Fascicular Substrate Modification to Treat Human Ventricular Fibrillation.

BACKGROUND: Purkinje fibers play an important role in initiation and maintenance of ventricular fibrillation (VF) and polymorphic ventricular tachycardia (PMVT). Fascicular substrate modification (FSM) approaches have been suggested to treat recurrent VF in case reports and small case series. OBJECTIVES: The aim of this study was to investigate outcomes of catheter-based FSM to treat VF and PMVT. METHODS: Of 2,212 consecutive patients with ventricular arrhythmia undergoing catheter ablation, 18 (0.81%) underwent FSM of the Purkinje fibers as identified with high-density mapping during sinus rhythm. Fascicular substrate and VF initiation were mapped using a multipolar catheter. The endpoint of the ablation was noninducibility of VF and PMVT. In select patients, remapping revealed elimination of the targeted Purkinje potentials. Demographic, clinical, and follow-up characteristics were prospectively collected in our institutional database. RESULTS: A total of 18 patients (mean age 56 ± 3.8 years, 22% women) were included in the study. Of those, 11 (61.1%) had idiopathic VF, 3 (16.7%) had nonischemic cardiomyopathy, and 4 (22.2%) had mixed cardiomyopathy. The average left ventricular ejection fraction was 42.5%. At least 2 antiarrhythmic drugs had failed preablation. At baseline, all patients had inducible VF or PMVT. At the end of the procedure, no patient demonstrated new evidence of fascicular block or bundle branch block. There were no procedure-related complications. After a median follow-up period of 24 months, 16 patients (88.9%) were arrhythmia free on or off drugs: 11 of 11 patients (100%) with idiopathic VF vs 5 of 7 patients (71.4%) with underlying cardiomyopathy (P = 0.06). CONCLUSIONS: Catheter ablation of human VF and PMVT with FSM is feasible and safe and appears highly effective, with high rates of acute VF noninducibility and long-term freedom from recurrent VF.

Long-term measurement and characterization of boundary layer optical turbulence.

The United States Naval Academy long-term scintillation measurement campaign was a multi-year effort to characterize optical turbulence in the near-maritime atmospheric boundary layer (ABL). At its core, the field experiment consists of in situ measurements of bulk atmospheric and oceanographic parameters, as well as path-averaged measurements of the refractive index structure parameter, C n2, collected using a large-aperture scintillometer. The field experiment ran from January 1st, 2020, through September 26th, 2023, representing the most comprehensive collection of optical turbulence measurements in the near-maritime ABL to date. Long-term measurements enable researchers to evaluate existing theory and develop new models applicable to this environment. The present study characterizes some of the physical relationships that affect optical turbulence. This characterization focuses on the relationship between local optical turbulence and select atmospheric and oceanographic parameters. The impact of temperature gradients on the extent of optical turbulence was analyzed, along with its interactions with relative humidity and wind speed. The diurnal and seasonal variations in measured C n2 were examined, with comparisons drawn against other environments. Further information and the full dataset are publicly available through the optical turbulence benchmark repository [Jellen et al., GitHub, 2023].

Best anticoagulation strategy with and without appendage occlusion for stroke-prophylaxis in postablation atrial fibrillation patients with cardiac amyloidosis.

