A device for the electrostimulation of body tissue, in particular a pacemaker, comprising: - an energy storage element for providing electrical stimulation energy; - an electrode terminal for connecting a stimulation electrode for delivering electrical stimulation pulses to body tissue; - a first switch by way of which the energy storage element is to be connected to the electrode terminal for the delivery of a stimulation pulse; - a unit for capture verification; - a short circuiting switch by way of which, after the delivery of the stimulation pulse, the electrode terminal is to be connected to a ground potential in such a way that, when an electrode lead is connected and implanted, a capacitance (24, 32) can be discharged via the body tissue and a ground electrode in such a way that a short circuit current flows through the body tissue, wherein the capacitance includes a Helmholtz capacitance, which develops on the surface of the stimulation electrode in conjunction with surrounding body fluid or body tissue; - and a control unit, which is connected to the switch and the short circuiting switch for switching the switches (S2, S3) and designed to disconnect the electrode lead terminal from the energy source after delivery of the stimulation pulse, by opening of the switch, and to connect the capacitance (24, 32) to the ground potential, by closing of the short circuiting switch, in such a way that the capacitance is short circuited via the body tissue, characterized in that the unit for capture verification is connected to the electrode terminal, after delivery of a stimulation pulse, and is designed, after delivery of the stimulation pulse, with switch being open and short circuiting switch being closed, to detect the temporal progression of a short circuit voltage or short circuit current present at the capacitance (24; 32) via the body tissue, or to detect the temporal progression of a variable that is associated with one of these variables. - an energy storage element for providing electrical stimulation energy; - an electrode terminal for connecting a stimulation electrode for delivering electrical stimulation pulses to body tissue; - a first switch by way of which the energy storage element is to be connected to the electrode terminal for the delivery of a stimulation pulse; - a unit for capture verification; - a short circuiting switch by way of which, after the delivery of the stimulation pulse, the electrode terminal is to be connected to a ground potential in such a way that, when an electrode lead is connected and implanted, a capacitance (24, 32) can be discharged via the body tissue and a ground electrode in such a way that a short circuit current flows through the body tissue, wherein the capacitance includes a Helmholtz capacitance, which develops on the surface of the stimulation electrode in conjunction with surrounding body fluid or body tissue; - and a control unit, which is connected to the switch and the short circuiting switch for switching the switches (S2, S3) and designed to disconnect the electrode lead terminal from the energy source after delivery of the stimulation pulse, by opening of the switch, and to connect the capacitance (24, 32) to the ground potential, by closing of the short circuiting switch, in such a way that the capacitance is short circuited via the body tissue,