# US 2018/0021567 A1 · Method and system for determining pace timing in a leadless cardiac pacemaker system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2018/0021567 A1 - Document ID: US20180021567A1 - Status: Published application - Kind: A1 - Application number: 15/646,999 - Filed: 2017-07-11 - Published: 2018-01-25 - Earliest claimed: 2016-07-20 - Assignees: Cardiac Pacemakers, Inc. - Applicants: Cardiac Pacemakers, Inc. - Inventors: Qi An; Jeffrey E. Stahmann; Pramodsingh Hirasingh Thakur; Michael J. Kane; Yinghong Yu; Keith R. Maile - Web page: https://patentgrep.com/patent/US20180021567A1 ## CPC - A61N 1/056: {Transvascular endocardial electrode systems} - A61B 7/00: Instruments for auscultation - A61N 1/36564: {controlled by blood pressure} - A61N 1/36585: {controlled by two or more physical parameters} - A61N 1/3706: {Pacemaker parameters (stimulation threshold A61N1/371)} - A61N 1/37205: {Microstimulators, e.g. implantable through a cannula} - A61N 1/375: Constructional arrangements, e.g. casings - A61N 1/3756: {Casings with electrodes thereon, e.g. leadless stimulators} - A61N 1/36507: {controlled by gradient or slope of the heart potential} - A61N 1/36521: {the parameter being derived from measurement of an electrical impedance} - A61N 1/36542: {controlled by body motion, e.g. acceleration} - 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) - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) ## Abstract A leadless cardiac pacemaker (LCP) is configured to sense cardiac activity and to pace a patient's heart and is disposable within a ventricle of the patient's heart. The LCP may include a housing, a first electrode and a second electrode that are secured relative to the housing and are spaced apart. A controller is disposed within the housing and is operably coupled to the first electrode and the second electrode such that the controller is capable of receiving, via the first electrode and the second electrode, electrical cardiac signals of the heart. The LCP may include a pressure sensor and/or an accelerometer. The controller may determine a pace time for a cardiac cycle based at least in part upon a signal from the pressure sensor. ## Claims ### Claim 1 A leadless cardiac pacemaker (LCP) configured to sense cardiac activity and to pace a patient's heart, the LCP disposable within a ventricle of the patient's heart, the LCP comprising: a housing; a first electrode secured relative to the housing; a second electrode secured relative to the housing, the second electrode spaced from the first electrode; a controller disposed within the housing and operably coupled to the first electrode and the second electrode; a pressure sensor disposed relative to the housing and operably coupled to the controller, the controller configured to receive a pressure signal from the pressure sensor; the controller configured to determine a pace time for a cardiac cycle for delivering a ventricle pacing pulse to the ventricle of the patient's heart, the controller determining the pace time based at least in part on the received pressure signal; and the controller configured to generate and deliver a ventricle pacing pulse at the pace time. ### Claim 2 (depends on 1) The LCP of claim 1, further comprising: an accelerometer secured relative to the housing and operably coupled to the controller, the controller configured to receive an accelerometer signal from the accelerometer; wherein the controller is configured to determine the pace time based at least in part on the received pressure signal and the received accelerometer signal. ### Claim 3 (depends on 2) The LCP of claim 2, wherein the controller is configured to determine the pace time based at least in part on a heart sound or endocardial acceleration represented in the received pressure signal and/or in the received accelerometer signal. ### Claim 4 (depends on 2) The LCP of claim 2, wherein the controller is configured to receive an electrical cardiac signal via the first electrode and the second electrode, and wherein the controller is configured to determine the pace time based at least in part on the received pressure signal, the received accelerometer signal and the received electrical cardiac signal. ### Claim 5 (depends on 1) The LCP of claim 1, wherein the controller is configured to receive an electrical cardiac signal via the first electrode and the second electrode, and wherein the controller is configured to determine the pace time based at least in part on the received pressure signal and the received electrical cardiac signal. ### Claim 6 (depends on 1) The LCP of claim 1, wherein the controller is configured to determine the pace time based at least in part on a diastolic pressure represented in the received pressure signal. ### Claim 7 (depends on 7) The LCP of claim 7, wherein the controller is configured to determine the pace time based at least in part on an A-wave represented in the received pressure signal. ### Claim 8 (depends on 1) The LCP of claim 1, wherein the controller is configured to determine the pace time based at least in part on a systolic pressure represented in the received pressure signal. ### Claim 9 (depends on 8) The LCP