Interatrial Conduction Block in Pediatric Patients with Ostium Secundum Atrial Septal Defect

Area of Science:

• Cardiology
• Pediatric Electrophysiology
• Congenital Heart Disease

Background:

• Atrial arrhythmias are common in patients with atrial septal defects (ASDs).
• Interatrial block (IAB) may predispose to atrial arrhythmias but its prevalence in pediatric ASD is unclear.
• This study investigates IAB in children with large ASD undergoing percutaneous closure.

Purpose of the Study:

• To characterize interatrial conduction patterns in pediatric patients with large ASD.
• To assess the prevalence and clinical correlates of IAB before and after percutaneous closure.
• To explore the relationship between IAB and anatomical/procedural factors.

Main Methods:

• Retrospective analysis of 37 pediatric patients with large ASD (median age 6 years).
• 12-lead ECGs analyzed pre- and post-percutaneous closure for P-wave parameters and IAB (Bayés de Luna criteria).
• Correlation analysis with defect size, hemodynamics, and anthropometric variables.

Main Results:

• IAB was present in 24.3% of patients pre-procedure, primarily first-degree IAB.
• IAB prevalence (29.7%) and P-wave parameters did not change significantly post-closure.
• IAB correlated with anthropometric variables but not with ASD size or hemodynamic burden.

Conclusions:

• Approximately one quarter of pediatric patients with large ASD exhibit IAB.
• IAB in this cohort appears unrelated to anatomical or procedural factors, suggesting a congenital origin.
• Early IAB detection may aid in long-term arrhythmic risk stratification for pediatric ASD patients.