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Slowly conducting BT
- More likely to be free wall then Posteroseptal then right free wall then Anteroseptal
- Initiation with VPD during sinus rhythm when the His is refractory is diagnostic and distinguishes it from F/S AVNRT.
- Should attempt to entrain tachycardia and show prolongation of VA interval due to decremental conduction in the BT
- If you delay the a during PVC on His then this is diagnostic of a decremental pathway.
Maneuvers
- PVC on His Maneuver preexcites a, delays a, or terminated with no a
- Increase VA interval with ipsilateral bundle branch block