INTRODUCTION: Both atrial fibrillation (AF) and amyloidosis increase stroke risk. We evaluated the best anticoagulation strategy in AF patients with coexistent amyloidosis. METHODS: Consecutive AF patients with concomitant amyloidosis were divided into two groups based on the postablation stroke-prophylaxis approach; group 1: left atrial appendage occlusion (LAAO) in eligible patients and group 2: oral anticoagulation (OAC). Group 1 patients were further divided into Gr. 1A: LAAO + half-does NOAC (HD-NOAC) for 6 months followed by aspirin 81 mg/day and Gr. 1B: LAAO + HD-NOAC. In group 1 patients, with complete occlusion at the 45-day transesophageal echocardiogram, patients were switched to aspirin, 81 mg/day at 6 months. In case of leak, or dense "smoke" in the left atrium (LA) or enlarged LA, they were placed on long-term half-dose (HD) NOAC. Group 2 patients remained on full-dose NOAC during the whole study period. RESULTS: A total of 92 patients were included in the analysis; group 1: 56 and group 2: 36. After the 45-day TEE, 31 patients from group 1 remained on baby-aspirin and 25 on HD NOAC. At 1-year follow-up, four stroke, one TIA and six device-thrombus were reported in group 1A, compared to none in patients in group 1B (5/31 vs. 0/25, p = .03). No bleeding events were reported in group 1, whereas group 2 had five bleeding events (one subdural hematoma, one retinal hemorrhage, and four GI bleedings). Additionally, one stroke was reported in group 2 that happened during brief discontinuation of OAC. CONCLUSION: In patients with coexistent AF and amyloidosis, half-dose NOAC following LAAO was observed to be the safest stroke-prophylaxis strategy.

Identifying the prevalence and characteristics of diversity, equity, and inclusion leaders in academic emergency medicine.

Objectives: Our study aims to better understand and describe the current state of diversity, equity, and inclusion (DEI) leadership in emergency medicine (EM) by identifying the prevalence of department DEI leadership positions, their demographics, and their job duty characteristics. Methods: We disseminated an electronic survey from April to July 2022 to Society for Academic Emergency Medicine (SAEM) Association of Academic Chairs of Emergency Medicine, Academy for Diversity and Inclusion in Emergency Medicine, and the Equity and Inclusion Committee to identify department DEI leads. From July to August 2022, a 45-question survey was sent to all identified DEI leaders on individual characteristics, DEI experience, and DEI lead job description. Results: We received a response from 79 out of 120 academic EM departments identified (65.8%). Of the responding institutions, 59 (74.7%) reported a DEI leader. A total of 74.6% of these DEI leaders responded at least partially to our survey and 57.6% responded in full. The most common titles were vice/associate chair of DEI (34.4%), director of DEI (28.1%), and DEI committee chair (18.8%). Most respondents (84.4%) were the inaugural DEI lead in their department and 84.4% of respondents did not have a formal DEI role in their department previously. On average, respondents have had their DEI title for 2 years (range 0-7 years) with an average of 7 years (range 0-30 years) of experience performing DEI work. Many (63.4%) do not receive any funded effort for their DEI roles. Most DEI leads were not tenure track (72.2%) and most commonly at the rank of assistant professor (47.2%) followed by associate professor (33.3%), full professor (16.7%), and instructor (2.8%). Conclusions: This is the first known study to assess the characteristics of DEI department leaders in EM. EM DEI leadership positions are new, common, and led by diverse personal identities and are often not funded. Future directions could gain qualitative insight into this workforce to guide best practices in EM DEI leadership.

Bailout Deep Septal LV Pacing to Treat Inadvertent Complete AV Block During Complex Ablation Procedure.

We present a case of persistent complete atrioventricular block that occurred during the diagnostic portion of a premature ventricular contractions' radiofrequency ablation in a complex heart failure patient. The case was managed by bailout deep left ventricular septal pacing after bipolar radiofrequency elimination of premature ventricular contractions.

Understanding clerkship experiences in emergency medicine and their potential influence on specialty selection: A qualitative study.

