Small patients, significant findings: electropathology of Bachmann Bundle in pediatric patients

Background Bachmann's Bundle (BB) may potentially play a role in the earlier onset and faster progression of atrial fibrillation (AF) in adult congenital heart disease (CHD) patients. It is unknown whether electropathology already exists at BB in pediatric CHD patients and whether it is related to aging. Objective To investigate BB electrophysiology in pediatric CHD patients and assess the impact of age on BB electropathology. Methods BB mapping was conducted in 55 patients (0.2-17.5years). Activation patterns, potential voltages, low-voltage areas (LVAs), potential morphology, and conduction disorders of BB were analyzed and correlated with age. Results Right-to-left activation across BB occurred in 96.4% patients. Potential voltage was on average 7.2±3.0 mV and LVAs occurred in 85.4% patients. Median local conduction velocity (CV) was 96.6 (72.9-121.0) cm/s and conduction block (CB) occurred in 56.4% patients. Most potentials were single and short-double potentials; long-double and fractionated potentials were recorded in respectively 49.1% and 72.7% patients. Age was weakly correlated with potential voltages (r=0.312, p=0.020) and moderately with local CV (r=0.439, p<0.001), but not with potential morphology or CB. Conclusions Conduction disorders, LVAs, long double potentials and fractionated potentials are present at BB in pediatric CHD patients, independent of age. Electropathology at BB early in life may contribute to increased AF susceptibility.