Abstract: A device and method can monitor or trend a patient's respiration rate measurements according to the time of day. The device, which may be implantable or external, collects and classifies respiration rate measurements over time. The trended information about particular classes of respiration rate measurements is then communicated to a remote external device, which in turn provides an indication of heart failure decompensation. Examples of classes of respiration rate measurements include a daily maximum respiration rate value, a daily minimum respiration rate value, a daily maximum respiration rate variability value, a daily minimum respiration rate variability value, and a daily central respiration rate value. These respiration rate measurements can be further classified into daytime or nighttime respiration rate measurements.

Abstract: The invention relates to a method and apparatus for determining a respiration of a subject (305) in which, with a single multi-axial accelerometer (310) positioned on a body of the subject (305), accelerometer signals are generated (101) indicative of the acceleration of the subject (305) along different spatial axes, a vector magnitude signal of the acceleration of the subject (305) along the different spatial axes is calculated (102) from the accelerometer signals, a non-respiratory motion contribution to the acceleration along the different spatial axes is identified (103, 203) from the vector magnitude signal, which non-respiratory motion contribution is not caused by the respiration, and a respiration signal indicative of the respiration of the subject is determined (104, 204) by filtering the non-respiratory motion contribution from at least one of the accelerometer signals.

Abstract: Systems and associated methods are provided for automatically identifying a problem with sensing heart activity. In use, a plurality of heartbeats is sensed utilizing an implantable medical device. Further, data associated with the heartbeats is collected and stored. To this end, a problem with the sensing of the heartbeats (e.g., oversensing, undersensing, etc.) may be automatically identified and corrected, utilizing the data.

Abstract: The invention is a distributed implantable neuro-stimulation system, comprising an implant controller including control logic to transmit two time-varying power signals, varying between two levels and out of phase with the other, and a command signal modulated onto at least one of the power signals. One or more electrode cells, each having control logic to extract charge from the power signals and recover commands from the command signal. A two-wire bus interconnecting the implant controller and all the electrode cells, to carry one of the time varying signals in each of the two wires, and to carry the command signal.

Abstract: An implantable medical device applies an electric signal to at least a portion of a heart in a subject. A resulting electric signal is collected from the heart and is used together with the applied signal for determining a cardiogenic impedance signal. The impedance signal is processed in order to estimate an isovolumetric contraction time, an isovolumetric relaxation time and an ejection time for a heart cycle. These three time parameters are employed for calculating a Tei-index of the heart. The Tei-index can be used as myocardial performance parameter in heart diagnosis and/or cardiac therapy adjustment.

Abstract: Methods of threshold testing and setting a voltage on an artificial pacemaker based on the output of a plethymograph, such as an oximeter, are disclosed herein. This is accomplished by determining blood volume in a limb or area of the body, and its change over time. As voltage is decreased in the pacemaker, a change in blood volume of the limb being measured by the oximeter is determined. This change can be a change in how often the blood volume level rises to its peak level and/or the blood volume level no longer rises substantially. Such changes, or lack thereof, can be based on a backup heart rate or no heart rate at all. Once the threshold voltage is determined where the artificial pacemaker ceases to cause a heartbeat, the voltage of the pacemaker can be set accordingly.

Abstract: A method of counterpulsation therapy is provided, the method comprising use of a combination of cardiac electrical activity and acoustic signals in such a manner that initially R wave on a cardiogram and then II (aortic) sound are determined, and, after the II sound has been determined, stimulation of muscles by means of electric impulses is initiated. A device for performing the above described method comprises a sensor of the signal of cardiac electrical activity and a sensor of cardiac acoustic signal; a unit for blocking the cardiac electrical activity signal; a unit for blocking the acoustic signal; and a control device coupled with muscle stimulating devices.

