Vigorous Exercise in Patients With Congenital Long-QT Syndrome: Results of the Prospective, Observational, Multinational LIVE-LQTS Study.

BACKGROUND: Whether vigorous exercise increases risk of ventricular arrhythmias for individuals diagnosed and treated for congenital long-QT syndrome (LQTS) remains unknown. METHODS: The National Institutes of Health-funded LIVE-LQTS study (Lifestyle and Exercise in Genetic Cardiovascular Conditions) prospectively enrolled individuals 8 to 60 years of age with phenotypic or genotypic LQTS from 37 sites in 5 countries from May 2015 to February 2019. Participants (or parents) answered physical activity and clinical events surveys every 6 months for 3 years with follow-up completed in February 2022. Vigorous exercise was defined as ≥6 metabolic equivalents for >60 hours per year. A blinded Clinical Events Committee adjudicated the composite end point of sudden death, sudden cardiac arrest, ventricular arrhythmia treated by an implantable cardioverter defibrillator, and likely arrhythmic syncope. A National Death Index search ascertained vital status for those with incomplete follow-up. A noninferiority hypothesis (boundary of 1.5) between vigorous exercisers and others was tested with multivariable Cox regression analysis. RESULTS: Among the 1413 participants (13% <18 years of age, 35% 18-25 years of age, 67% female, 25% with implantable cardioverter defibrillators, 90% genotype positive, and 49% with LQT1), 91% were treated with beta-blockers, left cardiac sympathetic denervation, or implantable cardioverter defibrillator; 52% participated in vigorous exercise (55% competitively). Thirty-seven individuals experienced the composite end point (including one sudden cardiac arrest and one sudden death in the nonvigorous group, one sudden cardiac arrest in the vigorous group) with overall event rates at 3 years of 2.6% in the vigorous and 2.7% in the nonvigorous exercise groups. The unadjusted hazard ratio for experience of events for the vigorous group compared with the nonvigorous group was 0.97 (90% CI, 0.57-1.67), with an adjusted hazard ratio of 1.17 (90% CI, 0.67-2.04). The upper 95% one-sided confidence level extended beyond the 1.5 boundary. Neither vigorous or nonvigorous exercise was found to be superior in any group or subgroup. CONCLUSIONS: Among individuals diagnosed with phenotypic or genotypic LQTS who were risk assessed and treated in experienced centers, LQTS-associated cardiac event rates were low and similar between those exercising vigorously and those not exercising vigorously. Consistent with the low event rate, CIs are wide, and noninferiority was not demonstrated. These data further inform shared decision-making discussions between patient and physician about exercise and competitive sports participation. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT02549664.

Patterns of Electrocardiographic Abnormalities in Children with Hypertrophic Cardiomyopathy.

Hypertrophic cardiomyopathy (HCM), a common cardiomyopathy in children, is an important cause of morbidity and mortality. Early recognition and appropriate management are important. An electrocardiogram (ECG) is often used as a screening tool in children to detect heart disease. The ECG patterns in children with HCM are not well described.ECGs collected from an international cohort of children, and adolescents (≤ 21 years) with HCM were reviewed. 482 ECGs met inclusion criteria. Age ranged from 1 day to 21 years, median 13 years. Of the 482 ECGs, 57 (12%) were normal. The most common abnormalities noted were left ventricular hypertrophy (LVH) in 108/482 (22%) and biventricular hypertrophy (BVH) in 116/482 (24%) Of the patients with LVH/BVH (n = 224), 135 (60%) also had a strain pattern (LVH in 83, BVH in 52). Isolated strain pattern (in the absence of criteria for hypertrophy) was seen in 43/482 (9%). Isolated pathologic Q waves were seen in 71/482 (15%). Pediatric HCM, 88% have an abnormal ECG. The most common ECG abnormalities were LVH or BVH with or without strain. Strain pattern without hypertrophy and a pathologic Q wave were present in a significant proportion (24%) of patients. Thus, a significant number of children with HCM have ECG abnormalities that are not typical for "hypertrophy". The presence of the ECG abnormalities described above in a child should prompt further examination with an echocardiogram to rule out HCM.

Impact of Obesity on Left Ventricular Thickness in Children with Hypertrophic Cardiomyopathy.

