Search

Objectives: Although conduction location can reliably be predicted in double inlet ventricle (DIV), ventricular septation continues to carry a significant risk of CHB. This study describes our experience with ventricular septation and intraoperative conduction mapping., Methods: Patients undergoing ventricular septation from 2017-2023 were identified. Conduction mapping was performed on the open, decompressed, beating heart to identify the His bundle. Mapped His bundle locations were compared to those predicted from MRI diagnoses by a senior pediatric cardiac electrophysiologist blinded to mapping results., Results: Ventricular septation was performed in 31 patients, 25 with hypoplastic RV and 6 with hypoplastic LV. Two-stage septation was performed in 25 patients and single-stage septation in 6. Mapped was performed in the last 25 consecutive patients. Mapped conduction location was concordant with expected location in 21/22 patients with predictions. CHB requiring a permanent pacemaker occurred in 4 patients despite successful mapping, while 10 patients required other reoperations, most commonly to address residual AV valve regurgitation or subpulmonary obstruction from the VSD patch. There has been no perioperative mortality, need for single-ventricle palliation or heart transplantation. All 13 patients who have progressed to complete septation and 18 patients with interstage circulation have acceptable hemodynamics, preserved ventricular function, and no heart failure symptoms at latest follow-up., Conclusions: Ventricular septation represents an alternative to Fontan that can be performed safely in a subset of patients with acceptable early outcomes. Conduction mapping is an adjunct strategy that may add precision to the well-established rules for reliably predicting conduction location., (Copyright © 2024. Published by Elsevier Inc.)

Background: Postoperative arrhythmias are most often transient and medically treated, but some patients may require electrophysiology study (EPS) and ablation., Objective: The purpose of this study was to describe the efficacy and safety of early postoperative ablation., Methods: This study presents a retrospective series of patients who underwent EPS within 12 months of surgery for congenital heart disease between 2000 and 2021. The procedural outcome included complete or partial success, empirical ablation or failure, and complications. The long-term outcome included arrhythmia recurrence and burden according to a 12-point clinical arrhythmia severity score (documented arrhythmia, arrhythmia severity, cardioversion, and antiarrhythmic medication)., Results: Among 28,902 operations during the study period, 24 patients (0.1%) underwent EPS within 3 months of surgery and 26 (0.1%) 3-12 months after surgery. Most patients had great (n = 27 [50%]) or moderate (n = 21 [42%]) congenital heart disease complexity. Mechanisms of arrhythmias included intra-atrial reentrant tachycardia (n = 23 [46%]), ectopic atrial tachycardia (n = 13 [26%]), accessory pathway (n = 6 [12%]), atrioventricular nodal reentrant tachycardia (n = 7 [14%]), twin atrioventricular node (n = 1 [2%]), atrial fibrillation (n = 1 [2%]), junctional ectopic tachycardia (n = 1 [2%]), and ventricular tachycardia (n = 2 [4%]). The procedure was acutely successful in 41 patients (82%), empirical in 5 (10%), and unsuccessful in 4 (8%). Complications occurred in 4 (8%) patients (major in 1, moderate in 1, and minor in 2). The recurrence of arrhythmia was documented in 27 patients (54%), although the burden of arrhythmia was significantly reduced., Conclusion: A minority of patients require early postoperative EPS and ablation. For those, the procedure can be performed with reasonable acute success and manageable morbidity even in critically ill patients with complex surgical anatomy., Competing Interests: Disclosures The authors have no conflicts of interest to disclose., (Copyright © 2024 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Objective: The need for permanent pacemaker (PPM) for iatrogenic atrioventricular block (AVB) after congenital heart surgery is approximately 1%. We aimed to evaluate the long-term outcomes of patients with PPM for iatrogenic AVB and compare them with patients with an optimal repair (trivial/no residual) Residual Lesion Score (RLS) Class 1 repair without PPM need., Methods: We reviewed 183 patients discharged with PPM for iatrogenic AVB from 2011 to 2022. Patients who survived to discharge with >30 days of follow-up were matched 1:1 with a cohort of patients categorized as RLS Class 1 on the basis of fundamental diagnosis and primary procedure., Results: Median age at PPM placement was 1.4 years (interquartile range, 4.3 months to 3.9 years). The cumulative incidence of moderate or greater ventricular dysfunction at 1 year and 5 years was 11% and 18% in patients with PPM, respectively, compared with 3% and 7% in patients categorized as RLS Class 1 (subdistribution hazard ratio, 2.6; 95% confidence interval, 1.2-6.1; P = .022). Independently, patients with PPM with hypoplastic left heart syndrome (P = .027) and who had undergone Society of Thoracic Surgeons-European Association for Cardio-Thoracic Surgery Mortality Category 5 procedures (P = .033) were at greater risk of ventricular dysfunction. Transplant-free survival at 1 year and 5 years was 94% and 89% in patients with PPM, respectively, compared with 98% and 97% in patients categorized as RLS Class 1 (P = .044). In addition, patients with PPM with palliated circulation had significantly lower transplant-free survival (P < .001)., Conclusions: Compared with patients with an optimal repair without PPM, patients with PPM for iatrogenic AVB are at greater risk of developing moderate or greater ventricular dysfunction and have lower transplant-free survival., Competing Interests: Conflict of Interest Statement The authors reported no conflicts of interest. The Journal policy requires editors and reviewers to disclose conflicts of interest and to decline handling or reviewing manuscripts for which they may have a conflict of interest. The editors and reviewers of this article have no conflicts of interest., (Copyright © 2024 The American Association for Thoracic Surgery. All rights reserved.)

Background: Catheter-based slow pathway modification (SPM) for atrioventricular nodal reentrant tachycardia (AVNRT) is traditionally performed at empiric sites using anatomical landmarks and test ablation feedback within the triangle of Koch (TK). While studies have described more tailored techniques such as bipolar low voltage bridge (LVB) and wavefront collision identification, few have systematically compared the diagnostic yields of each and none have investigated whether omnipolar mapping technology provides incremental benefit. The objective of this study was to compare the utility of omnipolar and bipolar-derived qualitative and quantitative measurements in identifying and localizing dual AVN substrate in patients with versus without AVNRT., Methods: A retrospective case-control study of consecutive patients with paroxysmal supraventricular tachycardia undergoing electrophysiology study with both omnipolar and bipolar mapping from 2022-2023., Results: Thirteen AVNRT cases (median age 16.1 years, 512 TK points) were compared to nine non-AVNRT controls (median age 15.7 years, 332 TK points). Among qualitative variables, an omnipolar activation vector pivot, defined as a ≥45 degree change in activation direction within the TK, had the highest positive (81%) and negative predictive values (100%) for identifying AVNRT cases and had a median distance of 1 mm from SPM sites. Among quantitative variables, the optimal discriminatory performance for successful SPM sites was observed using bipolar voltage restricted to a peak frequency >340 Hz (c statistic 0.75)., Conclusions: Omnipolar vector pivot analysis represents an automated, annotation-independent qualitative technique that is sensitive and specific for AVNRT substrate and co-localizes with successful SPM sites. Bipolar voltage quantitatively describes SP anisotropy better than omnipolar voltage, and the addition of peak frequency signal analysis further optimizes the selection of SPM sites., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Competing Interests: Conflict of interest: none declared.