Patent ID: 8548573

Claim:
A method of cardiac signal analysis in an implantable cardiac stimulus or monitoring device, the device comprising an implantable canister housing operational circuitry and having a plurality of electrodes coupled to the operational circuitry; the method comprising: capturing a signal from a chosen set of the plurality of electrodes; and performing cardiac beat detection by comparing a detection threshold to an amplitude of the captured signal by: a) using a signal that undergoes post-beat filtering for a predefined period of time following the detected cardiac event; and b) using a signal that undergoes default filtering once the predefined period of time has expired; wherein the post-beat filtering is configured to attenuate frequencies correlated to T-waves more greatly than the default filtering; wherein the method is performed on a beat-by-beat basis, such that after detection of a cardiac beat, beat detection using the post-beat filtering is performed and, if no additional beat is detected during the predefined period of time following the detected cardiac event, beat detection using the default filtering is performed.