Abstract: A method for operating a cardiac rhythm management device in which a clinical state vector is computed as a combination of a plurality of parameters related to a patient's heart failure status and compared to a previously computed clinical state vector to determine a clinical trajectory indicative of changes in the patient's heart failure status. Such detected changes in status can be used both as a clinical tool to evaluate treatment and to automatically adjust the operation of the device.

Abstract: A method of detecting a cardiac event in a medical device that includes sensing cardiac signals from a plurality of electrodes forming a first sensing vector and a second sensing vector, determining whether the first sensing vector and the second sensing vector is corrupted by noise, and determining, in response to one of the first sensing vector and the second sensing vector being corrupted by noise, whether the other of the first sensing vector and the second sensing vector is one of a first cardiac event and a second cardiac event different from the first cardiac event.

Abstract: A method of controlling the operation of a pulsatile heart assist device (14) in a patient (10). The method consisting of utilising sounds produced by the heart (12) to control the operation of the heart assist device (14).

Abstract: Systems, devices and methods provide for evaluation of heart failure symptoms. Sensor data associated with one or more symptoms of heart failure are acquired and trended. Statistical features, such as slope, are extracted from the data trend in a moving window and are used to develop a cumulative sum. The cumulative sum is compared to a threshold value or V-mask to detect a shift in cumulative sum indicating changes in heart failure symptoms. A shift beyond the threshold value may trigger an alert or implementation of therapy.

Abstract: A technique utilizing an endolymphatically implanted lead having one or more electrodes that may be used for sensing cardiac activity and/or delivering cardiac electrical stimulation by an implantable cardiac device. An electrode disposed in the thoracic duct is in close proximity to the left ventricle and generates an electrogram especially suitable for ischemia detection and/or discriminating between ventricular tachycardias and supraventricular tachycardias.

Abstract: An active implantable medical device such as a cardiac prosthesis for the treatment of a heart failure by controlled adjustment of the atrioventricular and interventricular delays. The device provides atrioventricular and/or biventricular stimulation, a sensor delivering at least one hemodynamic parameter correlated with time intervals representative of the succession of the systolic and diastolic phases, and circuits to adjust the AV delay and/or VV delay. The device determines (12) during one cardiac cycle several parameters such as the left ventricular pre-ejection interval LPEI, the left ventricular ejection time LVET, the diastolic filling time FT and the conduction time PR. The device compares (14, 18) these parameters with at least one predetermined criterion. If a condition is met, the device readjusts (16) the AV delay and/or VV delay to maximize the ventricular filling and ejection.

Abstract: An approach to providing disordered breathing therapy includes detecting disordered breathing and adapting a therapy to mitigate the disordered breathing. The therapy may be adapted to enhance therapy effectiveness, to provide therapy that reduces an impact of the therapy on the patient, or to achieve other therapeutic goals. Cardiac electrical therapy to mitigate the disordered breathing may include various cardiac pacing regimens and/or delivery of non-excitatory electrical stimulation to the heart.

Abstract: Manually and autonomously configured non-bioelectrical-monitoring backup and/or primary pacemaker sensing is provided in the right ventricle and in the right atrium. Non-bioelectrical-monitoring is accomplished via direct, in-chamber metering and analysis of right ventricle and right atrium dynamic intracardiac pressures. A sensor is located on the right ventricular lead, another on the right atrial lead, and both are connected to the pacemaker. Right ventricular and right atrial dynamic intracardiac pressures are monitored and analyzed to indicate the presence or absence of contraction, relaxation and acceptable rhythm.

Abstract: Energy efficient methods and systems for using multi-dimensional activity sensors with implantable cardiac devices are provided. In certain embodiments the output of a passive activity sensor (used for rate responsive pacing) is used to trigger temporary use of a relatively high power multi-dimensional activity sensor. In other embodiments, the output of a relatively low power oxygen saturation sensor is used to trigger temporary use of a relatively high power multi-dimensional activity sensor. This description is not intended to be a complete description of, or limit the scope of, the invention.

