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.

An Up-to-Date Narrative Review on Congenital Heart Disease Percutaneous Treatment in Children Using Contemporary Devices

Background: Congenital heart pathology has a significant burden regarding morbidity and mortality in the pediatric population. Several transcatheter interventions and devices have been designed as an alternative to surgical repair. Percutaneous interventions have been proven to yield good results in most cases but with less stress and trauma than that attributed to surgical treatment, especially in frail pediatric patients. We aimed to review the literature and to investigate the feasibility and efficacy of transcatheter interventions and implantable devices for congenital heart disease management in children. Methods: We performed a search in Scopus and MEDLINE databases using prespecified keywords to retrieve clinical studies published between 2000 and 2021. Results: This article provides an up-to-date review regarding the applicability of interventional techniques in simple inter-atrial or inter-ventricular defects, and in challenging congenital defects, such as hypoplastic left heart syndrome, tetralogy of Fallot, or coronary artery fistula. Furthermore, we reviewed recent indications for defibrillator and cardiac resynchronization therapy, and new and promising devices currently being tested. Conclusion: Transcatheter treatment represents a feasible and efficient alternative to surgical repair of congenital heart defects. Novel devices could extend the indications and possibilities of percutaneous interventions in pediatric patients with congenital heart diseases.

Implantable Cardioverter Defibrillators in Infants and Toddlers: Indications, Placement, Programming, and Outcomes

BACKGROUND

Limited data exist regarding implantable cardioverter defibrillator (ICD) usage in infants and toddlers. This study evaluates ICD placement indications, procedural techniques, programming strategies, and outcomes of ICDs in infants and toddlers.

METHODS

This is a single-center retrospective review of all patients ≤3 years old who received an ICD from 2009 to 2021.

RESULTS

Fifteen patients received an ICD at an age of 1.2 years (interquartile range [IQR], 0.1-2.4; 12 [80%] women; weight, 8.2 kg [IQR, 4.2-12.6]) and were followed for a median of 4.28 years (IQR, 1.40-5.53) or 64.2 patient-years. ICDs were placed for secondary prevention in 12 patients (80%). Diagnoses included 8 long-QT syndromes (53%), 4 idiopathic ventricular tachycardias/ventricular fibrillations (VFs; 27%), 1 recurrent ventricular tachycardia with cardiomyopathy (7%), 1 VF with left ventricular noncompaction (7%), and 1 catecholaminergic polymorphic ventricular tachycardia (7%). All implants were epicardial, with a coil in the pericardial space. Intraoperative defibrillation safety testing was attempted in 11 patients (73%), with VF induced in 8 (53%). Successful restoration of sinus rhythm was achieved in all tested patients with a median of 9 (IQR, 7.3-11.3) J or 0.90 (IQR, 0.68-1.04) J/kg. Complications consisted of 1 postoperative chylothorax and 3 episodes of feeding intolerance. VF detection was programmed to 250 (IQR, 240-250) ms with first shock delivering 10 (IQR, 5-15) J or 1.1 (IQR, 0.8-1.4) J/kg. Three patients (20%) received appropriate shocks for ventricular tachycardia/VF. No patient received an inappropriate shock. There were 2 (13%) ventricular lead fractures (at 2.6 and 4.2 years post-implant), 1 (7%) pocket-site infection, and 2 (13%) generator exchanges. All patients were alive, and 1 patient (7%) received a heart transplant.

CONCLUSIONS

ICDs can be safely and effectively placed for sudden death prevention in infants and toddlers with good midterm outcomes.

Early and Late Effects of Cardiac Resynchronization Therapy in Adult Congenital Heart Disease

Background

There are limited data about cardiac resynchronization therapy (CRT) in adult congenital heart disease. We aimed to assess early and late outcomes of CRT among patients with adult congenital heart disease.

