Abstract: An implantable infusion device includes a pump, a charge storage unit, and a charging circuit configured to supply current to the charge storage unit from a battery in preparation for actuating the pump. The implantable infusion device also includes a pump actuator circuit configured to actuate the pump using energy from the charge storage unit, and a voltage boost circuit configured to provide a boosted battery voltage generated from the battery. The charging circuit is configured to supply current to the charge storage unit from the voltage boost circuit instead of directly from the battery in response to (i) a comparison of a voltage of the battery with a predetermined threshold and (ii) a comparison of a voltage of the charge storage unit with the voltage of the battery.

Abstract: An implantable infusion device includes a voltage boost circuit configured to selectively generate an output voltage from a first voltage provided by a battery. The voltage boost circuit includes a signal generation circuit configured to generate control signals and a charge pump circuit configured to generate the output voltage in response to the control signals. In response to a request for a predetermined voltage, the signal generation circuit generates the control signals using a first profile for a first period of time, and generates the control signals using a second profile for a second period of time subsequent to the first period. The charge pump circuit increases the output voltage to (i) an intermediate voltage less than the predetermined voltage in response to the first profile of the control signals, and (ii) the predetermined voltage in response to the second profile of the control signals.

Abstract: Presented herein are systems, methods, and computer-readable media for recording event times in particle detection scenarios. The systems, methods, and computer-readable media involve the identification of one facility device as a grandmaster clock among at least two facility devices of a facility device set, where the respective facility devices are selected from a facility device type set including a beam monitor; a neutron instrument; a neutron chopper; a nuclear reactor; a particle accelerator; a network router; and a user workstation. The system, method, and computer-readable medium also involve configuring the facility devices to synchronize a clock component with the grandmaster clock; and, upon detecting an event, retrieve from the clock component of the selected facility device an absolute event timestamp that is independent of event times of other events, and store a record of the facility event and the absolute event timestamp in the data store.

Abstract: A system and method for using an implantable cardiac stimulation device to monitor a patient for the progress of an existing condition and/or early detection of an emerging condition based, at least in part, on measuring and evaluating the timing characteristics of the patient's atrial activity. The atrial timing characteristics are used as indicators or predictors of conditions of interest, such as heart failure (HF) and atrial fibrillation (AF). In certain implementations, the system can determine discriminating indicators of a predominant underlying cause of a condition, such as between vagal and non-vagal AF, as an indicator of a suggested therapy. The system can store data corresponding to the observed atrial timing for trending analysis as well as transmit data for offline analysis, such as via an external device.

Abstract: Systems and methods for controlling blood pressure by controlling atrial pressure and atrial stretch are disclosed. In some embodiments, a stimulation circuit may be configured to deliver a stimulation pulse to at least one cardiac chamber of a heart of a patient, and at least one controller may be configured to execute delivery of one or more stimulation patterns of stimulation pulses to the at least one cardiac chamber, wherein at least one of the stimulation pulses stimulates the heart such that an atrial pressure resulting from atrial contraction of an atrium overlaps in time a passive pressure build-up of the atrium, such that an atrial pressure of the atrium resulting from the stimulation is a combination of the atrial pressure resulting from atrial contraction and the passive pressure build-up and is higher than an atrial pressure of the atrium would be without the stimulation, and such that the blood pressure of the patient is reduced.

Abstract: Apparatus and methods are provided for use with a blood vessel of a subject, including a stent (20) configured to be placed in the blood vessel. The stent includes at least first (32), second (34), and third (36) strut portions disposed along the stent. The first and second strut portions are coupled to one another at a first junction (37A) that facilitates bending of the first and second strut portions with respect to one another. The second and third strut portions are coupled to one another at a second junction (37B) that facilitates bending of the second and third strut portions with respect to one another. At least one electrode (22) is disposed on at least an outer surface of the stent. Other applications are also described.

