ICD Therapy in Children and Young Adults: Low Incidence of Inappropriate Shock Delivery

Defibrillation Safety Margin Testing in Patients With Congenital Heart Disease: Results From the NCDR

OBJECTIVES

This study analyzed the predictors of defibrillation safety margin (DSM) testing at the time of implantable cardioverter-defibrillator (ICD) insertion and factors associated with inadequate DSM in patients with congenital heart disease (CHD).

BACKGROUND

There are few data about the prevalence and safety of DSM testing in those with CHD.

METHODS

A retrospective analysis was performed of all patients with atrial or ventricular septal defect, tetralogy of Fallot, transposition of the great vessels, Ebstein anomaly, or common ventricle undergoing a transvenous ICD procedure in the National Cardiovascular Data Registry (NCDR) ICD Registry from April 2010 to March 2016, and DSM testing was assessed. Inadequate DSM was defined as a lowest successful energy tested <10 J than the maximum output of the ICD generator.

RESULTS

Of all ICD recipients (N = 7,024), DSM testing was performed in 52.0% (n = 3,654). The mean lowest successful energy tested was 20.7 ± 7.3 J. Of those with DSM adequacy data available (n = 3,623), an inadequate DSM occurred in 13.8% (n = 501). After multivariable adjustment, DSM testing was not associated with in-hospital complications or death (odds ratio [OR]: 1.00; 95% confidence interval [CI]: 0.79 to 1.28) but was associated with lower odds of prolonged hospital stay (>3 days) (OR: 0.71; 95% CI: 0.60 to 0.84; p < 0.0001). An inadequate DSM was not associated with in-hospital death or complications (OR: 1.27; 95% CI: 0.79 to 2.04) or prolonged hospital stay (OR: 1.34; 95% CI: 0.995 to 1.81).

CONCLUSIONS

DSM testing is being performed less frequently over time and seems safe in those with CHD. An inadequate DSM was not associated with worse in-hospital outcomes.

Quality of life and psychological co-morbidities in children and adolescents with cardiac pacemakers and implanted defibrillators: a cohort study in Eastern Germany

INTRODUCTION

The implantation of a pacemaker or an implantable cardioverter-defibrillator during childhood may reduce quality of life and lead to mental health problems. This study aimed to evaluate potential mental health problems (i.e., depressive and anxiety symptoms) and quality of life in children with cardiac active devices in comparison to healthy peers.

METHODS

We analysed data of children with pacemakers or implantable cardioverter-defibrillators aged 6-18 years. Quality of life, depressive and anxiety symptoms were assessed by standardised questionnaires. The results were compared to age-matched reference groups.

RESULTS

Children with implantable cardioverter-defibrillator showed significant lower quality of life in comparison to reference group (p = 0.03), but there was no difference in quality of life between children with pacemaker and reference group. There was no significant difference in depressive symptoms between children with a cardiac rhythm device compared to reference group (self-report: p = 0.67; proxy report: p = 0.49). There was no significant difference in anxiety (p = 0.53) and depressive symptoms (p = 0.86) between children with pacemaker and children with implantable cardioverter-defibrillator.

CONCLUSIONS

Living with an implantable cardioverter-defibrillator in childhood seems to decrease the patients' quality of life. Although children with pacemaker and implantable cardioverter-defibrillator don't seem to show more depressive and anxiety symptoms in comparison to their healthy peers, there still can be an increased risk for those children to develop mental health problems. Therefore, treating physicians should be aware of potential mental health problems and provide the patients and their families with appropriate therapeutic offers.

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

BACKGROUND

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 15 year follow up.

METHODS

We reviewed the database of ICD recipients at the present institution and chose 73 consecutive patients who underwent implantation at age 6-21 years. We analyzed intervention rate, mortality, rate and characteristics of complications and treatment options.

RESULTS

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%).

CONCLUSION

Endocardial ICD implantation in children and young adults is a feasible and life-saving procedure, according to the present 15 year 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.

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

PURPOSE

The 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.

METHODS

This 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.

RESULTS

Fifteen 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.

CONCLUSION

The 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.

United Kingdom national experience of entirely subcutaneous implantable cardioverter-defibrillator technology: important lessons to learn

AIMS

The aim of this study was to describe the early phase United Kingdom (UK) clinical experience with a novel entirely subcutaneous implantable cardioverter-defibrillator (S-ICD).

METHODS AND RESULTS

A questionnaire was sent to all UK hospitals implanting S-ICDs. Nineteen of 25 (76%) hospitals responded with the details of 111 implanted patients [median 5/hospital (range 1-18)]. Mean duration of follow-up was 12.7 ± 7.1 months. Median patient age was 33 years (range 10-87 years). Underlying pathology was primary electrical disease in 43%, congenital heart disease 12%, hypertrophic cardiomyopathy 20%, ischaemic cardiomyopathy 14%, idiopathic dilated cardiomyopathy 5%, and other cardiomyopathies 7% patients. Nineteen (17%) patients required 20 re-operations, including permanent device explantation in 10 (9%). Twenty-four appropriate shocks were delivered in 13 (12%) patients, including 10 for ventricular fibrillation. One patient suffered arrhythmic death, but there were no failures to detect or terminate ventricular arrhythmias above the programmed detection rate. Fifty-one inappropriate shocks were delivered in 17 (15%) patients. Forty-one (80%) were for T-wave over-sensing and 1 (2%) for atrial flutter-wave over-sensing. The 11 patients who received inappropriate shocks due to T-wave over-sensing were significantly younger than patients who did not (24 ± 10 vs. 37 ± 19 years; P = 0.02).

CONCLUSION

The S-ICD is an important innovation in ICD technology. However, these data indicate that adverse event rates are significant during early clinical adoption. Important lessons in patient selection, implant technique, and device programming can be learnt from this experience.

Prospective evaluation of defibrillation threshold and postshock rhythm in young ICD recipients

BACKGROUND

Adaptation of implantable cardioverter defibrillator (ICD) systems to the needs of pediatric and congenital heart patients is problematic due to constraints of vascular and thoracic anatomy. An improved understanding of the defibrillation energy and postshock pacing requirements in such patients may help direct more tailored ICD therapy. We describe the first prospective evaluation of defibrillation threshold (DFT) and postshock rhythm in this population.

METHODS

We prospectively studied patients ≤ 60 kg at time of ICD intervention. DFTs were obtained using a binary search protocol with three VF inductions. Postshock pacing was programmed using a stepwise protocol, lowering the rate prior to each VF induction.

RESULTS

Twenty patients were enrolled: 11 had channelopathy, five congenital heart disease, and four cardiomyopathy. The median age was 16 years, median weight 48 kg. Twelve patients had a transvenous high-voltage coil; eight had pericardial +/- subcutaneous coil(s). Median DFT was 7 J (range 3-31 J); 19/20 patients had DFT ≤ 15 J and all patients <25 kg had DFT ≤ 9 J (n = 6). There was no difference in DFT between patients with transvenous versus pericardial +/- subcutaneous coils (median 7 J vs 6 J, P = 0.59). No patient with normal atrioventricular conduction prior to defibrillation required postshock pacing (n = 16). There were no adverse events.

CONCLUSIONS

These data suggest that many pediatric ICD patients have low DFTs and adequate postshock escape rhythm. This may help determine appropriate parameters for future design of pediatric-specific ICDs.

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

AIMS

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.

METHODS AND RESULTS

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.

CONCLUSION

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.