Translating Adult Electrophysiology Technology to Pediatric and Congenital Electrophysiology.

Implantable cardioverter defibrillators (ICDs) are intended to prevent sudden cardiac death yet also impose a risk of morbidity. This study describes the outcomes of ICDs in a pediatric and congenital heart disease (CHD) population from a single center. Retrospective cohort study of all patients with an ICD followed at the University of Michigan Congenital Heart Center from 2005-2013. The primary outcome was ICD system revision for any reason excluding routine generator change for battery depletion. There were 191 ICD systems in 131 patients, including 57 with CHD, 24 with hypertrophic cardiomyopathy, and 45 with structurally normal hearts. Median age was 16 years at initial implant. Total follow-up was 850 patient-years; median 4.9 years/patient. There were 43 (33%) patients who required 60 ICD revisions; 70 revisions/1,000 patient-years of follow-up. Revisions included 25 lead extractions with replacement, 21 lead additions, five lead repositions, and four full system revisions. Kaplan-Meier (K-M) median time to appropriate shock was similar to the median time to system revision. K-M time to system revision was significantly affected by recalled lead performance. The need for ICD system revision is high in this pediatric and CHD population and occurs at a rate similar to the rate of receiving appropriate therapy. These results highlight the need for judicious implant criteria and improved device longevity.

Among the congenital heart disease (CHD) population, intra-atrial reentrant tachycardia (IART) is a common sequela resulting from anatomical anomalies and surgical scars that significantly increases morbidity and mortality. Atrial antitachycardia pacing (ATP) delivered by atrial antitachycardia devices (ATDs) has been used to treat IART in the CHD population. However, there remains limited data on the safety and efficacy of ATP, as well as on comparisons of its effects amongst different CHD subtypes. The purpose of the current study is to describe the clinical history and ATP efficacy in three patients with unique forms of complex CHD. During this study, a single-center review of three patients with ATDs was performed. One patient with each of the following CHD anomalies was selected for inclusion: systemic left ventricle, systemic right ventricle, and single ventricle. Data collected included ATP success rates, medications in use, direct current (DC) cardioversions, and any complications related to the ATDs. Study findings revealed the patient with a systemic left ventricle had an ATD implanted for approximately 9.5 years, with 695 of 956 (73%) episodes successfully converted. Unsuccessfully treated episodes were generally asymptomatic and self-terminating in this patient. The patient with a systemic right ventricle had an ATD implanted for approximately 16 years, with 333 of 348 (96%) episodes being successfully converted. The patient with a single ventricle had an ATD implanted for approximately 12.5 years, with 404 of 416 (97%) episodes successfully converted. The patients with biventricular physiology were able to forgo DC cardioversion after receiving their ATDs. However, due to medical noncompliance as well as multiple episodes of IART, which presented with 1:1 conduction or low rates, the single-ventricle patient still required DC cardioversions post-ATD implantation. In conclusion, this study’s findings demonstrate that, while ATP can be effective in a wide variety of CHDs, experiences can vary based on individual arrhythmia substrates, cardiac anatomy, and medical compliance. Additionally, challenges remain in IART detection in patients with especially complex CHD anatomies.

The goal of this statement was to review the available literature on surveillance, screening, evaluation, and management strategies and put forward a scientific statement that would comprehensively review the literature and create recommendations to optimize neurodevelopmental outcome in the pediatric congenital heart disease (CHD) population. A writing group appointed by the American Heart Association and American Academy of Pediatrics reviewed the available literature addressing developmental disorder and disability and developmental delay in the CHD population, with specific attention given to surveillance, screening, evaluation, and management strategies. MEDLINE and Google Scholar database searches from 1966 to 2011 were performed for English-language articles cross-referencing CHD with pertinent search terms. The reference lists of identified articles were also searched. The American College of Cardiology/American Heart Association classification of recommendations and levels of evidence for practice guidelines were used. A management algorithm was devised that stratified children with CHD on the basis of established risk factors. For those deemed to be at high risk for developmental disorder or disabilities or for developmental delay, formal, periodic developmental and medical evaluations are recommended. A CHD algorithm for surveillance, screening, evaluation, reevaluation, and management of developmental disorder or disability has been constructed to serve as a supplement to the 2006 American Academy of Pediatrics statement on developmental surveillance and screening. The proposed algorithm is designed to be carried out within the context of the medical home. This scientific statement is meant for medical providers within the medical home who care for patients with CHD. Children with CHD are at increased risk of developmental disorder or disabilities or developmental delay. Periodic developmental surveillance, screening, evaluation, and reevaluation throughout childhood may enhance identification of significant deficits, allowing for appropriate therapies and education to enhance later academic, behavioral, psychosocial, and adaptive functioning.

