Abstract: Systems and methods to monitor cardiac mechanical vibrations using information indicative of lead motion are described. In an example, a system including an implantable medical device can include an excitation circuit configured to provide a non-tissue stimulating, non-therapeutic electrical excitation signal to a portion of an implantable lead. A receiver circuit can be configured to obtain information indicative of a mechanical vibration of the implantable lead due at least in part to one or more of an impact of at least a portion of the heart to the implantable lead, or friction contact between the implantable lead and cardiac tissue. The system can include a processor circuit configured to determine one or more of a lead mechanical status, or information indicative of valvular activity using the information indicative of the mechanical vibration of the implantable lead.

Abstract: A maximum pacing rate limiter for use in adaptive rate pacing in conjunction with a cardiac rhythm management system for a heart. The maximum pacing rate limiter may function to measure an interval, termed the ERT interval, between a paced ventricular evoked response and a T-wave. The maximum pacing rate limiter may further function to maintain the ERT interval at less than a certain percentage of the total cardiac cycle. In one disclosed embodiment, a maximum pacing rate limiter calculates an ERT rate based on the detected paced ventricular evoked response and the T-wave, and the pacing rate limiter module further communicates the minimum of the ERT rate and an adaptive-rate sensor indicated rate to a pacemaker.

Abstract: The present invention provides methods for detecting phrenic nerve stimulation. A pacing module is instructed to deliver pacing pulses having a predetermined pulse amplitude and/or width within the refractory period of the left ventricle. The pacing pulses are repeatedly delivered during a number of cardiac cycles and wherein the pacing pulses are delivered at different delays relative to an onset of the refractory period of the left ventricle in different cardiac cycles. Impedance signals are measured in time windows synchronized with the delivery of pacing pulses in the refractory period of the left ventricle using at least one electrode configuration. At least one impedance signal is gathered from each time window, aggregated impedance signals are created using the impedance signals from the different time windows, and the aggregated impedance signals are analyzed to detect PNS.

Abstract: The present invention provides implantable medical devices for detecting phrenic nerve stimulation. A pacing module is configured to deliver pacing pulses having a predetermined pulse amplitude and/or width within the refractory period of the left ventricle. The pacing pulses are repeatedly delivered during a number of cardiac cycles, and the pacing pulses are delivered at different delays relative to an onset of the refractory period of the left ventricle in different cardiac cycles. An impedance measurement module is configured to measure impedance signals in time windows synchronized with the delivery of pacing pulses in the refractory period of the left ventricle. A phrenic nerve stimulation, PNS, detection module is configured to gather at least one impedance signal from each time window, create aggregated impedance signals using the impedance signals from the different time windows, and analyze the aggregated impedance signals to detect PNS.

Abstract: The disclosure described techniques for associating therapy adjustments with intended patient posture states. The techniques may include receiving a patient therapy adjustment to a parameter of a therapy program that defines electrical stimulation therapy delivered to the patient, identifying a posture state of the patient, and associating the patient therapy adjustment with the posture state when the patient therapy adjustment is within a range determined based on stored adjustment information for the identified posture state.

Abstract: A neural stimulation system senses autonomic activities and applies neural stimulation to sympathetic and parasympathetic nerves to control autonomic balance. The neural stimulation system is capable of delivering neural stimulation pulses for sympathetic excitation, sympathetic inhibition, parasympathetic excitation, and parasympathetic inhibition.

Abstract: An implantable medical device, IMD, (100) conducts CRT settings searches at multiple CRT settings search periods during an optimization time period by testing different candidate CRT settings and selecting the optimal CRT setting based on output signals of a hemodynamic sensor (240). The respective optimal CRT settings determined during the optimization time period are employed in order to predict at least one future optimal CRT setting that can be used by the IMD (100) following the end of the optimization time period. The IMD (100) then generates and applies pacing pulses to a subject's (5) heart (10) according to a CRT setting of the at least one future optimal CRT setting. The embodiments therefore enable efficient cardiac resynchronization therapy without any sensor readings after the end of the optimization time period and can therefore provide cardiac resynchronization therapy even if the hemodynamic sensor (240) becomes inoperable.