Objectives: The specialty of emergency medicine (EM) is experiencing a significant decrease in student interest. In addition, women are historically underrepresented within the specialty at all levels of training and practice. We sought to understand how clinical experiences and perceptions of EM influence specialty selection by medical students, particularly women. Methods: Using a constructivist grounded theory approach, we analyzed semistructured interviews with senior medical students who considered EM as a specialty. We used purposive sampling to recruit from diverse learning environments and represent a variety of experiences. Participants reflected on their specialty selection process and experiences in EM including their perceived acceptance in the work environment. Results: Twenty-five medical students from 11 geographically diverse schools participated. A total of 68% (17/25) identified as women. The majority (21/25, 84%) planned on applying to EM residency. We identified four major themes: (1) distressing interpersonal interactions with patients and the ED care team negatively affect students; (2) EM culture includes behaviors that are perceived as exclusionary; (3) beliefs about the attributes of an ideal EM physician and the specialty itself have a gendered nature; and (4) ease of access to mentors, representation, and early exposure to EM environment increased interest in specialty. Conclusions: Our participants express that EM causes challenges for students to accept the norms of behavior in the field, which is an essential element in joining a group and professional identity formation. In addition, we raise concern that gendered perceptions and language may send exclusionary environmental cues that may negatively impact recruitment of a diverse physician workforce.

Acute Kidney Injury Resulting From Hemoglobinuria After Pulsed-Field Ablation in Atrial Fibrillation: Is it Preventable?

BACKGROUND: High-voltage pulses can cause hemolysis. OBJECTIVES: The authors evaluated the occurrence of hemoglobinuria after pulsed-field ablation (PFA) and its impact on renal function in patients with atrial fibrillation (AF). METHODS: A consecutive series of patients with AF undergoing PFA were included in this analysis. The initial patients who did not receive postablation hydration immediately after the procedure were classified as group 1 (n = 28), and the rest of the study patients who received planned fluid infusion (0.9% sodium chloride ≥2 L) after the procedure were categorized as group 2 (n = 75). RESULTS: Of the 28 patients in group 1, 21 (75%) experienced hemoglobinuria during the 24 hours after catheter ablation. The mean postablation serum creatinine (S-Cr) was significantly higher than the baseline value in those 21 patients (1.46 ± 0.28 mg/dL vs 0.86 ± 0.24 mg/dL, P < 0.001). Of those 21 patients, 4 (19%) had S-Cr. >2.5 mg/dL (mean: 2.95 ± 0.21 mg/dL). The mean number of PF applications was significantly higher in those 4 patients than in the other 17 patients experiencing hemoglobinuria (94.63 ± 3.20 vs 46.75 ± 9.10, P < 0.001). In group 2 patients, no significant changes in S-Cr were noted. The group 2 patients received significantly higher amounts of fluid infusion after catheter ablation than did those in group 1 (2,082.50 ± 258.08 mL vs 494.01 ± 71.65 mL, P < 0.001). In multivariable analysis, both hydration (R2 = 0.63, P < 0.01) and number of PFA applications (R2 = 0.33, P < 0.01) were independent predictors of postprocedure acute kidney injury. CONCLUSIONS: On the basis of our findings, both the number of PFA applications and postablation hydration were independent predictors of renal insult that could be prevented using planned fluid infusion immediately after the procedure.

Improving Graduate Medical Education by Aggregating Data Across the Medical Education Continuum.

ABSTRACT: Meaningful improvements to graduate medical education (GME) have been achieved in recent decades, yet many GME improvement pilots have been small trials without rigorous outcome measures and with limited generalizability. Thus, lack of access to large-scale data is a key barrier to generating empiric evidence to improve GME. In this article, the authors examine the potential of a national GME data infrastructure to improve GME, review the output of 2 national workshops on this topic, and propose a path toward achieving this goal.The authors envision a future where medical education is shaped by evidence from rigorous research powered by comprehensive, multi-institutional data. To achieve this goal, premedical education, undergraduate medical education, GME, and practicing physician data must be collected using a common data dictionary and standards and longitudinally linked using unique individual identifiers. The envisioned data infrastructure could provide a foundation for evidence-based decisions across all aspects of GME and help optimize the education of individual residents.Two workshops hosted by the National Academies of Sciences, Engineering, and Medicine Board on Health Care Services explored the prospect of better using GME data to improve education and its outcomes. There was broad consensus about the potential value of a longitudinal data infrastructure to improve GME. Significant obstacles were also noted.Suggested next steps outlined by the authors include producing a more complete inventory of data already being collected and managed by key medical education leadership organizations, pursuing a grass-roots data sharing pilot among GME-sponsoring institutions, and formulating the technical and governance frameworks needed to aggregate data across organizations.The power and potential of big data is evident across many disciplines, and the authors believe that harnessing the power of big data in GME is the best next step toward advancing evidence-based physician education.

