Multiple electrode vectors for implantable cardiac treatment devices

A method of cardiac signal analysis comprising:

• capturing a cardiac event along first and second sensing vectors using electrodes implanted in a patient to yield first and second event representations;
• analyzing the cardiac event by use of the first event representation to reach a first result;
• observing whether the first result is determinative and, if not,
• analyzing the cardiac event by use of the second event representation;
• wherein
• the step of analyzing the cardiac event by use of the first event representation includes observing a correlation between the first event representation and an event template, wherein the first result is related to the correlation;
• and
• the first result is the variance in a set of correlation waveform analysis scores, the set of correlation waveform analysis scores including a correlation waveform analysis score for the first event representation and the event template, and a number of correlation waveform analysis scores for first event representations for previous cardiac events and corresponding event templates, wherein the first result is determinative of a polymorphic ventricular tachycardia or a ventricular fibrillation if the variance is high.

A method of cardiac signal analysis comprising:

• capturing an individual cardiac event along first and second sensing vectors using electrodes implanted in a patient to yield first and second event representations along each of the first and second sensing vectors respectively, of the cardiac event, wherein:
• the first sensing vector is defined between an implantable cardiac stimulus device (ICSD) canister and a first electrode on a lead attached to the implantable cardiac stimulus device canister;
• the second sensing vector is defined between the ICSD canister and a second electrode on the lead;
• and
• the lead is disposed subcutaneously between the ribs and the skin of the patient without entering a blood vessel or contacting the heart of the patient;
• analyzing the first and second event representations to generate a first metric corresponding to the first event representation and a second metric corresponding to the second event representation;
• comparing the first metric to the second metric;
• and
• selecting one of the first or second event representations as a primary event representation, and identifying the non-selected event representation as an alternate event representation for the individual cardiac event;
• subsequent to selecting a primary event representation and an alternate event representation for a number of cardiac events, identifying a primary sensing vector and identifying an alternate sensing vector;
• performing cardiac analysis of later cardiac events and performing the following steps to determine whether a given cardiac event appears to indicate malignant or benign cardiac rhythm:
• analyzing the given cardiac event using signals captured with the primary sensing vector to generate a first result;
• observing whether the first result is determinative;
• and, if not,
• analyzing the given cardiac event by use of the alternate sensing vector.

A method of cardiac signal analysis comprising:

• A) capturing a cardiac event along first and second sensing vectors from sensors implanted in a patient to yield first and second event representations along each of the first and second sensing vectors respectively, of the cardiac event, wherein:
• the first sensing vector is defined between an implantable cardiac stimulus device (ICSD) canister and a first electrode on a lead attached to the implantable cardiac stimulus device canister;
• the second sensing vector is defined between the ICSD canister and a second electrode on the lead;
• and
• the lead is disposed subcutaneously between the ribs and the skin of the patient without entering a blood vessel or contacting the heart of the patient;
• B) analyzing the cardiac event by use of the first event representation to reach a first result;
• C) observing whether the first result is determinative and, if not, analyzing the cardiac event by use of the second event representation;
• wherein:
• the step of determining whether the first result is determinative is performed in a manner wherein, if the first result unambiguously indicates a non-malignant cardiac rhythm, the first result is found to be determinative;
• the step of analyzing the cardiac event by use of the first event representation includes observing a correlation between the first event representation and an event template, wherein the first result is related to the correlation.