GO:0086066

The process that mediates interactions between an atrial cardiomyocyte and its surroundings that contributes to the process of the atrial cardiomyocyte communicating with an AV node cell in cardiac conduction. Encompasses interactions such as signaling or attachment between one cell and another cell, between a cell and an extracellular matrix, or between a cell and any other aspect of its environment. [GOC:BHF, GOC:mtg_cardiac_conduct_nov11]