Abstract: Time delays between a feature of a signal indicative of electrical activity of a patient's heart and a feature of a plethysmograph signal indicative of changes in arterial blood volume are used to arrange the operation of an implantable device, such as a pacemaker. Shorter time delays between the feature of the signal indicative of electrical activity of a patient's heart and the feature of the plethysmograph signal indicative of changes in arterial blood volume are indicative of larger cardiac stroke volumes. The time delay can be used to select a pacing site or combination of pacing sites and/or to select a pacing interval set.

Abstract: A cardiac rhythm management (CRM) device can extract ventilation information from thoracic impedance or other information, and adjust a delivery rate of the CRM therapy. A tidal volume of a patient is measured and used to adjust a ventilation rate response factor. The measured tidal volume can optionally be adjusted using a ventilation rate dependent adjustment factor. The ventilation rate response factor can also be adjusted using a maximum voluntary ventilation (MVV), an age predicted maximum heart rate, a resting heart rate, and a resting ventilation determined for the patient. In various examples, a global ventilation sensor rate response factor (for a population) can be programmed into the CRM device, and automatically tailored to be appropriate for a particular patient.

Abstract: A differential or relative measurement between an orthogonal measurement vector and another measurement vector can be used to determine the location where fluid accumulation is occurring or the local change in such fluid accumulation. This can help diagnose or treat infection or hematoma or seroma at a pocket of an implanted cardiac rhythm management device, other implanted medical device, or prosthesis. It can also help diagnose or treat pulmonary edema, pneumonia, pulmonary congestion, pericardial effusion, pericarditis, pleural effusion, hemodilution, or another physiological condition.

Abstract: A rules engine acquires sensor data from sensors applied to the heart and determines whether an electrical waveform should be applied to the heart and, if so, the type of electrical waveform. A multi-phase cardiac stimulus generator generates waveforms in response to the rules engine from waveform data stored in a memory. The electrical waveform is applied to one or more electrodes implanted in or on the heart.

Abstract: A rules engine acquires sensor data from sensors applied to the heart and determines whether an electrical waveform should be applied to the heart and, if so, the type of electrical waveform. A multi-phase cardiac stimulus generator generates waveforms in response to the rules engine. The electrical waveform is applied to one or more electrodes implanted in or on the heart.

Abstract: Sensors are applied to the heart and sensor data is supplied to a rules engine. The rules engine applies rules that reflect a CRM pharmaceutical regime of the patient to the sensor data to determine whether an electrical waveform should be applied to the heart. When electrical stimulation is warranted, the drug “awareness” rules are used by the rules engine to instruct a multi-phase cardiac stimulus generator to generate an electrical waveform that improves the performance of the drugs administered to the patient, allow the patient to be administered a lower dose of a particular drug, and/or reduce or eliminate side effects from the drugs.

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 rules engine acquires sensor data from sensors applied to the heart and determines whether an electrical waveform should be applied to the heart and, if so, the type of electrical waveform. A multiphase cardiac stimulus generator generates waveforms in response to the rules engine. The electrical waveform is applied to one or more electrodes implanted in or on the heart.

Abstract: The flow rate of blood out of a blood pump is determined at least in part based on an acceleration of the pump's rotor and on the blood's viscosity. Considering the rotor acceleration when determining blood flow rate, increases the accuracy of the blood flow measurement thereby permitting the determination of a parameter related to the contractility of a patient's heart. The parameter may include a rate of pressure change of blood across the pump, a ratio of the rate of pressure change and a peak-to-peak value of the blood flow rate, or any other contractility index.

Abstract: Biventricular-triggered pacing is a pacing mode that can employ in cardiac resynchronization pacing at elevated heart rates. Described herein are methods and devices for implementing biventricular pacing in the context of multi-site left ventricular pacing.

Abstract: Herein is described a device and methods-of-use to treat multiple possible causes of sudden neurological dysfunction related to cardiac, cerebrovascular, or brain electrical abnormalities. The device can be employed so as to treat cardiac dysfunction such as arrhythmia and subsequently related dysfunction of the central nervous system such as stroke and seizure. Alternatively, the device can be employed so as to treat cardiac dysfunction simultaneous with treatment of dysfunction of the central nervous system. Finally, the device can be employed so as to augment the effectiveness of treating cardiac dysfunction, namely the restoration of cardiac output and blood flow to the brain, by dilating the arteries of the brain.

Abstract: Methods and/or devices for sampling a patient's intrinsic AV conduction time during cardiac therapy that may, e.g., change the AV delays to values based on the AV delays themselves, previously-sampled intrinsic AV conduction times, and/or one or more other parameters directly related to AV delays to provide a time period during which to measure the patient's intrinsic AV conduction time.