Obesity is associated with additional left ventricular hypertrophy (LVH) in adults with hypertrophic cardiomyopathy (HCM). It is not known whether obesity can lead to further LVH in children with HCM. Echocardiographic LV dimensions were determined in 504 children with HCM. Measurements of interventricular septal thickness (IVST) and posterior wall thickness (PWT), and patients' weight and height were recorded. Obesity was defined as a body mass index (BMI) ≥ 99th percentile for age and sex. IVST data was available for 498 and PWT data for 484 patients. Patient age ranged from 2 to 20 years (mean ± SD, 12.5 ± 3.9) and 340 (68%) were males. Overall, patient BMI ranged from 7 to 50 (22.7 ± 6.1). Obesity (BMI 18-50, mean 29.1) was present in 140 children aged 2-19.6 (11.3 ± 4.1). The overall mean IVST was 20.5 ± 9.6 mm and the overall mean PWT was 11.0 ± 8.4 mm. The mean IVST in the obese patients was 21.6 ± 10.0 mm and mean PWT was 13.3 ± 14.7 mm. The mean IVST in the non-obese patients was 20.1 ± 9.5 mm and mean PWT was 10.4 ± 4.3 mm. Obesity was not significantly associated with IVST (p = 0.12), but was associated with increased PWT (0.0011). Obesity is associated with increased PWT but not IVST in children with HCM. Whether obesity and its impact on LVH influences clinical outcomes in children with HCM needs to be studied.

Discrimination of the "Athlete's Heart" from real disease by electrocardiogram and echocardiogram.

Chronic physical training has been shown to produce multiple changes in the heart, resulting in the athlete's heart phenotype. Some of the changes can make it difficult to discern athlete's heart from true cardiac disease, most notably hypertrophic cardiomyopathy. Other diseases such as dilated cardiomyopathy and arrhythmogenic right ventricular cardiomyopathy may be difficult to rule in or out. In this article, the physiological cardiac changes of chronic athletic training are reviewed. A methodological approach using electrocardiography and echocardiography to differentiate between athlete's heart and cardiac disease is proposed.

Surgical management of major intrathoracic hemorrhage resulting from high-risk transvenous pacemaker/defibrillator lead extraction.

A method, based on well-established trauma principles, is described for surgical management of serious intrathoracic bleeding complications that can occur during the extraction of pacemaker or defibrillator leads. Using this method, four patients who experienced rapid hemodynamic deterioration due to traumatic injury of the superior vena cava and its tributaries during defibrillator lead extraction underwent successful surgical repair. Perioperative preparation for high-risk lead extractions, management of major bleeding complications, and surgical repair techniques are discussed. Major bleeding complications can be managed effectively with this strategy leading to excellent overall success rates for extractions without mortality.

Multi-institutional study of implantable defibrillator lead performance in children and young adults: results of the Pediatric Lead Extractability and Survival Evaluation (PLEASE) study.

BACKGROUND: Implantable cardioverter-defibrillator (ICD) therapy in children and congenital heart disease patients is hampered by poor long-term lead survival. Lead extraction is technically difficult and carries substantial morbidity. We sought to determine the outcomes of ICD leads in pediatric and congenital heart disease patients. METHODS AND RESULTS: The Pediatric Lead Extractability and Survival Evaluation (PLEASE) is a 24-center international registry. Pediatric and congenital heart disease patients with ICD lead implantations from 2005 to 2010 were eligible. Study subjects comprised 878 ICD patients (44% congenital heart disease). Mean±SD age at implantation was 18.6±9.8 years. Of the 965 total leads, 54% were thin (≤7F), of which 57% were Fidelis, and 23% were coated with expanded polytetrafluoroethylene. There were 139 ICD lead failures (14%) in 132 patients (15%) at a mean lead age of 2.0±1.4 years, causing shocks in 53 patients (40%). Independent predictors of lead failure included younger implantation age and Fidelis leads. Actuarial analysis showed an incremental risk of lead failure with younger age at implantation: <8 years compared with >18 years (P=0.015). The actuarial yearly failure rate was 2.3% for non-Fidelis and 9.1% for Fidelis leads. Extraction was performed on 143 leads (80% thin, 7% expanded polytetrafluoroethylene coated), with lead age as the only independent predictor for advanced extraction techniques. There were 6 major extraction complications (4%) but no procedural mortality. CONCLUSIONS: This study demonstrates that ICD leads in children and congenital heart disease patients have an age-related suboptimal performance, further compounded by a high failure rate of Fidelis leads. Advanced extraction techniques were common and correlated with older lead age. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT00335036.

