Method and apparatus for detection of tachyarrhythmia using cycle lengths

A method of determining a cardiac event, comprising:

• determining a plurality of cycle lengths associated with sensed cardiac signals;
• determining differences between consecutive cycle lengths of the determined plurality of cycle lengths;
• determining cluster signature metrics in response to the determined differences;
• identifying the cardiac event in response to the determined cluster signature metrics;
• generating a plot corresponding to the determined differences;
• determining a number of the determined differences that are located within a plurality of segments of the plot defined by a range of magnitudes and phases relative to an origin of the plot and corresponding to patterns associated with the cardiac event;
• determining a number of the determined differences that are located within each of the plurality of segments;
• determining a number of segments of the plurality of segments that have a determined difference located therein;
• determining, for each segment of the plurality of segments, a difference between the determined number of determined differences located therein and the determined number of segments having a determined difference located therein to generate density counts;
• and
• determining a sum of the density counts.

A method of determining a cardiac event, comprising:

• determining a plurality of cycle lengths associated with sensed cardiac signals;
• determining differences between consecutive cycle lengths of the determined plurality of cycle lengths;
• determining cluster signature metrics in response to the determined differences;
• identifying the cardiac event in response to the determined cluster signature metrics;
• generating a plot corresponding to the determined differences;
• determining a number of the determined differences that are located within a plurality of segments of the plot defined by a range of magnitudes and phases relative to an origin of the plot and corresponding to patterns associated with the cardiac event;
• determining a number of the determined differences that are located within each segment of first predetermined segments of the plurality of segments;
• determining a number segments of the plurality of segments that have a determined difference located therein;
• determining, for each segment of the first predetermined segments, a difference between the determined number of determined differences located therein and the determined number of segments having a determined difference located therein to generate first density counts;
• summing the first density counts to generate a first density sum;
• determining a number of the determined differences that are located within each segment of second predetermined segments of the plurality of segments;
• determining, for each segment of the second predetermined segments, a difference between the determined number of determined differences located therein and the determined number of segments having a determined difference located therein to generate second density counts;
• summing the second density counts to generate a second density sum;
• and
• determining a difference between the first density sum and the second density sum.

A method of determining a cardiac event, comprising:

• determining a plurality of cycle lengths associated with sensed cardiac signals;
• determining differences between consecutive cycle lengths of the determined plurality of cycle lengths;
• determining cluster signature metrics in response to the determined differences;
• identifying the cardiac event in response to the determined cluster signature metrics;
• generating a plot corresponding to the determined differences;
• and
• determining a number of the determined differences that are located within a plurality of segments of the plot defined by a range of magnitudes and phases relative to an origin of the plot and corresponding to patterns associated with the cardiac event, wherein a first segment of the plurality of segments corresponds to a predetermined area about the origin of the plot and further comprising determining a total number of the determined differences that are located within the plurality of segments other than the first segment to generate a first cluster signature metric M1.

A method of determining a cardiac event, comprising:

• determining a plurality of cycle lengths associated with sensed cardiac signals;
• determining differences between consecutive cycle lengths of the determined plurality of cycle lengths;
• determining cluster signature metrics in response to the determined differences;
• and
• identifying the cardiac event in response to the determined cluster signature metrics, wherein determining cluster signature metrics comprises;
• determining the number of a plurality of the determined differences that are within a predetermined range that corresponds to the cardiac event;
• and
• determining the proportion of the determined number of the plurality of the determined differences and a median of the plurality of the determined differences, and wherein determining the determined number of the plurality of the determined differences comprises:
• calculating a plurality of medians of determined differences corresponding to a plurality of respective sample windows occurring over a predetermined time period;
• and
• comparing the calculated plurality of medians to a predetermined baseline median associated with the cardiac event.

A method of determining a cardiac event, comprising:

• determining a plurality of cycle lengths associated with sensed cardiac signals;
• determining differences between consecutive cycle lengths of the determined plurality of cycle lengths;
• generating a representation of a plot corresponding to a temporal relationship between the determined differences;
• determining a number of the determined differences that are located within a plurality of segments of the plot defined by a range of magnitudes and phases relative to an origin of the plot and corresponding to patterns associated with the cardiac event;
• and
• identifying the cardiac event in response to the number of the determined differences that are located within the plurality of segments;
• determining a number of the determined differences that are located within each of the plurality of segments;
• determining a number segments of the plurality of segments that have a determined difference located therein;
• determining a number of the determined differences that are located within a first segment of the plurality of segments corresponding to a predetermined area about the origin of the plot;
• and
• determining, for predetermined segments of the plurality of segments, a difference between the determined number of determined differences located therein and the determined number of segments having a determined difference located therein to generate density counts.

A method of determining a cardiac event, comprising:

• determining a plurality of cycle lengths associated with sensed cardiac signals;
• determining differences between consecutive cycle lengths of the determined plurality of cycle lengths;
• generating a representation of a plot corresponding to a temporal relationship between the determined differences;
• determining a number of the determined differences that are located within a plurality of segments of the plot defined by a range of magnitudes and phases relative to an origin of the plot and corresponding to patterns associated with the cardiac event;
• identifying the cardiac event in response to the number of the determined differences that are located within the plurality of segments;
• determining a number of the determined differences that are located within each of the plurality of segments;
• determining a number segments of the plurality of segments that have a determined difference located therein;
• determining a number of the determined differences that are located within a first segment of the plurality of segments corresponding to a predetermined area about the origin of the plot;
• determining, for predetermined segments of the plurality of segments, a difference between the determined number of determined differences located therein and the determined number of segments having a determined difference located therein to generate density counts;
• calculating a plurality of medians of determined differences corresponding to a plurality of respective sample windows occurring over a predetermined time period;
• and
• comparing the calculated plurality of medians to a predetermined baseline median associated with the cardiac event.

A medical device for determining a cardiac event, comprising:

• means for determining a plurality of cycle lengths associated with sensed cardiac signals;
• means for determining differences between consecutive cycle lengths of the determined plurality of cycle lengths;
• means for generating a representation of a plot corresponding to a temporal relationship between the determined differences;
• means for determining a number of the determined differences that are located within a plurality of segments of the plot defined by a range of magnitudes and phases relative to an origin of the plot and corresponding to patterns associated with the cardiac event;
• means for identifying the cardiac event in response to the number of the determined differences that are located within the plurality of segments;
• means for determining a number of the determined differences that are located within each of the plurality of segments;
• means for determining a number segments of the plurality of segments that have a determined difference located therein;
• means for determining a number of the determined differences that are located within a first segment of the plurality of segments corresponding to a predetermined area about the origin of the plot;
• and
• means for determining, for predetermined segments of the plurality of segments, a difference between the determined number of determined differences located therein and the determined number of segments having a determined difference located therein to generate density counts.