# US 2019/0167991 A1 · Leadless cardiac pacemaker with reversionary behavior > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0167991 A1 - Document ID: US20190167991A1 - Status: Published application - Kind: A1 - Application number: 16/204,914 - Filed: 2018-11-29 - Published: 2019-06-06 - Earliest claimed: 2017-12-01 - Assignees: Cardiac Pacemakers, Inc. - Applicants: Cardiac Pacemakers, Inc. - Inventors: Jeffrey E. Stahmann; Keith R. Maile; Krzysztof Z. Siejko; Allan Charles Shuros; William J. Linder; Benjamin J. Haasl; Brendan Early Koop; Michael J. Kane - Web page: https://patentgrep.com/patent/US20190167991A1 ## CPC - A61N 1/368: comprising more than one electrode co-operating with different heart regions {(A61N1/3622, A61N1/3627 take precedence)} - A61N 1/3621: {for treating or preventing abnormally high heart rate} - A61N 1/36507: {controlled by gradient or slope of the heart potential} - A61N 1/36514: {controlled by a physiological quantity other than heart potential, e.g. blood pressure (controlled by two or more physical parameters A61N1/36585)} - A61N 1/36535: {controlled by body position or posture} - A61N 1/36564: {controlled by blood pressure} - A61N 1/36578: {controlled by mechanical motion of the heart wall, e.g. measured by an accelerometer or microphone} - A61N 1/36585: {controlled by two or more physical parameters} - A61N 1/37223: {Circuits for electromagnetic coupling} - A61N 1/37288: {Communication to several implantable medical devices within one patient} - A61N 1/3756: {Casings with electrodes thereon, e.g. leadless stimulators} - A61N 1/3787: {from an external energy source} - A61N 1/3956: {Implantable devices for applying electric shocks to the heart, e.g. for cardioversion} - A61N: ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY (measurement of bioelectric currents A61B; surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body A61B18/00; anaesthetic apparatus in general A61M; incandescent lamps H01K; infrared radiators for heating H05B) ## Abstract A ventricularly implantable medical device that includes a sensing module that is configured to detect an atrial fiducial and identify an atrial contraction based at least on part on the detected atrial fiducial. Control circuitry in the implantable medical device is configured to deliver a ventricular pacing therapy to a patient's heart based at least in part on the identified atrial contraction, and can automatically switch or revert the ventricular pacing therapies on the fly. ## Claims ### Claim 1 A leadless cardiac pacemaker (LCP) configured to sense cardiac activity and to deliver pacing therapy to a patient's heart, the LCP comprising: a housing; a first electrode secured relative to the housing and exposed to the environment outside of the housing; a second electrode secured relative to the housing and exposed to the environment outside of the housing; a sensing module disposed within the housing and responsive to the environment outside of the housing, the sensing module configured to detect one or more atrial fiducials that are indicative of an atrial contraction; a control module operatively coupled to the first electrode, the second electrode, and the sensing module, the control module is configured to: track the one or more atrial fiducials over a plurality of cardiac cycles; deliver a plurality of different ventricular pacing therapies to the patient's heart via the first electrode and the second electrode, wherein the control module selects which ventricular pacing therapy to deliver based, at least in part, on one or more of the tracked atrial fiducials. ### Claim 2 (depends on 1) The LCP of claim 1, wherein the plurality of different ventricular pacing therapies comprise two or more of VDD, VDDR, VVI, VVIR, VOO and VOOR. ### Claim 3 (depends on 1) The LCP of claim 1, wherein the plurality of different ventricular pacing therapies comprise a first ventricular pacing therapy having a first pacing rate and a second ventricular pacing therapy having a second pacing rate different from the first pacing rate. ### Claim 4 (depends on 1) The LCP of claim 1, wherein the control module is configured to dynamically select which ventricular pacing therapy to deliver based, at least in part, on one or more of the tracked atrial fiducials. ### Claim 5 (depends on 1) The LCP of claim 1, wherein the sensing module is further configured to detect one or more ventricle fiducials that are indicative of a ventricle contraction, and the control module is configured to track the one or more ventricle fiducials over a plurality of cardiac cycles. ### Claim 6 (depends on 5) The LCP of claim 5, wherein the control module is configured to select which ventricular pacing therapy to deliver based, at least in part, on one or more of the tracked atrial fiducials and one or more of the tracked ventricle fiducials. ### Claim 7 (depends on 6) The LCP of claim 6, wherein the control module is configured to change from a first ventricular pacing therapy to a second ventricular pacing therapy when a predetermined one of the tracked atrial fiducials comes too close in time to a predetermined one of the tracked ventricle fiducials. ### Claim 8 (depends on 1) The LCP of claim 1, wherein the one or more atrial fiducials comprise one or more of an electrical p-wave, a pressure a-wave, an acoustic S1 sound, an acoustic S2 sound, an