Abstract: An adaptive dual chamber pacemaker and/or cardioverter defibrillator for delivering ventricular stimulation to the heart correlated with hemodynamic performance of the heart, including a hemodynamic sensor for monitoring the hemodynamic performance of the heart, an atrial electrode and a ventricular electrode for sensing ventricular and atrial signals, and a learning module having a spiking neural network processor for learning to associate the ventricular-atrial intervals sensed by the electrodes with the hemodynamic performance sensed by the hemodynamic sensor, calculating ventricular-atrial intervals, replacing the ventricular-atrial intervals calculated from the sensed ventricular and atrial signals with the learned associated ventricular-atrial intervals, and causing delivery according to the learned associated ventricular-atrial intervals of a ventricular stimulation to the heart during atrial fibrillation episodes.

Abstract: Techniques are provided for use by an implantable medical device for optimizing the amount of ventricular dyssynchrony induced within a patient during protective pacing. In one example, the device analyzes intracardiac electrogram signals to detect an ischemic event within the heart. The device then delivers pacing stimulus in accordance with adjustable pacing parameters to induce ventricular dyssynchrony within the heart and adjusts the pacing parameters within a range of permissible values to achieve a preferred degree of ventricular dyssynchrony within the patient, so long as there is no significant reduction in left ventricular pumping functionality. Preferably, the pacing parameters are adjusted to maximize or otherwise optimize the degree of dyssynchrony induced within the patient. If a significant reduction in LV pumping functionality is detected, the dyssynchrony-inducing pacing is preferably suspended to avoid any deterioration in the condition of the heart.

Abstract: Systems and methods using a heart valve and an implantable medical device, such as for event detection and optimization of cardiac output. The cardiac management system includes a heart valve, having a physiological sensor. The physiological sensor is adapted to measure at least one of an intrinsic electrical cardiac parameter, a hemodynamic parameter or the like. The system further includes an implantable electronics unit, such as a cardiac rhythm management unit, coupled to the physiological sensor of the heart valve to receive physiological information. The electronics unit is adapted to use the received physiological information to control delivery of an electrical output to the subject.

Abstract: Various techniques are disclosed for facilitating selection of at least one vector from among a plurality of vectors for pacing a chamber of a heart. In one example, a method includes presenting, by a computing device, a plurality of criteria by which each of the plurality of vectors may be prioritized, selecting at least one criterion from among a plurality of criteria by which each of the plurality of vectors may be prioritized, measuring the at least one selected criterion for each of the plurality of vectors, and automatically prioritizing, by the computing device, the plurality of vectors based on the measurement of the at least one selected criterion.

Abstract: A medical device system includes electrodes for delivering cardiac pacing pulses to a patient's heart, a cardiac sensing module coupled to the electrodes and a cardiac pacing module coupled to the electrodes for generating cardiac pacing pulses. An acoustical sensor is used for obtaining heart sound signals. The system includes a processor that is configured to establish multiple conditions during which heart sound signals are received. The processor derives heart sound signal parameters from the heart sound signals and determines a heart sound profile comprising a trend of each of the heart sound signal parameters with respect to the multiple established conditions.

Abstract: A system to measure intracardiac impedance includes implantable electrodes and a medical device. The electrodes sense electrical signals of a heart of a subject. The medical device includes a cardiac signal sensing circuit coupled to the implantable electrodes, an impedance measurement circuit coupled to the same or different implantable electrodes, and a controller circuit coupled to the cardiac signal sensing circuit and the impedance measurement circuit. The cardiac signal sensing circuit provides a sensed cardiac signal. The impedance measurement circuit senses intracardiac impedance between the electrodes to obtain an intracardiac impedance signal. The controller circuit determines cardiac cycles of the subject using the sensed cardiac signal, and detects tachyarrhythmia using cardiac-cycle to cardiac-cycle changes in a plurality of intracardiac impedance parameters obtained from the intracardiac impedance signal.

