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Guidelines addressing magnetic resonance imaging (MRI) in patients with cardiac implantable electronic devices (CIEDs) provide algorithms for imaging pediatric and congenital heart disease (CHD) patients. Guideline acceptance varies by institution. Guidelines also do not support routine MRI scans in patients with epicardial or abandoned leads, common in pediatric and CHD patients. The purpose of this study was to determine the incidence of MRI-related complications in pediatric and CHD patients with CIEDs, including epicardial and/or abandoned leads. A multicenter retrospective review included patients with CIEDs who underwent any MRI between 2007 and 2022 at congenital cardiac centers. The primary outcome was any patient adverse event or clinically significant CIED change after MRI, defined as pacing lead capture threshold increase >0.5 V with output change, P- or R- wave amplitude decrease >50% with sensitivity change, or impedance change >50%. Across 14 institutions, 314 patients (median age 18.8 [1.3; 31.4] years) underwent 389 MRIs. There were 288 pacemakers (74%) and 87 implantable cardioverter-defibrillators (22%); 52% contained epicardial leads, and 14 (4%) were abandoned leads only. Symptoms or CIED changes occurred in 4.9% of MRI scans (6.1% of patients). On 9 occasions (2%), warmth or pain occurred. Pacing capture threshold or lead impedance changes occurred in 1.4% and 2.0% of CIEDs post-MRI and at follow-up. Our data provide evidence that MRIs can be performed in pediatric and CHD patients with CIEDs, including non–MRI-conditional CIEDs and epicardial and/or abandoned leads, with rare minor symptoms or CIED changes but no other complications. [ABSTRACT FROM AUTHOR]

Patients with repaired tetralogy of Fallot (TOF) are at risk for ventricular tachycardia (VT) related to well-described anatomical isthmuses. The purpose of this study was to explore QRS morphology as an indicator of anatomical isthmus conduction. Patients with repaired TOF and complete right bundle branch block referred for transcatheter pulmonary valve replacement (PVR) or presenting with sustained VT underwent comprehensive 3-dimensional mapping in sinus rhythm. Electrocardiographic characteristics were compared to right ventricular (RV) activation and anatomical isthmus conduction properties. Twenty-two patients (19 pre–pulmonary valve replacement and 3 clinical VT) underwent comprehensive 3-dimensional mapping (median 39 years; interquartile range [IQR] 27–48 years; 12 [55%] male). Septal RV activation (median 40 ms; IQR 34–46 ms) corresponded to the nadir in lead V 1 and free wall activation (median 71 ms; IQR 64–81 ms) to the transition point in the upstroke of the Rʹ wave. Patients with isthmus block between the pulmonary annulus and the ventricular septal defect patch and between the ventricular septal defect patch and the tricuspid annulus (when present), were more likely to demonstrate lower amplitude Rʹ waves in lead V 1 (5.8 mV vs 9.4 mV; P =.005), QRS fragmentation in lead V 1 (15 [94%] vs 2 [13%]; P <.001), and terminal S waves in lead aVF (15 [94%] vs 6 [40%]; P <.001) than those with intact conduction. During catheter ablation, these QRS changes developed during isthmus block. For patients with repaired TOF, the status of septal isthmus conduction was evident from sinus rhythm QRS morphology. Low-amplitude, fragmented Rʹ waves in lead V 1 and terminal S waves in the inferior leads were related to septal isthmus conduction abnormalities, providing a mechanistic link between RV activation and common electrocardiographic findings. [ABSTRACT FROM AUTHOR]

For patients with congenital heart disease (CHD), chronic ventricular pacing may lead to progressive cardiomyopathy owing to electromechanical dyssynchrony. Cardiac conduction system pacing (CSP) has been proposed as a physiologic pacing strategy—directly engaging the His–Purkinje system and preserving electromechanical synchrony. CSP may be indicated for a wide variety of children and adults with CHD and has emerged as an important tool in the armamentarium for cardiac implantable electronic device operators. This review provides the rationale, background, and supportive evidence for CSP in patients with CHD and discusses implant strategies and outcomes in the context of dominant ventricular morphologic categories. [ABSTRACT FROM AUTHOR]

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Together, heart failure and arrhythmia represent the most important cardiovascular sources of morbidity and mortality among adults with congenital heart disease (ACHDs). Although traditionally conceptualized as operating within 2 distinct clinical silos, these scenarios frequently coexist within the same individual; consequently the mechanistic, therapeutic, and prognostic overlap between them demands increased recognition. In fact, given the near ubiquity of heart failure and arrhythmia among ACHDs, there is perhaps no other arena within cardiology where this critical intersection is more frequently observed. Optimal care for ACHDs therefore requires a heightened awareness of the relevant interactions as well as the pharmacologic and interventional resources that are increasingly available to the treating cardiologist. This review explores and highlights the overlap between these 2 fields to recommend a parallel, yet interactive, multidisciplinary approach to clinical management. Congenital heart disease categories are broken down into their archetypal subtypes to highlight subtleties of the pathophysiology, evaluation, and therapeutic approach. [ABSTRACT FROM AUTHOR]

