I need a 2nd opinion on how to code upgrading a pacemaker to ICD generator with an LV lead.

The physician billed for removal of the pacemaker generator, RV lead and LV lead insertion. The codes he selected are: 33233, 33216 and 33224. The codes I selected are: 33233 – PM generator removal, 33249 ICD implant, single or dual lead and 33225 – LV lead. The physician explained that he was taught to use 33233, 33216 & 33224. In what scenario is 33224 billed? I use Dr. Z’s Medical coding reference for cardiology but it does not give any information how to use this code.

Thank you for your help.

Dolores