A left atrial appendage occlusion device is provided that acts in conjunction with a wireless transponder unit. The occlusion device provides a seal of the left atrial appendage opening, while the transponder is inserted into the left atrial appendage to sense one or more physiological conditions and relay the sensed information over wireless communication. Further, all or part of the left atrial appendage may be filled using a biocompatible inert filling material injected into the left atrial appendage as part of deployment of the transponder unit.