Table 1.

Criteria for RBBP

(1) Pacing lead in the distal His bundle region

(2) Evidence of conduction system capture (transitions in QRS morphology or selective conduction system capture)

(3) Paced V6RWPT > potential to V6RWPT (Δ > 10 ms)

(4) Additional findings which may be present: (a) Potential—QRS onset interval < 35 ms (b) Double transition in QRS morphology during threshold testing (requires different thresholds of the tissues): ȃns-HBP → ns-RBBP → RVSP → loss of capture ȃns-HBP → ns-RBBP → s-RBBP → loss of capture ȃns-HBP → s-HBP → s-RBBP → loss of capture (c) Selective paced QRS morphology ≠ intrinsic QRS morphology (unless baseline LBBB or RBBB) d) Paced latency > potential to QRS onset interval (requires selective capture) e) Δ V6RWPT ≤ 20 ms with loss of conduction system capture