  Consider the bidomain equations subject to ionic transport described by the
models of FitzHugh-Nagumo, Aliev-Panfilov, or Rogers-McCulloch. It is proved
that this set of equations admits a unique, strong T-periodic solution provided
it is innervated by T-periodic intra- and extracellular currents. The approach
relies on a new periodic version of the classical Da Prato-Grisvard theorem on
maximal L^p-regularity in real interpolation spaces.
