An implantable stimulation device including a stimulation module and a data communication module. The stimulation device includes electrodes to delivery stimulation pulses, a voltage source, a DC-blocking capacitor and autoshort switch. The voltage source is connected to the electrodes via stimulation-pulse-switch(s) that controls delivery pacing pulses. The DC-blocking capacitor is connected with the voltage source and an electrode. The autoshort switch allows discharging of the DC-blocking capacitor via the electrodes when closed. The data communication module includes a data transmission control module connected to the autoshort switch and/or the at least one stimulation-pulse-switch, to alternatingly open and close the autoshort switch or the at least one stimulation-pulse-switch respectively, during an autoshort period following the delivery of a stimulation pulse or during a stimulation pulse period, respectively, to modulate an autoshort pulse or a stimulation pulse peak amplitude, respectively.