Pulsed-Field Ablation Does Not Worsen Baseline Pulmonary Hypertension Following Prior Radiofrequency Ablations.

BACKGROUND: Studies have reported development of pulmonary hypertension (PH) secondary to reduced LA compliance following AF ablation. OBJECTIVES: This study aimed to compare the risk of worsening of baseline PH between non-paroxysmal AF patients undergoing pulsed-field ablation (PFA) and standard radiofrequency ablation (RFA). METHODS: This multicenter study included 28 nonparoxysmal AF patients with PH undergoing a PFA-based ablation procedure after >1 failed RFA. A cohort of 28 AF patients with PH, scheduled for repeat RFA, 1:1 propensity-score matched using a multivariable logistic model, were used as the comparator group. Right heart catheterization and echocardiography were performed before and after the procedure to assess the pulmonary artery pressure (PAP). PH was defined as resting mean PAP of >20 mm Hg. RESULTS: The baseline characteristics of the PFA and propensity-matched RFA groups were comparable. The mean PAP assessments at baseline, follow-up, and change from baseline were analyzed. The groups had comparable baseline mean pulmonary artery pressures (mPAP) (P = 0.177). After adjustment for baseline mPAP in an analysis of covariance model, the least-squares means change at 3 months after ablation was -1.71 ± 1.03 mm Hg and 19.67 ± 1.03 mm Hg in PFA and RFA, respectively (P <0.001). CONCLUSIONS: In this propensity-matched population, no worsening of mPAP was detected following pulsed-field ablation in patients with pre-existing PH undergoing a repeat procedure for recurrence.

Hybrid optical turbulence models using machine-learning and local measurements.

Accurate prediction of atmospheric optical turbulence in localized environments is essential for estimating the performance of free-space optical systems. Macro-meteorological models developed to predict turbulent effects in one environment may fail when applied in new environments. However, existing macro-meteorological models are expected to offer some predictive power. Building a new model from locally measured macro-meteorology and scintillometer readings can require significant time and resources, as well as a large number of observations. These challenges motivate the development of a machine-learning informed hybrid model framework. By combining a baseline macro-meteorological model with local observations, hybrid models were trained to improve upon the predictive power of each baseline model. Comparisons between the performance of the hybrid models, selected baseline macro-meteorological models, and machine-learning models trained only on local observations, highlight potential use cases for the hybrid model framework when local data are expensive to collect. Both the hybrid and data-only models were trained using the gradient boosted decision tree architecture with a variable number of in situ meteorological observations. The hybrid and data-only models were found to outperform three baseline macro-meteorological models, even for low numbers of observations, in some cases as little as one day. For the first baseline macro-meteorological model investigated, the hybrid model achieves an estimated 29% reduction in the mean absolute error using only one day-equivalent of observation, growing to 41% after only two days, and 68% after 180 days-equivalent training data. The data-only model generally showed similar, but slightly lower performance, as compared to the hybrid model. Notably, the hybrid model's performance advantage over the data-only model dropped below 2% near the 24 days-equivalent observation mark and trended towards 0% thereafter. The number of days-equivalent training data required by both the hybrid model and the data-only model is potentially indicative of the seasonal variation in the local microclimate and its propagation environment.

Catheter ablation approach and outcome in HIV+ patients with recurrent atrial fibrillation.

