Systems and methods for rhythm discrimination using the motion of an implantable lead are described. In an example, an implantable medical device can include a receiver circuit configured to be electrically coupled to an implantable lead and be configured to obtain information indicative of a movement of the implantable lead due at least in part to a motion of a heart. The device can include an arrhythmia detection circuit configured to determine an arrhythmia status using the information indicative of the movement of the implantable lead and an arrhythmia classification circuit configured to determine one or more of a location or a type of an arrhythmia, using the information indicative of the movement of the implantable lead, when the arrhythmia status indicates that an arrhythmia is occurring or has occurred.