Abstract: A leadless pacing device (LPD) includes a motion sensor configured to generate a motion signal as a function of heart movement. The LPD is configured to analyze the motion signal within an atrial contraction detection window that begins an atrial contraction detection delay period after activation of the ventricle, and detect a contraction of an atrium of the heart based on the analysis of the motion signal within the atrial contraction detection window. If the LPD does not detect a ventricular depolarization subsequent to the atrial contraction, e.g., with an atrio-ventricular (AV) interval beginning when the atrial contraction was detected, the LPD delivers a ventricular pacing pulse.

Abstract: Methods and/or devices used in delivering cardiac resynchronization therapy based on a plurality of device parameters (e.g., A-V delay, V-V delay, etc.) are optimized by setting a device parameter based on selection data. The selection data may be acquired by acquiring temporal fiducial points (e.g., heart sounds) associated with at least a part of a systolic portion of at least one cardiac cycle and/or temporal fiducial points associated with at least a part of a diastolic portion of the at least one cardiac cycle for each of a plurality of electrode vector configurations, and extracting measurements from the intracardiac impedance signal acquired for each of a plurality of electrode vector configurations based on the temporal fiducial points. The acquired selection data may be scored and used to optimize the device parameter.

Abstract: This disclosure describes techniques implemented by a medical device, such as an implantable medical device (IMD). The IMD may be configured to detect a posture state of a patient, and deliver posture-responsive therapy. In particular, the IMD not only detects the posture state of a patient, but also detects timing associated with the detected posture state, such as the time of day, the day of the week, or a specific time of day associated with a specific day. In this way, the posture-responsive therapy delivered by the IMD may be dependent not only on the posture state of the patient, but also on the timing associated with the posture state. The same posture state, therefore, may result in different types of therapy to the patient if the same posture occurs at different times of the day.

Abstract: An orthopedic implant having a three-axis accelerometer is disclosed. The three-axis accelerometer is used to detect micro-motion in the implant. The micro-motion can be due to loosening of the implant. The implant is configured to couple to the muscular-skeletal system. In one embodiment, the implant is configured to couple to bone. An impact force is imparted to the bone or implant. The impact force can be provided via a transducer coupled to the implant. In the example, the impact force is imparted along a single axis. The three-axis accelerometer measures the impact force along each axis. Resultant peaks of the quantitative measurement and the frequencies at which they occur are measured. The peaks and frequencies of the measurements correspond to micro-motion. Typically, the frequency of interest is less than 1 KHz to determine if micro-motion is occurring.

Abstract: A method and system of cardiac pacing is disclosed. A baseline rhythm is determined. The baseline rhythm includes a baseline atrial event and a baseline right ventricular RV event from an implanted cardiac lead or a leadless device, a pre-excitation interval determined from the baseline atrial event and the baseline RV event, and a plurality of activation times determined from a plurality of body-surface electrodes. A determination is made as to whether a time interval measured from an atrial event to a RV event is disparate from another time interval measured from the atrial event to an earliest RV activation time of the plurality of activation times. A correction factor is applied to the pre-excitation interval to obtain a corrected pre-excitation interval in response to determining the RV event is disparate from the earliest RV activation time.

Abstract: An implantable activity detector can detect metabolic stress levels, which can be normalized, such as to identify times of activities such as walking and running or to identify trends such as a decrease in metabolic activity. The data can be derived from different sources such as an accelerometer and pedometer. This data can be compared to independently specifiable thresholds, such as to trigger an alert or responsive therapy, or to display one or more trends. The information can also be combined with other congestive heart failure (CHF) indications. The alert can notify the patient or a caregiver, such as via remote monitoring. Metabolic activity data from one or more of the activity detectors can be used to establish a model of metabolic stress, to which further activity data can be compared for identifying periods of increased or decreased metabolic stress.

Abstract: An implantable medical device applies an electric signal to at least a portion of a heart in a subject. A resulting electric signal is collected from the heart and is used together with the applied signal for determining a cardiogenic impedance signal. The impedance signal is processed in order to estimate an isovolumetric contraction time, an isovolumetric relaxation time and an ejection time for a heart cycle. These three time parameters are employed for calculating a Tei-index of the heart. The Tei-index can be used as myocardial performance parameter in heart diagnosis and/or cardiac therapy adjustment.

