A cardiac therapy device and/or a cardiac monitoring device connected to at least one electrode lead that includes at least one first sensing electrode pole and at least one second sensing electrode pole. The at least one first and second sensing electrode poles move relative to one another during operation of the device. The device further includes a dislocation detection unit connected directly or indirectly to the at least one first and second sensing electrode poles. In order to detect dislocation, the dislocation detection unit evaluates detection times at the at least one first and second sensing electrode pole relative to one another. The detection times are ascribable to a cardiac event, such that the dislocation unit generates a dislocation signal if the relative time relationship of the detection times changes beyond a predetermined value, or a specifically determined value changes compared to a previously recorded reference value.