A noninvasive technique capable of characterizing material properties of the heart would be highly beneficial in clinical settings. Our group has been investigating the feasibility of using the Shearwave Dispersion Ultrasound Vibrometry (SDUV) method to estimate tissue viscoelasticity. Dispersion equations for the anti-symmetric Lamb and Rayleigh waves were derived and fitted to the experimental data to solve for elasticity and viscosity of the excised myocardium. The viscoelastic parameters obtained using the two methods agree within one standard deviation. The results suggest that the material properties of the myocardium can be obtained using both Lamb and Rayleigh wave excitation methods.