acoustic S3 sound, an acoustic S4 sound, an indication of ventricular volume, an indication of ventricular wall thickness, an indication of cardiac tissue vibration, an indication of mitral valve position, and indication of tricuspid valve position. ### Claim 9 (depends on 1) The LCP of claim 1, wherein the sensing module is configured to detect two or more atrial fiducials that are indicative of an atrial contraction, and wherein the control module is configured to select which ventricular pacing therapy to deliver based, at least in part, on a selected one of the tracked atrial fiducials. ### Claim 10 (depends on 1) The LCP of claim 1, wherein the sensing module is configured to detect two or more atrial fiducials that are indicative of an atrial contraction, and wherein the control module is configured to select which ventricular pacing therapy to deliver based, at least in part, on two or more of the tracked atrial fiducials. ### Claim 11 (depends on 1) The LCP of claim 1, wherein the control module continuously tracks the one or more atrial fiducials over a plurality of cardiac cycles. ### Claim 12 (depends on 1) The LCP of claim 1, wherein the control module intermittently tracks the one or more atrial fiducials over a plurality of cardiac cycles. ### Claim 13 (depends on 1) The LCP of claim 1, wherein the control module is configured to switch from delivering a first ventricular pacing therapy to a delivering second ventricular pacing therapy when the control module can no longer track one or more of the atrial fiducials. ### Claim 14 (depends on 13) The LCP of claim 13, wherein the control module enters a search mode to attempt to re-acquire the one or more of the atrial fiducials that can no longer be tracked. ### Claim 15 A leadless cardiac pacemaker (LCP) configured to sense cardiac activity and to deliver pacing therapy to a patient's heart, the LCP comprising: a housing; a first electrode secured relative to the housing and exposed to the environment outside of the housing; a second electrode secured relative to the housing and exposed to the environment outside of the housing; a sensing module disposed within the housing and responsive to the environment outside of the housing, the sensing module including one or more of a pressure measurement module and an acoustic measurement module, the sensing module configured to detect one or more atrial fiducials that are indicative of an atrial contraction and one or more ventricle fiducials that are indicative of a ventricle contraction; a control module operatively coupled to the first electrode, the second electrode, and the sensing module, the control module is configured to: track the one or more atrial fiducials and one or more ventricle fiducials over a plurality of cardiac cycles; deliver a plurality of different ventricular pacing therapies to the patient's heart via the first electrode and the second electrode, wherein the control module transitions from delivery of a first one of the different ventricular pacing therapies to a second one of the different ventricular pacing therapies based, at least in part, on one or more of the tracked atrial fiducials; and wherein the plurality of different ventricular pacing therapies comprise two or more of VDD, VDDR, VVI, VVIR, VOO and VOOR. ### Claim 16 (depends on 15) The LCP of claim 15, wherein the control module transitions from delivery of a first one of the different ventricular pacing therapies to a second one of the different ventricular pacing therapies based, at least in part, on one or more of the tracked atrial fiducials and one or more of the tracked ventricle fiducials. ### Claim 17 (depends on 15) The LCP of claim 15, wherein the control module is configured to switch from delivering a first ventricular pacing therapy to a delivering second ventricular pacing therapy when the control module can no longer track one or more of the atrial fiducials. ### Claim 18 (depends on 15) The LCP of claim 15, wherein the plurality of different ventricular pacing therapies comprise a ventricular pacing therapy having a first pacing rate and a ventricular pacing therapy having a second pacing rate different from the first pacing rate. ### Claim 19 A leadless cardiac pacemaker (LCP) configured to sense cardiac activity and to deliver pacing therapy to a patient's heart, the LCP comprising: a housing; a first electrode secured relative to the housing and exposed to the environment outside of the housing; a second electrode secured relative to the housing and exposed to the environment outside of the housing; a sensing module for sensing a hemodynamic state of the patient; a control module operatively coupled to the first electrode, the second electrode, and the sensing module, the control module is configured to: deliver a plurality of different ventricular pacing therapies to the patient's heart via the first electrode and the second electrode, wherein the control module dynamically selects which ventricular pacing therapy to deliver based, at least in part, on the sensed hemodynamic state of the patient; and wherein the plurality of different ventricular pacing therapies comprise two or more of VDD, VDDR, VVI, VVIR, VOO and VOOR. ### Claim 20 (depends on 19) The LCP of claim 19, wherein the sensing module comprises one or more of a pressure measurement module and an acoustic measurement module.