From Minor Monitoring to Major Insight: Predicting AF Development in the Congenital Heart Disease Population

Background: The prognostic value of electrocardiography (ECG)- and continuous rhythm monitoring (CRM)-derived markers for predicting atrial fibrillation (AF) onset and progression remains unclear in patients with congenital heart disease (CHD). Methods: We retrospectively analyzed 573 CHD patients who underwent 24 h Holter monitoring between 2003 and 2015. Baseline ECG and CRM parameters were assessed. Cox regression identified predictors of new-onset AF and AF progression, and interaction analyses explored effect modification by left atrial (LA) dilatation. Results: During 13 ± 5 years of follow-up, AF occurred in 107 patients (18.7%), of whom 32 (29.9%) progressed to persistent/permanent AF (PeAF). Patients with AF more frequently had prolonged PR and QTc intervals and higher atrial ectopy (AE) and ventricular ectopy burdens. Independent predictors of new-onset AF were older age, LA dilatation, higher AE burden, atrial tachycardia, and pacemaker implantation. AF progression was independently associated with older age, LA dilatation, higher AE burden, and prolonged PR interval. AE burden showed a stronger association with AF risk in patients without LA dilatation. Conclusions: In CHD patients, baseline ECG PR-intervals and CRM-derived AE burden independently predict AF onset and/or progression. These noninvasive markers may improve risk stratification and support earlier personalized rhythm management.