Abstract: An apparatus and method for reversing ventricular remodeling with electro-stimulatory therapy. A ventricle is paced by delivering one or more stimulatory pulses in a manner such that a stressed region of the myocardium is pre-excited relative to other regions in order to subject the stressed region to a lessened preload and afterload during systole. The unloading of the stressed myocardium over time effects reversal of undesirable ventricular remodeling.

Abstract: A method and device for delivering multi-site ventricular pacing therapy in conjunction with parasympathetic stimulation for reducing ventricular wall stress. Such reduction in ventricular wall stress is useful in reversing or preventing the ventricular remodeling which can occur in heart failure patients.

Abstract: An implantable cardiac rhythm management (CRM) device delivers a chronic therapy while detecting an ischemic state. When the ischemic state indicates the occurrence of an ischemic event, the implantable CRM device delivers a post-ischemia therapy. The post-ischemia therapy and the chronic therapy are adjusted using feedback control with the ischemic state and parameters indicative of the effectiveness of the post-ischemic therapy and the effectiveness of the chronic therapy as inputs.

Abstract: An arrhythmia discrimination device and method involves receiving electrocardiogram signals and non-electrophysiologic signals at subcutaneous locations. Both the electrocardiogram signals and non-electrophysiologic signals are used to discriminate between normal sinus rhythm and an arrhythmia. An arrhythmia may be detected using electrocardiogram signals, and verified using the non-electrophysiologic signals. A detection window may be initiated in response to receiving the electrocardiogram signal, and used to determine whether the non-electrophysiologic signal is received at a time falling within the detection window. Heart rates may be computed based on both the electrocardiogram signals and non-electrophysiologic signals. The rates may be used to discriminate between normal sinus rhythm and an arrhythmia, and used to determine absence of an arrhythmia.

Abstract: The present disclosure provides an apparatus and method of detecting ischemia with a pressure sensor. The method can include obtaining a pressure signal and determining a pressure rate of change. The method can also include identifying at least one of impaired relaxation and impaired contractility in order to detect ischemia.

Abstract: Impedance, e.g. 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. Other methods vary the AA interval to maximize impedance change over the entire cardiac cycle or during the atrial cycle.

Abstract: In a medical system and a method for operating such a system, the system includes an implantable medical device of a patient, a programmer device, and an extracorporeal stress equipment adapted to exert a physiological stress on the patient, for automatically determining settings of a sensor for sensing a physiological parameter of the patient or for automatically determining a pacing setting of the device over a broad range of workloads of the equipment. The ingoing units and/or devices of the medical system, i.e. the implantable medical device of the patient, the programmer device, and the extracorporeal stress equipment, communicate bi-directionally with each other and form a closed loop.

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: 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: Systems and methods are provided for adjusting atrioventricular timing of a cardiac resynchronization therapy device, based upon multi-modal sensory data. In one particular embodiment, one or more acoustic signals are processed and categorized into certain cardiac-related mechanical events. Impedance waveforms are obtained from implanted electrodes and analyzed to identify certain valvular events. The acoustic and impedance data is analyzed to optimize AV timing and improve cardiac performance.

Abstract: A system and method for filtering a pressure signal in a medical device in which a sensor terminal senses the pressure signal, an electrode terminal receives cardiac electrical signals, a signal filtering system filters the sensed pressure signal in response to a determined heart rate to generate a heart-rate dependent frequency response, and a microprocessor derives a respiration signal in response to the heart rate dependent frequency response, and determines metrics of hemodynamic function in response to the derived respiration signal.

Abstract: Cardioprotective pre-excitation pacing may be applied to stress or de-stress a particular myocardial region delivering of pacing pulses in a manner that causes a dyssynchronous contraction. Such dyssynchronous contractions are responsible for the desired cardioprotective effects of pre-excitation pacing but may also be hazardous. Described herein is a method and system that uses measures of a patient's physiological response to ventricular dyssynchrony to control the duty cycles of intermittent pre-excitation pacing.

