Abstract: Various embodiments of the present invention are directed to, or are for use with, an implantable system including a lead having multiple electrodes implantable in a patient's left ventricular (LV) chamber. In accordance with an embodiment, the patients LV chamber is paced at first and second sites within the LV chamber using a programmed LV1-LV2 delay, wherein the LV1-LV2 delay is a programmed delay between when first and second pacing pulses are to be delivered respectively at the first and second sites within the LV chamber. Evoked responses to the first and second pacing pulses are monitored for, and one or more LV pacing parameter is/are adjusted and/or one or more backup pulse is/are delivered based on results of the monitoring.

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: 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: 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 system and method are provided for monitoring ischemic development. The system and method identify a non-physiologic event and obtain cardiac signals along multiple sensing vectors, wherein at least a portion of the sensing vectors extend to or from electrodes located proximate to the left ventricle. The system and method monitor a segment of interest in the cardiac signals obtained along the multiple sensing vectors to identify deviations in the segment of interest from a baseline. The system and method record at least one of timing or segment shift information associated with the deviations in the segments of interest; and identify at least one of size, direction of development or rate of progression of an ischemia region based on the at least one of timing or segment shift information.

Abstract: An exemplary method includes selecting a first pair of electrodes to define a first vector and selecting a second pair of electrodes to define a second vector; acquiring position information during one or more cardiac cycles for the first and second pairs of electrodes wherein the acquiring comprises using each of the electrodes for measuring one or more electrical potentials in an electrical localization field established in the patient; and determining a dyssynchrony index by applying a cross-covariance technique to the position information for the first and the second vectors. Another method includes determining a phase shift based on the acquired position information for the first and the second vectors; and determining an interventricular delay based at least in part on the phase shift.

Abstract: The intrapericardial lead includes a lead body having a proximal portion and a flexible, pre-curved distal end portion. The distal end portion carries at least one electrode assembly containing an electrode adapted to engage pericardial tissue. The distal end portion further carries a pre-curved flexible wire member having ends attached to spaced apart points along the distal end portion of the lead body, the flexible wire member having a normally expanded state wherein an intermediate portion of the wire member is spaced apart from the distal end portion, and a generally straightened state wherein the wire member and the distal end portion are disposed in a more parallel, adjacent relationship so as to present a small frontal area to facilitate delivery into the pericardial space. The wire member re-expands to its normal state after delivery into the pericardial space to anchor the distal end portion of the lead body relative to the pericardial tissue.

Abstract: A method includes selecting an electrode located in a patient; acquiring position information with respect to time for the electrode where the acquiring uses the electrode for repeatedly measuring electrical potentials in an electrical localization field established in the patient; calculating a stability metric for the electrode based on the acquired position information with respect to time; and deciding if the selected electrode, as located in the patient, has a stable location for sensing biological electrical activity, for delivering electrical energy or for sensing biological electrical activity and delivering electrical energy. Position information may be acquired during one or both of intrinsic or paced activation of a heart and respective stability indexes calculated for each activation type.

Abstract: A device senses cardioelectrical signals using a right atrial (RA) lead, which might include far-field R-waves as well as near-field P-waves. The device concurrently senses events using a proximal electrode of an LV lead, which can sense both P-waves and R-waves as substantially near-field events. Suitable templates are then applied to the signals sensed via the proximal LV electrode to identify the origin of the signals (e.g. atrial vs. ventricular) so as to properly classify the corresponding events sensed in the RA as near-field or far-field events. In this manner, far-field oversensing is conveniently detected.

Abstract: Detection of T wave oversensing in an ICD is accomplished in order to prevent improper application of treatment to a patient. The ICD device senses for electrical impulses representing the R waves of a beating heart. In some instances the ICD device will sense T waves that it will assume to be R waves, because the ICD device expects or assumes that such sensed signals are R waves. Time intervals between each detected, assumed R waves are measured and a list of intervals is generated. The list is transformed into its frequency domain equivalent and analyzed for peaks and randomness criteria to determine whether T wave oversensing has occurred.

Abstract: Techniques are provided for use with implantable medical devices for addressing encapsulation effects, particularly in the detection of cardiac decompensation events such as heart failure (HF) or cardiogenic pulmonary edema (PE.) In one example, during an acute interval following device implant, cardiac decompensation is detected using heart rate variability (HRV), ventricular evoked response (ER) or various other non-impedance-based parameters that are insensitive to component encapsulation effects. During the subsequent chronic interval, decompensation is detected using intracardiac or transthoracic impedance signals. In another example, the degree of maturation of encapsulation of implanted components is assessed using impedance frequency-response measurements or based on the frequency bandwidth of heart sounds or other physiological signals.

Abstract: Techniques are provided for use with an implantable cardiac stimulation device equipped with a multi-pole left ventricular (LV) lead having a proximal electrode implanted near an atrioventricular (AV) groove of the heart of the patient. A left atrial (LA) cardioelectrical event is sensed using the proximal electrode of the LV lead and a corresponding LA cardiomechanical event is also detected, either using an implantable sensor or an external detection system. The electromechanical activation delay between the LA cardioelectrical event and the corresponding LA cardiomechanical event is determined and then pacing delays are set based on the electromechanical activation delay for use in controlling pacing. The pacing delays can include, e.g., AV delays for use with biventricular cardiac resynchronization therapy (CRT) pacing. Other techniques described herein are directed to exploiting right atrial (RA) cardioelectrical events detected via an RA lead for the purposes of setting pacing delays.