Methods and Results

We retrospectively studied 54 patients with adult congenital heart disease (median age, 46 years; range, 18–73 years; 74% men) who received CRT implantation (biventricular paced >90%) between 2004 and 2017. Clinical and echocardiographic data were analyzed at baseline and early (mean±SD: 1.8±0.8 years) and late (4.7±0.8 years) follow‐up after CRT. Compared with baseline, CRT was associated with significant improvement at early follow‐up in New York Heart Association functional class, QRS duration, and cardiothoracic ratio (P<0.05 for all); improvement in New York Heart Association class was sustained at late follow‐up. Among patients with a systemic left ventricle (LV; n=39), there was significant increase in LV ejection fraction and reduction in LV end‐systolic volume at early and late follow‐up (P<0.05 for both). For patients with a systemic right ventricle (n=15), there was a significant early but not late reduction in systemic right ventricular basal and longitudinal diameters. Eleven patients died, and 2 had heart transplantation unrelated to systemic ventricular morphological characteristics. Thirty‐five patients (65%) responded positively to CRT, but only baseline QRS duration was predictive of a positive response.

Conclusions

CRT results in sustained improvement in functional class, systemic LV size, and function. Patients with a systemic LV and prolonged QRS duration, independent of QRS morphological characteristics, were most likely to respond to CRT.

Current Trends in Implantable Cardioverter-Defibrillator Therapy in Children - Results From the JCDTR Database

BACKGROUND

Implantable cardioverter defibrillators (ICDs) are being used with increasing frequency in children. Our aim was to examine the current trend of pediatric ICD implantation in Japan. Methods and Results: Data was extracted from the Japanese Cardiac Device Treatment Registry (JCDTR), a nation-wide registry started in 2006. All patients aged less than 18 years who had an ICD implantation registered between 2006 and 2016 were included in the analysis. A total of 201 patients were included, with a median age of 16 years (range 1-18). The underlying cardiac diagnosis was primary electrical disease (67%), cardiomyopathy (26%) and congenital heart disease (4%), with idiopathic ventricular fibrillation (29%) and long QT syndrome (21%) being the 2 most common diagnoses. Implantation indication was primary prevention in only 30 patients (15%). There were 27 patients (13%) aged ≤12 years, with a larger proportion of patients with cardiomyopathy (33%). The indication in younger children was secondary prevention in all cases. Younger children may be under-represented in our study given the nature of the database as it is a predominantly adult cardiology database.

CONCLUSIONS

In the past decade, ICD implantation has been performed in approximately 20 children per year in Japan, mostly for secondary prevention. There was no increase in the trend nor a change in age distribution.

Echocardiographic assessment of ventricular contraction and synchrony in children with isolated complete atrioventricular block and epicardial pacing: Implications of interventricular mechanical delay

AIMS

To assess the correlations between interventricular mechanical delay (IVMD) and cardiac function in children with isolated complete atrioventricular block and epicardial pacing.

METHODS AND RESULTS

We enrolled 13 children (six boys) with an epicardial dual-chamber pacemaker due to isolated complete or advanced atrioventricular block. The patients were 9.8 (range, 6.8-15.3) years old, and none had symptomatic heart failure at the follow-up visit. Ventricular pacing sites, which remained the same for 7.2 (1.6-12.3) years, were the left ventricle (LV) in two patients, right ventricle (RV) in four patients, and both ventricles in seven patients. IVMD was ≤40 ms in six patients (short IVMD group) and >40 ms in seven patients (long IVMD group). Compared with the long IVMD group, the short IVMD group was associated with better LV longitudinal strain (-20% [-24% to -18%] vs -16% [-20% to -13%], P < .05). The short IVMD group had superior LV mechanical synchrony than the long IVMD group (septal to lateral delay of the time to peak longitudinal strain 15 [-16-78] ms vs 78 [13-93] ms, P < .05; standard deviation of the time to peak radial strain 13 [9-34] ms vs 35 [18-64] ms, P < .05).

CONCLUSION

In children with epicardial pacing at LV, RV, or both ventricles, a left-sided contraction delay was associated with poorer LV contraction and impaired LV synchrony. IVMD will help to stratify patients during follow-up.

Cardiac resynchronization therapy in a patient with a failing systemic right ventricle

Systemic right ventricular dysfunction is 1 of the late complications of the atrial switch operation for transposition of the great arteries. It has been reported that cardiac resynchronization therapy (CRT) for the failing systemic right ventricle (RV) improves symptoms and systolic function. However, patient selection for CRT in congenital heart disease is still challenging because the clinical standard for CRT in these patients is not established. We describe a case of successful implantation of a CRT device for a failing systemic RV aided by multimodality imaging and cardiac hemodynamic studies.