Abstract: Techniques are provided for estimating left atrial pressure (LAP) or other cardiac performance parameters based on measured conduction delays. In particular, LAP is estimated based interventricular conduction delays. Predetermined conversion factors stored within the device are used to convert the various the conduction delays into LAP values or other appropriate cardiac performance parameters. The conversion factors may be, for example, slope and baseline values derived during an initial calibration procedure performed by an external system, such as an external programmer. In some examples, the slope and baseline values may be periodically re-calibrated by the implantable device itself. Techniques are also described for adaptively adjusting pacing parameters based on estimated LAP or other cardiac performance parameters. Still further, techniques are described for estimating conduction delays based on impedance or admittance values and for tracking heart failure therefrom.

Abstract: A leadless implantable medical device (LIMD) includes a housing formed from a battery and an end cap. A proximal end of the end cap forms an LIMD proximal end and a distal end of the battery case forms an LIMD distal end. A non-conductive coupler mechanically secures a terminal end of the battery case to a mating end of the end cap, while maintaining the battery case and end cap electrically separated. A first electrode projects from the proximal end of the end cap. An intra-cardiac (IC) device extension projects from the distal end of the battery case. The extension includes a second electrode that is electrically connected to the battery case. The second electrode is located remote from the LIMD distal end. An electronics module is located within an internal cavity of the end cap and communicates with the first and second electrodes.

Abstract: A method for use with an implantable system including a lead having multiple electrodes implantable proximate to a patient's left ventricular (LV) chamber includes simultaneously delivering pacing pulses over corresponding pacing vectors defined by electrodes proximate to the LV chamber. The method includes recording evoked responses responsive to the pacing pulses that are measured over separate corresponding sensing channels. The method also includes comparing the evoked responses to a template that represents local capture of a local LV tissue region along one or more of the corresponding pacing vectors. The comparison is used to determine whether the pacing pulses achieved local capture along the corresponding pacing vectors. At least one of the pacing pulses or pacing vectors are updated based on the comparison of the evoked responses to the template in order to determine a local capture threshold for the corresponding pacing vectors.

Abstract: Techniques are provided for controlling and delivering spinal cord stimulation (SCS) or other forms of neurostimulation. In one example, neurostimulation pulses are generated wherein successive pulses alternate in polarity so that a pair of electrodes alternate as cathodes. Each pulse has a cathodic amplitude sufficient to achieve cathodic capture of tissues adjacent the particular electrode used as the cathode for the pulse. The neurostimulation pulses are delivered to patient tissues using the electrodes to alternatingly capture tissues adjacent opposing electrodes via cathodic capture to achieve a distributed virtual stimulation cathode. Various pulse energy savings techniques are also set forth that exploit the distributed virtual stimulation cathode.

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

Abstract: A neurostimulation lead including an elongated lead body having a distal end and a proximal base. The lead body may have an elastic property such that the lead body is capable of flexing between different geometries. The lead may also include electrodes positioned along the lead body. The lead body may be configured to be straightened into a substantially linear geometry for delivering the lead body into an epidural space and may be biased such that the lead body is configured to have a wave-like geometry when disposed within the epidural space. The lead body may form first and second lateral segments that are joined by a corresponding linking portion when in the wave-like geometry.

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

Abstract: A leadless intra-cardiac medical device (LIMD) includes an electrode assembly configured to be anchored within a first wall portion of a first chamber of a heart. The electrode assembly includes an electrode main body having a first securing helix, an electrode wire segment extending from the body, and a first segment-terminating contact positioned on the electrode wire segment. The device further includes a housing assembly configured to be anchored within a second wall portion of a second chamber of the heart. The housing assembly includes a body having a second securing helix, a housing wire segment extending from the body, and a second segment-terminating contact positioned on the housing wire segment. The device also includes a connector block that electrically connects the electrode wire segment to the housing wire segment by retaining the first and second segment-terminating contacts.

Abstract: A leadless implantable medical device (LIMD) includes a housing formed from a battery and an end cap. A proximal end of the end cap forms an LIMD proximal end and a distal end of the battery case forms an LIMD distal end. A non-conductive coupler mechanically secures a terminal end of the battery case to a mating end of the end cap, while maintaining the battery case and end cap electrically separated. A first electrode projects from the proximal end of the end cap. An intra-cardiac (IC) device extension projects from the distal end of the battery case. The extension includes a second electrode that is electrically connected to the battery case. The second electrode is located remote from the LIMD distal end. An electronics module is located within an internal cavity of the end cap and communicates with the first and second electrodes.