INTRODUCTION: Earlier studies have shown a clear association between severity of human immunodeficiency virus (HIV) infection and incident atrial fibrillation (AF). We present the long-term outcome of catheter ablation (CA) and electrophysiological characteristics in HIV+ AF patients. METHODS: This study evaluated 1438 consecutive AF patients [31 (2.15%) with HIV and 1407 (97.8%) without HIV diagnosis] undergoing their first CA at our center. A total of 31 HIV patients and 31 controls were generated by propensity matching, based on calculated risk factor scores, using a logistic model. During first procedure, all received isolation of pulmonary vein (PV) + posterior wall and superior vena cava. Non-PV triggers, defined as ectopic triggers originating from sites other than PVs, were identified at the redo ablation with high-dose isoproterenol challenge. RESULTS: Clinical characteristics were not different between the groups. When compared to the control, by the end of 5 years after the first procedure, recurrence was significantly greater in HIV group [100% vs. 54%, p < .001]. Among patients that underwent redo ablation non-PV triggers were higher in HIV group [93.5% vs. 54%, p < .001], and most frequently originated from the coronary sinus [67.7% vs. 45.2%, p < .001] and left atrial appendage [41.9% vs. 25.8%, p < .001]. After focal ablation of non-PV trigger, no difference in arrhythmia recurrence between two groups [80.6% vs. 87.1%, p = .753] at 1-year follow up was found. CONCLUSION: Our findings suggest that non-PV triggers are highly prevalent in HIV+ AF patients resulting in higher rate of the mid- and long-term arrhythmia recurrence.

Key Factors in Designing the Health System-Community Pathways Program for African American/Black Children and Young Adults.

Many of the ethnic and racial workforce inequities in the United States are present in health care systems. Low representation of African American/Black individuals in the health care system workforce can be traced to a history of exclusionary practices that leave such individuals less likely to pursue health careers. Past research found that low representation is driven by inequities in health, education, and employment that are a result of structural racism. Pathways programs have been identified as one of the methods to increase recruitment, retention, and promotion in health-related career fields for African American/Black individuals. As prior research has shown, these programs recruit and support the graduation of students from underrepresented communities at all educational stages to increase their representation in specific fields. This article describes the development of key factors in framework design for the Health System-Community Pathways Program (HCPP), which aims to increase representation of African American/Black communities in the health care system workforce and improve the quality of their experience in pursuing careers in these fields. The HCPP framework of key factors is informed by an environmental scan, interviews and focus groups, and an expert discussion panel session. The article's authors come from diverse backgrounds; the team included African American/Black physicians and members of other historically marginalized communities. The qualitative research drew insights from diverse African American/Black community stakeholders; the study was reviewed by many stakeholders to ensure that the design of the research and the end product maximally benefits the community on which it focuses.

Impact of Colchicine Monotherapy on the Risk of Acute Pericarditis Following Atrial Fibrillation Ablation.

BACKGROUND: Acute pericarditis is a known complication of ablation procedures for atrial fibrillation (AF). OBJECTIVES: This study aimed to evaluate the benefits of colchicine monotherapy in terms of reducing the risk of pericarditis and related hospitalization rate in AF patients undergoing catheter ablation. METHODS: Consecutive AF patients undergoing first catheter ablation were classified into 3 groups based on their colchicine use: Group 1: no colchicine; group 2: colchicine from 7 days before to 1 month after ablation; and group 3: colchicine from the day of the procedure to 1 month after. Standard institutional protocol was used to follow all patients for 1 year. RESULTS: A total of 1,075 patients were classified into groups 1 (n = 607), 2 (n = 213), and 3 (n = 255). Symptoms of acute pericarditis were reported in 129 patients (12%): group 1: n = 106 (17.5%); group 2: n = 4 (1.9%); and group 3: n = 19 (7.5%); P < 0.001. Rate of mild-moderate as well as severe pericarditis were significantly lower in group 2. In the multivariable regression analysis, pre- and post-ablation colchicine use was seen to be associated with significantly lower risk of acute pericarditis and related hospitalization compared with the other 2 groups. In addition, at 1-year follow-up, arrhythmia-free survival rate was significantly higher in paroxysmal AF patients receiving colchicine compared with the no-colchicine population. CONCLUSIONS: Colchicine therapy starting 7 days before to 1 month after the ablation procedure was associated with significantly lower risk of acute pericarditis and related hospitalization. In addition, paroxysmal AF patients receiving colchicine had a higher arrhythmia-free survival rate compared with those not receiving colchicine.

