Method and apparatus for controlling a double atrial triple chamber cardiac pacemaker having a fallback mode

Claim 1

A process for controlling a double atrial triple chamber cardiac pacemaker having a bipolar atrial electrode including a right atrial electrode terminal adapted to be coupled to the right atrium and a left atrial electrode terminal adapted to be coupled to the left atrium, the right and left atrial electrode terminals being connected to a single input of an atrial circuit for the detection of atrial events and the stimulation of the atria, and a ventricular electrode connected to a ventricular circuit for the detection of ventricular events and the stimulation of the ventricle, the pacemaker having a fallback mode of cardiac stimulation in which the ventricular stimulation is desynchronized from the atrial rhythm and a fallup mode of cardiac stimulation in which the ventricular stimulation is progressively resynchronized with the atrial rhythm, the process comprising the steps of: a) sensing at the input of the atrial circuit a succession of signals corresponding to atrial events; b) in response to a detection of a first signal from said succession of signals at the atrial circuit, establishing an inter-atrial propagation masking period for not sensing atrial events; c) applying the masking period and measuring an interval of time separating the first signal and sensing of a second signal, the second signal being sensed subsequent to the first signal and said masking period; d) comparing the measured time interval to a predetermined control value; and e) triggering the fallup mode of progressive re-synchronization in response to the measured time interval becoming greater than the control value.

Claim 5

An apparatus for controlling a double atrial triple chamber cardiac pacemaker comprising: an atrial circuit to detect atrial events and to stimulate at least one of the left atrium and the right atrium; an atrial electrode having a right atrial electrode terminal adapted to be coupled to the right atrium and a left atrial electrode terminal adapted to be coupled to the left atrium, the right and left atrial electrode terminals being operatively connected to the atrial circuit; a ventricular circuit to detect ventricular events and to stimulate a ventricle; a ventricular electrode adapted to be operatively connected to the ventricle and operatively connected to the ventricular circuit; a pacing control logic circuit having a fallback mode of cardiac stimulation in which a ventricular stimulation is desynchronized from an atrial rhythm detected by the atrial circuit, and a fallup mode of cardiac stimulation in which the ventricular stimulation is progressively resynchronized with the detected atrial rhythm; and means for changing the pacing control circuit from operation in the fallback mode to operation in the fallup mode, said means being operated to sense successive atrial events at the atrial circuit input; establish a masking time period corresponding to an inter-atrial propagation interval in response to a detected atrial event for not sensing atrial events; measure a time interval between a first sensed atrial event and a second sensed atrial event, the second sensed atrial event being sensed subsequent to the first sensed atrial event and the masking time period; compare the measured time interval to a control value; and initiate the fallup mode in response to the measured time interval becoming greater than the control value.

Claim 6

An apparatus for controlling a double atrial triple chamber cardiac pacemaker comprising: an atrial circuit to detect atrial events and to stimulate at least one of the left atrium and the right atrium; an atrial electrode having a right atrial electrode terminal adapted to be coupled to the right atrium and a left atrial electrode terminal adapted to be coupled to the left atrium, the right and left atrial electrode terminals being operatively connected to the atrial circuit; a ventricular circuit to detect ventricular events and to stimulate a ventricle; a ventricular electrode adapted to be operatively connected to the ventricle and operatively connected to the ventricular circuit; a pacing control logic circuit having a fallback mode of cardiac stimulation in which a ventricular stimulation is desynchronized from an atrial rhythm detected by the atrial circuit, and a fallup mode of cardiac stimulation in which the ventricular stimulation is progressively resynchronized with the detected atrial rhythm; and means for changing the pacing control circuit from operation in the fallback mode to operation in the fallup mode, said means being operated to sense successive atrial events at the atrial circuit input; establish a masking time period corresponding to an inter-atrial propagation interval in response to a detected atrial event for not sensing atrial events; measure a time interval between a first sensed atrial event and a second sensed atrial event, the second sensed atrial event being sensed subsequent to the first sensed atrial event and the masking time period; compare the measured time interval to a control value; and initiate the fallup mode in response to the measured time interval becoming greater than the control value.