Background: Catheter ablation outcomes for adults with congenital heart disease (ACHD) are described, but recurrence mechanisms remain largely unknown.Objective: The purpose of this study was to identify the electrophysiological characteristics of atrial tachycardia (AT) recurrence in ACHD.Methods: ACHD atrial tachycardia procedures over a 10-year period were explored for AT or atrial fibrillation (AF) recurrence.Results: At 299 procedures in 250 ACHD (mean age 39 ± 15 years; 130 [52%] male), 464 ATs (360 intra-atrial reentrant tachycardia, 104 focal AT; median 2 [IQR 1-3] ATs per procedure) were targeted. Complete (n = 256 [86%]) or partial (n = 37 [12%]) success was achieved in 98% of procedures. Over a median of 3.0 (IQR 1.4-5.3) years of follow-up, 67 patients (27%) developed AT/AF recurrence after the index procedure. Repeat vs index tachycardias were more often focal AT (26/69 [38%] vs 73/378 [19%]; P < .001), demonstrated longer cycle length (325 ms vs 280 ms; P = .003), required isoproterenol (34/69 [50%] vs 121/378 [32%]; P = .03), and involved the pulmonary venous atrium (PVA)/septum (26/69 [38%] vs 67/378 [18%]; P < .001). AF history (hazard ratio [HR] 2.0; interquartile range [IQR] 1.2-3.4; P = .01), incomplete success (HR 3.6; IQR 2.1-6.4; P < .001), and PVA substrate (HR 2.1; IQR 1.2-3.5; P = .006) were independently associated with AT/AF recurrence. With complete index procedure success and no AF history, 5-year actuarial freedom from AT/AF and AT alone were 77% and 80%.Conclusion: After catheter ablation in ACHD, repeat ATs were more frequently focal, required isoproterenol administration, or involved intra-atrial reentrant tachycardia within the PVA or atrial septum. Negative factors were partial success, index PVA substrate, and remote history of AF. These data support aggressive pharmacological provocation to eliminate all inducible tachycardias and coexisting PVA substrates at index procedures for ACHD. [ABSTRACT FROM AUTHOR]

Background: Biatrial tachycardia (BiAT) is a rare form of macroreentry not previously characterized in adults with congenital heart disease (ACHD).Objective: The purpose of this study was to determine the prevalence, mechanisms, and outcomes of catheter ablation for BiAT in ACHD.Methods: All ACHD undergoing catheter ablation for macroreentrant atrial tachycardia over a 10-year period were evaluated for evidence of BiAT. Patients were categorized as prior Senning, Fontan, or other biventricular operation. A novel biatrial global activation histogram (GAH) analysis was used to demonstrate the presence of interatrial connections (IACs).Results: Among 263 ACHD, BiAT was identified at 11 procedures in 10 patients (4.2%; median age 35 years; 30% male). The congenital category was Fontan in 6, Senning in 3, and biventricular in 2. Diagnosis of BiAT was associated with ablation era and mapping technology (P <.001) and could be confirmed with a novel GAH mapping approach for normally septated atrial connections. Catheter ablation targeted an IAC in 5 cases (Bjork Fontan and biventricular operations), a posterior isthmus in 3 (Senning operation), and the cavotricuspid isthmus or equivalent in 3 (lateral tunnel [LT] Fontan). Recurrence was isolated to ablation to sites at the expected location of the Bachmann bundle, and durable success could be achieved after repeat ablation.Conclusion: BiAT occurs in approximately 4% of ACHD but is likely underrecognized. BiAT could be targeted at an IAC for normally septated atria and at a conventional critical isthmus after Senning and LT Fontan operations. [ABSTRACT FROM AUTHOR]

Patients with a systemic right ventricle (SRV) are at high risk for development of heart failure early in life. An SRV is encountered in patients with congenitally corrected transposition of the great arteries (CCTGA) or dextro-transposition of the great arteries (DTGA) with previous atrial switch repair (Mustard or Senning procedure). Progressive heart failure is one of the leading cause of mortality in these patients. Therefore, cardiac resynchronization therapy (CRT) has gained increasing momentum for use in this challenging congenital heart disease (CHD) population. However, current guidelines differ in recommendations for CRT in patients with an SRV as evidence supporting CRT has thus far only been described in case reports and retrospectively in relatively small study populations. In fact, the European Society of Cardiology Guideline for the management of grown-up congenital heart disease consider CRT to be 'experimental' in this population. This systematic review critically summarizes current literature on CRT in SRV patients and provides future perspectives for further research in this challenging and growing CHD population. • Cardiac resynchronization therapy (CRT) can be an effective treatment for patients with a failing systemic right ventricle. • Guidelines are cautious with CRT recommendations for SRV patients as evidence supporting CRT has been limited. • This systematic review summarizes current experience of CRT in this challenging population. [ABSTRACT FROM AUTHOR]