Best ablation strategy in patients with premature ventricular contractions with multiple morphology: a single-centre experience.

AIMS: This study aimed to examine the clinical benefits of targeted ablation of all Premature ventricular complex (PVC) morphologies vs. predominant PVC only. METHODS AND RESULTS: A total of 171 consecutive patients with reduced left ventricular ejection fraction (LVEF) and ≥2 PVC morphology with high burden (>10%/day) undergoing their first ablation procedure were included in the analysis. At the initial procedure, prevalent PVC alone was ablated in the majority. However, at the redo, all PVC morphologies were targeted for ablation. : At the first procedure, 152 (89%) patients received ablation of the dominant PVC only. In the remaining 19 (11%) patients, all PVC morphologies were ablated. At two years, high PVC burden was detected in 89 (52%) patients. Repeat procedure was performed in 78 of 89, where all PVC morphologies were ablated. At 5 years after the repeat procedure, 71 (91%) had PVC burden of <5% [3.8 ± 1.1% vs. 15.4 ± 4.3% in successful vs. failed subjects (P < 0.001)]. In patients with low PVC burden after the initial procedure, LVEF improved from 37.5% to 41.6% [mean difference (MD): 3.39 ± 2.9%, P < 0.001], whereas a reduction in LVEF from 39.8% to 34.5% (MD: 6.45 ± 4.7%, P < 0.001) was recorded in patients with high PVC burden. One year after the repeat procedure, LVEF improved from 36.2% to 41.7% (MD: 5.5 ± 4.3%, P < 0.001) in patients with successful ablation. CONCLUSION: In this observational series, ablation of all PVC morphologies was associated with significantly lower PVC burden and improvement of LVEF at long-term follow-up, compared with ablation of the dominant morphology only.

Implementation of the SIMPL (Society for Improving Medical Professional Learning) performance assessment tool in the emergency department: A pilot study.

Background: Feedback and assessment are difficult to provide in the emergency department (ED) setting despite their critical importance for competency-based education, and traditional end-of-shift evaluations (ESEs) alone may be inadequate. The SIMPL (Society for Improving Medical Professional Learning) mobile application has been successfully implemented and studied in the operative setting for surgical training programs as a point-of-care tool that incorporates three assessment scales in addition to dictated feedback. SIMPL may represent a viable tool for enhancing workplace-based feedback and assessment in emergency medicine (EM). Methods: We implemented SIMPL at a 4-year EM residency program during a pilot study from March to June 2021 for observable activities such as medical resuscitations and related procedures. Faculty and residents underwent formal rater training prior to launch and were asked to complete surveys regarding the SIMPL app's content, usability, and future directions at the end of the pilot. Results: A total of 36/58 (62%) of faculty completed at least one evaluation, for a total of 190 evaluations and an average of three evaluations per faculty. Faculty initiated 130/190 (68%) and residents initiated 60/190 (32%) evaluations. Ninety-one percent included dictated feedback. A total of 45/54 (83%) residents received at least one evaluation, with an average of 3.5 evaluations per resident. Residents generally agreed that SIMPL increased the quality of feedback received and that they valued dictated feedback. Residents generally did not value the numerical feedback provided from SIMPL. Relative to the residents, faculty overall responded more positively toward SIMPL. The pilot generated several suggestions to inform the optimization of the next version of SIMPL for EM training programs. Conclusions: The SIMPL app, originally developed for use in surgical training programs, can be implemented for use in EM residency programs, has positive support from faculty, and may provide important adjunct information beyond current ESEs.

Prevalence of atrial fibrillation and procedural outcome in patients undergoing catheter ablation for premature ventricular complexes.