Abstract: In general, techniques and systems for detecting acoustic signals and generating phonocardiograms are described. In one example, a system may include an acoustic sensor configured to detect an acoustic signal from a heart of a patient. The system may also include a sensing module configured to detect an electrical signal from the heart of the patient via two or more electrodes and at least one processor configured to generate a composite phonocardiogram based the acoustic signal and the electrical signal detected over a plurality of cardiac cycles of the heart, wherein the composite phonocardiogram is generated for a representative cardiac cycle. The system may be provided in a single device or multiple devices configured to transmit information between the devices.

Abstract: An intracardiac capsule comprises a cylindrical body having an atraumatic rounded surface and a helical anchoring screw integral with the cylindrical body. The helical anchoring screw is able to penetrate tissue of a wall of the heart and is configured to provide temporary attachment, in rotation and in translation, of the capsule to an implantation site. The helical anchoring screw surrounds at least a portion of the length of the cylindrical body forming a contact region intended to come into contact with the wall of the cavity of the heart. Over the length of the contact region, the external diameter of the cylindrical body is less than the inner diameter of the helical anchoring screw, so as to leave a free gap there between. The helical anchoring screw is secured to the cylindrical body near the proximal end of the contact region, and extends freely to the opposite distal end.

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

Abstract: A method and medical device for determining a P-wave of a cardiac signal that includes sensing the cardiac signal, determining a P-wave sensing window in response to the sensed cardiac signal, the P-wave sensing window having a first portion and a second portion, determining signal characteristics of the sensed cardiac signal within the first portion and within the second portion, comparing the determined signal characteristics, and determining the P-wave in response to the comparing.

Abstract: A system for managing care of a person receiving emergency cardiac assistance is disclosed that includes one or more capacitors for delivering a defibrillating shock to a patient; one or more electronic ports for receiving signals from sensors for obtaining indications of an electrocardiogram (ECG) for the patient; and a patient treatment module executable on one or more computer processors using code stored in non-transitory media and to provide a determination of a likelihood of success from delivering a future defibrillating shock to the person with the one or more capacitors, using (a) a mathematical transform from a time domain to a frequency domain applied to the indication of the ECG, and (b) a tapered window for identifying the portion of the indications of the ECG on which the transform is performed.

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: A system and method provide precise detection of the time of occurrence of a cardiac event of a heart. The method comprises the steps of sensing electrical activity of the heart to generate an electrogram of the heart and applying the electrogram to an event detector having a plurality of spaced apart thresholds. The thresholds are selected such that the electrogram has an amplitude for crossing at least one of the thresholds. The method further comprises determining a characteristic identifying feature of the electrogram at each threshold crossing of the electrogram, comparing the determined characteristic identifying features to an electrogram template, and identifying the time of occurrence of the cardiac event based upon the comparison.

Abstract: The invention relates to an implantable capsule, particularly an autonomous capsule of cardiac stimulation, comprising a tubular body provided at the distal end of an anchoring element with a helical screw adapted to penetrate tissue a wall of an organ of a patient, the body housing a set of functional elements of the capsule. It comprises an annular support integral with the body and coaxial therewith, said support surrounding the base of the anchoring element and comprising a series of openings radially extending. The base of the anchoring element comprises a series of rods or tubes projecting in a generally radial direction, and engaged in said openings to thereby secure the anchoring element to the support.

Abstract: An epicardial screw lead for stimulation/defibrillation implantable by a guide-catheter inserted into the pericardial space is described. The lead is a monodiameter lead with a helical anchoring screw extending axially of the lead body. The guide-catheter (24) has a pre-shaped tube having, in the absence of stress, a first bend (26) for supporting the lead body on the outer wall of the pericardial space (38), and a second bend (28) for orienting the end of the guide-catheter tube in the direction of the outer wall of the myocardium (34) and keeping the axis of the anchoring screw (14) in that same direction during a combined movement of screwing and insertion of the lead head.

