An electromedical implant, having a far-field electrocardiogram capturing unit for recording a far-field electrocardiogram signal, which is connected or can be connected to at least two electrodes for recording electric signals reflecting the curve of the far-field electrocardiogram of the right and left atria, a detection unit, which is designed to detect signal features characterizing atrial cardiac actions in an electrocardiogram signal, an averaging unit, which is connected to the recording unit and the detection unit and designed to generate an averaged P-wave signal in that the averaging unit averages a plurality of signal sections of the electrocardiogram signal associated with a particular detected atrial cardiac action, and an evaluation unit, which is connected to the averaging unit and designed to determine the duration of an averaged P-wave in the particular averaged P-wave signal.