Background: Although they are at lower risk, patients with previous extracardiac conduit (EC) Fontan still may require catheter ablation for supraventricular arrhythmia.Objective: The purpose of this study was to determine the optimal approach to pulmonary venous atrium (PVA) access after EC Fontan operation.Methods: All electrophysiological procedures requiring PVA over a 10-year period at the UCLA Medical Center were reviewed. PVA was grouped by transcaval cardiac puncture (TCP) or direct conduit puncture. Procedural characteristics and outcomes were compared.Results: Between June 2009 and November 2019, 23 electrophysiological procedures requiring PVA access were performed in 17 EC Fontan patients (53% male; median age 25 years; interquartile range 11-34). Cavoatrial overlap was identified in 14 patients by preprocedural imaging (10 cardiac computed tomography, 4 cardiac magnetic resonance). PVA access was obtained via TCP in 11, direct conduit puncture in 6, pre-existing fenestration in 5, and pulmonary artery puncture in 1. Time to PVA was significantly shorter for TCP vs direct conduit puncture (0.2 vs 1.1 hours, respectively; P = .03). The only predictor of successful TCP was the length of cavoatrial overlap by preprocedural imaging (14 vs 3 mm; P = .02). No procedural complications occurred. No change in oxygen saturation was noted, and no evidence of residual shunting was detected by follow-up echocardiography.Conclusion: TCP is feasible in most patients after EC Fontan surgery and can be predicted by preprocedural advanced imaging. TCP is associated with shorter time to PVA and was uncomplicated in this single-center study. Preoperative assessment of cavoatrial overlap should be considered before catheter ablation for EC Fontan. [ABSTRACT FROM AUTHOR]

Background: Congenitally corrected transposition of the great arteries (CCTGA) is associated with spontaneous AV block and pacing-induced cardiomyopathy. His bundle pacing (HBP) is a potential alternative to conventional CRT.Objectives: To determine the outcomes of HBP for CCTGA.Methods: Retrospective data were collected from 10 international centers.Results: HBP or left bundle branch pacing (LBBP) was attempted for 15 CCTGA patients (median 23 yrs, 87% male). Prior surgery had been performed in 5 and chronic ventricular pacing in 6. Conduction system pacing (HBP=11, LBBP=2; non-selective in 10, selective in 3) was acutely successful in 13 (86%) without complication. In 9 cases, electro-anatomical mapping was available and identified the distal His bundle and proximal LBBs within the morphologic LV below the pulmonary valve separate from the mitral annulus. The median implant HV interval was 42 ms (IQR 35 - 48), R wave 6 mV (IQR 5 - 18) and threshold 0.5V (IQR 0.5 - 1.2) at median 0.5 ms. The QRSd was unchanged as compared to junctional escape rhythm (124 vs 110 ms, p=0.17) and decreased significantly compared to baseline ventricular pacing (112 vs 164 ms, p<0.01). At a median of 8 months, all patients were alive without significant change in pacing threshold or lead dysfunction. NYHA class improved in 5 patients.Conclusions: Permanent conduction system pacing is feasible in CCTGA by either HBP or proximal LBBP. Narrow paced QRS and stable lead thresholds were observed at intermediate follow-up. Unique anatomical characteristics may favor this approach over conventional CRT. [ABSTRACT FROM AUTHOR]

