, observational, retrospective study on S-ICD implantations. Patients <18 years old who underwent S-ICD implantations were enrolled. The detailed data on the device implantations and eligibility tests, incidence of appropriate- and inappropriate shocks, and follow-up data were assessed.

RESULTS

A total of 62 patients were enrolled from 30 centers. The patients ranged in age from 3 to 18 (median 14 years old [IQR 11.0-16.0 years]). During a median follow up of 27 months (13.3-35.8), a total of 16 patients (26.2%) received appropriate shocks and 13 (21.3%) received inappropriate shocks. The common causes of the inappropriate shocks were sinus tachycardia (n = 4, 30.8%) and T-wave oversensing (n = 4, 30.8%). In spite of the physical growth, the number of suitable sensing vectors did not change during the follow up. No one had any lead fractures or device infections in the chronic phase.

CONCLUSIONS

Our study suggested that S-ICDs can prevent sudden cardiac death in the pediatric population with a low incidence of lead complications or device infections. The number of suitable sensing vectors did not change during the patients' growth.

Subcutaneous Implantable Cardioverter Defibrillators for the Prevention of Sudden Cardiac Death: Pediatric Single-Center Experience

BACKGROUND

The subcutaneous implantable cardioverter defibrillator (S-ICD) was developed as an alternative to the transvenous ICD, to prevent lead-related complications associated with the latter. The absence of intravascular or intracardiac components offers potential advantages to pediatric patients.

AIMS

The aim of the study is to present an overview of our experience with S-ICDs in the pediatric center that, currently, has performed the largest number of implantations in children in Poland.

METHODS

Retrospective analysis of data from medical history, qualification, implantation procedure, and S-ICD post-implantation observations in 11 pediatric patients were performed.

RESULTS

S-ICDs were implanted in 11 patients, 8 boys and 3 girls, aged 12-17 years. The S-ICD was implanted for primary prevention in seven patients: four with hypertrophic cardiomyopathy (HCM), two with dilated cardiomyopathy (DCM), and one with arrhythmogenic right ventricular cardiomyopathy (ARVC). It was implanted for secondary prevention in four patients: two with sudden cardiac arrest (SCA) in the course of idiopathic ventricular fibrillation (IVF), one with long QT syndrome (LQTS) after probable SCA, and one with Brugada syndrome after SCA. In all patients, the device was implanted intramuscularly. One patient did not have a defibrillation test performed due to the presence of an intracardiac thrombus. In one patient, during screening, it was decided to implant an electrode on the right side of the sternum. There were no early or late complications with any of the procedures. So far, no inadequate discharges have been observed.

CONCLUSIONS

Our results prove the efficacy of the S-ICD treatment option along with technically simple surgery, which supports its further and more widespread application in children.

Case report of an S-ICD implantation for secondary prevention in a patient with complex congenital heart disease, dextrocardia, and situs solitus

Background

Dextrocardia is a congenital anomaly in which the apex of the heart is abnormally located on the right side of the chest. Situs solitus describes viscera that are in the normal position, with the stomach on the left side. In these patients, implantation of transvenous implantable cardioverter-defibrillator (ICD) can be limited by anatomical abnormalities commonly associated with this condition.

Case summary

We present the case of a young female patient with absent right atrioventricular connection, morphologically left systemic ventricle, muscular restrictive ventricular septal defect, and dextrocardia with situs solitus who was indicated for secondary prophylactic ICD implantation after resuscitation for polymorphic ventricular tachycardia. Due to a bilateral bidirectional Glenn anastomosis, transvenous access via the vena cava superior to the right ventricle could not be achieved. For this reason, we successfully implanted a subcutaneous ICD (S-ICD) with an individually optimized right parasternal electrode position. Potential complications of epimyocardial implantation via re-thoracotomy could thus be circumvented.

Discussion

In patients with complex congenital heart disease, the S-ICD is an effective method of preventing sudden cardiac death. Our case report demonstrates the feasibility of left S-ICD implantation even in the presence of dextrocardia with situs solitus.