Abstract: A chronically implanted medical device, connected to a medical electrical lead that includes a sensor, is used to detect cardiac afterload. Electrical stimulation is delivered proximate to aortic arch tissue of a patient in order to reduce a patient's cardiac afterload. Electrical stimulation is terminated after a termination condition is met.

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: In a system and method for controlling an implantable stimulator capable of producing pacing pulses to be delivered to cardiac tissue, as well as vagal stimulation pulses to be delivered to vagus nerve sites, upon detection of a premature cardiac event, such as a premature ventricular or atrial contraction, a simulated heart rate turbulence (HRT) procedure is applied if the intrinsic heart rate turbulence is weakened or absent. The simulated HRT includes a first phase in which the heart rate is increased, from the existing level, for a number of heart beats, a second phase in which the heart rate is decreased for a number of heart beats, and an optional third phase in which the heart rate is returned to said existing level.

Abstract: A system for controlling a position of a patient's tongue includes attaching at least one electrode to the patient's Hypoglossal nerve and applying an electric signal through the electrode to at least one targeted motor efferent located within the Hypoglossal nerve to stimulate at least one muscle of the tongue. The system may also include the use of more than one contact to target more than one motor efferent and stimulating more than one muscle. The stimulation load to maintain the position of the tongue may be shared by each muscle. The position of the patient's tongue may be controlled in order to prevent obstructive sleep apnea.

Abstract: A device and method for delivering electrical stimulation to the heart in order to improve cardiac function in heart failure patients. The stimulation is delivered as high-output pacing in which the stimulation is excitatory and also of sufficient energy to augment myocardial contractility. The device may be configured to deliver high-output pacing upon detection of cardiac decompensation.

Abstract: The disclosure relates to an apparatus and method for inducing ventricular fibrillation in a patient to facilitate defibrillation threshold testing. The apparatus includes a plurality of output capacitors that are dynamically configurable in a selected stacking arrangement that facilitates delivery of energy for inducing the ventricular fibrillation. An output of the apparatus is coupled to patient electrodes and a threshold energy level delivered by the output capacitors is determined.

Abstract: Implantable cardiac pacing systems and methods for providing substernal pacing are described. In one example, a cardiac pacing system includes a pacemaker implanted in a patient and an implantable medical electrical lead. The implantable medical electrical lead includes an elongated lead body having a proximal end and a distal portion, a connector configured to couple to the pacemaker at the proximal end of the elongated lead body, and one or more electrodes along the distal portion of the elongated lead body, wherein the distal portion of the elongated lead body of the lead is implanted substantially within an anterior mediastinum of the patient and the pacemaker is configured to deliver pacing pulses to a heart of the patient.

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: Systems, methods, and graphical user interfaces are described herein for identification of optimal electrical vectors for use in assisting a user in implantation of implantable electrodes to be used in cardiac therapy. Cardiac improvement information may be generated for each pacing configuration, and one or more pacing configuration may be selected based on the cardiac improvement information. Optimal electrical vectors using the selected pacing configurations may be identified using longevity information generated for each electrical vector. Electrodes may then be implanted for use in cardiac therapy to form the optimal electrical vector.

Abstract: Various aspects relate to a method. In various embodiments, a therapy of a first therapy type is delivered, and it is identified whether a therapy of a second therapy type is present to affect the therapy of the first therapy type. Delivery of the therapy is controlled based on the presence of the therapy of the second therapy type. Some embodiments deliver the therapy of the first type using one set of parameters in the presence of a therapy of a second type, and deliver the therapy of the first type using another set of parameters when the therapy of the second type is not present. In various embodiments, one of the therapy types includes a cardiac rhythm management therapy, and the other includes a neural stimulation therapy. Other aspects and embodiments are provided herein.

Abstract: An implantable cardiac prosthesis device conducting an analysis of a patient tolerance to a pacing mode favoring the spontaneous atrioventricular conduction is disclosed. The device operates in a dual chamber (DDD or biventricular) mode and in a pacing mode favoring the spontaneous atrioventricular conduction such as an AAI mode (10) with a ventricular sensing or a mode with hysteresis of the atrioventricular delay. The device controls (10-18) the conditional switching from one mode to the other. The device comprises a hemodynamic sensor, including an endocardial acceleration sensor, derives a hemodynamic index representative of the hemodynamic tolerance of the patient to the spontaneous atrioventricular conduction. The device controls inhibiting or (20) forcing the conditional switching of the device to the DDD (or biventricular) mode according to the evolution of the hemodynamic index.