Abstract: A rules engine acquires sensor data from sensors applied to the heart and detects an intrinsic beat of the heart. The rules engine determines whether an electrical waveform should be applied to the heart and, if so, the type of electrical waveform.

Abstract: A method and a system of phrenic nerve stimulation detection in conjunction with posture sensing is disclosed. In an embodiment, the method may include receiving a trigger for conducting a pace-induced phrenic nerve stimulation (PS) search using the IMD within the patient. On receiving the trigger, the IMD may be used for conducting the PS search. A procedure of conducting the PS search may include measuring a posture of the patient using an implantable posture sensor, searching for PS while the patient is in the measured posture and obtaining a PS result from the PS search for the measured posture. The method may include recording both the PS result and the measured posture in a memory of the IMD.

Abstract: A wireless communication device (200) and method (300) customizable power management. The method (300) can include: providing (310) a wireless communication device including an energy storage device; sensing (320) heart rate data of a user; and configuring (330) the wireless communication device's functionality based on the sensed heart rate data. Advantageously, the device (200) and method (300) can provide a real-time attribute of a user, which can be used to configure the functionality of a device and conserve power.

Abstract: A method of controlling pulmonary capillary pressure is disclosed which includes increasing the output of a first ventricle (V1) (e.g., a left ventricle) relative to second ventricle (e.g., right ventricle) by increasing the magnitude of a post extrasystolic potentiation (PESP) therapy effect in the first ventricle relative to the magnitude of a PESP therapy effect produced in the second ventricle. In certain embodiments of the invention, this may be accomplished by adjusting the extra-stimulus interval (ESI) in either or both of the left ventricle and the right ventricle, for example.

Abstract: Techniques are provided for estimating electrical conduction delays with the heart of a patient based on measured immittance values. In one example, impedance or admittance values are measured within the heart of a patient by a pacemaker or other implantable medical device, then used by the device to estimate cardiac electrical conduction delays. A first set of predetermined conversion factors may be used to convert the measured immittance values into conduction delay values. In some examples, the device then uses the estimated conduction delay values to estimate LAP or other cardiac pressure values. A second set of predetermined conversion factors may be used to convert the estimated conduction delays into pressure values. Techniques are also described for adaptively adjusting pacing parameters based on estimated LAP.

Abstract: An active implantable medical device includes digital processor circuits configured to sense right and left atrial depolarizations and deliver left atrial stimulation pulses according to a stimulation protocol. The stimulation protocol includes delivering a left atrial stimulation pulse at an inter-atrial coupling interval. The inter-atrial coupling interval is a coupling interval shorter than the sinus rhythm coupling interval, so as to deliver a premature pulse. The protocol further includes delivering a not premature left-atrial stimulation pulse during an immediately subsequent cardiac cycle, at an inter-atrial coupling interval corresponding to the sinus rhythm coupling interval. The protocol also includes assessing the right atrial coupling interval between the right atrial depolarizations and comparing the right atrial coupling interval to the sinus rhythm coupling interval. And finally, modifying an adjustable controlling parameters if necessary according to the result of the comparison.

Abstract: Methods and devices for determining optimal Atrial to Ventricular (AV) pacing intervals and Ventricular to Ventricular (VV) delay intervals in order to optimize cardiac output. Impedance, preferably sub-threshold impedance, is measured across the heart at selected cardiac cycle times as a measure of chamber expansion or contraction. One embodiment measures impedance over a long AV interval to obtain the minimum impedance, indicative of maximum ventricular expansion, in order to set the AV interval. Another embodiment measures impedance change over a cycle and varies the AV pace interval in a binary search to converge on the AV interval causing maximum impedance change indicative of maximum ventricular output. Another method varies the right ventricle to left ventricle (VV) interval to converge on an impedance maximum indicative of minimum cardiac volume at end systole. Another embodiment varies the VV interval to maximize impedance change.

