Abstract: Techniques are provided for use by an implantable medical device for assessing and controlling concurrent anodal/cathodal capture. In one example, the device delivers bipolar pacing stimulus while sensing a bipolar intracardiac electrogram (IEGM) and while adjusting a magnitude of the pacing stimulus. The device analyzes the bipolar IEGM signals to detect an indication of activation representative of concurrent anodal and cathodal capture. Preferably, the pulse magnitude is set relative to the anodal/cathodal capture threshold based upon clinician programming in response to the needs of the patient. In this manner, concurrent anodal and cathodal capture can be selectively activated or deactivated based on clinician instructions received from a device programmer or other external programming device. Techniques exploiting both bipolar and unipolar IEGM signals to assess and control concurrent anodal/cathodal capture are also described.

Abstract: An implantable medical device controls the excitation of and processes signals received from passive pressure sensor components of an implantable lead. The passive pressure sensor components include an inductor-capacitor (L-C) resonant circuit that has a resonant frequency that corresponds in some aspects to the pressure external to the implantable lead. The capacitive circuit portion of the resonant circuit may be flexible such that changes in pressure at the capacitive circuit cause changes in the capacitance of the capacitive circuit. Thus, changes in pressure at the pressure sensor are reflected by changes in the resonant frequency of the excited resonant circuit. The L-C resonant circuit is excited by a signal coupled to the L-C resonant circuit by the implantable medical device. In some embodiments, the implantable medical device receives such an excitation signal from an external device. In some embodiments, the implantable medical device generates the excitation signal.

Abstract: Embodiments of the present invention are directed to implantable systems, and methods for use therewith, that monitor and modify a patient's arterial blood pressure without requiring an intravascular pressure transducer. In accordance with an embodiment, for each of a plurality of periods of time, there is a determination one or more metrics indicative of pulse arrival time (PAT), each of which are indicative of how long it takes for the left ventricle to generate a pressure pulsation that travels from the patient's aorta to a location remote from the patient's aorta. Based on the one or more metrics indicative of PAT, the patient's arterial blood pressure is estimated. Changes in the arterial blood pressure are monitored over time. Additionally, the patient's arterial blood pressure can be modified by initiating and/or adjusting pacing and/or other therapy based on the estimates of the patient's arterial blood pressure and/or monitored changes therein.

Abstract: An exemplary method includes accessing cardiac information acquired via a catheter located at various positions in a venous network of a heart of a patient wherein the cardiac information comprises position information with respect to time for one or more electrodes of the catheter; performing a principal component analysis on at least some of the position information; and selecting at least one component of the principal component analysis to represent an axis of a cardiac coordinate system. Various other methods, devices, systems, etc., are also disclosed.

Abstract: An implantable system terminates atrial fibrillation by applying optimized anti-tachycardia pacing (ATP). In one implementation, the system senses and paces at multiple sites on the left atrium. At each site, the system senses reentrant circuits causing the atrial fibrillation. In one implementation, the system applies ATP tuned to the frequency of the reentrant circuit at the electrode that senses the most regular reentrant circuit. In another implementation, the system applies ATP at multiple electrodes, delivering each pulse at each site when the excitable gap is near the site. In other variations, the ATP is optimized for different patterns of sequential, simultaneous, or syncopated delivery to terminate the atrial fibrillation. The system can also monitor multiple heart chambers for cardiac events that favor terminating atrial fibrillation via ATP. The system then times delivery of the ATP according to these cardiac events.

Abstract: Techniques are provided for use by an implantable medical device or diagnostic sensor for detecting and discriminating euvolemia, hypervolemia and hypovolemia. In one example, the device detects a pressure signal within the patient representative of changes in cardiac pressure overall several cardiac cycles. The device generates separate time-domain and frequency-domain representations of the pressure signal and then discriminates among euvolemia, hypervolemia and hypovolemia within the patient based on an analysis of the time-domain and the frequency-domain representations of the signal. Depending upon the capabilities of the device, suitable warnings may be generated to alert the patient or caregiver. Diuretics or other medications can be titrated to address abnormal fluid conditions such as a fluid overload during hypervolemia. Techniques for detecting a pressure alternans pattern indicative of imminent decompensation are also described.