Abstract: In specific embodiments, one or more cardiogenic impedance signal template is stored, where each template has a corresponding morphology. Additionally, one or more cardiogenic impedance signal is obtained using electrodes implanted within a patient, where each signal has a corresponding morphology. The morphology of one or more obtained cardiogenic impedance signal is compared to the morphology of one or more stored template, to determine one or more metric indicative of similarity between the compared morphologies. The one or more metric indicative of similarity is used to analyze the patient's cardiac condition, to discriminate among arrhythmias and/or to adjust a cardiac pacing parameter.

Abstract: A medical device and associated method for delivery of a cardiac therapy that includes determining a first impedance signal along a thoracic electrode vector extending within a portion of a thoracic cavity, determining a second impedance signal along an extra-thoracic electrode vector extending outside the thoracic cavity, comparing first amplitude measurements corresponding to the first impedance signals and second amplitude measurements corresponding to the second impedance signals, comparing first slope measurements corresponding to the first impedance signals and second slope measurements corresponding to the second impedance signals, and determining delivery of the cardiac therapy in response to the comparing.

Abstract: A set of cardiogenic impedance signals are detected along different sensing vectors passing through the heart of the patient, particularly vectors passing through the ventricular myocardium. A measure of mechanical dyssynchrony is detected based on differences, if any, among the cardiogenic impedance signals detected along the different vectors. In particular, differences in peak magnitude delay times, peak velocity delay times, peak magnitudes, and waveform integrals of the cardiogenic impedance signals are quantified and compared to detect abnormally contracting segments, if any, within the heart of the patient. Warnings are generated upon detection of any significant increase in mechanical dyssynchrony. Diagnostic information is recorded for clinical review. Pacing therapies such as cardiac resynchronization therapy (CRT) can be activated or controlled in response to mechanical dyssynchrony to improve the hemodynamic output of the heart.

Abstract: An implantable cardiac function management device including a programmable controller can be used to include a user-specifiable therapy control parameter set. The therapy control parameter set may then be configured to include at least one therapy control parameter that is user-configurable to automatically switch from a first parameter value to a second parameter value at a time that occurs between separate user programming sessions of the device. Various attributes of physiological measures may allow for refinement of the parameter sets to adapt to changed conditions of the subject. Methods of use are also presented.

Abstract: An implantable medical device includes a sensor configured to generate an endocardial acceleration (EA) signal representative of activity of a patient's heart. The device further includes one or more circuits configured to identify within the EA signal at least one EA signal component corresponding to at least one peak of endocardial acceleration, and extract from the at least one EA signal component at least two characteristic parameters. The one or more circuits are further configured to generate a composite index based on a combination of the at least two characteristic parameters, determine a plurality of values of the composite index for a plurality of pacing configurations, and select a current pacing configuration from among the plurality of pacing configurations based on the plurality of values of the composite index.

Abstract: A method for modulating one or more functions of an implanted medical device is disclosed. The method includes measuring a cardiovascular pressure of a patient; evaluating the cardiovascular pressure based on one or more characteristics of a cardiac cycle of the patient at the time the pressure was measured; and modulating one or more functions of the device based on the pressure. Also disclosed is a method for assessing a cardiovascular pressure of a patient with an implanted medical device that includes detecting one or more characteristics of a cardiac cycle of the patient's heart; detecting the cardiovascular pressure of the patient; classifying the cardiovascular pressure based on one or more characteristics of the cardiac cycle of the patient's heart; and displaying the cardiovascular pressure along with the classification. Also disclosed is a system for collection and display of a cardiovascular pressure of a patient.

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: 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: A zero flow responsive heart stimulator contains a zero flow sensors, which generate signals at the moment of the termination of blood inflow in the right atrium and the right ventricle, sensing this the most precisely in the places, where the sinoatrial node and atrioventricular node reside, for the right atrium and the right ventricle, respectively. The stimulator is based on our discovery, that the two nodes are the same sensors in the biological systems, based on the fact that until the filling of the said two chambers continues, the venous blood flow sucks on Bernoulli's principle the Ca and Na cations from the two nodes interstices, preventing the inward currant in their cells, thus delaying the completion of the 0-phase of their depolarization and the action potential, until the blood flow stops.

Abstract: A device adapted to attach to a subject for detecting an ECG signal of the subject. The device includes a first, a second, and a third electrode, where the electrodes form an orthogonal configuration. Two channels of ECG data can be obtained using a common electrode, and can be further combined to obtain a further channel using vector mathematics. The channel combination can be performed at vector angles suitable for optimizing the detection of various features of the ECG spectra of the subject. A method of using an implantable cardiac device together with surface-attached wireless sensor(s) is also provided where the acquired data from the implantable cardiac device and from the surface-attached wireless sensor(s) are both used for diagnosing patient's heart conditions and administering appropriate therapies.