Extracorporeal membrane oxygenation support for intractable primary arrhythmias and complete congenital heart block in newborns and infants: short-term and medium-term outcomes.

OBJECTIVES: To describe the experience with extracorporeal membrane oxygenation support for intractable primary arrhythmias in newborns and infants. DESIGN: Retrospective study. SETTING: A tertiary care pediatric hospital. PATIENTS: Patients younger than 1 yr supported with extracorporeal membrane oxygenation for primary cardiac arrhythmias were identified from the institutional extracorporeal membrane oxygenation registry. INTERVENTIONS: Extracorporeal membrane oxygenation support. MEASUREMENTS AND MAIN RESULTS: Clinical characteristics and outcomes were investigated for patients with primary cardiac arrhythmia supported with extracorporeal membrane oxygenation. Outcomes investigated were time from initiation of extracorporeal membrane oxygenation support to arrhythmia control, duration of extracorporeal membrane oxygenation support, and results of interventions performed while supported with extracorporeal membrane oxygenation. We summarized the independent categorical and continuous variables using frequencies, percentages, and medians and ranges, respectively. Extracorporeal membrane oxygenation support was used in nine patients for rescue therapy for primary tachyarrhythmia and bradycardia. The primary arrhythmias were: focal atrial tachycardia (n = 2); reentrant supraventricular tachycardia (n = 3); junctional ectopic tachycardia (n = 2); and congenital complete atrioventricular block (n = 2) patients. Seven patients presented with severe hemodynamic compromise, with six patients requiring extracorporeal cardiopulmonary resuscitation. All patients required extracorporeal membrane oxygenation within 24 hrs of initial presentation. Balloon atrial septostomy was performed in three patients and ablation was performed in two patients. Sinus rhythm was achieved in all reentrant supraventricular tachycardia and rate control was established in both patients with focal atrial tachycardia and in one patient with junctional ectopic tachycardia while using extracorporeal membrane oxygenation support. All patients survived to hospital discharge, and median follow-up for the cohort was 5 yrs. There was one late death; all survivors had good overall and neurologic outcomes. CONCLUSIONS: The requirement of extracorporeal membrane oxygenation support in newborns and infants with intractable arrhythmia is rare. Extracorporeal membrane oxygenation support does potentially carry morbidity; however, to prevent arrhythmia-related mortality, extracorporeal membrane oxygenation support and/or extracorporeal cardiopulmonary resuscitation should be considered in the management of hemodynamically unstable primary arrhythmias as an emergent lifesaving procedure.

Familial Recurrence Patterns in Congenitally Corrected Transposition of the Great Arteries: An International Study.

BACKGROUND: Congenitally corrected transposition of the great arteries (ccTGA) is a rare disease of unknown cause. We aimed to better understand familial recurrence patterns. METHODS: An international, multicentre, retrospective cohort study was conducted in 29 tertiary hospitals in 6 countries between 1990 and 2018, entailing investigation of 1043 unrelated ccTGA probands. RESULTS: Laterality defects and atrioventricular block at diagnosis were observed in 29.9% and 9.3%, respectively. ccTGA was associated with primary ciliary dyskinesia in 11 patients. Parental consanguinity was noted in 3.4% cases. A congenital heart defect was diagnosed in 81 relatives from 69 families, 58% of them being first-degree relatives, including 28 siblings. The most prevalent defects in relatives were dextro-transposition of the great arteries (28.4%), laterality defects (13.6%), and ccTGA (11.1%); 36 new familial clusters were described, including 8 pedigrees with concordant familial aggregation of ccTGA, 19 pedigrees with familial co-segregation of ccTGA and dextro-transposition of the great arteries, and 9 familial co-segregation of ccTGA and laterality defects. In one family co-segregation of ccTGA, dextro-transposition of the great arteries and heterotaxy syndrome in 3 distinct relatives was found. In another family, twins both displayed ccTGA and primary ciliary dyskinesia. CONCLUSIONS: ccTGA is not always a sporadic congenital heart defect. Familial clusters as well as evidence of an association between ccTGA, dextro-transposition of the great arteries, laterality defects and in some cases primary ciliary dyskinesia, strongly suggest a common pathogenetic pathway involving laterality genes in the pathophysiology of ccTGA.

