Patent ID: 7085602

Claim:
An implantable heart stimulating device comprising: a control circuit having a memory; a first sensing circuit adapted for connection to a first sensing member, adapted to be positioned to interact with a first ventricle of a heart, to supply signals to said first sensing circuit for sensing cardiac events related to said first ventricle; a second sensing circuit adapted for connection to a second sensing member, adapted to be positioned to interact with a second ventricle of the heart, to supply signals to said second sensing circuit for sensing cardiac events related to the second ventricle; a first stimulation circuit adapted for connection to a first stimulation member, adapted to be positioned to interact with the first ventricle, to deliver stimulation signals to the first ventricle from the first stimulation circuit; a second stimulation circuit adapted for connection to a second stimulation member, adapted to be positioned to interact with the second ventricle, for delivering stimulation signals from the second stimulation circuit to the second ventricle; and said control circuit being operable with a time cycle corresponding to a normal cardiac cycle, and said control circuit performing an algorithm wherein said control circuit: (a) determines whether, during a time cycle in which no stimulation signal is delivered by said second stimulation circuit, a signal S 2 a , sensed by said second sensing circuit, occurs substantially simultaneously with a signal S 1 a sensed by said first sensing circuit, (b) determines whether a further signal S 2 b is sensed by the second sensing circuit within a predetermined time interval following said signal S 2 a , and within a same time cycle as said signal S 2 a , said predetermined time interval starting at a time between 20 and 200 ms after said signal S 2 a , and (c) if both (a) and (b) occur, said control circuit storing in said memory an indication that said signal S 2 a has been detected, said signal S 2 a , constituting a candidate as a far field signal.