[en] Complete text of publication follows. This paper reports on our recent discovery of a high-K isomeric decay in very neutron rich nuclei like ¹⁹⁰W₁₁₆ using the novel technique of isomer spectroscopy [1] following a relativistic projectile fragmentation reaction. A 1 GeV/nucleon ²⁰⁸Pb beam, provided by the SIS synchrotron at GSI, was used to bombard a 1.6 g/cm² Be target. The nuclei of interest were identified using the FRagment Separator (FRS) [2] and slowed down in a variable thickness aluminium degrader and finally stopped in an aluminium catcher. The catcher was surrounded by four clover style germanium detectors with a total γ-ray efficiency of 6% at 1.33 MeV. The time difference was measured between the implantation of the fragment in the stopper and the subsequently detected γ-ray in the Ge-array. The good time resolution allowed the measurement of decays from short lived isomeric states. In several exotic settings of the FRS a number of new isotopes in the mass A ∼ 180-200 region were discovered. The γ-ray spectroscopy from the decay of the K-isomers proves to be a novel method to access nuclear structures properties of excited medium and high spin states in very neutron rich radioactive nuclei which are not reachable by other types of reaction. As an example the population of the previously unknown yrast-band in ¹⁹⁰W will be discussed. When compared with the systematics of this mass region, the experimental data can be interpreted as a signature of a dramatic reduction in deformation and increase in gamma softness at N = 116 for the Z = 74 isotopes. This interpretation is supported by the low hindrance factor observed for the decay out of the isomer. The results open up the prospect of further high-spin studies in currently inaccessible, heavy neutron-rich nuclei, and further investigation of the role of triaxiality in the demise of the K-quantum number. (author)