Abstract: The invention relates to cardiac rhythm management systems, and more particularly, to rate adaptive cardiac pacing systems and methods. In an embodiment, the invention includes a cardiac rhythm management device. The device can include a pulse generator for generating electrical pulses to be delivered to a heart at a pacing rate, a processor in communication with the pulse generator, and one or more sensors for sensing pulmonary function and cardiac function. The processor can be configured to increase the pacing rate if the pulmonary function is increasing with time and the cardiac function is not decreasing with time, maintain the pacing rate if the pulmonary function is increasing with time and the cardiac function is decreasing with time, and decrease the pacing rate if the respiratory function is decreasing with time.

Abstract: A medical device having a unit in communication with ancillary components wherein the unit and the ancillary components each have a sensory output through which communication with a user of the medical device may be accomplished and to which the user's attention directed. In one aspect, the medical device is an AED unit with associated pads, which are an ancillary component electrically connected to the AED unit. In this illustrative example, the unit has a unit sensory output (e.g., a speaker or a display), and the pads, and/or their associated packaging, have an ancillary sensory output (e.g. a speaker or display). Programming in the AED unit controls output to the sensory outputs such that the user's attention is directed between the unit and the ancillary components.

Abstract: This document discusses, among other things, an apparatus comprising an implantable cardiac depolarization sensing circuit, an electrical stimulation circuit, and a pacing mode controller. The pacing mode controller is configured to deliver pacing therapy according to a first pacing mode that is a normal operating mode, and to deliver pacing therapy according to second and third pacing modes. The second and third pacing modes increase mechanical stress on at least a particular portion of the ventricle as compared to the pacing therapy delivered during the first pacing mode. The pacing mode controller alternates between the second and third pacing modes when pacing is changed from the normal operating mode to a stress augmentation mode. The pacing mode controller suspends the change from the normal operating mode to the stress augmentation mode when a condition to prevent the change is detected.

Abstract: Aspects of the invention are directed to advanced monitoring and control of medium voltage therapy (MVT) in implantable and external devices. Apparatus and methods are disclosed that facilitate dynamic adjustment of MVT parameter values in response to new and changing circumstances such as the patient's condition before, during, and after administration of MVT. Administration of MVT is automatically and dynamically adjusted to achieve specific treatment or life-support objectives, such as prolongation of the body's ability to endure and respond to MVT, specifically addressing the type of arrhythmia or other pathologic state of the patient with targeted treatment, a tiered-intensity MVT treatment strategy, and supporting patients in non life-critical conditions where the heart may nevertheless benefit from a certain level of assistance.

Abstract: This patent document discusses, among other things, systems, devices, and methods for enhancing detection of pulmonary edema using, in addition to thoracic impedance, one or a combination of: physiologic information about a subject, at least one statistical parameter, a user-programmable detection level, at least one parameter associated with a previous pulmonary edema event, and patient symptom information about the subject. In one example, a (base) thoracic impedance threshold is modified to an adjusted thoracic impedance threshold. The adjusted thoracic impedance threshold provides an increased sensitivity of pulmonary edema detection as compared to the base thoracic impedance threshold. In another example, an alert is provided to a subject, a caregiver, or other user based on a pulmonary edema indication determined by the present systems, devices, and methods. In a further example, a therapy (provided to the subject) is adjusted or initiated in response to the pulmonary edema indication.

Abstract: Methods of treating acute heart failure in a patient in need thereof. Methods include inserting a therapy delivery device into a pulmonary artery of the patient and applying a therapy signal to autonomic cardiopulmonary fibers surrounding the pulmonary artery. The therapy signal affects heart contractility more than heart rate. Specifically, the application of the therapy signal increases heart contractility and treats the acute heart failure in the patient. The therapy signal can include electrical or chemical modulation.