Update on cardiovascular implantable electronic device infections and their management: a scientific statement from the American Heart Association.

Despite improvements in cardiovascular implantable electronic device (CIED) design, application of timely infection control practices, and administration of antibiotic prophylaxis at the time of device placement, CIED infections continue to occur and can be life-threatening. This has prompted the study of all aspects of CIED infections. Recognizing the recent advances in our understanding of the epidemiology, risk factors, microbiology, management, and prevention of CIED infections, the American Heart Association commissioned this scientific statement to educate clinicians about CIED infections, provide explicit recommendations for the care of patients with suspected or established CIED infections, and highlight areas of needed research.

A 37-Year-Old Woman with Hypertrophic Cardiomyopathy with a Dual-Chamber Implantable Cardioverter-Defibrillator Requiring Percutaneous Transvenous Lead Extraction and Multidisciplinary Management.

BACKGROUND Percutaneous transvenous lead extraction (TLE) of cardiac implantable electronic devices can be performed with a high success rate. However, TLE has its limitations and challenges. Recognizing the challenges at an early stage during the procedure is vital for appropriate patient management. We present a challenging case of implantable cardioverter-defibrillator (ICD) lead extraction in which we aborted TLE in favor of elective surgical extraction (SE). This potentially prevented a major catastrophic complication of vascular tear, which would have required an emergent thoracotomy. CASE REPORT A 37-year-old woman with history of hypertrophic cardiomyopathy had a primary prevention dual-chamber ICD implant in 2001 and underwent right ventricular ICD lead revision in 2009 due to lead fracture. In 2019, she was again found to have right ventricular ICD lead malfunction. TLE was attempted, but no meaningful progression could be made despite using multiple extraction tools. Therefore, TLE was aborted in favor of SE. During elective SE, significant adhesions were noted, and the innominate vein was completely avulsed during removal of the leads, requiring venous reconstruction by the vascular surgery team. After SE and vascular reconstruction, an epicardial ICD system was placed, and the patient had an uneventful postoperative recovery. CONCLUSIONS This case report highlights the limitations of TLE and the importance of recognizing them in a timely manner. In all challenging cases, conversion to elective SE should be considered to avoid potential injuries warranting emergent surgical repair.

Characterization of left ventricular cavity flow, wall stress and energy loss by color doppler vector flow mapping in children and adolescents with cardiomyopathy.

BACKGROUND: Vector flow mapping is an emerging echocardiographic method allowing for investigation of intracardiac blood flow mechanics, wall shear stress (WSS), and energy loss (EL). We hypothesized that alterations in EL and WSS will differ among subjects with hypertrophic (HCM), dilated (DCM) cardiomyopathy, and normal controls. METHODS: Echocardiograms were prospectively performed with the ProSound F75CV (Hitachi HealthCare., Tokyo, Japan) on all subjects. 2D color Doppler cine loop images were obtained from apical 5 and the apical long axis views and stored digitally. Measurements were averaged over three cardiac cycles using VFM software to derive flow patterns, WSS, and EL. Standard left ventricular (LV) systolic and diastolic functional parameters were also obtained. RESULTS: A total of 85 subjects, 22 with HCM (age 18 ± 9 yrs.), 18 DCM (age 18 ± 9 yrs.), and 45 age and gender matched controls were included in the study. Diastolic wall shear stress was found significantly different in HCM (0.004 ± 0.185 N/m2) compared with DCM (0.397 ± 0.301 N/m2, P < 0.001), and controls (0.175 ± 0.255 N/m2, P = 0.027). Furthermore, indexed systolic EL was found to be significantly elevated in HCM (13.91 ± 13.17 mW/m2/m3) compared with DCM (8.17 ± 9.77 mW/m2/m3, P < 0.001), but not controls (6.45 ± 7.47 mW/m2/m3). CONCLUSION: Differences in abnormal ventricular mechanics observed in HCM and DCM are reflected in both EL and WSS, and are suggestive that changes in energetic parameters may represent novel indices of ventricular dysfunction.