Subcutaneous and Transvenous ICDs: an Update on Contemporary Questions and Controversies

PURPOSE OF REVIEW

While the subcutaneous (S-) implantable cardioverter-defibrillator (ICDs) is an alternative to the transvenous (TV-) ICD in many patients, optimal use remains unclear. In this review, we summarize recent clinically relevant data on sensing algorithms, inappropriate shocks, defibrillation testing, and battery and electrode failures.

RECENT FINDINGS

Changes in sensing algorithms and S-ICD programming have significantly decreased inappropriate shock rates. Avoiding fat below the S-ICD coil and can is key for reducing the defibrillation threshold. While S-ICD battery and electrode failures have resulted in recalls, system components remain commercially available since failure rates are low and no other similar devices are available. The S-ICD is a good alternative to the TV-ICD for many patients, and particularly in light of recently developed device algorithms and improvements in implant technique. Future research will need to better understand: the impact of S-ICD electrode and battery failures and the potential for integrating leadless pacing into a modular S-ICD platform.

S-ICDs: advantages and opportunities for improvement

INTRODUCTION

The subcutaneous implantable cardioverter defibrillator (S-ICD) is currently in its third generation and has been adopted in guidelines and in mainstream clinical practice. Considerable improvements have been made since the introduction of this device over a decade ago.

AREAS COVERED

A literature search was undertaken in Pubmed on articles relating to the S-ICD.

EXPERT OPINION

The therapy has been proven to be safe and effective and is a valuable option in selected patients. Nevertheless, there remain many shortcomings of the S-ICD which are discussed in this review, and which hopefully will be addressed by future generations of the device.

ICD Outcome in Pediatric Cardiomyopathies

Background: Pediatric patients with cardiomyopathies are at risk of malignant arrhythmias and sudden cardiac death (SCD). An ICD may prevent SCD. The aim of this study was to evaluate ICD implantation outcomes, and to compare transvenous and subcutaneous ICDs (S-ICDs) implanted in pediatric patients with cardiomyopathies. Methods: The study is single center and retrospective, and includes pediatric patients with cardiomyopathies who required ICD implantation (2010–2021). Outcomes were recorded for appropriate/inappropriate ICD therapy and surgical complications. Transvenous ICD and S-ICD were compared. Data are presented as median values (25th–75th centiles). Results: Forty-four patients with cardiomyopathies (hypertrophic 39%, arrhythmogenic 32%, dilated 27%, and restrictive 2%) underwent transvenous (52%) and S-ICD (48%) implantation at 14 (12–17) years of age, mostly for primary prevention (73%). The follow-up period was 29 (14–60) months. Appropriate ICD therapies were delivered in 25% of patients, without defibrillation failures. Lower age at implantation and secondary prevention were significant risk factors for malignant ventricular arrhythmias that required appropriate ICD therapies. ICD-related complications were surgical complications (18%) and inappropriate shocks (7%). No significant differences in outcomes were recorded, either when comparing transvenous and S-ICD or comparing the different cardiomyopathies. Conclusions: In pediatric patients with cardiomyopathy, ICD therapy is effective, with a low rate of inappropriate shocks. Neither ICD type (transvenous and S-ICDs) nor the cardiomyopathies subgroup revealed divergent outcomes.

2021 PACES expert consensus statement on the indications and management of cardiovascular implantable electronic devices in pediatric patients

In view of the increasing complexity of both cardiovascular implantable electronic devices (CIEDs) and patients in the current era, practice guidelines, by necessity, have become increasingly specific. This document is an expert consensus statement that has been developed to update and further delineate indications and management of CIEDs in pediatric patients, defined as ≤21 years of age, and is intended to focus primarily on the indications for CIEDs in the setting of specific disease categories. The document also highlights variations between previously published adult and pediatric CIED recommendations and provides rationale for underlying important differences. The document addresses some of the deterrents to CIED access in low- and middle-income countries and strategies to circumvent them. The document sections were divided up and drafted by the writing committee members according to their expertise. The recommendations represent the consensus opinion of the entire writing committee, graded by class of recommendation and level of evidence. Several questions addressed in this document either do not lend themselves to clinical trials or are rare disease entities, and in these instances recommendations are based on consensus expert opinion. Furthermore, specific recommendations, even when supported by substantial data, do not replace the need for clinical judgment and patient-specific decision-making. The recommendations were opened for public comment to Pediatric and Congenital Electrophysiology Society (PACES) members and underwent external review by the scientific and clinical document committee of the Heart Rhythm Society (HRS), the science advisory and coordinating committee of the American Heart Association (AHA), the American College of Cardiology (ACC), and the Association for European Paediatric and Congenital Cardiology (AEPC). The document received endorsement by all the collaborators and the Asia Pacific Heart Rhythm Society (APHRS), the Indian Heart Rhythm Society (IHRS), and the Latin American Heart Rhythm Society (LAHRS). This document is expected to provide support for clinicians and patients to allow for appropriate CIED use, appropriate CIED management, and appropriate CIED follow-up in pediatric patients.