Abstract: Techniques are provided for use with an implantable cardiac stimulation device equipped for multi-site left ventricular (MSLV) pacing using a multi-pole LV lead. In one example, MSLV interelectrode conduction delays are determined among the electrodes of the multi-pole LV lead. MSLV interelectrode pacing delays are then set based on the MSLV interelectrode conduction delays for use in delivering MSLV pacing. To this end, various criteria are exploited for determining optimal values for the pacing delays based on the interelectrode conduction delays. MSLV pacing is then controlled using the specified MSLV interelectrode pacing delays. In some examples, the optimization procedure is performed by the implantable device itself. In other examples, the procedure is performed by an external programmer device. In such an embodiment, the external device determines optimal MSLV interelectrode pacing delays and then transmits programming commands to the implantable device to program the device to use the pacing delays.

Abstract: A tissue stimulator including a sensing unit, wherein the sensing unit includes an A/D converter that samples an analog signal using a sampling clock and converts the analog signal into a digital signal. The tissue stimulator includes a digital filter with an input, wherein the input is connected to an output of the A/D converter. Using a filter clock, the digital filter filters the digital signal, and wherein the filter clock is a multiple of the sampling clock for a specific period of time T.

Abstract: A system for use during revascularization includes a catheter having an adjustable balloon for delivery a stent, one or more pacing electrodes for delivering one or more pacing pulses to a patient's heart, and a pacemaker configured to generate the one or more pacing pulses to be delivered to the heart via the one or more pacing electrodes. The one or more pacing pulses are delivered at a rate substantially higher than the patient's intrinsic heart rate without being synchronized to the patient's intrinsic cardiac contractions, and are delivered before, during, or after an ischemic event to prevent or reduce cardiac injury.

Abstract: Physiological parameters of a patient can be used to monitor patient status and/or in conjunction with patient therapy. Physiological cycles may be monitored by implanting a monitoring system into the patient, the system including an implantable pulse generator operably connected to a lead implanted on a carotid sinus of the patient, measuring at least one signal indicative of a physiological parameter of the patient along at least two vectors selected from: a first vector defined between a first electrode of the lead and a second electrode of the lead, a second vector defined between the first electrode of the lead and an electrode integrated into an implantable pulse generator, and a third vector defined between the second electrode of the lead and the electrode integrated into the implantable pulse generator, and providing an output indicative of the at least one signal indicative of the physiological parameter.

Abstract: Cardiac resynchronization therapy (CRT) delivered to a heart of a patient may be adjusted based on detection of a surrogate indication of the intrinsic atrioventricular conduction of the heart. In some examples, the surrogate indication is determined to be a sense event of the first depolarizing ventricle of the heart within a predetermined period of time following the delivery of a fusion pacing stimulus to the later depolarizing ventricle. In some examples, the CRT is switched from a fusion pacing configuration to a biventricular pacing configuration if the surrogate indication is not detected, and the CRT is maintained in a fusion pacing configuration if the surrogate indication is detected.

Abstract: The present disclosure provides systems and methods for providing both neurostimulation and defibrillation therapy. The system includes an implantable pulse generator (IPG), at least one neurostimulation electrode electrically coupled to the IPG and configured to apply neurostimulation pulses to a subject, and at least one defibrillation electrode electrically coupled to the IPG and configured to apply defibrillation pulses to the subject.

Abstract: A medical device system including an pacemaker implantable in a chamber of a patient's heart is configured to sense near field events from a cardiac electrical signal, establish a lower rate interval to control a rate of delivery of pacing pulses and schedule a first pacing pulse by starting a pacing escape interval set equal to the lower rate interval. The pacemaker withholds the scheduled pacing pulse in response to sensing a near-field event during the pacing escape interval and schedules a next pacing pulse to be delivered at the lower rate interval from a time that the pacing escape interval is scheduled to expire.