Abstract: A header of an implantable medical pulse generator may include a lead connector end receiving receptacle for transmitting electrical pulses from the can to the lead through an electrically conductive setscrew contact in electrical communication with a terminal of the lead connector end. The setscrew contact includes a setscrew hole and a lead connector hole. The lead connector hole is aligned with the lead connector end receiving receptacle, and the setscrew hole includes a setscrew threadably received therein. Inner circumferential surfaces of the setscrew hole and lead connector hole are generally tangentially to each other such that a window is created by the overlap of the inner circumferential surfaces.

Abstract: A passive pressure sensor is used with an implantable lead to measure pressure within a patient's heart. In some embodiments, the passive pressure sensor is incorporated into an implantable lead. In other embodiments, the passive pressure sensor is incorporated into a device that is slid onto an implantable lead.

Abstract: A method and system are provided for controlling radio frequency (RF) scanning attributes of an implantable medical device (IMD) that include configuring an IMD to establish an RF connection over a predetermined frequency band based on a scan attribute. The method and system may also include storing, in the IMD, predetermined first and second values for the scan attribute to define different first and second scan modes, respectively. The method and system may also include determining a posture state of a patient, in which the IMD is implanted, and switching between the predetermined first and second values for the scan attribute, based on the posture state determined, to cause the IMD to switch between the first and second scan modes.

Abstract: Disclosed herein is a pressure sensing left atrial occluding implantable medical device. The implantable medical device includes a cardiac plug and a micro electro-mechanical system (“MEMS”). The cardiac plug includes an expandable lobe and an expandable disc proximal the lobe. The expandable lobe is configured to expand into an anchoring arrangement within the left atrial appendage. The expandable lobe is configured to expand into an occluding arrangement with the left atrial appendage. The MEMS is coupled to the cardiac plug proximal of the disc. The MEMS is configured to sense surrounding fluid pressure.

Abstract: Techniques are provided for use by implantable medical devices such as cardiac resynchronization therapy (CRT) devices for detecting pulmonary edema based on transthoracic impedance sensed using cardiac pacing/sensing leads, wherein detection can be performed while lead maturation occurs. Briefly, the implantable device determines whether the leads are within an initial post-implant interval following implant during which lead maturation generally occurs. The device then detects pulmonary edema or related medical conditions within the patient based on transthoracic impedance using a set of detection parameters adjusted for use during the post-implant interval. Thus, rather than “blanking” impedance data during lead maturation, the device instead detects and processes impedance during this period to identify possible episodes of pulmonary edema so that appropriate measures can be undertaken, such as delivery of warnings or titration of appropriate medications.

Abstract: A method and system for tracking quality of life in a patient with angina includes obtaining activity data and cardiac data, determining a level of physical activity of the patient and identifying an ischemic episode based on the cardiac data obtained during the physical activity. The method also provides for recording an activity level at the time the ischemic episode occurs. Furthermore, the method also provides for presenting activity level trends related to activity levels at the onset of ischemia to a user.

Abstract: In one embodiment, an implantable stimulation apparatus includes a vagal nerve stimulator configured to generate electrical pulses below a cardiac threshold of a heart, and an electrode coupled to the vagal nerve stimulator which is configured to transmit the electrical pulses below the cardiac threshold, to a vagal nerve so as to inhibit injury resulting from an ischemia and/or reduce injury resulting from an ischemia. In another embodiment, an implantable stimulation apparatus includes a vagal nerve stimulator configured to generate electrical pulses below a cardiac threshold, and includes an electrode, which is coupled to the vagal nerve stimulator and configured transmit electrical pulses to a vagal nerve so as to reduce a defibrillation threshold of the heart.

