Beyond Symptoms: Rhythm Surveillance in Congenital Heart Disease

BackgroundPatients with congenital heart disease (CHD) face a lifelong risk of arrhythmias, many of which remain asymptomatic and undetected. ObjectiveTo evaluate the diagnostic yield of different rhythm surveillance strategies, assess symptom-arrhythmia correlation, and determine the clinical value of arrhythmia screening in patients with CHD. MethodsWe retrospectively analyzed 552 CHD patients (66.1% female; median age 34 years) who underwent 7-day patch rhythm monitoring at a tertiary center between December 2022 and January 2025.Patients were grouped as symptomatic or asymptomatic (screening).The patch device also functioned as an event recorder, with the first 24 hours analyzed as standard Holter monitoring. ResultsThe symptomatic group consisted of 349 patients, and the screening group consisted of 203 patients.Any arrhythmias were detected in 64.8% of symptomatic J o u r n a l P r e -p r o o f and 68.5% of screening group (P = 0.410), with significant arrhythmias observed in 16.9% and 19.2%, respectively (P = 0.494).In total, the detection rate was highest with 7-day monitoring (66.1%) compared to Holter (46.9%) or event recorder (17.3%).Significant arrhythmia prevalence increased with CHD complexity and age, exceeding 15% in the fourth decades of life.Symptom-arrhythmia correlation was weak and reached statistical significance only in the asymptomatic group (P = 0.05).The treatment change rate was 9.4% with 7-day monitoring and was comparable between symptomatic and screening groups. ConclusionsArrhythmias in CHD are common, age-dependent, and poorly predicted by symptoms.Prolonged monitoring enhances detection and guides management, supporting risk-stratified surveillance based on age and disease complexity.