Pitfalls and Nuances of Parahisian pacing: A revisit through an interesting case

Varying VA intervals during Para‐Hisian pacing maneuver—What is the mechanism?

“… 1 Occasionally true VA during His capture can be very short masquerading as DAC when supra‐his conduction is brisk. 2 It is also interesting to note that even during true VA conduction with His capture (third beat in Figure 1 and first beat in Figure 2 ), the A‐EGM can paradoxically precede the local V‐EGM (distinctly noted here in CS 34 and CS 56). This is because during His capture, the local VA in CS catheter is not a result of an activation in series, rather it is an activation in parallel, analogous to an AVNRT circuit.…”