Several diseases (cancer, neurological) show geographic clustering, giving insights into possible genetic and environmental causes. The pathogenesis of Congenital Heart Disease (CHD) remains largely unknown and analysis of geographic distribution of CHD cases lacks input from large, national-scale datasets.People with structural CHD were selected from the Australia and New Zealand CHD Registry. Of people known to be still living, from linkage with the National Death Index, addresses were geocoded and aggregated to standardised geographic regions with measures of the Australian population. Areas were described based on measures of their remoteness and driving time to hospitals. The relationship between the distribution of the CHD and Australian populations was compared with bivariate spatial correlation.Of 81,349 people with structural CHD in the Registry, 63,863 were still living and could be geocoded. Overall, most people lived in Major Cities, and within 1-hour drive from a hospital, with the proportion the same across the CHD population, the “complex CHD” population and the Australian population. Across the country, there was a strong positive correlation between the Australian population and the CHD population. There were only a small number of areas (6%) where the Australian and the CHD populations were proportionally different.Overall, there was clear evidence that the geographic distribution of the CHD population proportionally follows the general Australian population. This suggests that there is unlikely to be any spatial clusters that are driven by genetic or environmental causes.Author SummaryPeople living with congenital heart disease have overgone many changes over recent decades. As surgical intervention has improved, people with congenital heart disease are living longer and a greater proportion are now adults. This is success brings new challenges surrounding their healthcare. What kinds of complications will older people with congenital heart disease face, how will our health services cope with the increasing demands, and how should we deploy health services? We aimed to answer some of these question by assessing where people with congenital heart disease lived in Australia, and how that distribution compares with the general Australian population. This research is made possible by the Australia and New Zealand Congenital Heart Disease Registry, which enables this analysis to be conducted at a national scale for the first time. Most of the congenital heart disease population was living in major cities, and within a 1-hour drive of a hospital. Overall, their geographic distribution was very similar to that of the Australia population. These results suggest that there are not any environmental factors that are causing congenital heart disease, or that people with congenital heart disease are choosing to live in different places, compared to the general Australian population.

The number of patients with congenital heart disease (CHD) has significantly increased over the last decades. The CHD population has a high prevalence of heart failure during late follow-up and this is a major cause of mortality. Cardiac resynchronization therapy (CRT) may be a promising therapy to improve the clinical outcome of CHD and paediatric patients with heart failure. However, the CHD and paediatric population is a highly heterogeneous group with different anatomical substrates that may influence the effects of CRT. Echocardiography is the mainstay imaging modality to evaluate CHD and paediatric patients with heart failure and novel echocardiographic tools permit a comprehensive assessment of cardiac dyssynchrony that may help selecting candidates for CRT. This article reviews the role of CRT in the CHD and paediatric population with heart failure. The current inclusion criteria for CRT as well as the outcomes of different anatomical subgroups are evaluated. Finally, echocardiographic assessment of mechanical dyssynchrony in the CHD and paediatric population and its role in predicting response to CRT is comprehensively discussed.

