[en] A general expression for the effective electron-electron interaction mediated by electron-lattice coupling is derived. It is shown that for the Cooper channel the pairing can be divided in two parts: a retarded and a non-retarded one. Depending on the strength and range of the electron-phonon coupling the one or the other part is adequate for the description of the superconducting state. Furthermore, consequences of electronic and structural local inhomogeneities for the electron-lattice interaction of high Tc superconductors are discussed. Two parts of the coupling appear to be characteristic for these systems. The first one is the short-range part due to imperfect screening. The anisotropy of the superconducting gap in the ab plane and its symmetry are studied for the two interactions. (author)