Background: Tricuspid valve (TV) surgery is often required for adult congenital heart disease (ACHD), but may hinder catheter ablation when an artificial material or imbricated tissue covers the tricuspid annulus.Objective: The purpose of this study was to determine the outcomes of catheter ablation after TV surgery in a large ACHD cohort.Methods: An international retrospective study involving 7 centers was conducted. Patients who did and did not undergo TV surgery were matched for age, lesion classification, and postsurgical duration. TV operations were classified as valve ring/replacement vs repair.Results: One hundred thirty-six patients (42 ring/replacement, 39 repair, and 55 no TV surgery; median 32 years [IQR 20 - 46]) underwent 180 procedures targeting 239 tachycardias (cavotricuspid-isthmus dependent intraatrial reentrant tachycardia 36%, other intraatrial reentrant tachycardia 29%, focal atrial tachycardia 18%, and other supraventricular tachyarrhythmia 17%). Post-TV surgery, procedures were longer (4.3 hours vs 3.3 hours; P = .003) and required longer fluoroscopy time (31 minutes vs 18 minutes; P = .001). At least partial acute success was achieved in 81% of procedures in the TV ring/replacement group vs 94% in both TV repair and no TV surgery groups (P = .03). The difference was driven mainly by ablation of annular substrates, with acute success in 73% of TV ring/replacement, 92% of TV repair, and 94% of no TV surgery groups (P = .01). Over a median of 3.0 years, tachycardia recurred after 26% of procedures. TV ring/replacement predicted recurrence in the multivariable analysis (hazard ratio 2.4; 95% confidence interval 1.2-5.2; P = .009).Conclusion: After surgery for ACHD, catheter ablation success was lower and tachycardia recurrence was higher after TV valve ring/replacement surgery. The findings of this retrospective report support future larger multicenter series and prospective evaluation to determine the role of empirical annular substrate ablation. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Background: An increasing number of adults with congenital heart disease (CHD) are undergoing catheter ablation for atrial fibrillation (AF). Data on ablation strategy and outcomes in CHD are limited. Rhythm control is often believed to be of greater importance among patients with complex CHD.Objective: The purpose of this study was to examine the safety and efficacy of AF ablation in adult patients with CHD.Methods: A multicenter retrospective analysis was performed of CHD patients undergoing AF ablation. Clinical data were collected, including AF and CHD type, procedural data, and outcomes. Patients were divided into 3 groups (simple, moderate, and severe) based on CHD complexity, as defined by the 2014 PACES/HRS (Pediatric and Congenital Electrophysiology Society/Heart Rhythm Society) consensus statement. One-year procedural success was defined as freedom from recurrent AF, off antiarrhythmic drugs (complete) or off/on previously failed antiarrhythmic drugs (partial).Results: Overall, 84 CHD patients (mean age 51.5 ± 12.1 years; 65.5% male; 45.2% with paroxysmal AF) undergoing AF ablation (51 simple, 22 moderate, 11 severe complexity) were included. Pulmonary vein isolation was performed in 80 (95.2%), of whom 30 (35.7%) underwent pulmonary vein isolation alone. Overall, complete and complete/partial freedom was achieved at 1 year in 53.1% and 71.6%, respectively, with no significant differences between those with simple, moderate, or severe complexity. There were no major complications and 7 minor complications, and 2 patients died during follow-up.Conclusion: There are dramatic differences in the degree of CHD complexity among patients referred for AF ablation. When performed at experienced centers, AF ablation is safe and effective even among patients with the most complex forms of CHD. [ABSTRACT FROM AUTHOR]

Introduction: Chronic pulmonary regurgitation (PR) following surgical correction in Tetralogy of Fallot (TOF) leads to right ventricular (RV) dysfunction, arrhythmias and sudden cardiac death (SCD). Pulmonary valve replacement (PVR) decreases PR and improves RV function, but data regarding QRS duration reduction remain scarce.Methods: All adult TOF patients undergoing transcatheter PVR or surgical PVR from 2010 to 2016 were included. Clinical characteristics and QRS duration were measured and compared to post-intervention QRS duration using an institutional software and manually verified. Significantly wide QRS was defined as QRS >140 ms.Results: Of 133 PVR patients, 85 had TOF and 27 (21.1%) had QRS > 140 ms (14 transcatheter, 13 surgical) and were included in this analysis. A 6 ms decrease in QRS duration was seen at 3-year follow-up (168.0 ± 3.5 ms vs. 161.8 ± 3.5 ms, p = .04). There was a significant decrease in the median RV size (defined as RV/LV diameter ratio) pre-intervention to 3-year post-intervention: (0.96 vs 0.89, p = .03). The median PR decreased significantly from moderate-severe to mild post-intervention (p < .0001).Conclusions: Replacement of the pulmonary valve in high risk TOF patients reduces QRS duration at 3 years. Further study is needed to assess whether this QRS duration reduction may identify patients at lower risk of ventricular arrhythmias. [ABSTRACT FROM AUTHOR]

Background: Patients with congenitally corrected transposition of the great arteries (CCTGA) are at risk of congestive heart failure (CHF). There are limited data on cardiac resynchronization therapy (CRT) techniques and long-term outcomes in this population.Objective: The purpose of this study was to determine implantation techniques and efficacy of CRT for CCTGA.Methods: A 15-year retrospective review of patients with CCTGA undergoing CRT was performed.Results: Twenty patients were identified (mean age 40.1 ± 15.3 years; baseline New York Heart Association class 2.0 [interquartile range 1.5-3.5]). Indication was pacing-induced ventricular dysfunction in 12 (60%), atrioventricular block with anticipation for >40% ventricular pacing in 5 (25%), and intact atrioventricular conduction with CHF and QRS prolongation in 3 (15%). A transvenous approach was successful in 18 of 19 patients (95%) in whom it was attempted, with cannulation of a posteroseptal ostium in 14 (78%), vein of Marshall in 2 (11%), and superior ectopic ostium in 2 (11%). Of patients with baseline CHF, 8 (67%) were acute responders, with loss of response in 2 patients (median 1.1 and 1.5 years, respectively). Of 4 patients referred for heart transplantation, 3 (75%) could be de-listed following CRT. Only lead location in the right ventricular outflow tract predicted poor CRT response (P = .026). Post-procedure, the QRS duration increased by 4.3 ms/y (P < .001) despite stable pacing characteristics. CRT revision was required in 4 patients for infection (n = 2) or phrenic nerve capture (n = 2) and was associated with loss of CRT response in 1 patient.Conclusion: A transvenous approach to CRT involving distinct coronary venous patterns is feasible for most patients with CCTGA anatomy. Long-term outcome is favorable, but is characterized by return of right ventricular dysfunction in some patients. [ABSTRACT FROM AUTHOR]

