The　leadless　multichamber　pacemaker　offers　significant　advantages　in　treating　arrhythmias　and　enhancing　cardiac　function.　Intracardiac　communication　is　essential　for　ensuring　coordinated　pacing　of　multi-chamber　pacemakers　that　do　not　have　leadless　technology.　However,　the　dynamic　changes　in　the　intracardiac　channel　present　a　significant　challenge.　Hence,　mastering　the　dynamic　characteristics　of　intracardiac　channels　and　accurately　modeling　them　is　crucial.　In　this　paper,　we　introduce　a　validated　intracardiac　channel　equivalent　circuit　model　that　accounts　for　the　electrical　characteristics　of　cardiac　tissue　and　the　volume　fluctuations　in　cardiac　chambers.　The　results　demonstrate　that　the　agreement　coefficient　between　the　circuit　model　and　the　in　vitro　pig　heart　model　reached　80.7%　in　the　time　domain.　The　proposed　equivalent　circuit　model　demonstrates　high　accuracy　and　stability　in　addressing　the　challenge　of　dynamic　changes　in　intracardiac　channels　and　simplifying　in　vivo　or　in　vitro　experiments.