Safety and efficacy of atrial antitachycardia pacing in congenital heart disease

The congenital heart disease (CHD) population is growing and aging. We aim to examine the impact by describing the temporal trend and causes of lifetime hospitalization burden among the CHD population. From the Danish National Patient Registry, 23 141 patients with CHD and their hospitalizations from 1977 to 2018 were identified, excluding patients with extracardiac malformation. Patients with CHD were categorized into major CHD and minor CHD, and each patient was matched with 10 controls by sex and year of birth. The rate of all-cause hospitalization increased over time from 28.3 to 36.4 hospitalizations per 100 person-years (PY) with rate difference (RD) per decade of 2.5 (95% CI, 2.0-3.1) hospitalizations per 100 PY for the patients with CHD, compared with the increase from 10.8 to 17.0 per 100 PY (RD per decade, 2.0 [95% CI, 1.8-2.2] per 100 PY) for the control group (RD for CHD versus control, P=0.08). The all-cause hospitalization rate remained constant for the major CHDs (RD per decade, -0.2 [95% CI, -1.2 to 0.9] per 100 PY) but increased for the minor CHDs (RD per decade, 5.2 [95% CI, 4.3-6.0] per 100 PY). For all patients with CHD, the cardiovascular hospitalization rate remained constant over time (RD per decade, 0.2 [95% CI, -0.3 to 0.6] per 100 PY) whereas the noncardiovascular hospitalization rate increased (RD per decade, 2.1 [95% CI, 1.6-2.7] per 100 PY). The length of all-cause hospital stays for all patients with CHD decreased from 2.7 (95% CI, 2.6-2.8) days per PY in 1977 to 1987 to 1.6 (95% CI, 1.6-1.7) days per PY in 2008 to 2018. Compared with previous decades, patients with CHD have an increasing hospitalization rate, similar to the general population, but a decreasing length of hospital stay. The increase in hospitalization rate was driven by noncardiovascular hospitalizations, with the patients with minor CHD being the key contributor to the increasing rate.

In addition to the depiction of anatomy and function, tissue characterization of the myocardium has emerged as an important asset of cardiac magnetic resonance (CMR). Among the tissue properties that are quantifiable by CMR is diffuse myocardial fibrosis. Diffuse fibrosis is regarded to be the common pathological pathway toward loss of myocardial function in many cardiac conditions, including congenital heart disease.1–4 As fibrosis seems to have a major role in myocardial failure and may be reversible,5–8 its assessment by CMR has the potential to transform the way we monitor and treat our patients.9 In this review, we describe the technical aspects of fibrosis quantification with CMR and outline past and potential applications in congenital and pediatric heart disease. Diffuse myocardial fibrosis, which is present to a varying degree in children with acquired and congenital heart disease, has been attributed to abnormal loading conditions, cyanosis, and genetic predisposition.1,7,10,11 Myocardial fibrosis manifests in the pressure-loaded left ventricle of infants and children with aortic stenosis and coarctation.1 In patients with tetralogy of Fallot right ventricular myofiber disorganization and interstitial fibrosis have been demonstrated histologically.2,12 Interestingly, right ventricular fibrosis not only occurs in late adult survivors, but is already present in infants with this condition.12 The changes in myocardial architecture observed with fibrotic remodeling can be detrimental to heart function: Fibrous endocardial thickening of the right ventricular infundibulum is a predictor of poor right ventricular function in patients after tetralogy of Fallot repair.3 In patients with tricuspid atresia myocardial fibrosis is associated with systolic ventricular dysfunction early in life.4,13 In addition to being a mediator of cardiac dysfunction, diffuse fibrosis is the substrate for electric instability and a risk factor for life-threatening ventricular arrhythmia.14 Antifibrotic drugs have …

Incidence and Mortality of Adults With Pulmonary Hypertension and Congenital Heart Disease

