Method and apparatus for detecting arrhythmias in a medical device

A method of detecting a cardiac event of a cardiac signal generated by a heart of a patient with a medical device having a plurality of electrodes forming a first sensing vector and a second sensing vector and a buffer configured to store data sensed by the electrodes, comprising the steps of:

• sensing data representative of the cardiac signal with the plurality of electrodes;
• storing the data representative of the cardiac signal in the buffer;
• determining a first heart rate estimate associated with data representative of the cardiac signal sensed from the first sensing vector and a second heart rate estimate associated with data representative of the cardiac signal sensed from the second sensing vector, each of the first heart rate estimate and the second heart rate estimate being based, at least in part, on a metric of heart rate associated with the cardiac signal corresponding to at least one of a mean of a plurality of RR intervals associated with the sensed cardiac signals, a trimmed mean of the plurality of RR intervals, a median of the plurality of RR intervals, and a predetermined RR interval of the plurality of RR intervals, and wherein the data representative of the cardiac signal sensed from the first sensing vector is sensed, at least in part, concurrently with the data representative of the cardiac signal sensed from the second sensing vector;
• determining whether asystole is detected for at least one of the cardiac signal sensed from the first sensing vector and the cardiac signal sensed from the second sensing vector;
• clearing the buffer in response to asystole being detected for at least one of the cardiac signal sensed from the first sensing vector and the cardiac signal sensed from the second sensing vector;
• determining a reliability for each of the first heart rate estimate and the second heart rate estimate based, at least in part, on an RR interval stored in the buffer;
• delivering a therapy to the patient if:
• only one of the first heart rate estimate and the second heart rate estimate is reliable and the reliable one of the first heart rate estimate and the second heart rate estimate is greater than a predetermined heart rate threshold;
• or
• both of the first heart rate estimate and the second heart rate estimate are reliable and the first heart rate estimate is not equal to the second heart rate estimate and the first heart rate estimate and the second heart rate estimate exceed the predetermined heart rate threshold.

A non-transitory computer readable medium having computer executable instructions for performing a method of detecting a cardiac event of a cardiac signal generated by a heart of a patient with a medical device having a plurality of electrodes, comprising the steps of:

• sensing data representative of the cardiac signal with the a plurality of electrodes;
• determining a first heart rate estimate associated with data representative of the cardiac signal sensed from the first sensing vector and a second heart rate estimate associated with data representative of the cardiac signal sensed from the second sensing vector, wherein the data representative of the cardiac signal sensed from the first sensing vector is sensed, at least in part, concurrently with the data representative of the cardiac signal sensed from the second sensing vector, the first heart rate estimate and the second heart rate estimate being based, at least in part, on a metric of heart rate;
• determining a reliability for each of the first heart rate estimate and the second heart rate estimate;
• delivering a therapy to the patient if:
• only one of the first heart rate estimate and the second heart rate estimate is reliable and the reliable one of the first heart rate estimate and the second heart rate estimate is greater than a predetermined heart rate threshold;
• or
• both of the first heart rate estimate and the second heart rate estimate are reliable and the first heart rate estimate is not equal to the second heart rate estimate and the first heart rate estimate and the second heart rate estimate exceed the predetermined heart rate threshold.