Abstract: A system may include an external medical device (e.g., a patch) including one or more physiological sensors configured to sense one or more physiological parameters of a subject when the subject is ambulatory. The external medical device may be configured to communicate information related to the sensed one or more physiological parameters for determining and/or modifying at least one cardiac therapy parameter of an implantable medical device (e.g., pacemaker, implantable cardioverter defibrillators, or cardiac resynchronization therapy device). In some situations, an indication or notification may be generated corresponding to the determined and/modified cardiac therapy parameter.

Abstract: Pacing parameters may be adjusted to increase the cardiac output of a patient's heart while a patient is awake and/or active and the demand placed on the heart may be greatest, and to decrease or hemodynamic efficiency while a patient is at rest so that the heart itself has time to rest before the next period of higher demand for efficiency begins. This may aid in lessening the strain placed on the heart by making the heart work hard when needed such as when the patient is active, and by permitting the heart to “rest” when the patient is relatively inactive.

Abstract: This document describes an apparatus including an implantable medical device having a printed circuit board. The apparatus can include a connector block for a lead terminal of the implantable medical device mounted directly to the printed circuit board.

Abstract: Devices and methods for improving device therapy such as cardiac resynchronization therapy (CRT) by determining a desired value for a device parameter are described. An ambulatory medical device can receive one or more physiologic signals and generate multiple signal metrics from the physiologic signals. The ambulatory medical device can determine a desired value for a device parameter, such as a timing parameter used for controlling the delivery of CRT pacing to various heart chambers, using information fusion of signal metrics that are selected based on one or more of a signal metric sensitivity to perturbations to the device parameter in response to a stimulation, a signal metric variability in response to a stimulation, or a covariability between two or more signal metrics in response to a stimulation. The ambulatory medical device can program a stimulation using the desired device parameter value, and deliver the programmed stimulation to one or more target sites to achieve desired therapeutic effects.

Abstract: A system and method control a pacing parameter in a closed-loop manner by determining a value of an EGM-based index corresponding an optimal electrical activation condition of a patient's heart and adjusting a pacing therapy to maintain the EGM-based index value. The closed loop control method performed by the system may establish a relationship between an EGM-based index and multiple settings of a pacing control parameter. Values of the EGM-based index are stored with corresponding setting shifts relative to a previously established optimal setting. A processor of an implantable medical device monitors the EGM-based index during cardiac pacing. Responsive to detecting an EGM-based index value corresponding to a non-optimal setting of the control parameter, the processor determines an adjustment of the control parameter from the stored index values and corresponding setting shifts.

Abstract: A method for allowing cardiac signals to be sensed and pacing pulse vectors to be delivered between two or more electrodes. In one embodiment, cardiac signals are sensed and pacing pulse vectors are delivered between at least one of a first left ventricular electrode and a second left ventricular electrode. Alternatively, cardiac signals are sensed and pacing pulse vectors are delivered between different combinations of the first and second left ventricular electrodes and a first supraventricular electrode. In addition, cardiac signals are sensed and pacing pulse vectors are delivered between different combinations of the first and second left ventricular electrode, the first supraventricular electrode and a conductive housing. In an additional embodiment, a first right ventricular electrode is used to sense cardiac signals and provide pacing pulses with different combinations of the first and second left ventricular electrodes, the first supraventricular electrode and the housing.

Abstract: Systems and methods provide for sensing, during an event of tachycardia, hemodynamic signals concurrently from at least two spatially separated locations within a patient, and quantifying a spatial relationship between the hemodynamic signals. Hemodynamic stability or state of the patient during the tachycardia event is determined based at least in part on the quantified spatial relationship. One or more anti-tachycardia therapies to treat the tachycardia may be selected based at least in part on the determined stability or state of patient hemodynamics, and the selected one or more anti-tachycardia therapies may be delivered to treat the tachycardia. The hemodynamic signals may comprise at least two, or a mixed combination, of cardiac impedance signals, cardiac chamber pressure signals, arterial pressure signals, heart sounds; and acceleration signals.

Abstract: A method and device for delivering ventricular resynchronization pacing therapy in conjunction with electrical stimulation of nerves which alter the activity of the autonomic nervous system is disclosed. Such therapies may be delivered by an implantable device and are useful in preventing the deleterious ventricular remodeling which occurs as a result of a heart attack or heart failure. The device may perform an assessment of cardiac function in order to individually modulate the delivery of the two types of therapy.