Abstract: Methods for timing pacing pulses in an implantable single chamber pacemaker create a simulated, or virtual chamber in order to apply dual chamber-type algorithms and modes. For example, a virtual atrium may be constructed based on information provided by the ventricle, that is, the timing of actual intrinsic ventricular events, and the timing of paced ventricular events, both of which may be sensed as ventricular depolarization by electrodes of the implanted system.

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: 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: An apparatus comprises a cardiac signal sensing circuit configured to sense an electrical cardiac signal from at least one of an atrium or ventricle of a heart of a subject, a therapy circuit configured to provide electrical pacing therapy and electrical autonomic neural modulation therapy to the subject, and a control circuit. The control circuit is configured to initiate delivery of the autonomic modulation neural therapy, and the control circuit includes a signal detection circuit configured to detect delivery of the autonomic neural modulation therapy in the sensed cardiac signal. The control circuit is configured to change, in response to detecting the delivery, a sensitivity of the cardiac signal sensing circuit during delivery of the autonomic neural modulation therapy.

Abstract: An adaptive dual chamber pacemaker and/or cardioverter defibrillator for delivering ventricular stimulation to the heart correlated with hemodynamic performance of the heart, including a hemodynamic sensor for monitoring the hemodynamic performance of the heart, an atrial electrode and a ventricular electrode for sensing ventricular and atrial signals, and a learning module having a spiking neural network processor for learning to associate the ventricular-atrial intervals sensed by the electrodes with the hemodynamic performance sensed by the hemodynamic sensor, calculating ventricular-atrial intervals, replacing the ventricular-atrial intervals calculated from the sensed ventricular and atrial signals with the learned associated ventricular-atrial intervals, and causing delivery according to the learned associated ventricular-atrial intervals of a ventricular stimulation to the heart during atrial fibrillation episodes.

Abstract: Method and systems related to monitoring right ventricular function during pacing by a cardiac rhythm management device are described. One or more pacing parameters are selected to provide cardiac resynchronization therapy. For example, the one or more pacing parameters may be selected to provide an optimal or improved therapy. The heart is paced using the selected pacing parameters. While pacing with the selected parameters, pressure is sensed via a pressure sensor disposed the pulmonary artery. The sensed pressure is analyzed to determine right ventricular function achieved during the pacing using the selected pacing parameters. A signal, such as an alert signal or control signal, is generated based on the right ventricular function achieved during the pacing.

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: A system comprising implantable device, the implantable medical device including an intrinsic cardiac signal sensor, an impedance measurement circuit configured to apply a specified current to a transthoracic region of a subject and to sample a transthoracic voltage resulting from the specified current, and a processor coupled to the intrinsic cardiac signal sensor and the impedance measurement circuit. The processor is configured to initiate sampling of a transthoracic voltage signal in a specified time relation to a fiducial marker in a sensed intrinsic cardiac signal, wherein the sampling attenuates or removes variation with cardiac stroke volume from the transthoracic voltage signal, and determine lung respiration using the sampled transthoracic voltage signal.

Abstract: An implantable electrode lead for tissue stimulation adapted to be attached to an implantable tissue stimulator provided with a pulse generator, has at least two stimulation electrodes to apply stimulation pulses to said tissue and arranged close to the distal end of the electrode lead, and at least two electrical conductors to connect said electrodes to said pulse generator. The electrode lead further has a switching unit arranged close to the distal end of the electrode lead and adapted to switch the electrode lead between a local pacing mode and a normal pacing mode, the switching unit being controlled by a mode control signal. Further, a pacing module is arranged close to the distal end of the electrode lead and in relation to the switching unit and being connectable to said at least two stimulation electrodes, the pacing module includes a pulse generating unit to generate stimulating pulses to be applied to the tissue by the stimulation electrodes.