Assessment of mitral valve function in children and young adults with hypertrophic cardiomyopathy using three-dimensional echocardiography.

OBJECTIVE: The objective of this study was to assess papillary muscle (PM) and mitral valve (MV) structure and function in children and young adults with mild and moderate hypertrophic cardiomyopathy (HCM) using real-time three-dimensional echocardiography (3DE) and to correlate them with HCM related adverse outcomes. METHODS: Transthoracic research 3DE was performed in HCM patients and controls matched for age and gender. Anterolateral and posteromedial PM mass, apical displacement of anterolateral PM, and left ventricular (LV) mass were measured and indexed to body surface area. The MV annulus and leaflet structure and function were analyzed. Individual PMs were manually planimetered by tracing the endocardial borders on each mid systole frame, taking care to distinguish PMs as distinct from the LV wall. Apical PM displacement was expressed as ratio of the distance between the apex and the base of the anterolateral PM to the entire length of the LV lateral wall (APL index). All 3DE measurements were correlated to adverse outcomes. RESULTS: Forty subjects were studied, including 20 HCM patients (age 18.1 ± 9.6 years, 16 male and 4 female), and 20 controls (18.2 ± 9.6 years, 16 male and 4 female). The indexed LV mass in HCM was 74.8 ± 25.8 g/m2 compared to 50.8 ± 12.4 g/m2 in controls (p = 0.001). The anterolateral, posteromedial and combined PM mass were 3.1 ± 2.2 g/m2, 1.7 ± 1.2 g/m2 and 4.9 ± 2.7 g/m2 in HCM, in contrast to respective measurements of 1.1 ± 0.6 g/m2, 1.2 ± 0.6 g/m2 and 2.3 ± 0.8 g/m2 in controls (p < 0.001, p = 0.062, and p < 0.001, respectively). The mitral valve annular parameters (annulus circumference, height and area) in HCM were not significantly different from controls. The APL index in HCM was less than in controls (0.44 ± 0.07 vs. 0.55 ± 0.04, p < 0.001). The LV lateral wall length and LV mass correlated with adverse HCM outcomes, while the APL index and PM total mass were not associated with adverse events. CONCLUSION: It is feasible to evaluate PM muscles and MV annulus geometry in children and young adults with HCM using 3DE. The morphologic and functional changes of anterolateral PM may occur in the absence of MV annulus changes. Prospective validation will be required to determine if LV lateral wall length and LV mass may be used as predictors of adverse events.

Sudden Death in the Young: Information for the Primary Care Provider.

There are multiple conditions that can make children prone to having a sudden cardiac arrest (SCA) or sudden cardiac death (SCD). Efforts have been made by multiple organizations to screen children for cardiac conditions, but the emphasis has been on screening before athletic competition. This article is an update of the previous American Academy of Pediatrics policy statement of 2012 that addresses prevention of SCA and SCD. This update includes a comprehensive review of conditions that should prompt more attention and cardiology evaluation. The role of the primary care provider is of paramount importance in the evaluation of children, particularly as they enter middle school or junior high. There is discussion about whether screening should find any cardiac condition or just those that are associated with SCA and SCD. This update reviews the 4 main screening questions that are recommended, not just for athletes, but for all children. There is also discussion about how to handle post-SCA and SCD situations as well as discussion about genetic testing. It is the goal of this policy statement update to provide the primary care provider more assistance in how to screen for life-threatening conditions, regardless of athletic status.

Loss of ventricular preexcitation during noninvasive testing does not exclude high-risk accessory pathways: A multicenter study of WPW in children.