Abstract: Techniques are provided for use with implantable medical devices such as pacemakers for optimizing interventricular (VV) pacing delays for use with cardiac resynchronization therapy (CRT). In one example, ventricular electrical depolarization events are detected within a patient in whom the device is implanted. The onset of isovolumic ventricular mechanical contraction is also detected based on cardiomechanical signals detected by the device, such as cardiogenic impedance (Z) signals, S1 heart sounds or left atrial pressure (LAP) signals. Then, an electromechanical time delay (T_QtoVC) between ventricular electrical depolarization and the onset of isovolumic ventricular mechanical contraction is determined. VV pacing delays are set to minimize the time delay to the onset of isovolumic ventricular mechanical contraction. Various techniques for identifying the onset of isovolumic ventricular contraction based on Z, S1 or LAP or other cardiomechanical signals are described.

Abstract: Techniques and systems for monitoring cardiac arrhythmias and delivering electrical stimulation therapy using a subcutaneous device (e.g. subcutaneous implantable (SD)) and a leadless pacing device (LPD) are described. In one or more embodiments, a computer-implemented method includes sensing a first electrical signal from a heart of a patient through a SD. The first signal is stored into memory and serves as a baseline rhythm for a patient. Subsequently, a second signal is sensed from the heart through the SD. A cardiac condition can be detected within the sensed second electrical signal through the SD. A determination is made as to whether cardiac resynchronization therapy (CRT) is appropriate to treat the detected cardiac condition. A determination can then be made as to the timing of pacing pulse delivery to cardiac tissue through a leadless pacing device (LPD). The LPD receives communication from the SD requesting the LPD to deliver CRT to the heart.

Abstract: Techniques and systems for monitoring cardiac arrhythmias and delivering electrical stimulation therapy using a subcutaneous device (e.g. subcutaneous implantable (SD)) is described. In one or more other embodiments, SD is implanted into a patient's heart. Electrical signals are then sensed which includes moderately lengthened QRS duration data from the patient's heart. A determination is made as to whether cardiac resynchronization pacing therapy (CRT pacing) is appropriate based upon the moderately lengthened QRS duration in the sensed electrical signals. The CRT pacing pulses are delivered to the heart using electrodes. In one or more embodiments, the SD can switch between fusion pacing and biventricular pacing based upon data (e.g. moderately lengthened QRS, etc.) sensed from the heart.

Abstract: Disclosed techniques include monitoring a physiological characteristic of a patient with a sensor that is mounted to an inner wall of a thoracic cavity of the patient, and sending a signal based on the monitored physiological characteristic from the sensor to a remote device.

Abstract: In a device and a method for providing correlated measures for predicting potential occurrence of atrial fibrillation, an impedance of the patient is measured to obtain impedance information; cardiogenic data is determined from the information; respiratory data is determined from the information; at least one hemodynamic measure is calculated from the cardiogenic data and at least one apnea measure is calculated from the respiratory data; the hemodynamic and apnea measures are correlated such that the correlated measures can be utilized for predicting potential occurrence of atrial fibrillation.

Abstract: An implantable medical device, comprised of at least one lead configured to be located proximate to a heart, the at least one lead including electrodes, at least a portion of the electrodes configured to sense cardiac activity. A therapy module configured to control delivery of pacing pulses in accordance with a therapy timing and based on the cardiac sensed activity sensed. Cardiac impedance (CI) sensor circuitry configured to be coupled to at least a first combination of the electrodes to sense cardiac impedance (CI), the CI sensor circuitry generating an impedance data stream associated with a corresponding CI sensing vector.

Abstract: Methods and devices for analyzing posture-induced changes to physiological parameters of a patient (e.g., ejection time, heart rate, etc.) to provide an assessment of one or more conditions of the patient.