Abstract: A pacing system delivers cardiac protection pacing to protect the heart from injuries associated with ischemic events. The pacing system detects an ischemic event and, in response, initiates one or more cardiac protection pacing sequences each including alternative pacing and non-pacing periods. In one embodiment, the pacing system initiates cardiac protection pacing sequences including at least one postconditioning sequence to protect the heart from a detected ischemic event and a plurality prophylactic preconditioning sequences to protect the heart from probable future ischemic events.

Abstract: Implantable systems, and methods for use therewith, are provided for monitoring a patient's diastolic function and/or heart failure (HF) condition. A signal indicative of changes in arterial blood volume and a signal indicative of electrical activity of the patient's heart are obtained. Beginnings of diastolic periods can be detected based on a feature of the signal indicative of changes in arterial blood volume. Ends of the diastolic periods can be detected based on a feature of the signal indicative of electrical activity of the patient's heart, or on the signal indicative of changes in arterial blood volume. Diastolic periods (DPs), isovolumic relaxation times (IVRTs) and/or diastolic filling times (DiFTs) can be estimated based on the detected beginnings of the diastolic periods and detected ends of the diastolic periods. The patient's diastolic function and/or HF condition (and/or changes therein) can be monitored based on the estimates of DP, IVRT and/or DiFT.

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: Techniques for determining when to deliver a pre-excitation signal to damaged cardiac tissue, e.g., infarct tissue, of a ventricle during cardiac pacing are described. A medical device detects an intrinsic or paced atrial depolarization, and then detects a subsequent mechanical event, e.g., contraction, in a ventricle. As examples, the mechanical event may be detected by measuring ventricular movement, or changes in intracardiac or systemic blood pressure. The medical device determines an interval between the atrial depolarization and the ventricular mechanical event, which may be referred to as an A-Vm interval. By subtracting a pre-excitation interval (PEI) from the A-Vm, the medical device determines an A-V interval between an atrial depolarization and delivery of the pre-excitation signal.

Abstract: A cardiac rhythm management system comprises a medical electrical lead, a pressure sensing element, and an implantable pulse generator. The lead is sized to be advanced through the right atrium and coronary sinus into a coronary vein adjacent to the left ventricle. The lead includes an opening intermediate its proximal and distal ends, and a lumen extending longitudinally within the body in communication with the opening. The pressure sensing element is movably disposed in lead lumen and is dimensioned to extend through the opening in the lead, and includes a flexible, elongated conductive member having a distal end, and a pressure transducer coupled to the distal end of the conductive member. The pulse generator is configured to receive cardiac rhythm signals from the electrode and fluid pressure signals from the pressure transducer.

Abstract: This document discusses, among other things, systems and methods for measuring the dynamics of pulmonary congestion in heart failure subjects over time to monitor the subjects susceptibility to pulmonary edema, including sensing and receiving information indicative of a bodily pressure and information indicative of pulmonary fluid, and using the transient responses of these measurements to compute parameters related to the dynamics of thoracic fluid accumulation, such as a critical pressure (Pc), a critical time (Tc), or a filtration index (Kfi).

Abstract: Cardiac dyssynchrony of a patient may be evaluated based on electrical activity of a heart of the patient and corresponding chest wall motion of the patient sensed via an external accelerometer. In one example, an acceleration signal indicative of the chest wall motion is generated by an external accelerometer positioned on the chest wall of the patient. A processor of a diagnostic device integrates the acceleration signal to generate a velocity signal and temporally correlates the velocity signal and an electrical cardiac signal. The processor determines a time delay between a deflection of the electrical cardiac signal indicating ventricular electrical activation and a subsequent greatest peak of the velocity signal. The time delay may indicate a degree of electromechanical delay of the left ventricle. In some examples, the processor generates an output indicative of a cardiac dyssynchrony status based on the time delay.

Abstract: An aspect of the present subject matter relates to a baroreflex stimulator. An embodiment of the stimulator includes a pulse generator to provide a baroreflex stimulation signal through an electrode, and a modulator. The modulator modulates the baroreflex stimulation signal to increase the baroreflex stimulation therapy by a predetermined rate of change to lower systemic blood pressure to a target pressure. Other aspects are provided herein.