Abstract: An implantable cardiac stimulation device provides bichamber pacing and dynamic bichamber and single chamber sensing. The device includes a sensing circuit that senses activity of a heart, a lead system coupled to a plurality of chambers of the heart, and a cardiac rate circuit that determines a cardiac rate of the heart. A control circuit causes the lead system to couple the sensing circuit to corresponding chambers of the heart to enable bichamber trigger pacing when the cardiac rate is below a given rate and to a single chamber of the heart when the cardiac rate is above the given rate to enable enhanced tachycardia sensing.

Abstract: An exemplary method includes providing a maximum right ventricular systolic pressure value and corresponding time during a cardiac cycle, providing a left ventricular displacement value for the corresponding time, determining a product of the maximum right ventricular systolic pressure value and the magnitude of the left ventricular displacement value and assessing ventricular synchrony for the cardiac cycle based at least in part on the product. Such a method may include adjusting one or more cardiac pacing parameters based at least in part on the product. Other exemplary methods, devices, systems, etc., are also disclosed.

Abstract: An exemplary method includes delivering stimulation according to one or more stimulation parameters to cause contraction of the diaphragm, monitoring chest activity related to respiration and, in response to the monitoring, adjusting one or more of the one or more stimulation parameters during contraction of the diaphragm and continuing the delivering. Various other exemplary methods, devices, systems, etc., are also disclosed.

Abstract: An implantable device and method for monitoring S1 heart sounds with a remotely located accelerometer. The device includes a transducer that converts heart sounds into an electrical signal. A control circuit is coupled to the transducer. The control circuit is configured to receive the electrical signal, identify an S1 heart sound, and to convert the S1 heart sound into electrical information. The control circuit also generates morphological data from the electrical information. The morphological data relates to a hemodynamic metric, such as left ventricular contractility. A housing may enclose the control circuit. The housing defines a volume coextensive with an outer surface of the housing. The transducer is in or on the volume defined by the housing.

Abstract: An implantable medical device system and associated method are provided for measuring an excitation-physiological response delay. The method includes sensing a first signal responsive to electrical activity in a first cardiac chamber, sensing a second signal responsive to a physiologic response to the electrical activity in the first cardiac chamber; and determining an excitation-physiologic response delay in response to the first signal and the second signal.

Abstract: An implantable cardiac rhythm management (CRM) device delivers a chronic therapy while detecting an ischemic state. When the ischemic state indicates the occurrence of an ischemic event, the implantable CRM device delivers a post-ischemia therapy. The post-ischemia therapy and the chronic therapy are adjusted using feedback control with the ischemic state and parameters indicative of the effectiveness of the post-ischemic therapy and the effectiveness of the chronic therapy as inputs.

Abstract: A device, such as an implantable cardiac device, and methods for determining exercise diagnostic parameters of a patient are disclosed. Specifically, a maximum observed heart rate of a patient during exercise can be identified when an activity level and a heart rate measurement of the patient exceed predetermined thresholds. Included are methods for filtering out premature heartbeats or noise from the maximum heart rate determination. Methods of determining other exercise parameters, such as workload are also disclosed. The device includes hardware and/or software for performing the described methods.

Abstract: Techniques are provided for evaluating and optimizing the contribution of particular heart chambers to pacing efficacy. Briefly, a pacemaker temporarily alters the mode with which pacing therapy is delivered so as to selectively alter the heart chambers that are paced. The pacemaker detects any transient changes in pacing efficacy following the alteration in pacing mode. The pacemaker then assesses the contribution of particular heart chambers to pacing efficacy based on the alteration in the pacing mode and on any transient changes in the pacing efficacy. Additionally, techniques are provided herein for automatically adjusting pacing parameters to optimize the contribution of particular chambers to pacing efficacy.