Background: Subcutaneous implantable cardioverter-defibrillator (SICD) shows promise for select patients at risk of sudden cardiac death. However, patients need to pass an electrocardiographic (ECG) screening (ECG-S) test before they can receive an SICD. Predictors of ECG-S failure in children are unclear.Objective: The purpose of this study was to identify the incidence and predictive factors for failure of ECG-S in children.Methods: Patients 18 years and younger with a preexisting ICD underwent ECG-S for SICD. ECG and demographic data were analyzed for factors predictive of failure.Results: Seventy-three patients (mean age 14.2 ± 3.3 years; range 5-18 years) with hypertrophic cardiomyopathy (n = 24, 33%), long QT syndrome (n =18, 25%), other inherited arrhythmia syndromes (n = 20, 27%), congenital heart disease (n = 9, 12%), and miscellaneous conditions (n = 2) with an existing transvenous ICD underwent prospective ECG-S. Nineteen (26%) failed ECG-S. Failed patients had a longer corrected QT (QTc) interval (457 ms vs 425 ms; P = .03), a longer QRS duration (120 ms vs 98 ms; P = .04), and a lower ratio of R-wave to T-wave amplitudes (R:T ratio) in lead aVF (4 vs 5; P = .001). Multivariable logistic regression identified QTc interval (odds ratio [OR] 4.31; P = .04), QRS duration (OR 4.93; P = .03), R:T ratio in lead aVF (OR 3.13; P = .08) as predictors of failure. A risk score with 1 point each for QTc interval >440 ms, QRS duration >120 ms, and R:T ratio <6.5 in lead aVF was associated with probability of failure of 15.4% (1 point), 47.4% (2 points), and 88.6% (3 points), respectively.Conclusion: ECG-S failure for SICD occurred in 26% of children, which is higher than the reported incidence in adults. Factors predicting ECG-S failure included longer QTc interval, longer QRS duration, and lower R:T ratio in lead aVF. [ABSTRACT FROM AUTHOR]

Background: The Senning and Mustard operations for dextro-transposition of the great arteries are associated with an increased risk for supraventricular tachycardia. Catheter ablation has been shown to be acutely successful for achieving rhythm control in this population, but the mechanisms of recurrence are ill-defined.Objective: We hypothesized that the type and degree of recurrence would vary by the surgical technique used.Methods: All consecutive catheter ablation procedures for dextro-transposition of the great arteries after the Mustard or Senning operation between 2004 and 2016 at a single center were reviewed. Tachycardia mechanisms were determined by complete 3-dimensional mapping in addition to a standard electrophysiological technique for all cases.Results: Twenty-eight patients underwent 38 procedures during the study period. The most common mechanism at the index procedure was intra-atrial reentrant tachycardia using the cavotricuspid isthmus. Over a median follow-up period of 1.6 years, 9 patients experienced recurrent tachycardia (32%), all of whom underwent repeat catheter ablation. Tachycardia recurrence was more common after the Senning vs the Mustard operation (6 of 10 [60%] vs 3 of 18 [17%]; P = .034). In addition, substrates for recurrence were different from those encountered at the index procedure in 10 of 13 tachycardias (77%), with the single most common location being the posterior anastomosis after the Senning operation. Complete control was ultimately achieved in 27 patients (96%) when considering all procedures.Conclusion: Recurrent tachycardia after catheter ablation appears to be more common after the Senning operation and to involve substrates unique to this repair. The posterior anastomosis is commonly implicated and should not be overlooked. [ABSTRACT FROM AUTHOR]