2021 PACES Expert Consensus Statement on the Indications and Management of Cardiovascular Implantable Electronic Devices in Pediatric Patients: Developed in collaboration with and endorsed by the Heart Rhythm Society (HRS), the American College of Cardiology (ACC), the American Heart Association (AHA), and the Association for European Paediatric and Congenital Cardiology (AEPC) Endorsed by the Asia Pacific Heart Rhythm Society (APHRS), the Indian Heart Rhythm Society (IHRS), and the Latin American Heart Rhythm Society (LAHRS)

In view of the increasing complexity of both cardiovascular implantable electronic devices (CIEDs) and patients in the current era, practice guidelines, by necessity, have become increasingly specific. This document is an expert consensus statement that has been developed to update and further delineate indications and management of CIEDs in pediatric patients, defined as ≤21 years of age, and is intended to focus primarily on the indications for CIEDs in the setting of specific disease categories. The document also highlights variations between previously published adult and pediatric CIED recommendations and provides rationale for underlying important differences. The document addresses some of the deterrents to CIED access in low- and middle-income countries and strategies to circumvent them. The document sections were divided up and drafted by the writing committee members according to their expertise. The recommendations represent the consensus opinion of the entire writing committee, graded by class of recommendation and level of evidence. Several questions addressed in this document either do not lend themselves to clinical trials or are rare disease entities, and in these instances recommendations are based on consensus expert opinion. Furthermore, specific recommendations, even when supported by substantial data, do not replace the need for clinical judgment and patient-specific decision-making. The recommendations were opened for public comment to Pediatric and Congenital Electrophysiology Society (PACES) members and underwent external review by the scientific and clinical document committee of the Heart Rhythm Society (HRS), the science advisory and coordinating committee of the American Heart Association (AHA), the American College of Cardiology (ACC), and the Association for European Paediatric and Congenital Cardiology (AEPC). The document received endorsement by all the collaborators and the Asia Pacific Heart Rhythm Society (APHRS), the Indian Heart Rhythm Society (IHRS), and the Latin American Heart Rhythm Society (LAHRS). This document is expected to provide support for clinicians and patients to allow for appropriate CIED use, appropriate CIED management, and appropriate CIED follow-up in pediatric patients.

2021 PACES expert consensus statement on the indications and management of cardiovascular implantable electronic devices in pediatric patients

In view of the increasing complexity of both cardiovascular implantable electronic devices (CIEDs) and patients in the current era, practice guidelines, by necessity, have become increasingly specific. This document is an expert consensus statement that has been developed to update and further delineate indications and management of CIEDs in pediatric patients, defined as ≤21 years of age, and is intended to focus primarily on the indications for CIEDs in the setting of specific disease categories. The document also highlights variations between previously published adult and pediatric CIED recommendations and provides rationale for underlying important differences. The document addresses some of the deterrents to CIED access in low- and middle-income countries and strategies to circumvent them. The document sections were divided up and drafted by the writing committee members according to their expertise. The recommendations represent the consensus opinion of the entire writing committee, graded by class of recommendation and level of evidence. Several questions addressed in this document either do not lend themselves to clinical trials or are rare disease entities, and in these instances recommendations are based on consensus expert opinion. Furthermore, specific recommendations, even when supported by substantial data, do not replace the need for clinical judgment and patient-specific decision-making. The recommendations were opened for public comment to Pediatric and Congenital Electrophysiology Society (PACES) members and underwent external review by the scientific and clinical document committee of the Heart Rhythm Society (HRS), the science advisory and coordinating committee of the American Heart Association (AHA), the American College of Cardiology (ACC), and the Association for European Paediatric and Congenital Cardiology (AEPC). The document received endorsement by all the collaborators and the Asia Pacific Heart Rhythm Society (APHRS), the Indian Heart Rhythm Society (IHRS), and the Latin American Heart Rhythm Society (LAHRS). This document is expected to provide support for clinicians and patients to allow for appropriate CIED use, appropriate CIED management, and appropriate CIED follow-up in pediatric patients.