Abstract: A method and system of providing therapy to a patient implanted with an array of electrodes is provided. A train of electrical stimulation pulses is conveyed within a stimulation timing channel between a group of the electrodes to stimulate neural tissue, thereby providing continuous therapy to the patient. Electrical parameter is sensed within a sensing timing channel using at least one of the electrodes, wherein the first stimulation timing channel and sensing timing channel are coordinated, such that the electrical parameter is sensed during the conveyance of the pulse train within time slots that do not temporally overlap any active phase of the stimulation pulses.

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

Abstract: A system and method for cardiac rhythm management using a programmable cardiac rhythm management device is described, wherein the method includes storing parameter interaction constraints between different programmable parameters, storing programmable parameters for the device, wherein each programmable parameter has a predefined set of possible values, wherein one programmable parameter is a delay value, and calculating initial seed values for user-set delay range input fields, wherein the seed values do not violate any parameter interaction constraints and maximize the difference between ends of the user-set delay range, wherein the user-set delay range provides the outer limits of a programmed delay value. The method further includes presenting an input screen to the user on a user display device, wherein the input screen comprises user-set delay range input fields containing the initial seed values.

Abstract: A medical device system including a pacemaker implantable in an atrial chamber of a patient's heart is configured to sense near field atrial events from a cardiac signal received by a sensing module of the pacemaker and to sense far field ventricular events. The pacemaker is configured to establish an atrial lower rate interval to control a rate of delivery of atrial pacing pulses, determine a rate of the far field ventricular events sensed by the sensing module, determine an atrial event rate, compare the rate of the sensed far field ventricular events to the atrial event rate, and adjust the atrial lower rate interval in response to the comparison.

Abstract: Techniques are provided for use by implantable medical devices for controlling multi-site left ventricular (MSLV) pacing using a multi-pole left ventricular (LV) lead. In various examples, a reduced number of “V sense”, “RV pace”, and “LV pace” tests are performed to determine preferred or optimal interventricular pacing delays (VV) for use with MSLV pacing. Additionally, techniques are described for sorting the order by which LV sites are to be paced during MSLV pacing. Furthermore, techniques are described for detecting and addressing circumstances where AV/PV delays are longer than corresponding AR/PR delays during MSLV.

Abstract: Methods and/or devices may be configured to monitor ventricular activation times and modify an atrioventricular delay (AV delay) based on the monitored ventricular activation times. Further, the methods and/or devices may determine whether the AV delay should be modified based on the measured activation times before modifying the AV delay.

Abstract: An exemplary method for optimizing pacing configuration includes providing distances between electrodes of a series of three or more ventricular electrodes associated with a ventricle; selecting a ventricular electrode from the series; delivering energy to the ventricle via the selected ventricular electrode, the energy sufficient to cause an evoked response; acquiring signals of cardiac electrical activity associated with the evoked response via non-selected ventricular electrodes of the series; based on signals of cardiac electrical activity acquired via the non-selected ventricular electrodes and the distances, determining conduction velocities; based on the conduction velocities, deciding if the selected ventricular electrode is an optimal electrode for delivery of a cardiac pacing therapy; and, if the selected ventricular electrode comprises an optimal electrode for delivery of the cardiac pacing therapy, calling for delivery of the cardiac pacing therapy using the selected ventricular electrode.

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: A preferred atrial-based pacing method and apparatus is provided using an intelligent cardiac pacing system to having the ability to continue atrial-based pacing as long as relatively reliable AV conduction is present. In the event that such relatively reliable AV conduction is not present, mode switching to a DDD/R or a DDI/R pacing mode while continually biased to mode switch back to atrial-based pacing. The standard or relatively reliable AV conduction may be changed either automatically or manually. This increases pacing that utilizes natural AV conduction however possible so as to gain all the benefits of cardiac contractile properties resulting therefrom, while tolerating the occasional missed ventricular depolarization (i.e., non-conducted P-wave). In the event where relatively reliable AV conduction is not present, the pacing mode is switched to a DDD/R mode while detecting a return of the relatively reliable AV conduction (and resulting mode switch to preferred atrial based pacing).