A broad suite of 87 contaminants of emerging concern (CECs), including 26 polybrominated diphenyl ethers (PBDEs), 23 non-PBDEs halogenated FRs (NPHFRs), 16 organophosphate esters (OPEs), 4 perfluorinated sulfonates (PFSAs), 13 perfluorinated carboxylic acids (PFCAs) and 5 emerging perfluoroalkyl acids (PFAAs) or precursors, were determined in 30 individual Caspian tern (listed as a threatened species in the U.S. State of Michigan) eggs collected in 2013 and 2014 from Michigan nesting sites on Two Tree Island (St, Mary's River), Charity Reef (Saginaw Bay) and Channel-Shelter Island (a Confined Disposal Facility (CDF) in Saginaw Bay). The same CEC suite was determined in 10 herring gull eggs on the Pipe Island Twins in the lower St. Mary's River. In tern eggs, the order of concentrations were ΣPFSA (mean: 793 ng/g wet weight (ww); range: 116–4690 ng/g ww) > ΣPFCAs (131; 30.4–506 ng/g ww) ≈ ΣPBDEs (86.7; 32.4–189 ng/g ww) » ΣNPHFRs (0.67; ND-4.3 ng/g ww) ≈ ΣOPEs (0.46; ND-2.89 ng/g ww). Compared to gull eggs collected from the same area, tern egg exposure contained significantly lower concentrations of ΣPBDE, but with up to 10 times greater mean concentrations of ΣPFSAs and ΣPFCAs. This study highlights the importance of consistent monitoring in eggs of different Great Lakes birds of PBDEs, perfluorooctane sulfonate (PFOS) and perfluoro-4-ethylcyclohexane sulfonate (PFEtCHxS) given that: 1) PBDE concentrations in all analyzed avian eggs exceeded or approached a concentration of 29 ng/g ww, which for birds is the current Canadian FEQG (Federal Environmental Quality Guideline); 2) ΣPBDE concentrations were comparable to lowest observed effect concentration (LOEC) values reported in the literature; 3) PFOS concentrations in Caspian tern eggs were extremely high with many eggs across sites exceeding 1 ppm, and with the greatest being up to 4.7 ppm; and 4) PFEtCHxS, a potentially persistent and bioaccumulative substance, showed a detection frequency of 100% in 40 of the analyzed eggs. [ABSTRACT FROM AUTHOR]

Background: Extracardiac total cavopulmonary connection (E-TCPC) is widely performed for single ventricle palliation, yet there is little experience with catheter ablation in this population.Objectives: We hypothesized that atrial tachycardia substrates after primary E-TCPC would be similar to those in other forms of congenital heart disease and that catheter ablation could be performed effectively using a primarily transconduit approach.Methods: Catheter ablation characteristics of patients with E-TCPC from 9 centers were collected. Acute procedural success was defined as elimination of all sustained supraventricular tachyarrhythmias. Procedural complications, acute success, and recurrences were assessed.Results: Forty-six catheter ablation procedures were performed in 36 patients. Access to the atrium was by transconduit puncture in 29 procedures (63%). The most common supraventricular tachyarrhythmia mechanism was intra-atrial reentrant tachycardia (IART) in 21 patients (58%); and for all patients with primary E-TCPC and IART, an isthmus between the atrioventricular valve annulus and the oversewn inferior vena cava was critical for maintenance of tachycardia. Overall, acute success was achieved in 38 procedures (83%). There were 8 complications, with only 1 requiring intervention (epicardial pacemaker) and none related to conduit puncture. Recurrence after the final procedure occurred in 6 patients (17%) over a median follow-up duration of 0.4 years (interquartile range 0.1-1.5 years).Conclusion: Catheter ablation could be performed effectively in this group of patients with E-TCPC, and the underlying IART substrate after primary E-TCPC appears to be reproducible. Catheter ablation may be a reasonable alternative to long-term antiarrhythmic therapy in this patient group. [ABSTRACT FROM AUTHOR]

Background Tachycardia arising from the pulmonary venous atrium (PVA) has not been adequately characterized in the setting of surgically repaired congenital heart disease (CHD). Objective The purpose of this study was to determine the mechanisms, approach, and outcomes of catheter ablation of PVA tachycardia after CHD repair. Methods The adult CHD procedural database was searched for consecutive ablation procedures over a 4-year period. Procedural characteristics of the population with tachycardia arising from the PVA were compared to those without PVA tachycardia. Groups were classified as (1) biventricular CHD, (2) single ventricle, or (3) d -transposition of the great arteries (DTGA)-baffle. Results Complete 3-dimensional mapping was possible for 113 of 124 sustained tachycardias during 81 procedures. Of these, 31 (19%) arose from the PVA, including 11 (15%) tachycardias in biventricular CHD, 8 (31%) in single ventricle, and 12 (80%) in DTGA-baffle procedures. Intra-atrial reentrant tachycardia was less frequently observed in the PVA vs the systemic venous atrium (SVA) ( P = .012). Independent predictors of PVA tachycardia were absence of biventricular CHD (odds ratio 0.19, confidence interval 0.05–0.64, P = .010) and ipsilateral atrial surgery (odds ratio 15.7, confidence interval 4.8–59.9, P <.001). PVA procedure duration was greater than SVA-only procedures (median 5.3 hours vs 4.0 hours, P = .012), but acute success was similar (87% vs 82%, respectively, P = NS). Conclusion PVA tachycardia is not unusual after surgical repair of CHD. Predictors include ipsilateral atrial surgery and absence of biventricular CHD. Such procedures involve increased complexity and unique tachycardia substrates but appear equally amenable to catheter ablation. [ABSTRACT FROM AUTHOR]

