Patent ID: 8600489

Claim:
A method of operation in an implantable cardiac stimulus (ICS) system comprising a canister housing operational circuitry for the ICS system, the canister having a canister electrode disposed thereon, and a lead having at least a first lead electrode disposed thereon, the canister electrode and the first lead electrode electrically coupled to the operational circuitry; the method comprising: detecting electrical events occurring within the patient, wherein the detected electrical events are separated by intervals; calculating a cardiac rate using a set of the detected electrical events; identifying one or more detected events as likely occurring due to overdetection; analyzing intervals around the events identified as likely occurring due to overdetection to determine whether the likely overdetection is likely a T-wave and: a) if the likely overdetection is likely a T-wave, correcting data relating to the overdetection to reduce calculated cardiac rate; or b) if the likely overdetection is unlikely to be a T-wave, disabling data correction methods in the ICS system for at least the likely overdetection; determining whether a likely cardiac arrhythmia is occurring and, if so, determining whether stimulus is needed; and if stimulus is needed, delivering electrical stimulus to the patient from the ICS system.