The Advisor™ HD Grid mapping catheter (Abbott Laboratories; Chicago, IL) allows for bipolar electrogram collection in both orthogonal and perpendicular planes, unique when compared to traditional and branch catheters. Experience in pediatric patients and congenital heart disease (CHD) is limited. The purpose of this work was to evaluate the utility and safety of the Advisor™ HD Grid mapping catheter in pediatric and CHD populations. Retrospective review of all pediatric patients and those with CHD (regardless of age) at Children's Hospital Colorado and University of Colorado undergoing electrophysiologic study in which the Advisor™ HD Grid mapping catheter was utilized. Sixty-five procedures in 60 patients (N = 31 female (47.6%), median age 17years (15-24.1)) were included. Patients had CHD in 30 procedures (46.1%). Eight-eight arrhythmia substrates were mapped including atrial flutter/intra-atrial reentrant tachycardia (N = 33), focal atrial tachycardia (N = 20), isolated PVCs (N = 10), accessory pathways (N = 9), atrioventricular nodal reentrant tachycardia (N = 7), right ventricular substrate mapping (N = 7), and ventricular tachycardia (N = 2). Median time per map was 11.8 (7.5-20.1) min with 3.2 (± 1.7) maps per procedure and a median of 2634 (1767-7654) points used per map. Patients with CHD required more maps (p < 0.001) and points per map (p < 0.001). Ablation was successful in 92.4% of procedures. The Advisor™ HD Grid mapping catheter is safe and effective in the pediatric and congenital heart disease population. A wide variety of arrhythmia substrates can be mapped with high point density and low mapping time.

Left bundle pacing in transposition of the great arteries with previous atrial redirection operation

Recent studies have suggested that routine defibrillation threshold (DFT) testing of implantable cardioverter defibrillators (ICDs) in adults may not be necessary. The congenital heart disease and pediatric populations are a unique group of ICD recipients having a higher incidence of lead failure. We investigated the utility of follow-up DFT testing in this population. The records of 155 ICD recipients at one center were retrospectively reviewed, and patients having one or more follow-up DFT tests were analyzed. The patients were divided into two groups. The "routine" group consisted of 58 follow-up DFT procedures in 46 patients, without known changes in ICD parameters. The "prompted" group consisted of 21 follow-up DFT procedures in 18 patients, motivated by clinical concerns about changes in ICD lead status. Of 58 "routine" DFTs performed at a mean postimplant duration of 32 +/- 23 months (range 2-78), 7 (12%) had reprogramming, and 1 required a hardware change as a result of the testing. Of the 21 "prompted" DFTs performed, 7 required device reprogramming, and 3 required hardware upgrade. Overall, 19 (24%) of 79 procedures detected clinically significant changes, requiring reprogramming or ICD system revision. No complications were seen from follow-up DFT testing. A high rate of abnormalities was found at follow-up DFT testing in this population, especially in the group of patients with clinically prompted testing. Clinically indicated DFT testing, as expected, has a high yield of important information on device function in congenital heart disease and pediatric populations.

<i>Circulation: Heart Failure</i> Editors’ Picks

BackgroundCardiac rehabilitation (CR) is underused in pediatric and congenital heart disease populations. Concern about arrhythmia risk may be an obstacle to CR referral. We sought to describe the frequency and risk factors for arrhythmia in patients who participated in a standardized CR program.MethodsWe conducted a retrospective chart review of all patients who completed at least 1 CR encounter from 2017 to 2022 at a pediatric cardiology center. We used descriptive statistics to determine the frequency of atrial and ventricular ectopy. Logistic regression was performed to identify predictors of frequent ventricular ectopy, nonsustained ventricular tachycardia, or ventricular tachycardia.ResultsThere were 177 patients who participated in 4494 rehabilitation encounters over the 6‐year study period (median age, 17 years [14–22]). Most patients had congenital heart disease (63%). Moderate or severe systolic dysfunction was noted in 14% of patients. Presence of an implantable cardioverter‐defibrillator (9% of patients) and a ventricular assist device (5% of patients) was noted. Nonsustained ventricular tachycardia occurred in 7 patients (3.9%) across 18 sessions (0.4%). There was an episode of sustained ventricular tachycardia resulting in an appropriate implantable cardioverter‐defibrillator shock. There were no deaths. Patients ≥18 years old (odds ratio, 2.7 [95% CI, 1.1 – 6.4]) were more likely to have frequent ventricular ectopy, nonsustained ventricular tachycardia, or ventricular tachycardia.ConclusionsSupervised CR in pediatric and congenital heart disease populations is associated with a low risk for clinically significant arrhythmias, and should not be an obstacle to referral for individuals who would otherwise benefit from CR.

