The present invention provides implantable systems that communicate wirelessly with each other using a unique format that enables devices configurations and applications heretofore not possible. Embodiments of the present invention provide communication apparatuses and methods for exchanging information with implantable medical devices. In some embodiments, two implantable devices communicate with each other using quasi-electrostatic signal transmission in a long wavelength/low frequency electromagnetic band, with the patient's body acting as a conductive medium.