  We study the effects of initial state fluctuations on the dynamical evolution
of heavy quarks inside a quark-gluon plasma created in relativistic heavy-ion
collisions. The evolution of heavy quarks in QGP matter is described utilizing
a modified Langevin equation that incorporates the contributions from both
collisional and radiative energy loss. The spacetime evolution of the fireball
medium is simulated with a (2+1)-dimensional viscous hydrodynamic model. We
find that when the medium traversed by the heavy quark contains a fixed amount
of energy, heavy quarks tend to lose more energy for greater fluctuations of
the medium density. This may result in a larger suppression of heavy flavor
observables in a fluctuating QGP matter than in a smooth one. The possibility
of using hard probes to infer the information of initial states of heavy-ion
collisions is discussed.
