  The renormalization of the Wiedemann-Franz (WF) ratio in strongly correlated
electron systems is analyzed within the Landau quasiparticle picture. We
demonstrate that the WF law is violated: (i) at the quantum critical point,
where the effective mass diverges, and (ii) beyond a point of fermion
condensation, where the single-particle spectrum $\epsilon(p)$ becomes flat.
Results of the analysis are compared with available experimental data.
