Arrhythmic risk in paediatric patients undergoing surgical repair for pulmonary atresia with intact ventricular septum

Introduction: While previous studies only focused on the arrhythmic risk associated with specific correction stra-tegies, this study evaluates this risk in a large cohort of paediatric patients with all phenotypes of PA-IVS after surgical repair. Methods: In this single centre observational cohort study, we retrospectively evaluated 165 patients with a diagnosis of PA-IVS and we excluded those with an exclusively percutaneous treatment, patients lost or with insufficient follow-up and those affected by other arrhythmic syndromes. Surgical history and clinical outcomes were reviewed. Results: 86 patients were included in the study (54 male [62.8%], mean age 16.4 ± 6.1 years), with median follow-up from definitive repair of 12.8 years (6.4–18.9 years). They underwent three different final repairs: 23 patients (26.7%) univentricular palliation, 43 (50%) biventricular correction, and 20 (23.3%) one and a half ventricle correction. Thirteen patients (15%) developed arrhythmia: 6 patients (all the subgroups) sinus node disfunction (SND); 2 (biventricular repair) premature ventricular complexes; 2 (one and a half ventricle repair) non-sustained ventricular tachycardia; 1 (biventricular repair) intra-atrial re-entrant tachycardia; 1 (one and a half ventricle repair) supraventricular tachyarrhythmia; 1 (biventricular repair) atrial fibrillation. Three patients with SND needed a pacemaker implantation. Only Fontan circulation showed an association with SND, while the other two groups heterogeneous types of arrhythmias. Conclusions: The low arrhythmic risk is related to surgical repair, it does not appear to be associated with native cardiomyopathy, and it appears to increase with length of follow up. Continuous follow-up in specialized centres is necessary to make an early diagnosis and to manage the potential haemodynamic impact at medium-long term.