Anomalous Left Coronary Artery Connected to the Pulmonary Artery in a 15-Year-Old Girl: Case Report and Discussion on Secondary Prevention of Sudden Death

Background. Anomalous left coronary artery connected to the pulmonary artery (ALCAPA) is a rare congenital heart disease. Adaptive development of sufficient heterocoronary collaterality in the newborn may allow survival to a later age. In older children or adults, malignant ventricular arrhythmias can reveal the disease. Case Report. A 15-year-old girl was referred to the local hospital after a resuscitated out-of-hospital cardiac arrest. CT scan and coronary angiography revealed an ALCAPA. Direct aortic reimplantation of the left coronary artery was performed. Postoperative ECG monitoring showed short episodes of nonsustained ventricular tachycardia. Transthoracic echocardiography and cardiac MRI revealed subendocardial fibrosis of the anterolateral papillary muscle. Beta-blockade therapy was initiated at first intention. After hospital discharge, the patient reported several fainting without loss of consciousness. Considering sudden death nonrelated to effort, episodes of nonsustained ventricular tachycardia, and areas of myocardial fibrosis, the patient underwent subcutaneous cardioverter-defibrillator implantation. 6-month follow-up is satisfactory without clinical or rhythmic abnormalities. Discussion. Indication for surgical correction of ALCAPA is well defined, but rhythmic secondary prevention after resuscitated cardiac arrest is less consensual. Cardiac MRI is an essential tool in the identification of a potential rhythmic substrate and should be taken into account in the discussion of a preventive cardioverter-defibrillator implantation.

2021 PACES Expert Consensus Statement on the Indications and Management of Cardiovascular Implantable Electronic Devices in Pediatric Patients

In view of the increasing complexity of both cardiovascular implantable electronic devices (CIEDs) and patients in the current era, practice guidelines, by necessity, have become increasingly specific. This document is an expert consensus statement that has been developed to update and further delineate indications and management of CIEDs in pediatric patients, defined as ≤21 years of age, and is intended to focus primarily on the indications for CIEDs in the setting of specific disease categories. The document also highlights variations between previously published adult and pediatric CIED recommendations and provides rationale for underlying important differences. The document addresses some of the deterrents to CIED access in low- and middle-income countries and strategies to circumvent them. The document sections were divided up and drafted by the writing committee members according to their expertise. The recommendations represent the consensus opinion of the entire writing committee, graded by class of recommendation and level of evidence. Several questions addressed in this document either do not lend themselves to clinical trials or are rare disease entities, and in these instances recommendations are based on consenus expert opinion. Furthermore, specific recommendations, even when supported by substantial data, do not replace the need for clinical judgment and patient-specific decision-making. The recommendations were opened for public comment to Pediatric and Congenital Electrophysiology Society (PACES) members and underwent external review by the scientific and clinical document committee of the Heart Rhythm Society (HRS), the science advisory and coordinating committee of the American Heart Association (AHA), the American College of Cardiology, (ACC) and the Association for European Paediatric and Congenital Cardiology (AEPC). The document received endorsement by all the collaborators and the Asia Pacific Heart Rhythm Society (APHRS), the Indian Heart Rhythm Society (IHRS), and the Latin American Heart Rhythm Society (LAHRS). This document is expected to provide support for clinicians and patients to allow for appropriate CIED use, appropriate CIED management, and appropriate follow-up in pediatric patients.