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, referred to herein as QuickStim, cardiac pacing configurations are optimized based on an assessment of hemodynamic benefit and device longevity. In another example, referred to herein as QuickSense, cardiac sensing configurations are optimized based on sensing profiles input by a clinician. Various virtual sensing channels are also described that provide for the multiplexing or gating of sensed signals. Anisotropic oversampling is also described.

Abstract: A method of calculating a timing delay for an implantable medical device based on cardiogenic impedance estimates cardiogenic impedance from a signal between a first electrode and a second electrode positioned in at least one chamber of a heart. The method also determines the timing delay based on the estimated cardiogenic impedance.

Abstract: Techniques are provided for detecting and distinguishing stroke and cardiac ischemia within a patient using an implantable medical device. In one example, a preliminary indication of stroke is detected by a pacemaker or similar implantable device based on an analysis of features of an intracardiac electrogram (IEGM) sensed by the device. Exemplary IEGM features indicative of possible stroke include the onset of prominent U-waves, the onset of notched T-waves, and changes in ST segment duration or QT duration. Upon detection of a possible stroke, the device then detects one or more hemodynamic parameters that are typically affected by cardiac ischemia. Such hemodynamic parameters can include, e.g., cardiac contractility or stroke volume. The device then distinguishes stroke and cardiac ischemia from one another based on whether any changes detected in the hemodynamic parameters are consistent with cardiac ischemia.

Abstract: Cardiac activity is sensed over a plurality of heart beats defining a beat set. For each beat in the set, it is determined whether the beat is a non-classified beat (e.g., paced beat, a beat outside of a specified heart rate range or a PVC), or a classified beat. For each classified beat, it is determined whether the beat is a non-detect beat, a minor beat or a major beat. Counts of classified beats, non-classified beats, major beats, minor beats, and non-detect beats are maintained. The beat set is declared to be one of a non-classified set, a major set, a minor set or a non-detect set based on the relative counts of classified beats, non-classified beats, major beats, minor beats, and non-detect beats. Over a period of time, counts of beat-set types are maintained and entry into and exit from ST episodes are determined based on these beat-set counts.

Abstract: A method for detecting potential failures by a lead of an implantable medical device is provided. The method includes sensing a first signal over a first channel between a first combination of electrodes on the lead and sensing a second signal from a second channel between a second combination of electrodes on the lead. The method determines whether at least one of the first and second signals is representative of a potential failure in the lead and identifies a failure and the electrode associated with the failure based on which of the first and second sensed signals is representative of the potential failure. Optionally, when the first and second sensed signals are both representative of the potential failure, the method further includes determining whether the first and second sensed signals are correlated with one another. When the first and second sensed signals are correlated, the method declares an electrode common to both of the first and second combinations to be associated with the failure.

Abstract: While a cardiac device is in AAI(R) mode, a ventricular channel is monitored for a premature ventricular contraction (PVC). In response to detecting a PVC while the device is in AAI(R) mode, a refractory period is started in an atrial channel to prevent a retrograde atrial event that may occur due to the PVC from resetting an atrial escape interval (AEI). Additionally, during such a relative refractory period in the atrial channel, the atrial channel is monitored for a retrograde atrial event that may occur due to the PVC. If a retrograde atrial event is detected, then the refractory period in the atrial channel is terminated, and an antegrade conduction restoration interval (ACRI) is started. The ACRI is a programmed period that specifies how long to wait after a retrograde atrial event is detected before pacing the atrium.

Abstract: A method of analyzing myocardial instability includes obtaining a physiological parameter representative of myocardial behavior over a set of cardiac cycles and determining reversal points in the physiological parameter over the set of cardiac cycles. The method also includes identifying myocardial instability based on the reversal points in the physiological parameter. A reversal point may correspond to a value of the physiological parameter, during a current cardiac cycle, that exceeds or is less than the values of the physiological parameter during prior and subsequent cardiac cycles. Optionally, the method includes calculating differences between values of the physiological parameter for consecutive cardiac cycles and detecting the reversal points when a current difference exceeds or is less than differences for prior and subsequent cardiac cycles.