Abstract: A method of treating autonomic imbalance in a patient includes energizing a first therapeutic element disposed in a superior vena cava of the patient to deliver therapy to a parasympathetic nerve fiber (e.g. vagus nerve), and energizing a second therapeutic element disposed within the superior vena cava to deliver therapy to a sympathetic cardiac nerve fiber. A neuromodulation system includes a parasympathetic therapy element adapted for positioning within a blood vessel, a sympathetic therapy element adapted for positioning within the blood vessel; and a stimulator to energize the parasympathetic therapy element to deliver parasympathetic therapy to a parasympathetic nerve fiber disposed external to the blood vessel and energize the sympathetic therapy element within the blood vessel to deliver sympathetic therapy to a sympathetic nerve fiber disposed external to the blood vessel. The therapy decreases the patient's heart rate and elevates or maintains the blood pressure of the patient.

Abstract: In general, the disclosure describes techniques for modifying therapy provided to a patient by a medical device. The techniques may be applicable to electrical stimulation therapy or other therapies. Modification of therapy may include adjustment of one or more therapy parameter values that define one or more characteristics of stimulation therapy delivered to a patient. The therapy modification may be based on activity of a patient that is detected by an IMD, such as a change in a detected posture state occupied by the patient. Different therapy modifications may be applied for different changes in detected posture state. An IMD may modify therapy based on a transition from one posture state to another posture state, and apply different modifications for different transitions. In some aspects, the modification may include a profile, such as a ramp up or ramp down in a parameter value over a period of time. The profile may be different for different posture transitions.

Abstract: Techniques are provided for use by implantable medical devices for controlling ventricular pacing, particularly during atrial fibrillation. In one example, during a V sense test for use in optimizing ventricular pacing, the implantable device determines relative degrees of variation within antecedent and succedent intervals detected between ventricular events sensed on left ventricular (LV) and right ventricular (RV) sensing channels. Preferred or optimal ventricular pacing delays are then determined, in part, based on a comparison of the relative degrees of variation obtained during the V sense test. In another example, during RV and LV pace tests, the device distinguishes QRS complexes arising due to interventricular conduction from QRS complexes arising due to atrioventricular conduction from the atria, so as to permit the determination of correct paced interventricular conduction delays for the patient. The paced interventricular conduction delays are also used to optimize ventricular pacing.

Abstract: An exemplary 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 medical device includes one or more sensors used to acquire a multi-dimensional signal. In one embodiment, principal component analysis is performed on the multi-dimensional signal to produce signal data. The principal component analysis results are used to cancel signal artifact in one embodiment. A medical device controller produces one of a therapy control and a diagnostic output in response to the signal data.

Abstract: A method and apparatus for adjusting the electrogram (EGM) sensitivity level of an implantable medical device using intracardiac pressure data. An EGM is monitored to detect electrical events and intracardiac pressure is monitored to detect pressure waves. The electrical waves and pressure waves are analyzed to determine the presence of a one-to-one correlation, with the absence of a one-to-one correlation indicating the need to adjust the sensitivity level.

Abstract: An active implantable medical device for cardiac resynchronization therapy with effort based rate-responsive pacing is described. The device calculates a rate-responsive stimulation frequency based on output signal of an effort sensor between a base frequency (fbase) and a maximum frequency (fmax). The device determines a target stimulation frequency based on the difference between a first frequency and the maximum frequency (fmax). The first frequency is the higher frequency of the base frequency (fbase) and the spontaneous frequency of the patient. The device calculates a stimulation frequency that has an immediate increase in the pacing rate from the higher of the initial value of the current stimulation frequency, or the spontaneous frequency to the target stimulation frequency, within a predetermined time, or a predetermined number of cardiac cycles. A plurality of consecutive effort zones (Z1-Z4) is defined over the extent of the dynamic range of the output signal of the effort sensor.