Abstract: Methods and systems are provided for determining pacing parameters for an implantable medical device (IMD). The methods and systems provide electrodes in the right atrium (RA), right ventricle (RV) and left ventricle (LV). The methods and systems sense RV cardiac signals and LV cardiac signals at an RV electrode and an LV electrode, respectively, over multiple cardiac cycles, to collect global activation information. The methods and systems identify a T-wave in the LV cardiac signal. The methods and systems calculate a repolarization index based at least in part on a timing of the T-wave identified in the LV cardiac signal. The methods and systems set at least one pacing parameter based on the repolarization index, wherein the at least one pacing parameter that is set represents at least one of an AV delay, an inter-ventricular interval and an intra-ventricular interval.

Abstract: Pacing related timing is determined for an implantable medical device (IMD) by pacing at an RV pacing site, a first LV pacing site and a second LV pacing site in accordance with a first site, a second site and a third site pacing order, and further in accordance with a first inter-electrode pacing delay between pacing at the first site and pacing at the second site and a second inter-electrode pacing delay between pacing at the second site and pacing at the third site. At least one of a sensed event or a paced event is detected for at each of the second site and the third site. The first inter-electrode pacing delay and the second inter-electrode pacing delay are adjusted to avoid sensed events in favor of paced events at each of the second site and the third site. An atrio-ventricular delay may also be adjusted to avoid sensed events or lack of capture due to possible fusion at the first site, in favor of paced events at the first site.

Abstract: Described herein are implantable systems and devices, and methods for use therewith, that can be used to perform arrhythmia discrimination. A plurality of different sensing vectors are used to obtain a plurality of different IEGMs, each of which is indicative of cardiac electrical activity at a different ventricular region. The plurality of different IEGMs can include, e.g., an IEGM indicative of cardiac electrical activity at a first region of the patient's left ventricular (LV) chamber and an IEGM indicative of cardiac electrical activity at a second region of the patient's LV chamber. Additionally, the plurality of different IEGMs can further include an IEGM indicative of cardiac electrical activity at a region of a patient's right ventricular (RV) chamber. For each of the IEGMs, there is a determination of a corresponding localized R-R interval stability metric indicative of the R-R interval stability at the corresponding ventricular region. This can include, e.g.

Abstract: Described herein are implantable systems and devices, and methods for use therewith, that can be used to increase compliance with a predetermined preferred ventricular electrical activation pattern. Such implantable systems preferably includes a first lead having at least one electrode implantable in a right ventricular (RV) chamber, and a second lead having at least two electrodes implantable in a left ventricular (LV) chamber. A plurality of different sensing vectors are used to obtain a plurality of IEGMs that collectively enable electrical activations to be detected in at least the RV chamber and at at least two separate regions of the LV chamber. The IEGMs can be obtained while the patient's LV chamber is not being paced, or during bi-ventricular (BiV) pacing that includes pacing at only a single site within the LV chamber. An actual ventricular electrical activation pattern is determined based on the plurality of IEGMs.

Abstract: Described herein are implantable systems, and methods for use therewith, to predict whether ventricular tachycardia (VT) or ventricular fibrillation (VF) is imminent, estimate ischemic burden and/or characterize an electrical substrate of the LV chamber. For each of a plurality of cardiac cycles, a pacing vector comprising a first set of electrodes is used to deliver a pre-pacing pulse at a site within the LV chamber (wherein the pre-pacing pulse is delivered prior to an intrinsic activation of the LV chamber), and a sensing vector comprising a second set of electrodes is used to detect an evoked response to the pre-pacing pulse. The detected evoked responses to the pre-pacing pulses are analyzed, and results of the analysis are used predict whether VT or VF is imminent, estimate ischemic burden and/or characterize an electrical substrate of the LV chamber.

Abstract: An exemplary method includes use of a multielectrode device that can help position a cardiac stimulation lead to an optimal site in the heart based at least in part on cardiac motion information acquired via the multielectrode device and one or more pairs of current delivery electrodes that establish potential fields (e.g., for use as a coordinate system). An exemplary mutlielectrode device may be a multielectrode catheter or a multifilar, electrode-bearing guidewire. Various other exemplary methods, devices, systems, etc., are also disclosed.

Abstract: CRT settings for an implantable medical device are determined by applying pacing pulses to heart chambers of a scheme of different combinations of interchamber delays. A respective width parameter value representing an R or P wave width is determined for each such delay combination based on an ECG representing signal and the width parameter values are employed to estimate a parametric model defining the width parameter as a function of interchamber delays. Candidate interchamber delays that minimize the width parameter are determined from the parametric model and employed to determine optimal CRT settings. The technique provides an efficient way of finding optimal CRT settings when multiple pacing sites are available in a heart chamber.

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 where the cardiac information comprises position information, electrical information and mechanical information; mapping local electrical activation times to anatomic positions to generate an electrical activation time map; mapping local mechanical activation times to anatomic positions to generate a mechanical activation time map; generating an electromechanical delay map by subtracting local electrical activation times from corresponding local mechanical activation times; and rendering at least the electromechanical delay map to a display. Various other methods, devices, systems, etc., are also disclosed.