Conductive　intracardiac　communication　(CIC)　is　an　essential　approach　for　achieving　multichamber　pacing　in　leadless　pacemakers　(LCPs),　significantly　enhancing　the　therapeutic　outcomes　for　conditions,　such　as　bradycardia.　However,　the　characteristics　of　the　intracardiac　channel　are　profoundly　affected　by　the　heart＇s　rhythmic　contractions.　Accurately　understanding　the　dynamic　transmission　mechanisms　and　channel　parameters　under　various　cardiac　pathological　states　is　crucial　for　enhancing　the　multichamber　pacing　functionality　of　LCPs.　In　this　article,　the　relationship　between　cardiac　chamber　volume　and　channel　impedance　is　mapped　based　on　the　electrocardiogram　(ECG)　data.　This　mapping　enables　precise,　real-time　adjustments　to　variable　impedance,　simulating　the　impedance　changes　occurring　with　each　heartbeat.　Through　this　approach,　a　time-frequency　equivalent　circuit　phantom　is　proposed　to　accurately　simulate　channel　characteristics　for　various　pacemaker　indications　(PIs).　Utilizing　a　quasi-dual-pump　structural　analogy　to　the　heart,　we　designed　a　dynamic　experimental　measurement　platform　capable　of　simulating　the　cardiac　beating　process　under　various　PIs,　which　is　employed　to　validate　the　accuracy　of　the　circuit　phantom.　The　results　demonstrate　that　the　correlation　coefficients　in　the　frequency　and　time　domains　are　greater　than　0.9432　and　0.9150,　respectively,　with　a　time-domain　consistency　coefficient　of　less　than　3.25.　Through　cross　validation　in　both　frequency　and　time　domains,　the　circuit　effectively　simulates　the　channel　characteristics　of　normal　and　PI　hearts.　The　empirical　formula　established　based　on　the　time-domain　measurement　results　can　be　utilized　for　the　rapid　estimation　of　the　right　atrium　(RA)-right　ventricle　(RV)　channel　characteristics.　The　proposed　phantom　offers　a　highly　accurate　and　reproducible　experimental　method　for　the　design　of　intracardiac　communication　transceivers,　advancing　the　development　and　validation　of　leadless　multichamber　pacemaker　systems.