Abstract: An exemplary embodiment includes acquiring an electroneurogram of the right carotid sinus nerve or the left carotid sinus nerve, analyzing the electroneurogram for at least one of chemosensory information and barosensory information and calling for one or more therapeutic actions based at least in part on the analyzing. Therapeutic actions may aim to treat conditions such as sleep apnea, an increase in metabolic demand, hypoglycemia, hypertension, renal failure, and congestive heart failure. Other exemplary methods, devices, systems, etc., are also disclosed.

Abstract: A device produces at least two distinct temporal components (Vbip, Vuni) from two separate endocardial electrogram (EGM) signals concurrently collected. The capture test determines a non-temporal 2D characteristic (VGM) representative of the cardiac cycle to be analyzed. The VGM is constructed using variations of one of the temporal components (Vuni) according to the other (Vbip). The devices determines the presence or absence of capture by analysis of this characteristic relative to a two dimensional domain.

Abstract: An implantable medical device such as an implantable pulse generator that includes EEG sensing for monitoring and treating neurological conditions, and leadless ECG sensing for monitoring cardiac signals. The device includes a connector block with provisions for cardiac leads which may be used/enabled when needed. If significant co-morbid cardiac events are observed in patients via the leadless ECG monitoring, then cardiac leads may be subsequently connected for therapeutic use.

Abstract: Devices and methods for detecting physiological target event such as events indicative of heart failure (HF) decompensation status are described. An ambulatory medical device (AMD) can detect device site maturation such as in a device encapsulation pocket, and classify the maturation status into one of two or more device site maturation states. The AMD can include an electrical impedance analyzer circuit that can measure a first maturation-insensitive impedance vector and a second maturation-sensitive impedance vector. At least one impedance vector can be selected or a composite impedance vector can be generated in accordance with the classified device site maturation state. The AMD can generate an impedance indicator using the selected or composite impedance vector, and detect a target physiologic event indicative of worsening of HF using the impedance indicator.

Abstract: A device includes a signal generator module, a processing module, and a housing. The signal generator module is configured to deliver pacing pulses to an atrium. The processing module is configured to detect a ventricular activation event and determine a length of an interval between the ventricular activation event and a previous atrial event that preceded the ventricular activation event. The processing module is further configured to schedule a time at which to deliver a pacing pulse to the atrium based on the length of the interval and control the signal generator module to deliver the pacing pulse at the scheduled time. The housing is configured for implantation within the atrium. The housing encloses the stimulation generator and the processing module.

Abstract: Described herein are implantable systems and devices, and methods for use therewith, that can be used to perform arrhythmia discrimination. A plurality of different sensing vectors are used to obtain a plurality of different IEGMs, each of which is indicative of cardiac electrical activity at a different ventricular region. The plurality of different IEGMs can include, e.g., an IEGM indicative of cardiac electrical activity at a first region of the patient's left ventricular (LV) chamber and an IEGM indicative of cardiac electrical activity at a second region of the patient's LV chamber. Additionally, the plurality of different IEGMs can further include an IEGM indicative of cardiac electrical activity at a region of a patient's right ventricular (RV) chamber. For each of the IEGMs, there is a determination of a corresponding localized R-R interval stability metric indicative of the R-R interval stability at the corresponding ventricular region. This can include, e.g.

Abstract: Various system embodiments comprise a stimulator adapted to deliver a stimulation signal for a heart failure therapy, a number of sensors adapted to provide at least a first measurement of a heart failure status and a second measurement of the heart failure status, and a controller. The controller is connected to the stimulator and to the number of sensors. The controller is adapted to use the first and second measurements to create a heart failure status index, and control the stimulator to modulate the signal using the index. Other aspects and embodiments are provided herein.

Abstract: An implantable cardiac device includes a sensor for sensing patient activity and detecting phrenic nerve activation. A first filter channel attenuates first frequencies of the sensor signal to produce a first filtered output. A second filter channel attenuates second frequencies of the accelerometer signal to produce a second filtered output. Patient activity is evaluated using the first filtered output and phrenic nerve activation caused by cardiac pacing is detected using the second filtered output.

