The invention refers to polynucleotides selected from the group consisting of a) polynucleotides encoding for the polypeptide RBM20 comprising a P638L mutation for a human polypeptide RBM20, or a P641L mutation for a rat polypeptide RBM20, b) polynucleotides with a reverse complementary sequence of the polynucleotide of a) above, and c) polynucleotides with an identity at least 50 % to a polynucleotide of a) or b) above
