Computer implemented method and system for aiding mapping heart rhythm abnormalities

A computer implemented method for analyzing electrograms acquired from the heart to identify one or more regions of the heart responsible for supporting or initiating abnormal heart rhythms, the computer implemented method using electrogram data recorded from a plurality of electrodes on multipolar cardiac catheters obtained from a corresponding series of sensing locations on the heart over a recording time period, the method comprising the steps of:

• defining specific regions within a chamber of the heart as potential drivers of abnormal heart rhythms by analysis of electrical activation sequences,
• weighting classification of a region as a potential driver according to factors including if:
• the direction of the activation generated wavefront is progressing from the potential driver site to one or more nearby electrodes compared to that driver site during the same acquisition;
• the sequence and timing of activation is within a biologically plausible manner, with reference to conduction velocities and paths being within plausible activation sequence;
• activation occurs across at least 2 electrodes subtending less than a defined angle, for example less than 180 degrees from the vertex subtended by the potential driver site, and
• at least one electrogram activation is determined as later than the potential driver site within a defined arc of excitable tissue, and
• a further acquisition performed in an adjacent location subtending the missing arc of the first potential driver site does not fail to confirm a potential driver site at a similar location, and
• displaying refined potential drivers in a highlighted manner according to the weighting, the display being in relation to a computer representation of the heart chamber.

A computer system for identifying one or more areas of the heart muscle responsible for supporting or initiating abnormal heart rhythms using electrogram data recorded from a plurality of electrodes on multipolar cardiac catheters obtained from a corresponding series of sensing locations on the heart over a recording time period, the system comprising:

• a processor;
• a first memory for storing received electrogram data;
• and
• a second memory having program code stored therein that when executed by the processor causes the system to:
• identify, from the electrograms, regions within a chamber of the heart which have electrical activation sequences which characterize them as potential drivers of abnormal heart rhythms,
• for each sensing location at or substantially about said region, determining from predominant activations, an earliest activating electrode site;
• for each determined earliest activating electrode site:
• calculating a value for each of a plurality of modifiers associated with the electrode site, the modifiers being determined from the electrogram data for the site, tissue characteristics of the site or anatomical characteristics of the site;
• determine a ranking factor calculated from the plurality of modifiers;
• rank the each of said earliest activating electrode sites in dependence on its ranking factor;
• and
• output data identifying said regions, the data varying prominence of each of the determined earliest activating electrode sites in dependence on said ranking.