Abstract: Treatment of heart failure in a patient by electrically modulating both the sympathetic and parasympathetic autonomic cardiac nerve fibers that innervate the patient's heart at an extravascular site in the pericardial space of the heart. The extravascular site is any suitable single location inside the chest cavity that carries both sympathetic and parasympathetic cardiac nerves such as the cardiac plexus or the pericardial transverse sinus or any two separate extravascular sites with one site carrying predominantly sympathetic cardiac nerves and the other site carrying predominantly parasympathetic cardiac nerves for electrically modulating the balance of autonomic cardiac nerve control.

Abstract: Techniques are provided for controlling spinal cord stimulation (SCS) or other forms of neurostimulation. Far-field cardiac electrical signals are sensed using a lead of the SCS device and neurostimulation is selectively delivering using a set of adjustable SCS control parameters. Parameters representative of cardiac rhythm are derived from the far-field cardiac electrical signals. The parameters representative of cardiac rhythm are correlated with SCS control parameters to thereby map neurostimulation control settings to cardiac rhythm parameters. The delivery of further neurostimulation is then controlled based on the mapping of neurostimulation control settings to cardiac rhythm parameters to, for example, address any cardiovascular disorders detected based on the far-field cardiac signals. In this manner, a closed loop control system is provided to automatically adjust SCS control parameters to respond to changes in cardiac rhythm such as changes associated with ischemia, arrhythmia or heart failure.

Abstract: A heart rate variability or heart rate variation can be identified using sensed and/or paced heart beats. One or more patient metrics, such as a variability index or a variation index, can correspond to the identified heart rate variability or heart rate variation. The patient metrics can be used to identify a need for a particular therapy, such as a rate-responsive pacing therapy. The patient metrics can be used to identify patients at an elevated risk of death. Methods and systems to identify therapy indications or at-risk patients are provided. In an example, a patient risk profile can be adjusted, such as in response to an identified patient heart rate variability or heart rate variation. In an example, a rate-responsive pacing mode can be used to adjust the patient risk profile.

Abstract: Methods, systems and computer program products for cardiac pacing are provided. For pacing using biventricular synchronization in a patient, a first stimulation signal is applied to a first region of a heart of the patient at a first time and a second stimulation signal applied to a second region of the heart of the patient at a second time to provide biventricular synchronization stimulation of the heart. Cardiac function of the patient associated with application of the first and the second stimulation signals is sensed and a timing relationship of the first stimulation signal to the second stimulation signal is adjusted based on the sensed cardiac function.

Abstract: An electrode stimulation delivery system is described having a unit and a network of wireless remote electrodes configured for implantation within a plurality of spaced apart locations in the tissue, e.g. myocardium, of a patient. The control unit is configured to be positioned at or subcutaneous to the patient's skin, and includes a processor, an antenna configured for delivering RF energy in proximity to the plurality of wireless remote electrodes, and programming executable on the processor for wirelessly communicating to the network of wireless remote electrodes via the delivered RF energy to individually control pacing of the plurality of wireless remote electrodes. Each of the plurality of wireless remote electrodes comprises a metamaterial-based biomimetic harvesting antenna comprising a Van Atta array zero-phase transmission lines to receive the RF energy to power activation of the plurality of wireless remote electrodes.

Abstract: A system and method provide for systolic interval analysis. In an example, an implantable device measures a cardiac impedance signal. A transformation of the cardiac impedance interval is generated. The device also measures a heart sound signal. A time interval between a point on the transformed signal of the cardiac impedance signal and a point on the heart sound signal is calculated.

Abstract: A method and system are provided to analyze valve related timing and monitor heart failure. The method and system comprise collecting cardiac signals associated with an atrial chamber of interest; collecting dynamic impedance (DI) data along an atria-function focused (AFF) vector to form a DI data set, the DI data set including information corresponding to a mechanical function (MF) of a valve associated with the atrial chamber of interest; identifying, from the cardiac signals, an intra-atrial conduction timing (IACT) associated with the atrial chamber of interest; estimating an MF landmark at which the mechanical function of the valve occurs based on the DI data set; analyzing a timing delay between the MF landmark and the IACT; and adjusting a therapy, based on the timing delay, to encourage atrial contribution to ventricular filling.