Abstract: Techniques for using multiple physiological parameters to provide an early warning for worsening heart failure are described. A medical device monitors a primary diagnostic parameter that is indicative of worsening heart failure, such as intrathoracic impedance or pressure, and one or more secondary diagnostic parameters. The medical device detects worsening heart failure in the patient based on the primary diagnostic parameter when an index that is changed over time based on the primary diagnostic parameter value is outside a range of values, termed the threshold zone. When the index is within the threshold zone, the medical device detects worsening heart failure in the patient based on the one or more secondary diagnostic parameters. Upon detecting worsening heart failure, the medical device may, for example, provide an alert that enables the patient to seek medical attention before experiencing a heart failure event.

Abstract: Heart-monitoring systems, apparatus, and methods adapted to detect CS, CI and/or MI. In one embodiment, a system comprising at least two first-tier sensors capable of measuring and converting into signals at least two aspects related to cardiac function, at least one second-tier sensor that is also a first-tier sensor, at least one signal processor capable of transmitting a first-tier and second-tier trigger signal when coronary syndrome, cardiac ischemia or myocardial infarction has been detected, at least one communication device capable of communicating, at least one control element adapted to produce a first-tier and second-tier trigger signal when at least one first-tier sensor exceeds its threshold signal level, to exclude the signal from the first-tier sensor that exceeded its threshold and lower at least one threshold of the at least one first-tier sensor is provided.

Abstract: An apparatus comprises an implantable sensor, which provides a plurality of physiologic sensor signals of a subject, and a processor. The processor includes a feature module and a detection module. The feature module is configured to identify a feature in the sensor signals and to determine a measure of quality of the feature in the sensor signals. The detection module is configured to perform a morphology analysis of a subsequent portion of at least one of the sensor signals using the feature when the measure of quality of the feature satisfies a quality measure threshold.

Abstract: A method for determining an optimal pacing timing control parameter setting is provided for use in an implantable medical device programmed to deliver a pacing pulse in response to the timing control parameter. The method includes storing a user-selected optimization metric, iteratively adjusting the timing control parameter setting, sensing a first signal that varies in response to left ventricular wall acceleration, measuring the user-selected optimization metric in response to the sensed first signal, and determining an optimal timing control parameter value in response to the measured user-selected optimization metric.

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: System and methods for assessing sensed signals for determining a reliability measure of their accuracy with respect to a patient's true physiological status. As one example, the signals can include multiple, independently obtained signals, such as an electro-chemically based measure of cardiac activity and a plethysmography based measure of hemodynamic output which typically exhibit different morphologies and varying phase shifts with respect to each other. One manner of assessing the signals is to transform them into the frequency domain, such as via a Fast Fourier Transform (FFT), and evaluate them, such as by a coherence determination, to determine the degree of their mutual agreement. This can be used to assess the reliability of the sensing. Therapy can be delivered under certain observed conditions, such as a condition of hemodynamic insufficiency where anti-tachycardia pacing and/or shocking therapy can be delivered.

Abstract: Methods, systems, and apparatus for the treatment of heart failure (both systolic and diastolic), hypertension, and arrhythmia in patients by stimulating one or more nerves, particularly peripheral nerves, using neurostimulation are described. The therapeutic treatment is accomplished by applying electrical signals to at least one or more nerves using cutaneous, subcutaneous, implantable, or catheter-based neurostimulation assemblies, alone or in combination with one or more additional therapy or stimulation devices associated with the patient's heart, and/or with one or more therapeutic drug infusions or therapies, such as immune modulation therapy (IMT).

Abstract: A cardiac rhythm management system identifies a relationship between one or more hemodynamic parameters sensed from a patient and levels of hemodynamic tolerability of the patient. The identified relationship allows an implantable medical device to control delivery of anti-tachyarrhythmia therapy using the patient's hemodynamic tolerability during a detected tachyarrhythmia episode, in addition to classifying the detected tachyarrhythmia episode by its type and origin.

