修正大血管転位症

BACKGROUND: Twin atrioventricular nodes (AVNs) occasionally occur in congenitally corrected transposition of the great arteries (ccTGA). CASE SUMMARY: A 14-year-old adolescent girl with ccTGA died suddenly after cardiopulmonary arrest. The electrocardiogram showed QRS widening from age 6. At autopsy, a Rastelli conduit and a fibrotic scar from ventricular septal defect patch closure were present. Serial sections revealed isolated anterior and posterior AVNs. The posterior AVN continued into an elongated His bundle that was disrupted by fibrosis, whereas the anterior AVN was interrupted by fibrofatty tissue. DISCUSSION: QRS widening was likely caused by interruption of the elongated His bundle. Although posterior-dominant AVN is uncommon, it should be considered when planning surgery for ccTGA. TAKE-HOME MESSAGE: A posterior-dominant AVN is uncommon; however, it should be considered when planning surgery for ccTGA with usual atrial arrangement.

We report a case in which a new synthetic hybrid patch inducing autologous tissue ingrowth was used to replace the obstructed Senning atrial baffle in a double switch operation for congenitally corrected transposition of the great arteries. However, recurrent baffle obstruction developed after 10 months postoperatively and was removed. Histology of the excised specimen showed promising tissue ingrowth but cautionary peripheral folding of the patch in this clinically challenging condition.

AIM: The aim of this study was to highlight the hypothesis that embryological development and morphological aspects necessitate a comprehensive analysis of all situses and a detailed description of each anomaly, rather than attempting to force the malformation into the rigid categories of heterotaxy syndrome (HS) - left or right isomerism. This hypothesis is supported by describing the anatomy of a complex patient with multiple laterality defects resulting in multiple cardiac and organ malformations. CASE PRESENTATION: The unique aspect of the presented patient's morphological diagnosis lies in the presence of a leftward heart loop with an unusual shape and direction, with the right ventricle (RV) positioned posterosuperior to the left ventricle (LV). This configuration suggests congenitally corrected transposition of the great arteries, although it deviates from the typical presentation. Additionally, there is an arrest in the development of other embryonic structures, including an atrioventricular septal defect (AVSD) with asymmetric ventricles, hypoplasia of the left-sided morphological RV, and malposition of the great arteries, with the aorta positioned anteriorly and to the right of the stenotic pulmonary artery. There is also another important inconsistency: the atrial situs is solitus within the context of HS, accompanied by left bronchial isomerism, polysplenia, interrupted inferior vena cava, and bilateral superior vena cavae. CONCLUSIONS: In our patient's case, the segmental analysis revealed a rare morphological cardiac anatomy. Understanding both normal and pathological embryological cardiac development, and correlating it with the current morphological anatomy, was crucial in ensuring the correct diagnosis and treatment for our patient.

Left bundle branch area pacing (LBBAP) has emerged as a promising alternative to right ventricular apical pacing in patients with congenital heart disease (CHD), yet its application in this population remains underexplored despite unique anatomical and physiological challenges. This review synthesizes current evidence on LBBAP in CHD, including anatomical considerations of the conduction system, lead selection between lumenless and stylet-driven leads, technical modifications for different substrates, and clinical outcomes. In congenitally corrected transposition of the great arteries (CCTGA), the paradoxically anterior conduction system creates favorable anatomy for LBBAP, with reported success rates of 86%-100% in small observational series. CHD-specific data from Moore et al. demonstrated superior QRS narrowing with conduction system pacing (CSP) compared to conventional CRT (35 vs. 14 ms; p = 0.04). One randomized trial and multiple meta-analyses comparing lumenless and stylet-driven leads demonstrate comparable success rates but distinct safety profiles, with implications for lead choice in CHD patients requiring lifelong pacing. The 2023 HRS/APHRS/LAHRS and 2025 ACC/AHA guidelines now recognize CSP as a therapeutic option in selected patients, though these endorsements are not specific to LBBAP in CHD. CHD-specific evidence remains limited to case series and small observational studies. This review provides a practical framework for patient selection, lead choice, and procedural planning while identifying key research priorities for this growing patient population.

BACKGROUND: Anatomic repair (AR) of congenitally corrected transposition of the great arteries (ccTGA) restores the morphologic right and left ventricles to their natural positions (subpulmonary and subsystemic, respectively). AR consists of a combined atrial switch and either an arterial switch or a Rastelli operation and is associated with unknown atrial arrthymia risk. Arrhythmia burden is presumed high, based on significant atrial arrhythmia burden for d-transposition of the great arteries after atrial switch operation, but published arrhythmia data specifically for anatomically repaired ccTGA patients are limited. OBJECTIVES: This study sought to assess the incidence and burden of mid- and long-term atrial arrhythmia associated with AR and to determine which anatomic, preoperative, operative, and postoperative characteristics were associated with increased risk and burden of atrial arrhythmias. METHODS: A retrospective cohort study of patients who underwent AR for ccTGA between 1993 and 2017 at a single center was conducted. RESULTS: During a median follow-up of 10.6 years, 28% (24/85) of the cohort experienced at least one significant atrial tachyarrhythmia (AT) at a median onset time of 9.0 years after AR. The need for atrioventricular valve reintervention increased long-term risk of AT (HR: 4.4; 95% CI: 1.4-13.8; P = 0.01). The majority of patients who experienced AT had a low disease burden. CONCLUSIONS: Patients who underwent AR are at significant risk for developing AT, even within a short timeframe after the index surgery, with increasing incidence over time. The need for atrioventricular valve reintervention after AR increases the risk of AT.