Abstract: Systems and methods for optimizing the stimulation of a heart of a patient are disclosed herein. The method comprises delivering pacing therapy to the patient according to a pacing therapy setting schedule, using specific pacing intervals via specific electrode configurations. Further, sinus rate values are recorded over at least one cardiac cycle at each pacing therapy setting and it is determined whether a sinus rate value satisfies predetermined measurement conditions, wherein sinus rate values are used for trending the sinus rate over time if the measurement conditions are satisfied. The accepted sinus rate values, i.e. values that satisfy the measurement conditions, are trended over time, wherein each trended sinus rate value is created based on recordings from at least one cardiac cycle. A preferred pacing therapy setting is determined to be the pacing therapy setting that provides a lowest sinus rate.

Abstract: A neurostimulation system measures a cardiac parameter at various cardiac intervals and analyzes its restitution, including computing a restitution slope being a rate of change of the restitution parameter with respect to change in the cardiac interval. In various embodiments, the system uses the restitution slope to provide for adaptive control of neurostimulation. In various embodiments, one or more cardiac parameters such as action potential duration (APD), conduction velocity (CV), QT interval (QT), and/or T-wave morphology (TM) parameter are measured and analyzed for restitution of each parameter, which is then used to control the delivery of the neurostimulation.

Abstract: A medical device system includes electrodes for delivering cardiac pacing pulses to a patient's heart, a cardiac sensing module coupled to the electrodes and a cardiac pacing module coupled to the electrodes for generating cardiac pacing pulses. An acoustical sensor is used for obtaining heart sound signals. The system includes a processor that is configured to establish multiple conditions during which heart sound signals are received. The processor derives heart sound signal parameters from the heart sound signals and determines a heart sound profile comprising a trend of each of the heart sound signal parameters with respect to the multiple established conditions.

Abstract: An implantable medical device includes a multi-axial acceleration sensor and an evaluation unit connected thereto. The evaluation unit is configured to (1) split the accelerometer output signal into at least two signal components, one of which is associated with a right-ventricular contraction and another of which is associated with a left-ventricular contraction; (2) detect events in the signal components, and/or determine signal features therein; and (3) determine at least one characteristic value K by evaluating the signal components, and/or the events and/or signal features therein.

Abstract: Described herein are methods and apparatus for treating hypertension with electrical pre-excitation pacing therapy. Electrical pre-excitation of a hypertrophic region advances the timing of the regional contraction and reduces its contribution to the overall contraction. Such pre-excitation pacing therapy may be beneficial to hypertensive patients with an abnormal distribution of ventricular wall stress/strain.

Abstract: The present disclosure provides an apparatus and method of optimizing a pacing heart rate. The method can include obtaining a preload-frequency relation and a force-frequency relation from histogram data for a patient condition and determining an optimal pacing heart rate for the patient condition. The optimal pacing heart rate can be substantially between a first heart rate corresponding to a minimum preload condition based on the preload-frequency relation and a second heart rate corresponding to a sustained ionotropic reserve condition based on the force-frequency relation.

Abstract: Techniques are provided for use with implantable medical devices equipped to deliver paired postextrasystolic potentiation (PESP) pacing to control the paired pacing rate based on changes in patient activity. In one example, the current activity level of the patient is detected during paired pacing using an accelerometer. The cardiac output level needed to maintain the current activity level of the patient is determined with reference to pre-stored lookup tables relating activity levels with corresponding minimum necessary cardiac output levels for the particular patient. The minimum paired pacing rate sufficient to achieve the cardiac output level is then determined based, e.g., on stroke volume derived from cardiogenic impedance signals. Paired pacing is then delivered at the minimum paired pacing rate sufficient to achieve the needed cardiac output, thereby assuring that the paired pacing rate is sufficient to meet the current physiological demands of the patient without consuming too much oxygen.