Background: Tachycardia-induced cardiomyopathy (TIC) carries significant risk of morbidity and mortality, although full recovery is possible. Little is known about the myocardial recovery pattern. Objective: The purpose of this study was to determine the time course and predictors of myocardial recovery in pediatric TIC. Methods: An international multicenter study of pediatric TIC was conducted. Children ≤18 years with incessant tachyarrhythmia, cardiac dysfunction (left ventricular ejection fraction [LVEF] <50%), and left ventricular (LV) dilation (left ventricular end-diastolic dimension [LVEDD] z-score ≥2) were included. Children with congenital heart disease or suspected primary cardiomyopathy were excluded. Primary end-points were time to LV systolic functional recovery (LVEF ≥55%) and normal LV size (LVEDD z-score <2). Results: Eighty-one children from 17 centers met inclusion criteria: median age 4.0 years (range 0.0–17.5 years) and baseline LVEF 28% (interquartile range 19–39). The most common arrhythmias were ectopic atrial tachycardia (59%), permanent junctional reciprocating tachycardia (23%), and ventricular tachycardia (7%). Thirteen required extracorporeal membrane oxygenation (n = 11) or ventricular assist device (n = 2) support. Median time to recovery was 51 days for LVEF and 71 days for LVEDD. Two (4%) underwent heart transplantation, and 1 died (1%). Multivariate predictors of LV systolic functional recovery were age (hazard ratio [HR] 0.61, P = .040), standardized tachycardia rate (HR 1.16, P = .015), mechanical circulatory support (HR 2.61, P = .044), and LVEF (HR 1.33 per 10% increase, p=0.005). For normalization of LV size, only baseline LVEDD (HR 0.86, P = .008) was predictive. Conclusion: Pediatric TIC resolves in a predictable fashion. Factors associated with faster recovery include younger age, higher presenting heart rate, use of mechanical circulatory support, and higher LVEF, whereas only smaller baseline LV size predicts reverse remodeling. This knowledge may be useful for clinical evaluation and follow-up of affected children. [Copyright &y& Elsevier]

Heart donor candidates have severe neurologic injuries that have been associated with significant prolongation of the corrected QT (QTc) interval. Screening for an underlying abnormality of cardiac repolarization such as the long-QT syndrome thus becomes difficult. The aims of this study were to establish normal values and determine factors associated with prolongation of pre- and post-transplantation QTc intervals in a large cohort of heart transplantation donors and recipients. The medical records of 179 donors and 112 recipients were reviewed for historical, electrocardiographic, and neuroimaging data. After linear regression analysis, gunshot wounds were associated with the shortest mean pre-transplantation QTc interval of 447 ± 51 ms (p = 0.016), whereas all other mechanisms of brain injury were associated with markedly prolonged QTc intervals. Overall, the mean QTc interval decreased from 467 ± 58 to 446 ± 47 ms (p <0.001), the mean QRS duration increased from 87 ± 16 to 98 ± 21 ms (p <0.001), and the mean QT dispersion did not change significantly after transplantation. The only factor associated with a prolonged QTc interval in the post-transplantation period was hypokalemia, with a mean QTc of 468 ± 37 ms (p = 0.047). In conclusion, the mechanism of donor brain injury is associated with alterations in the pre-transplantation QTc interval, with the shortest intervals related to gunshot wounds. Fewer than 5% of the donor population was found to have QTc interval ≥580 ms. For those afflicted by gunshot wounds, <5% had QTc intervals ≥550 ms. This information can be used in pre-transplantation donor assessment, and post-transplantation management can be tailored to avoid the occurrence of ventricular arrhythmia. [Copyright &y& Elsevier]

COMPARABLE OUTCOMES FOR ADULT CONGENITAL HEART DISEASE. CRYO-BALLOON PULMONARY VEIN AND LEFT ATRIAL POSTERIOR WALL ISOLATION FOR THE TREATMENT OF ATRIAL FIBRILLATION. [Extracted from the article]