BackgroundToday’s standard of care, in the congenital heart disease (CHD) population, involves performing cardiac catheterization under x-ray fluoroscopy and cardiac magnetic resonance (CMR) imaging separately. The unique ability of CMR to provide real-time functional imaging in multiple views without ionizing radiation exposure has the potential to be a powerful tool for diagnostic and interventional procedures. Limiting fluoroscopic radiation exposure remains a challenge for pediatric interventional cardiologists.This pilot study’s objective is to establish feasibility of right (RHC) and left heart catheterization (LHC) during invasive CMR (iCMR) procedures at our institution in the CHD population. Furthermore, we aim to improve simultaneous visualization of the catheter balloon tip, MR-conditional guidewire, and cardiac/vessel anatomy during iCMR procedures.MethodsSubjects with CHD were enrolled in a pilot study for iCMR procedures at 1.5 T with an MR-conditional guidewire. The CMR area is located adjacent to a standard catheterization laboratory. Using the interactive scanning mode for real-time control of the imaging location, a dilute gadolinium-filled balloon-tip catheter was used in combination with an MR-conditional guidewire to obtain cardiac saturations and hemodynamics. A recently developed catheter tracking technique using a real-time single-shot balanced steady-state free precession (bSSFP), flip angle (FA) 35–45°, echo time (TE) 1.3 ms, repetition time (TR) 2.7 ms, 40° partial saturation (pSAT) pre-pulse was used to visualize the gadolinium-filled balloon, MR-conditional guidewire, and cardiac structures simultaneously. MR-conditional guidewire visualization was enabled due to susceptibility artifact created by distal markers. Pre-clinical phantom testing was performed to determine the optimum imaging FA-pSAT combination.ResultsThe iCMR procedure was successfully performed to completion in 31/34 (91%) subjects between August 1st, 2017 to December 13th, 2018. Median age and weight were 7.7 years and 25.2 kg (range: 3 months – 33 years and 8 – 80 kg). Twenty-one subjects had single ventricle (SV) anatomy: one subject was referred for pre-Glenn evaluation, 11 were pre-Fontan evaluations and 9 post-Fontan evaluations for protein losing enteropathy (PLE) and/or cyanosis. Thirteen subjects had bi-ventricular (BiV) anatomy, 4 were referred for coarctation of the aorta (CoA) evaluations, 3 underwent vaso-reactivity testing with inhaled nitric oxide, 3 investigated RV volume dimensions, two underwent branch PA stenosis evaluation, and the remaining subject was status post heart transplant. No catheter related complications were encountered. Average time taken for first pass RHC, LHC/aortic pull back, and to cross the Fontan fenestration was 5.2, 3.0, and 6.5 min, respectively. Total success rate to obtain required data points to complete Fick principle calculations for all patients was 331/337 (98%). Subjects were transferred to the x-ray fluoroscopy lab if further intervention was required including Fontan fenestration device closure, balloon angioplasty of pulmonary arteries/conduits, CoA stenting, and/or coiling of aortopulmonary (AP) collaterals.Starting with subject #10, an MR-conditional guidewire was used in all subsequent subjects (15 SV and 10 BiV) with a success rate of 96% (24/25). Real-time CMR-guided RHC (25/25 subjects, 100%), retrograde and prograde LHC/aortic pull back (24/25 subjects, 96%), CoA crossing (3/4 subjects, 75%) and Fontan fenestration test occlusion (2/3 subjects, 67%) were successfully performed in the majority of subjects when an MR-conditional guidewire was utilized.ConclusionFeasibility for detailed diagnostic RHC, LHC, and Fontan fenestration test occlusion iCMR procedures in SV and BiV pediatric subjects with complex CHD is demonstrated with the aid of an MR-conditional guidewire. A novel real-time pSAT GRE sequence with optimized FA-pSAT angle has facilitated simultaneous visualization of the catheter balloon tip, MR-conditional guidewire, and cardiac/vessel anatomy during iCMR procedures.