# US 10,118,042 B2 · Lead integrity testing triggered by sensed asystole > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,118,042 B2 - Document ID: US10118042B2 - Status: Granted - Kind: B2 - Application number: 12/262,443 - Filed: 2008-10-31 - Published: 2010-05-06 - Granted: 2018-11-06 - Earliest claimed: 2008-10-31 - Assignees: Medtronic, Inc. - Applicants: Bruce D. Gunderson; William J. Havel - Inventors: Bruce D. Gunderson; William J. Havel - Web page: https://patentgrep.com/patent/US10118042B2 ## CPC - A61N 1/37: Monitoring; Protecting - A61N 1/37258: {Alerting the patient} - 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 method includes sensing a cardiac electrogram (EGM) signal of a patient via one or more electrodes on at least one implantable medical lead. An asystolic EGM signal is detected from the patient, and a lead integrity test of the at least one implantable medical lead is initiated in response to the asystolic EGM signal. ## Claims ### Claim 1 A method comprising: sensing a cardiac electrogram (EGM) signal of a patient via one or more electrodes on at least one implantable medical lead; detecting an asystolic EGM signal from the patient, wherein detecting the asystolic EGM signal comprises detecting an absence of a cardiac depolarization in the cardiac EGM signal for at least a threshold time, and the threshold time is at least one second; initiating a lead integrity test of the at least one implantable medical lead during the asystolic EGM signal in response to detecting the asystolic EGM signal; detecting a lead-related condition based on the lead integrity test; and responsive to detecting the lead-related condition, modifying at least one of a sensing configuration and a therapy configuration and/or withholding delivery of therapeutic stimulation. ### Claim 2 (depends on 1) The method of claim 1, wherein initiating a lead integrity test comprises measuring an impedance for at least one electrical path that includes the electrodes on the at least one implantable lead, further wherein detecting the lead-related condition based at least on the measured impedance being greater than an impedance threshold. ### Claim 3 (depends on 1) The method of claim 1, wherein detecting the asystolic EGM signal and initiating the lead integrity test comprises detecting the asystolic EGM signal and triggering the lead integrity test with an implantable medical device coupled to the at least one implantable medical lead. ### Claim 4 (depends on 1) The method of claim 1, further comprising: receiving a signal that varies based on mechanical activity of the heart; and determining whether the signal that varies based on mechanical activity of the heart indicates asystole, wherein initiating the lead integrity test comprises initiating the lead integrity test in response to the asystolic EGM signal when the signal that varies based on mechanical activity of the heart does not indicate asystole. ### Claim 5 (depends on 4) The method of claim 4, wherein receiving a signal that varies based on mechanical activity of the heart comprises receiving a cardiac pressure signal. ### Claim 6 (depends on 1) The method of claim 1, wherein detecting the absence of the cardiac depolarization in the cardiac EGM signal for at least the threshold time, the threshold time being at least one second, comprises detecting the absence of the cardiac depolarization in the cardiac EGM signal for at least the threshold time, the threshold time being greater than one second. ### Claim 7 A method comprising: sensing a cardiac electrogram (EGM) signal of a patient via one or more electrodes on at least one implantable medical lead; detecting an asystolic EGM signal from the patient, wherein detecting the asystolic EGM signal comprises detecting an absence of a cardiac depolarization in the cardiac EGM signal for at least a threshold time, and the threshold time is at least one second: initiating a lead integrity test of the at least one implantable medical lead during the asystolic EGM signal in response to detecting the asystolic EGM signal; detecting a lead-related condition based on the lead integrity test; and at least one of storing the asystolic EGM signal or providing an alert in response to a result of the lead integrity test detecting the lead-related condition. ### Claim 8 A system comprising: at least one implantable medical lead comprising one or more electrodes; an implantable medical device (IMD) coupled to the at least one lead, wherein the IMD is configured to sense a cardiac electrogram (EGM) signal of a patient via the electrodes; and a processor configured to: detect an asystolic EGM signal based on detecting an absence of a cardiac depolarization in the cardiac EGM for at least a threshold time, wherein the threshold time is at least one second; control the IMD to perform a lead integrity test of the at least one lead in response to detecting the asystolic EGM signal, wherein the processor controls the IMD to perform the integrity test during the asystolic EGM signal; detect a lead-related condition based on the lead integrity test; and responsive to detecting the lead-related condition, control the IMD to at least one of change a sensing configuration, change a therapy configuration, withhold delivery of therapeutic stimulation, and/or generate an alert. ### Claim 9 (depends on 8) The system of claim 8, wherein the IMD comprises an impedance measurement module, and the processor controls the impedance measurement module to measure an impedance of each of one or more electrical paths that include the electrodes on the at least one implantable medical lead in response to the detection of the asystolic EGM signal and detect the lead-related condition based at least on the measured impedance being greater than an impedance threshold. ### Claim 10 (depends on 8) The system of claim 8, further comprising an analog-to-digital converter to digitize the signal, wherein the processor compares an amplitude of the digitized signal to a threshold to detect the absence of a cardiac depolarization in the cardiac EGM signal. ### Claim 11 (depends on 8) The system of claim 8, wherein the processor detects the absence of a cardiac depolarization in the cardiac EGM signal for at least the threshold time by at least detecting the absence of a cardiac depolarization in the cardiac EGM signal for at least one of a threshold duration or a threshold number of samples of the cardiac EGM signal. ### Claim 12 (depends on 8) The system of claim 8, further comprising an external programmer that presents the alert to a user in response to the integrity test. ### Claim 13 (depends on 8) The system of claim 8, wherein the processor comprises a processor of the IMD. ### Claim 14 (depends on 8) The system of claim 8, wherein the IMD comprises at least one of a pacemaker, a cardioverter, or a defibrillator. ### Claim 15 (depends on 8) The system of claim 8, further comprising a memory, wherein the processor at least one of: stores the sensed cardiac EGM signal in the memory in response to detecting the asystolic EGM signal, or activates a second alert in response to detecting the asystolic EGM signal. ### Claim 16 (depends on 8) The system of claim 8, further comprising a sensor coupled to the implantable medical lead, wherein the processor receives a signal that varies based on mechanical activity of the heart from the sensor, determines whether the signal that varies based on mechanical activity of the heart indicates asystole, and initiates the lead integrity test in response to the asystolic EGM signal when the signal that varies based on mechanical activity of the heart does not indicate asystole. ### Claim 17 (depends on 16) The system of claim 16, wherein the sensor comprises a pressure sensor and the signal that varies based on mechanical activity of the heart comprises a cardiac pressure signal. ### Claim 18 A system comprising: means for detecting an asystolic cardiac electrogram (EGM) signal of a patient via one or more electrodes on at least one implantable medical lead, wherein sensing the asystolic cardiac EGM signal comprises sensing an absence of cardiac depolarization in the cardiac EGM signal for at least a threshold time, and wherein the threshold time is at least one second; and means for initiating a lead integrity test of the at least one implantable medical lead during the asystolic EGM signal in response to the detection of the asystolic cardiac EGM signal means for detecting a lead-related condition based on the lead integrity test; and responsive to detecting the lead-related condition, means for adjusting operation of the system, wherein the adjusting comprise at least one of changing a sensing configuration, changing a therapy configuration, withholding delivery of therapeutic stimulation, and/or generating an alert.