A method and system for use with an implantable medical device for subcutaneous implant within a patient to determine a likelihood of the patient experiencing a cardiac event that includes sensing a cardiac signal along a plurality of different sensing vectors, determining state information of each vector of the plurality of sensing vectors, determining a cross correlation of the determined state information of each vector of the plurality of sensing vectors, comparing the cross correlation of the determined state information of each vector of the plurality of sensing vectors to a threshold, and detecting the cardiac event in response to the comparing.

A method and system for use with an implantable medical device for subcutaneous implant within a patient to determine a likelihood of the patient experiencing a cardiac event that includes sensing a cardiac signal along a plurality of different sensing vectors, determining state information of each vector of the plurality of sensing vectors, determining a cross correlation of the determined state information of each vector of the plurality of sensing vectors, comparing the cross correlation of the determined state information of each vector of the plurality of sensing vectors to a threshold, and detecting the cardiac event in response to the comparing.

A method and system for use with an implantable medical device for subcutaneous implant within a patient to determine a likelihood of the patient experiencing a cardiac event that includes sensing a cardiac signal along a plurality of different sensing vectors, determining state information of each vector of the plurality of sensing vectors, determining a cross correlation of the determined state information of each vector of the plurality of sensing vectors, comparing the cross correlation of the determined state information of each vector of the plurality of sensing vectors to a threshold, and detecting the cardiac event in response to the comparing.

A subcutaneously implantable cardiac medical device and a method of sensing a cardiac signal therein that includes a plurality of electrodes to sense a cardiac signal along a plurality of sensing vectors to detect a first interval and a second interval associated with a first detected event, and a processor configured to determine whether the first interval and the second interval are shorter than a predetermined threshold, determine whether the first interval and the second interval are similar, and determine, in response to the first interval and the second interval being similar, whether the sensed cardiac signal is either a noisy signal or a QRS signal.

A method and apparatus for detecting a cardiac event in a medical device that includes sensing cardiac signals from a plurality of electrodes, the plurality of electrodes forming a first sensing vector and a second sensing vector, initiating charging of an energy storage device in response to the sensed cardiac signals, and determining whether a predetermined number of morphologies associated with cardiac signals sensed along the first sensing vector and the second sensing vector during corresponding sensing windows are indicative of the cardiac event.

A method and system for use with an implantable medical device for subcutaneous implant within a patient to determine a likelihood of the patient experiencing a cardiac event that includes sensing a cardiac signal along a plurality of different sensing vectors, determining state information of each vector of the plurality of sensing vectors, determining a cross correlation of the determined state information of each vector of the plurality of sensing vectors, comparing the cross correlation of the determined state information of each vector of the plurality of sensing vectors to a threshold, and detecting the cardiac event in response to the comparing.