BACKGROUND: Abrupt loss of ventricular preexcitation on noninvasive evaluation, or nonpersistent preexcitation, in Wolff-Parkinson-White syndrome (WPW) is thought to indicate a low risk of life-threatening events. OBJECTIVE: The purpose of this study was to compare accessory pathway (AP) characteristics and occurrences of sudden cardiac arrest (SCA) and rapidly conducted preexcited atrial fibrillation (RC-AF) in patients with nonpersistent and persistent preexcitation. METHODS: Patients 21 years or younger with WPW and invasive electrophysiology study (EPS) data, SCA, or RC-AF were identified from multicenter databases. Nonpersistent preexcitation was defined as absence/sudden loss of preexcitation on electrocardiogram, Holter monitoring, or exercise stress test. RC-AF was defined as clinical preexcited atrial fibrillation with shortest preexcited R-R interval (SPERRI) ≤ 250 ms. AP effective refractory period (APERP), SPERRI at EPS , and shortest preexcited paced cycle length (SPPCL) were collected. High-risk APs were defined as APERP, SPERRI, or SPPCL ≤ 250 ms. RESULTS: Of 1589 patients, 244 (15%) had nonpersistent preexcitation and 1345 (85%) had persistent preexcitation. There were no differences in sex (58% vs 60% male; P=.49) or age (13.3±3.6 years vs 13.1±3.9 years; P=.43) between groups. Although APERP (344±76 ms vs 312±61 ms; P<.001) and SPPCL (394±123 ms vs 317±82 ms; P<.001) were longer in nonpersistent vs persistent preexcitation, there was no difference in SPERRI at EPS (331±71 ms vs 316±73 ms; P=.15). Nonpersistent preexcitation was associated with fewer high-risk APs (13% vs 23%; P<.001) than persistent preexcitation. Of 61 patients with SCA or RC-AF, 6 (10%) had nonpersistent preexcitation (3 SCA, 3 RC-AF). CONCLUSION: Nonpersistent preexcitation was associated with fewer high-risk APs, though it did not exclude the risk of SCA or RC-AF in children with WPW.

The low specificity of low voltage bridges associating atrioventricular nodal reentry in pediatric patients.

PURPOSE: Patients with atrioventricular nodal reentry tachycardia (AVNRT) often are managed successfully by ablation of the slow pathway with success rates reported as high as 99%. Low voltage bridges (LVBs) have been demonstrated to be helpful in guiding AVNRT ablation. Patients may present to the electrophysiology lab without evidence of inducible arrhythmia. In these scenarios, the demonstration of LVBs may be diagnostic and guide catheter ablation treatment. The purpose of our study was to prospectively investigate the specificity of LVBs as a diagnostic marker of AVNRT. METHODS: Patients aged < 19 years with narrow complex tachycardia prospectively underwent electrophysiology study with intention to perform catheter ablation. In each patient, the primary objective was the collection of right atrial voltage data that was then used to identify LVBs. RESULTS: Twenty-four patients were included after exclusion criteria were applied. Final diagnosis was 11 AVNRT and 13 non-AVNRT (nAVNRT). LVBs were identified in 11/11 AVNRT patients and 9/13 non-AVNRT patients (p = 0.09). CONCLUSIONS: LVBs are not specific to patients with AVNRT and cannot solely be used for diagnosis. However, in patients with documented AVNRT, the LVB can be used to identify the location of the slow pathway.

Risk factors for lethal arrhythmic events in children and adolescents with hypertrophic cardiomyopathy and an implantable defibrillator: An international multicenter study.

BACKGROUND: Predictors of risk of lethal arrhythmic events (LAE) is poorly understood and may differ from adults in children with hypertrophic cardiomyopathy (HCM). OBJECTIVE: The purpose of this study was to determine predictors of LAE in children with HCM. METHODS: A retrospective data collection was performed on 446 children and teenagers 20 years and younger (290 [65%] male; mean age 10.1 ± 5.7 years) with idiopathic HCM from 35 centers. Patients were classified as group 1 (HCM with LAE) if having a secondary prevention implantable cardioverter-defibrillator (ICD) or primary prevention ICD with appropriate interventions or group 2 (HCM without LAE) if having a primary prevention ICD without appropriate interventions. RESULTS: There were 152 children (34%) in group 1 and 294 (66%) in group 2. Risk factors for group 1 by univariate analysis were septal thickness, posterior left ventricular (LV) wall thickness, lower LV outflow gradient, and Q wave > 3 mm in inferior electrocardiographic leads. Factors not associated with LAE were family history of SCD, abnormal blood pressure response to exercise, and ventricular tachycardia on ambulatory electrocardiographic monitoring. Risk factors for SCD by multivariate analysis were age at ICD placement (hazard ratio [HR] 0.9; P = .0025), LV posterior wall thickness z score (HR 1.02; P < .005), and LV outflow gradient < 30 mm Hg (HR 2.0; P < .006). LV posterior wall thickness z score ≥ 5 was associated with LAE. CONCLUSION: Risk factors for LAE appear different in children compared to adults. Conventional adult risk factors were not significant in children. Further prospective studies are needed to improve risk stratification for LAE in children with HCM.

