In an implantable medical device, in particular an implantable heart-stimulation device, and a method for operating an implantable heart-stimulation device and a heart-stimulation system, stimulation pulses are delivered via a number of stimulation channels to selected sites on or about a patient's heart via electrodes, and wherein coupling capacitors included in the stimulation channels are subsequently discharged through a sequence of temporally non-overlapping partial discharges of the respective coupling capacitors. By this configuration, the risk of charge neutrality of a stimulation channel not being maintained at the end of a stimulation sequence, comprising the delivery of stimulation pulses via stimulation channels, is reduced or eliminated.