Serial assessment of accessory pathway antegrade conduction in children.

There is limited longitudinal data on accessory pathway (AP) antegrade conduction throughout childhood, with implications for risk stratification. Ten patients underwent serial electrophysiology study (EPS) with assessment of fastest 1:1 AP conduction. The median age at first and follow-up EPS was 0 (median 4 days) and 53 months. Median fastest 1:1 AP conduction was 255 ms at initial EPS and 275 ms at follow-up (P=0.24). The interval of time between studies had no influence on stability over time, nor was there any appreciable effect following changes in retrograde AP conduction. In conclusion, no patient displayed any marked shortening of 1:1 AP conduction over time.