Impact of manufacturer advisories and FDA recalls of implantable cardioverter defibrillator generators in pediatric and congenital heart disease patients.

INTRODUCTION: Recalls of implantable cardioverter defibrillator (ICD) generators have affected many patients. No information is available regarding the impact specifically on pediatric and congenital heart disease (CHD) patients. This study was undertaken to determine implications of ICD manufacturers' advisories and recalls on children and CHD patients. METHODS: The first part of this study involved single-center review of patients who underwent ICD placement between 2000 and 2005. Patients with ICDs affected by the 2005 advisories/recalls were reviewed for incidence of explantation, malfunction and complications. Secondly, members of the Pediatric and Congenital Electrophysiology Society (PACES) were queried for patients with affected devices, incidences of explantation, malfunction, and explant-related complications. Data were pooled for aggregate summary. RESULTS: Among 233 patients who underwent ICD implantation at our institution during the study period, 58 (25%) patients had advisory/recalled devices and 13 of 58 (22%) underwent explantation following 3.1 +/- 1.3 years implant duration. No defects were identified by the manufacturer. No patients experienced complications requiring reintervention or rehospitalization. Questionnaire responses were received from 22 PACES institutions, included 177 patients with affected devices, of which 76 (43%) were removed. One patient died from complications following revision, and 1 patient had complications requiring reoperation. Two explanted devices had loose headers; no other defects were discovered. Taken together, 2 of 89 explanted devices were defective, and 2 complications occurred from explantation. CONCLUSIONS: Advisories and recalls affect substantial numbers of pediatric and CHD patients. A significant proportion underwent explantation. Although complications are infrequent, there are important medical, psychosocial, and financial impacts associated with ICD replacement.

Safety and Efficacy of Cardiac Ultrasound Contrast in Children and Adolescents for Resting and Stress Echocardiography.

BACKGROUND: Small pilot studies of ultrasound contrast (UC) echocardiography in children have suggested that it is safe; therefore, larger scale evaluation of safety and efficacy in this population is of particular interest. METHODS: This was a retrospective study (January 2005 to June 2014). Known intracardiac shunt was the only exclusion criterion. UC echocardiography was performed on commercially available ultrasound systems using Definity (3% infusion). When indicated, real-time myocardial contrast echocardiography was performed at rest and stress, with examination of myocardial contrast replenishment, plateau intensity, and wall motion. The primary outcome was short-term safety and efficacy (<24 hours). RESULTS: In all, 113 patients (55% male; mean age, 17.8 ± 3 years; age range, 5-21 years) underwent UC echocardiography for left ventricular opacification or stress wall motion and perfusion analysis. Diagnosis categories were congenital heart disease (30%), acquired heart disease (21%), and other (suspected cardiac complications of disease of other organ systems; 49%). Twelve patients (11%) with right ventricular systolic pressures > 40 mm Hg received UC without complications; four of these (33%) had the highest right ventricular-right atrial gradient recorded with ultrasound contrast-enhanced Doppler. Myocardial perfusion and/or UC echocardiography-detected wall motion abnormalities were seen in 13 patients (12%); four had confirmed correlations by angiography or magnetic resonance imaging. There were 13 instances of adverse events or reported symptoms during UC echocardiography. All symptoms and events were transient, all patients completed protocols, and there were no immediate sequelae. CONCLUSIONS: These data demonstrate the usefulness and safety of UC echocardiography in children and adolescents for a wide variety of indications. UC echocardiography provided myocardial perfusion and wall motion information important in clinical decision making.