Figure legends:
Fig 1: Short HV (26 ms) after ablation of the manifest atrioventricular
AP. The small signal in front of the ventricular electrogram in His
catheter was validated as ‘H’ during decremental atrial pacing in the
last beat. The fixed HV on surface ECG confirmed a FVP.
Fig 2: Para-Hisian pacing showing the first 2 beats were Vc and last one
was H+Vc. There is a paradoxical SA prolongation in the narrower last
beat.
Fig 3: Another protocol of PHP revealed a pure Hc in the first beat. The
CS catheter was out, hence no assessment of VA was made.