Abstract: A method and apparatus is provided for determining whether a current atrial-ventricular (AV) delay during cardiac pacing is appropriate for proper mechanical coupling of the atrium and ventricle. If proper mechanical coupling is determined to not exist, an additional atrial contraction is induced within the same ventricular cycle to maintain atrial-ventricular mechanical coupling.

Abstract: A method and apparatus for treatment of hypertension and heart failure by increasing secretion of endogenous atrial hormones by pacing of the heart atria. Atrial pacing is done during the ventricular refractory period resulting in premature atrial contraction that does not result in ventricular contraction. Pacing results in the atrial wall stress, peripheral vasodilation, ANP secretion. Concomitant reduction of the heart rate is monitored and controlled as needed with backup pacing.

Abstract: One aspect of the present disclosure relates to a method for treating a menopause-related condition in a subject. One step of the method can include inserting a therapy delivery device into a vessel of the subject. Next, the therapy delivery device can be advanced to a point substantially adjacent a target site of the sympathetic nervous system (SNS) that is associated with the menopause-related condition. The therapy delivery device can then be activated to deliver a therapy signal to the target site of the SNS in an amount and for a time sufficient to effect a change in sympathetic activity in the subject and thereby treat the menopause-related condition.

Abstract: Methods of treating auditory hallucinations, hyperacusis, schizophrenia, and/or phonophobia include applying at least one stimulus to a stimulation site within a patient with an implanted stimulator in accordance with one or more stimulation parameters. The stimulation site may include, for example, at least one or more of a cochlear nucleus, auditory striae, superior olivary complex, lateral lemniscus, inferior colliculus, brachium of the inferior colliculus, medial geniculate body, primary auditory cortex, secondary auditory cortical area, and auditory radiation. Systems for treating auditory hallucinations, hyperacusis, schizophrenia, and/or phonophobia include an implanted stimulator configured to apply at least one stimulus to a stimulation site within a patient in accordance with one or more stimulation parameters.

Abstract: A medical device is provided that includes an input/output, at least one sensor, a memory, a controller and at least one delivery member. The input/output is configured to provide a communication path to and from the medical device. The at least one sensor is used to monitor at least one patient function. The memory is used to store patient specific data from the at least one sensor and operating parameters of the medical device. The controller is used to control operations of the medical device. The controller is in communication with the at least one sensor, the memory and the input/output. The controller is configured to deny device operational change requests received via the input/output based at least in part on the patient specific data sensed by the at least one sensor. The at least one delivery member is under the control of the controller and is configured to provide a therapeutic function of the medical device.

Abstract: Methods and apparatus are provided for selective destruction or temporary disruption of nerves and/or conduction pathways in a mammalian body for the treatment of pain and other disorders. Apparatus comprises catheters having electrodes for targeting and affecting nerve tissue at a cellular level to reversible and irreversible nerve poration and incapacitation.

Abstract: Systems and methods for determining pacing timing intervals based on the temporal relationship between the timing of local and non-local cardiac signal features are described. A device includes a plurality of implantable electrodes electrically coupled to the heart and configured to sense local and non-local cardiac signals. Sense circuitry coupled to first and second electrode pairs senses a local cardiac signal via a first electrode pair and a non-local cardiac signal via a second electrode pair. Detection circuitry is used to detect a feature of the local signal associated with activation of a heart chamber and to detect a feature of the non-local signal associated with activation of the heart chamber. A control processor times delivery of one or more pacing pulses based on a temporal relationship between timing of the local signal feature and timing of the non-local signal feature.

Abstract: The present invention includes methods and devices for treating hypotension, such as in cases of shock, including septic shock, anaphylactic shock and hypovolemia. The method includes the step of applying at least one electrical impulse to at least one selected region of a parasympathetic nervous system of the patient. The electrical impulse is sufficient to modulate one or more nerves of the parasympathetic nervous system to increase the ratio of blood pressure to heart rate and relieve the condition and/or extend the patient's life.