The molecular mechanisms underlying Fontan-associated liver disease (FALD) remain largely unknown. This study aimed to assess intrahepatic transcriptomic differences among patients with FALD according to the degree of liver fibrosis and clinical outcomes. This retrospective cohort study included adults with the Fontan circulation. Baseline clinical, laboratory, imaging, and hemodynamic data as well as a composite clinical outcome (CCO) were extracted from medical records. Patients were classified into early or advanced fibrosis. RNA was isolated from formalin-fixed paraffin-embedded liver biopsy samples; RNA libraries were constructed with the use of an rRNA depletion method and sequenced on an Illumina Novaseq 6000. Differential gene expression and gene ontology analyses were performed with the use of DESeq2 and Metascape. A total of 106 patients (48% male, median age 31 years [IQR: 11.3 years]) were included. Those with advanced fibrosis had higher B-type natriuretic peptide levels and Fontan, mean pulmonary artery, and capillary wedge pressures. The CCO was present in 23 patients (22%) and was not predicted by advanced liver fibrosis, right ventricular morphology, presence of aortopulmonary collaterals, or Fontan pressures on multivariable analysis. Samples with advanced fibrosis had 228 upregulated genes compared with early fibrosis. Samples with the CCO had 894 upregulated genes compared with those without the CCO. A total of 136 upregulated genes were identified in both comparisons and were enriched in cellular response to cytokine stimulus or oxidative stress, VEGFA-VEGFR2 signaling pathway, TGF-β signaling pathway, and vasculature development. Patients with FALD and advanced fibrosis or the CCO exhibited upregulated genes related to inflammation, congestion, and angiogenesis. [Display omitted] [ABSTRACT FROM AUTHOR]

Background: Palliation of the single ventricle (SV) circulation is associated with a burden of lifelong complications. Previous studies have identified that the need for a permanent ventricular pacing system (PPMv) may be associated with additional adverse long-term outcomes.Objectives: The goal of this study was to quantify the attributable risk of PPMv in patients with SV, and to identify modifiable risk factors.Methods: This international study was sponsored by the Pediatric and Congenital Electrophysiology Society. Centers contributed baseline and longitudinal data for functionally SV patients with PPMv. Enrollment was at implantation. Controls were matched 1:1 to PPMv subjects by ventricular morphology and sex, identified within center, and enrolled at matched age. Primary outcome was transplantation or death.Results: In total, 236 PPMv subjects and 213 matched controls were identified (22 centers, 9 countries). Median age at enrollment was 5.3 years (quartiles: 1.5-13.2 years), follow-up 6.9 years (3.4-11.6 years). Median percent ventricular pacing (Vp) was 90.8% (25th-75th percentile: 4.3%-100%) in the PPMv cohort. Across 213 matched pairs, multivariable HR for death/transplant associated with PPMv was 3.8 (95% CI 1.9-7.6; P < 0.001). Within the PPMv population, higher Vp (HR: 1.009 per %; P = 0.009), higher QRS z-score (HR: 1.19; P = 0.009) and nonapical lead position (HR: 2.17; P = 0.042) were all associated with death/transplantation.Conclusions: PPMv in patients with SV is associated with increased risk of heart transplantation and death, despite controlling for increased associated morbidity of the PPMv cohort. Increased Vp, higher QRS z-score, and nonapical ventricular lead position are all associated with higher risk of adverse outcome and may be modifiable risk factors. [ABSTRACT FROM AUTHOR]

Long-term outcomes of cardiac implantable electronic devices (CIEDs) are ill-defined in adult congenital heart disease (ACHD). To assess outcomes of transvenous (TV) and epicardial (EPI) CIEDs in ACHD. A retrospective review of CIEDs implanted in patients >18 yrs. followed at the Ahmanson/UCLA ACHD Center was performed. Patients were grouped by implant approach. Primary outcomes included time to CIED dysfunction, lead dysfunction and unplanned CIED reintervention. Over a 27-year period, 283 CIEDs (208 TV, 75 EPI) were implanted in 260 ACHD patients. Dysfunction developed in 77 CIEDs (50 TV, 27 EPI) for which 62 underwent unplanned reintervention (47 TV, 15 EPI). Time to CIED dysfunction and unplanned reintervention did not differ by implant approach; however lead dysfunction was greater for EPI vs TV (HR 2.0, 95% CI 1.2–3.2, p = 0.01). Independent predictors of lead failure included cyanosis (HR 2.6, 95% CI 1.1–6.3; p = 0.03), implant indication other than bradycardia (HR 3.3, 95% CI 1.6–6.5; p < 0.01), right-sided Maze operation (HR 2.5, 95% CI 1.3–5.0; p = 0.01), and unipolar lead design (HR 4.5, 95% CI 1.8–11.5; p < 0.01). Importantly, EPI vs TV approach was not associated with lead dysfunction after adjusting for baseline covariates (HR 0.6, 95% CI 0.6–4.3; p = 0.3). Overall CIED system dysfunction and reinterventions are similar, whereas lead dysfunction is greater among EPI than TV devices. Patient and procedural differences, rather than EPI vs TV implant approach alone, appear to drive CIED lead outcomes in the ACHD population. • Transvenous and epicardial cCIEDs demonstrate similar rates of dysfunction and reintervention in ACHD. • Lead failure is more common for epicardial versus transvenous CIEDs, but similar when considering baseline factors. • Lead failure in adult congenital heart disease may be preventable and better anticipated during post-procedure surveillance. [ABSTRACT FROM AUTHOR]