INTRODUCTION: Atrial fibrillation (AF) and premature ventricular complexes (PVC) are common arrhythmias. We aimed to investigate AF prevalence in patients with PVC and its impact on PVC ablation outcomes. METHODS: Consecutive patients undergoing PVC ablation at a single institution between 2016 and 2019 were included and prospectively followed for 2 years. Patients with severe valvular heart disease, hyperthyroidism, malignancy, alcohol use disorder and advanced renal/hepatic diseases were excluded. Twelve-lead electrocardiograms were used to diagnose AF and assess PVC morphology. All PVCs were targeted for ablation using 4-mm irrigated-tip catheters at standardized radiofrequency power guided by 3-D mapping and intracardiac echocardiography. Patients were followed with remote monitoring, device interrogations and office visits every 6 months for 2 years. Detection of any PVCs in follow-up was considered as recurrence. RESULTS: A total of 394 patients underwent PVC ablation and 96 (24%) had concurrent AF. Patients with PVC and AF were significantly older (68.2 ± 10.8 vs. 58.3 ± 15.8 years, p < .001), had lower LV ejection fraction (43.3 ± 13.3% vs. 49.6 ± 12.4%, p < .001), higher CHA2 DS2 -VASc (2.8 ± 1.3 vs. 2.0 ± 1.3, p < .001) than those without. PVCs with ≥2 morphologies were detected in 60.4% and 13.7% patients with vs without AF (p < .001). At 2-year follow-up, PVC recurrence rate was significantly higher in patients with vs without AF (17.7% vs. 9.4%, p = .02). CONCLUSION: AF was documented in 1/4 of patients undergoing PVC ablation and was associated with lower procedural success at long-term follow-up. This was likely attributed to older age, worse LV function and higher prevalence of multiple PVC morphologies in patients with concurrent AF.

Catheter Ablation for Atrial Fibrillation in Adult Congenital Heart Disease: An International Multicenter Registry Study.

BACKGROUND: Data on atrial fibrillation (AF) ablation and outcomes are limited in patients with congenital heart disease (CHD). We aimed to investigate the characteristics of patients with CHD presenting for AF ablation and their outcomes. METHODS: A multicenter, retrospective analysis was performed of patients with CHD undergoing AF ablation between 2004 and 2020 at 13 participating centers. The severity of CHD was classified using 2014 Pediatric and Congenital Electrophysiology Society/Heart Rhythm Society guidelines. Clinical data were collected. One-year complete procedural success was defined as freedom from atrial tachycardia or AF in the absence of antiarrhythmic drugs or including previously failed antiarrhythmic drugs (partial success). RESULTS: Of 240 patients, 127 (53.4%) had persistent AF, 62.5% were male, and mean age was 55.2±13.3 years. CHD complexity categories included 147 (61.3%) simple, 68 (28.3%) intermediate, and 25 (10.4%) severe. The most common CHD type was atrial septal defect (n=78). More complex CHD conditions included transposition of the great arteries (n=14), anomalous pulmonary veins (n=13), tetralogy of Fallot (n=8), cor triatriatum (n=7), single ventricle physiology (n=2), among others. The majority (71.3%) of patients had trialed at least one antiarrhythmic drug. Forty-six patients (22.1%) had reduced systemic ventricular ejection fraction <50%, and mean left atrial diameter was 44.1±8.2 mm. Pulmonary vein isolation was performed in 227 patients (94.6%); additional ablation included left atrial linear ablations (40%), complex fractionated atrial electrogram (19.2%), and cavotricuspid isthmus ablation (40.8%). One-year complete and partial success rates were 45.0% and 20.5%, respectively, with no significant difference in the rate of complete success between complexity groups. Overall, 38 patients (15.8%) required more than one ablation procedure. There were 3 (1.3%) major and 13 (5.4%) minor procedural complications. CONCLUSIONS: AF ablation in CHD was safe and resulted in AF control in a majority of patients, regardless of complexity. Future work should address the most appropriate ablation targets in this challenging population.