Abstract: Evaluation of an implanted electrical lead condition includes comparing electrogram template features with test electrogram features. The evaluating also includes determining the implanted electrical lead condition based solely on the electrogram comparison. The compared test electrogram features and template electrogram features may be atrial amplitudes and ventricular amplitudes. The sensing may be with a quad polar lead. The compared test electrogram features and electrogram template features may account for different patient postures and/or may account for respiration modulation.

Abstract: An implantable medical device is provided for sensing cardiac activity within a patient's body. The device comprises a canister, control circuitry disposed within the canister, and a lead assembly extending from the canister. At least one sense electrode is coupled to the circuitry and disposed on the lead assembly for sensing cardiac activity. At least one spacer is coupled between the lead assembly and the canister for maintaining a minimum predetermined distance between the at least one sense electrode and the canister.

Abstract: An apparatus may include an implantable therapy circuit that provides bi-ventricular pacing to a subject, a heart sound signal sensing circuit that produces a sensed heart sound signal that is representative of at least one heart sound associated with mechanical cardiac activity, a memory circuit to store one or more heart sound templates of cardiac capture, and a comparison circuit that compares a segment of the sensed heart sound signal to the one or more heart sound templates of cardiac capture to identify ventricles in which cardiac capture was induced by the bi-ventricular pacing. In some situations, an indication of the ventricles in which cardiac capture was induced may be generated according to the comparison.

Abstract: An medical device for stimulating the heart using biventricular stimulation. The device includes a sensor for detecting an endocardial acceleration parameter and a processing circuit configured to receive the endocardial acceleration parameter. The device further includes stimulation electronics coupled to the processing circuit. The processing circuit is configured to use the EA parameter to evaluate the biventricular stimulation. The evaluation includes comparing the value of the EA parameter in biventricular mode to the value of the EA parameter in left only mode or right only mode, and using the comparison and an assessment of the variability of the EA parameter as a function of the AVD in the left or right mode to distinguish between cases comprising: (a) normal operation, (b) a loss of RV or LV capture, (c) possible anodal stimulation. The processing circuit is further configured to conduct at least one update to operational parameters of the device based on the determined case.

Abstract: There is provided a method of generating a pulmonary index value of a patient, which includes receiving two or more measured patient parameters, wherein at least one of the measured parameters originates from a pulmonary sensor; and computing the pulmonary index value based on the two or more measured patient parameters.

Abstract: A lead system for an implantable medical device and applications for the lead system. Also includes therapeutic systems, devices, and processes for detecting and treating disordered breathing and treating cardiac and breathing issues together with an implantable device.

Abstract: A medical diagnostic/monitoring system is disclosed herein. The medical diagnostic/monitoring system includes a data acquisition device having a first near field communication device, and a data storage device wirelessly connected to the data acquisition device. The data storage device includes a second near field communication device. The first near field communication device and the second near field communication device are collectively configured to wirelessly transfer power and data from the data acquisition device to the data storage device.

Abstract: Methods and devices for treating anaphylaxis, anaphylactic shock, bronchial constriction, and/or asthma include providing an electrical impulse to a selected region of the vagus nerve of a patient suffering from anaphylaxis to block and/or modulate nerve signals that would regulate the function of, for example, myocardial tissue, vasodilation/constriction and/or pulmonary tissue.

Abstract: Cardiac monitoring and/or stimulation methods and systems employing dyspnea measurement. An implantable cardiac device may sense transthoracic impedance and determine a patient activity level. An index indicative of pulmonary function is implantably computed to detect an episode of dyspnea based on a change, trend, and/or value exceeding a threshold at a determined patient activity level. Trending one or more pulmonary function index values may be done to determine a patient's pulmonary function index profile, which may be used to adapt a cardiac therapy. A physician may be automatically alerted in response to a pulmonary function index value and/or a trend of the patient's pulmonary index being beyond a threshold. Computed pulmonary function index values and their associated patient's activity levels may be stored periodically in a memory and/or transmitted to a patient-external device.

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