Abstract: A first lead provides therapeutic stimulation to the heart and includes a first mechanical sensor that measures physical contraction and relaxation of the heart. A controller induces delivery of therapeutic stimulation via the first lead. The controller receives signals from the first mechanical sensor indicative of the contraction and relaxation; develops a template signal that corresponds to the contraction and relaxation; and uses the template signal to modify the delivery of therapeutic stimulations. In another arrangement, a second lead, with a second mechanical sensor also provides signals to the controller indicative of contraction and relaxation. The first mechanical sensor is adapted to be positioned at the interventricular septal region of the heart, and the second mechanical sensor is adapted to be positioned in the lateral region of the left ventricle. The controller processes the signals from the first mechanical sensor and the second mechanical sensor to develop a dysynchrony index.

Abstract: Safety pacing in multi-site cardiac rhythm management (CRM) devices is provided. According to various method embodiments, a first cardiac signal from a first cardiac region and a second cardiac signal from a second cardiac region are sensed. The first cardiac region is paced to maintain at least a minimum cardiac rate, and the second cardiac region is paced to maintain at least the minimum cardiac rate when a pace in the first cardiac region is inhibited. Other aspects and embodiments are provided herein.

Abstract: Electrical noise may be discriminated from sensed heart signals based on cardiovascular pressure. A plurality of detected cardiovascular pressure values are respectively associated with a plurality of detected tachyarrhythmia events. In some examples, a variance in the cardiovascular pressure, e.g., above a threshold range, may indicate that the detected tachyarrhythmia events are at least partially attributable to electrical noise. In some examples, stimulation therapy to a heart of a patient may be controlled based on the detection of a tachyarrhythmia episode and a variability in the cardiovascular pressure values that are associated with the tachyarrhythmia episode. In other examples, a sensing integrity indication may be generated upon determining that a tachyarrhythmia episode was associated with a variable cardiovascular pressure.

Abstract: A method and system for calculating an atrio-ventricular delay interval based upon an inter-atrial delay exhibited by a patient's heart. The aforementioned atrio-ventricular delay interval may optimize the stroke volume exhibited by a patient's heart. The aforementioned atrio-ventricular delay interval may be blended with another atrio-ventricular delay interval that may optimize another performance characteristic, such as left ventricular contractility. Such blending may include finding an arithmetic mean, geometric mean, or weighted mean of two or more proposed atrio-ventricular delay intervals.

Abstract: Calibration of adaptive-rate pacing by a cardiac rhythm management system using an intrinsic chronotropic response. The cardiac rhythm management system may include an adaptive-rate pacing device. The adaptive-rate pacing device may include an adaptive-rate sensor module for measuring an activity level of the individual. A monitor module may be coupled to the adaptive-rate sensor module, the monitor module monitoring an intrinsic chronotropic response. A calculator module may be coupled to the monitor module, the calculator module calculating a calibrated parameter for the adaptive-rate pacing device based on the intrinsic chronotropic response. An adjuster module may be coupled to the calculator module, wherein the adjuster module adjusts the adaptive-rate pacing device based on the calibrated parameter. The parameters of the adaptive-rate pacing device adjusted by the adjuster module may include a sensor rate target, a maximum sensor rate, and a response factor.

Abstract: Adaptive rate pacing for improving heart rate kinetics in heart failure patients involves determining onset and sustaining of patient activity. The patient's heart rate response to the sustained activity is evaluated during a time window defined between onset of the activity and a steady-state exercise level. If the patient's heart rate response to the sustained activity is determined to be slow, a pacing therapy is delivered at a rate greater than the patient's intrinsic heart rate based on a profile of the patient's heart rate response to varying workloads. If determined not to be slow, the pacing therapy is withheld. Monitoring-only configurations provide for acquisition and organization of physiological data for heart failure patients. These data can be acquired on a per-patient basis and used to assess the HF status of the patient.