of claim 8, wherein the controller is configured to determine the pace time based at least in part on a dP/dt parameter during systole represented in the received pressure signal. ### Claim 10 (depends on 8) The LCP of claim 8, wherein the controller is configured to determine the pace time based at least in part on when the received pressure signal crossing a predetermined threshold during systole. ### Claim 11 (depends on 1) The LCP of claim 1, wherein the controller is configured to determine the pace time based at least in part on an A-V delay relative to a previously determined atrial contraction timing fiducial, and wherein the controller adjusts the A-V delay based at least in part on one or more of the received pressure signal, the received accelerometer signal and a received electrical cardiac signal. ### Claim 12 A leadless cardiac pacemaker (LCP) configured to sense cardiac activity and to pace a patient's heart, the LCP disposable within a ventricle of the patient's heart, the LCP comprising: a housing; a first electrode secured relative to the housing; a second electrode secured relative to the housing, the second electrode spaced from the first electrode; a controller disposed within the housing and operably coupled to the first electrode and the second electrode; a memory disposed within the housing and operably coupled to the controller, the memory configured to store a previously determined atrial contraction timing fiducial; a pressure sensor disposed relative to the housing and operably coupled to the controller, the controller configured to receive a pressure signal from the pressure sensor; the controller configured to determine an A-V delay relative to the previously determined atrial contraction timing fiducial, the controller configured to adjust the A-V delay based at least in part on the pressure signal; and the controller configured to generate and deliver a ventricle pacing pulse after the adjusted A-V delay following the previously determined atrial contraction timing fiducial. ### Claim 13 (depends on 12) The LCP of claim 12, further comprising: an accelerometer disposed relative to the housing and operably coupled to the controller, the controller configured to receive an accelerometer signal from the accelerometer; and wherein the controller is configured to adjust the A-V delay based at least in part on the accelerometer signal. ### Claim 14 (depends on 12) The LCP of claim 12, wherein the pressure signal comprises a pulse pressure and the controller is configured to adjust the A-V delay relative to the previously determined atrial contraction timing fiducial based at least in part on the pulse pressure. ### Claim 15 (depends on 12) The LCP of claim 12, wherein the pressure signal comprises a rate of change in pressure over time (dP/dt) and the controller is configured to adjust the A-V delay relative to the previously determined atrial contraction timing fiducial based at least in part on the dP/dt. ### Claim 16 (depends on 12) The LCP of claim 12, wherein the pressure signal comprises an A-wave signal, and the controller is configured to progressively reduce the A-V delay until the A-wave signal is not detected, and then progressive increase the A-V delay until the A-wave signal is detected, at which point the A-V delay may be considered to be optimal. ### Claim 17 (depends on 12) The LCP of claim 12, wherein the controller is configured to adjust the A-V delay in response to an LV volume related impedance signal received at the first electrode and the second electrode, and the controller adjusts the A-V delay relative to the previously determined atrial contraction timing fiducial in order to increase an LV ejection fraction. ### Claim 18 (depends on 12) The LCP of claim 12, wherein the controller is configured to adjust the A-V delay in response to an electrical cardiac signal received via the first electrode and the second electrode including a QRS complex, from which a QRS width can be determined, and the controller is configured to adjust the A-V delay relative to the previously determined atrial contraction timing fiducial in order to minimize the QRS width. ### Claim 19 (depends on 12) The LCP of claim 12, wherein the controller is configured to adjust the A-V delay in response to a received signal indicative of mitral regurgitation from the pressure sensor and/or an accelerometer, and the controller adjusts the A-V delay relative to the previously determined atrial contraction timing fiducial in order to minimize mitral regurgitation. ### Claim 20 A method for generating a ventricle pacing pulse using a leadless cardiac pacemaker (LCP) disposed within a patient's left ventricle, the method comprising: sensing for a signal representative of cardiac performance; determining a timing fiducial for a cardiac cycle; adjusting a pacing time relative to the timing fiducial based at least in part on the sensed signal; generating and delivering the ventricle pacing pulse at the pacing time in the cardiac cycle; and following the ventricle pacing pulse, sensing for the signal representative of cardiac performance to determine if the cardiac performance improved using the adjusted pacing time.