In this paper, we design a prototype of a leadless, wireless, and multi-site pacemaker for the future development of leadless pacemaker devices. Specifically, we have designed a wireless architecture modelling low-powered intracardiac data processing algorithms optimized for the unique limitations shifting to a leadless model creates. Computation is separated between two distinct units: an aggregator that acts as a central power distributor and information aggregation unit, and a network of energy harvesting nodes that provide local sensing and pacing functionality on the heart.