Abstract: An approach to providing disordered breathing therapy involves the use of a plurality of therapy devices to deliver a coordinated disordered breathing therapy regimen to the patient. The plurality of disordered breathing devices includes at least a therapy device that delivers an electrical stimulation therapy modulating a patient's baroreflex response. Other therapy devices may include a cardiac electrical stimulation device, an external respiratory therapy device, and/or other therapy devices used in the treatment of disordered breathing. A therapy controller coordinates the therapies delivered by the plurality of therapy devices.

Abstract: System and methods for assessing sensed signals for determining a reliability measure of their accuracy with respect to a patient's true physiological status. As one example, the signals can include multiple, independently obtained signals, such as an electro-chemically based measure of cardiac activity and a plethysmography based measure of hemodynamic output which typically exhibit different morphologies and varying phase shifts with respect to each other. One manner of assessing the signals is to transform them into the frequency domain, such as via a Fast Fourier Transform (FFT), and evaluate them, such as by a coherence determination, to determine the degree of their mutual agreement. This can be used to assess the reliability of the sensing. Therapy can be delivered under certain observed conditions, such as a condition of hemodynamic insufficiency where anti-tachycardia pacing and/or shocking therapy can be delivered.

Abstract: An implantable medical device for generating a cardiac pressure-volume loop, the implantable medical device comprising a pulse generator including control circuitry, a first cardiac lead including a proximal end and a distal end and coupled to the pulse generator at the proximal end, a first electrode located at the distal end of the cardiac lead and operatively coupled to the control circuitry, a sound sensor operatively coupled to the control circuitry, and a pressure sensor operatively coupled to the control circuitry, wherein the implantable medical device is adapted for measuring intracardiac impedance. A method of using the implantable medical device to optimize therapy delivered to the heart.

Abstract: An implantable heart stimulating device has a stimulation pulse generator that emits stimulation pulses at an adjustable stimulation rate, an activity sensor that emits an activity signal in response to detected activity of the patient, and a physiological parameter sensor that generates a physiological sensor signal in response to a detected physiological parameter. The activity and physiological sensor signals are supplied to a control arrangement that sets the stimulation rate for the stimulation pulse generator by executing a stimulation rate algorithm dependent on those signals. In the stimulation rate algorithm, if the physiological signal indicates an emotional stress on the part of the patient, the stimulation rate is increased to an adjustable emotional stress rate level, and if no increase in the activity signal occurs during a predetermined time period following the stimulation rate increase, the stimulation rate is decreased.

Abstract: A method of providing cardiac stimulation therapy and a device for providing the therapy. A patient's cardiac activity as well as cyclical respiration is monitored. Cardiac stimulation is provided as indicated as therapeutic intervention for a variety of cardiac arrhythmias according to variable timing parameters. One or more of the timing parameters under which cardiac pacing stimulations are provided is varied or modulated with the cyclical variations in respiration. The one or more timing parameters are generally shortened or elongated in concert with the alternating inspiration/exhalation phases of respiration. In certain implementations, the patient's respiration is inferred from cardiac based physiologic signals. The methods and devices for providing cardiac stimulation therapy more accurately emulate natural healthy physiologic activity.

Abstract: A computer method, employable during an at-rest period of a pacemaker patient, for controlling the operation of the pacemaker so as maximally to support the patient's hemodynamic behavior in a context involving inhibiting fluid overload. The method involves (a) collecting simultaneously occurring ECG and heart-sound information, (b) processing the collected information to obtain at least S3 data, and in certain instances also EMAT and/or % LVST data, (c) utilizing such obtained data, and during the at-rest period, applying (a) pacing rate, (b) pacing intensity, (c) atrio-ventricular delay, and (d) inter-ventricular delay control to the pacemaker.

Abstract: An implantable medical device is adapted for implantation into body tissue. The implantable medical device comprises a housing and a header coupled to the housing. A cavity is located in the header. An ultrasonic transducer adapted to transmit acoustic waves at a communication frequency is located in the cavity, and a coupling surface is interposed between the ultrasonic transducer and the body tissue and is acoustically coupled with the body tissue.