Horizontal polarization of the plasma during electron cyclotron resonance heating (ECRH) is capable of suppressing the reversed-shear Alfvén eigenmodes. The suppression mechanism consists in the formation of a potential 'hill' for the cascade modes when the ECRH power is deposited slightly inside of the qmin-surface. This mechanism can be responsible for the cascade suppression during ECRH in the DIII-D tokamak (Van Zeeland et al 2008 Plasma Phys. Control. Fusion50 035009).