Abstract: A system for the detection of cardiac events occurring in a human patient. At least two electrodes are included in the system for obtaining an electrical signal from a patient's heart. An electrical signal processor is electrically coupled to the electrodes for processing the electrical signal. The system receives data regarding the patient's state (e.g. asleep, exercising). Patient state information is stored in a patient state array, thereby enabling the system to track the patient's state over time, and to select an appropriate test for detecting a cardiac event based on both past and present data regarding the patient's state.

Abstract: A method and system are provided for removing, from an implant chamber of a heart, a leadless implantable medical device (LIMD) having a distal end and a proximal end. The distal end is configured to be actively secured to tissue in the implant chamber of the heart. The proximal end is configured to be coupled to a distal end of an indwelling retrieval mechanism (IRM). The IRM extends from the heart along a vessel, the IRM having a proximal end configured to be anchored at a temporary anchor site. The method comprises detaching the IRM from the anchor site, loading a retrieval tool over the proximal end of the IRM and along the body of the IRM. The retrieval tool has a lumen therein that receives the IRM as the retrieval tool re-enters the vessel, thereby allowing the retrieval tool to engage the LIMD.

Abstract: A cardiac medical device and associated method control delivery of dual chamber burst pacing pulses in response to detecting tachycardia. A number of cardiac cycles occurring in a first cardiac chamber are identified subsequent to the dual chamber pacing pulses. The number of sensed intrinsic events occurring in a second cardiac chamber during the first chamber cardiac cycles is determined as a number of second chamber events. The tachycardia episode is classified in response to the number of second chamber events.

Abstract: A cardiac rhythm management system modulates the delivery of pacing and/or autonomic neurostimulation pulses based on heart rate variability (HRV). An HRV parameter being a measure of the HRV is produced to indicate a patient's cardiac condition, based on which the delivery of pacing and/or autonomic neurostimulation pulses is started, stopped, adjusted, or optimized. In one embodiment, the HRV parameter is used as a safety check to stop an electrical therapy when it is believed to be potentially harmful to continue the therapy.

Abstract: Methods, apparatus, and systems are provided to stimulate multiple sites in a heart. A controller senses electrical activity associated with sinus rhythm of the heart. A signal generator is configured to generate an electrical signal for stimulating the heart. Based on the electrical signal, a distributor circuit then distributes the stimulating signals, such as pacing pulses, to a heart. The distributor circuit may vary the delay time between stimulating signals, inhibit a stimulating signal, trigger application of a stimulating signal, or vary the characteristics, such as the pulse width and amplitude, of a stimulating signal.

Abstract: The present disclosure is directed to a method of using an implantable medical device. One embodiment of the present disclosure comprises delivering electrical stimulation proximate nerve tissue of a patient during a transient physiological effect period separated by a recovery period. The transient physiological effect period is when electrical stimulation has an increased level of efficacy and the recovery period is when additional electrical stimulation does not provide a beneficial physiological effect to the patient.

Abstract: A system and method for estimating a hemodynamic performance parameter value of a patient's heart. The system includes a pulse generator and a medical electrical lead implanted partially within a coronary vein of the heart. The lead includes at least one sensor located within the coronary vein configured to generate a signal indicative of at least one dimensional parameter of the coronary vein. Changes in the dimensional parameter during one or more cardiac cycles are measured. The hemodynamic performance parameter is estimated based on the change in the dimensional parameter of the coronary vein.

Abstract: Systems and methods involve an intrathoracic cardiac stimulation device operable to provide autonomous cardiac sensing and energy delivery. The cardiac stimulation device includes a housing configured for intrathoracic placement relative to a patient's heart. A fixation arrangement of the housing is configured to affix the housing at an implant location within cardiac tissue or cardiac vasculature. An electrode arrangement supported by the housing is configured to sense cardiac activity and deliver stimulation energy to the cardiac tissue or cardiac vasculature. Energy delivery circuitry in the housing is coupled to the electrode arrangement. Detection circuitry is provided in the housing and coupled to the electrode arrangement. Communications circuitry may optionally be supported by the housing. A controller in the housing coordinates delivery of energy to the cardiac tissue or cardiac vasculature in accordance with an energy delivery protocol appropriate for the implant location.

Abstract: A method of modifying the force of contraction of at least a portion of a heart chamber, including providing a subject having a heart, comprising at least a portion having an activation, and applying a non-excitatory electric field having a given duration, at a delay after the activation, to the portion, which causes the force of contraction to be increased by a least 5%.