Abstract: An implantable sensor circuit can be configured to generate a first sensor signal representative of mechanical activation of a first chamber of a heart of a subject and a second sensor signal representative of mechanical activation of a second chamber of the heart. A chamber synchrony measurement circuit can be configured to generate a measure of synchrony of the mechanical activations of the first heart chamber and the second heart chamber using the first and second sensor signals, a tachyarrhythmia detector circuit, and a control circuit. The control circuit can be configured to receive an indication of a detected episode of tachyarrhythmia, and to initiate, select, or adjust a device-based therapy at least in part using the measure of synchrony of the mechanical activations in response to the tachyarrhythmia detection.

Abstract: The invention relates to improved cardiac pacemakers and methods of use thereof. In particular the cardiac pacemakers are useful for normalizing heart rates over resting heart rates in order to condition the heart to improve overall cardiac output.

Abstract: Devices and methods for sleep detection involve the use of an adjustable threshold for detecting sleep onset and termination. A method for detecting sleep includes adjusting a sleep threshold associated with a first sleep-related signal using a second sleep-related signal. The first sleep-related signal is compared to the adjusted threshold and sleep is detected based on the comparison. The sleep-related signals may be derived from implantable or external sensors. Additional sleep-related signals may be used to confirm the sleep condition. A sleep detector device implementing a sleep detection method may be a component of an implantable pulse generator such as a pacemaker or defibrillator.

Abstract: Medical devices and methods for providing breathing therapy (e.g., for treating heart failure, hypertension, etc.) may determine at least the inspiration phase of one or more breathing cycles based on the monitored physiological parameters and control delivery of a plurality of breathing therapy sessions (e.g., each of the breathing therapy sessions may be provided during a defined time period). Further, each of the plurality of breathing therapy sessions may include delivering stimulation after the start of the inspiration phase of each of a plurality of breathing cycles to prolong diaphragm contraction during the breathing cycle.

Abstract: Approaches to rank potential left ventricular (LV) pacing vectors are described. Early elimination tests are performed to determine the viability of LV cathode electrodes. Some LV cathodes are eliminated from further testing based on the early elimination tests. LV cathodes identified as viable cathodes are tested further. Viable LV cathode electrodes are tested for hemodynamic efficacy. Cardiac capture and phrenic nerve activation thresholds are then measured for potential LV pacing vectors comprising a viable LV cathode electrode and an anode electrode. The potential LV pacing vectors are ranked based on one or more of the hemodynamic efficacy of the LV cathodes, the cardiac capture thresholds, and the phrenic nerve activation thresholds.

Abstract: A medical device system performs a method for determining presence of scar tissue through an implanted lead having an electrode for cardiac pacing and sensing. A sensing module senses heart activity with the electrode to produce a unipolar electrogram (EGM) waveform. A processor receives the unipolar EGM waveform and extracts two or more features representative of heart activity at the electrode. Scar tissue is identified at the site of the first electrode based upon at least two of the extracted features indicating scar tissue.

Abstract: A method and system of cardiac pacing is disclosed. A baseline rhythm is determined. The baseline rhythm includes a baseline atrial event and a baseline right ventricular RV event from an implanted cardiac lead or a leadless device, a pre-excitation interval determined from the baseline atrial event and the baseline RV event, and a plurality of activation times determined from a plurality of body-surface electrodes. A determination is made as to whether a time interval measured from an atrial event to a RV event is disparate from another time interval measured from the atrial event to an earliest RV activation time of the plurality of activation times. A correction factor is applied to the pre-excitation interval to obtain a corrected pre-excitation interval in response to determining the RV event is disparate from the earliest RV activation time.