Pacemaker mediated tachycardia detection and termination in dual chamber leadless pacemaker systems

A method for terminating a pacemaker mediated tachycardia (PMT) by a dual chamber leadless pacemaker system comprising:

• an atrial leadless pacemaker (aLP) configured to be implanted in or on an atrial cardiac chamber and comprising at least two electrodes arranged to sense an intrinsic atrial event, pace the atrial cardiac chamber and perform implant-to-implant (i2i) communication;
• and
• a ventricular leadless pacemaker (vLP) configured to be implanted in or on a ventricular cardiac chamber and comprising at least two electrodes arranged to sense an intrinsic ventricular event, pace the ventricular cardiac chamber and perform i2i communication, the method comprising:
• the vLP monitoring for a PMT in response to reception of an i2i communication from the aLP indicating compromised i2i communication from the vLP to the aLP;
• the vLP initiating, following detection of a PMT, a PMT PV interval in response to reception of an i2i communication from the aLP indicating an atrial sensed event, wherein the PMT PV interval is shorter than a PV interval that the vLP would otherwise use for ventricular pacing if the PMT was not detected;
• and
• the vLP delivering a ventricular pacing pulse to the ventricular cardiac chamber in response to the PMT PV interval expiring without an intrinsic ventricular event being detected during the PMT PV interval.

A dual chamber leadless pacemaker system comprising:

• an atrial leadless pacemaker (aLP) configured to be implanted in or on an atrial cardiac chamber and comprising at least two electrodes arranged to sense an intrinsic atrial event, pace the atrial cardiac chamber and perform implant-to-implant (i2i) communication;
• and
• a ventricular leadless pacemaker (vLP) configured to be implanted in or on a ventricular cardiac chamber and comprising at least two electrodes arranged to sense an intrinsic ventricular event, pace the ventricular cardiac chamber and perform i2i communication, wherein
• the aLP is configured to monitor for a pacemaker mediated tachycardia (PMT) based on intrinsic atrial events detected by the aLP and i2i communications from the vLP indicating ventricular paced events;
• the aLP is configured to, in response to detection of compromised i2i communication from the vLP to the aLP, transmit an i2i communication to the vLP indicating compromised i2i communication from the vLP to the aLP;
• the aLP is configured to interrupt its monitoring for PMT until i2i communication from the vLP to the aLP is functional;
• and
• the vLP is configured to, in response to reception of the i2i communication from the aLP indicating compromised i2i communication from the vLP to the aLP, monitor for a PMT based on ventricular paced events caused by the vLP and i2i communications from the aLP indicating atrial sensed events.

A method for terminating a pacemaker mediated tachycardia (PMT) by a dual chamber leadless pacemaker system comprising:

• an atrial leadless pacemaker (aLP) configured to be implanted in or on an atrial cardiac chamber and comprising at least two electrodes arranged to sense an intrinsic atrial event, pace the atrial cardiac chamber and perform implant-to-implant (i2i) communication;
• and
• a ventricular leadless pacemaker (vLP) configured to be implanted in or on a ventricular cardiac chamber and comprising at least two electrodes arranged to sense an intrinsic ventricular event, pace the ventricular cardiac chamber and perform i2i communication, the method comprising:
• the aLP monitoring for a pacemaker mediated tachycardia (PMT) based on intrinsic atrial events detected by the aLP and i2i communications from the vLP indicating ventricular paced events;
• the aLP transmitting, in response to detection of compromised i2i communication from the vLP to the aLP, an i2i communication to the vLP indicating compromised i2i communication from the vLP to the aLP;
• the aLP interrupting its monitoring for PMT until i2i communication from the vLP to the aLP is functional;
• and
• the vLP monitoring, in response to reception of the i2i communication from the aLP indicating compromised i2i communication from the vLP to the aLP, for a PMT based on ventricular paced events caused by the vLP and i2i communications from the aLP indicating atrial sensed events.