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

Abstract: A method and system are provided for characterizing chamber specific function. The method and system comprise collecting cardiac signals associated with asynchronous timing between first and second chambers of the heart; collecting dynamic impedance (DI) data along a chamber-specific function (CSF) vector to form a DI data set, the DI data set collected during a collection window that is temporally aligned based on a timing feature of interest (FOI); repeating the collection operations over multiple cardiac cycles (CC) to obtain an ensemble of DI data sets; and combining the ensemble of DI data sets to form a composite DI data set that is coupled to a chamber functional mechanic of interest (FMOI) associated with the first chamber and decoupled from functional mechanics associated with the second chamber; and analyzing the composite DI data set to obtain a CSF indicator associated with the chamber FMOI of the first chamber.

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

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

Abstract: A method for use with an implantable system including a lead having multiple electrodes implantable proximate to a patient's left ventricular (LV) chamber includes simultaneously delivering pacing pulses over corresponding pacing vectors defined by electrodes proximate to the LV chamber. The method includes recording evoked responses responsive to the pacing pulses that are measured over separate corresponding sensing channels. The method also includes comparing the evoked responses to a template that represents local capture of a local LV tissue region along one or more of the corresponding pacing vectors. The comparison is used to determine whether the pacing pulses achieved local capture along the corresponding pacing vectors. At least one of the pacing pulses or pacing vectors are updated based on the comparison of the evoked responses to the template in order to determine a local capture threshold for the corresponding pacing vectors.

Abstract: Techniques are provided for estimating left atrial pressure (LAP) or other cardiac performance parameters based on measured conduction delays. In particular, LAP is estimated based interventricular conduction delays. Predetermined conversion factors stored within the device are used to convert the various the conduction delays into LAP values or other appropriate cardiac performance parameters. The conversion factors may be, for example, slope and baseline values derived during an initial calibration procedure performed by an external system, such as an external programmer. In some examples, the slope and baseline values may be periodically re-calibrated by the implantable device itself. Techniques are also described for adaptively adjusting pacing parameters based on estimated LAP or other cardiac performance parameters. Still further, techniques are described for estimating conduction delays based on impedance or admittance values and for tracking heart failure therefrom.

Abstract: Methods, systems, and apparatus for signal detection are described. In one example, a detection assembly includes a signal detector. The signal detector is configured to receive a sensor signal having a peak magnitude and a first frequency and generate an output signal having a magnitude proportional to the peak magnitude of the sensor signal and having a second frequency less than the first frequency of the sensor signal.

Abstract: Systems and methods are provided wherein intracardiac electrogram (IEGM) signals are used to determine a set of preliminary optimized atrioventricular (AV/PV) and interventricular (VV) pacing delays. In one example, the preliminary optimized AV/VV pacing delays are used as a starting point for further optimization based on impedance signals such as impedance signals detected between a superior vena cava (SVC) coil electrode and a device housing electrode, which are influenced by changes in stroke volume within the patient. Ventricular pacing is thereafter delivered using the AV/VV pacing delays optimized via impedance. In another example, parameters derived from IEGM signals are used to limit the scope of an impedance-based optimization search to reduce the number of pacing tests needed during impedance-based optimization. Biventricular and multi-site left ventricular (MSLV) examples are described.

Abstract: A leadless intra-cardiac medical device (LIMD) is configured to be implanted entirely within a heart of a patient. The LIMD comprises a housing configured to be securely attached to an interior wall portion of a chamber of the heart, and a stabilizing intra-cardiac (IC) device extension connected to the housing. The stabilizing IC device extension may include a stabilizer arm, and/or an appendage arm, or an elongated body or a loop member configured to be passively secured within the heart.

Abstract: Methods, systems, and apparatus for signal detection are described. In one example, a detection assembly includes a signal detector. The signal detector is configured to receive a sensor signal having a peak magnitude and a first frequency and generate an output signal having a magnitude proportional to the peak magnitude of the sensor signal and having a second frequency less than the first frequency of the sensor signal.

Abstract: A renal denervation system includes a renal denervation catheter and a flow determining system. The renal denervation catheter includes a plurality of ablation members positioned at a distal end portion thereof. The renal denervation catheter is insertable into a renal artery. The flow determining system includes a processor and first and second flow determining members spaced apart on the renal denervation catheter. The processor is configured to determine a change in blood flow through the renal artery resulting from a renal denervation procedure using the renal denervation catheter in response to input from the first and second flow determining members.