The present invention provides compositions and methods useful for treating disorders amenable to therapy via introduction of multigenic expression vectors. More particularly, the invention provides vectors and polynucleotides encoding polypeptides for treatment of cardiac disorders wherein said polypeptides may comprise a cytokine, a chemokine, and/or an angiogenic polypeptide, or functional derivatives thereof. Also provided, as compositions of the invention, are linkers useful for connecting and expressing functional (biologically active) polypeptides from single, multigenic-expression constructs.