Abstract: Systems, devices and methods for determining sensing quality changes and drops in an implantable medical device, remotely and/or within the device itself. A cardiac implantable medical device tracks, over time, a number of counters, the contents of which are communicated to a processor which may be part of a remote monitoring device or which may be a customer service center that receives data from remote monitoring devices and/or programmers. Counter data is analyzed to identify changes in sensing quality and/or to provide information useful for clinical investigations, system integrity checking, or device reprogramming.