Abstract: Techniques are provided for detecting and distinguishing stroke and cardiac ischemia based on electrocardiac signals. In one example, the device senses atrial and ventricular signals within the patient along a set of unipolar sensing vectors and identifies certain morphological features within the signals such as PR intervals, ST intervals, QT intervals, T-waves, etc. The device detects changes, if any, within the morphological features such as significant shifts in ST interval elevation or an inversion in T-wave shape, which are indicative of stroke or cardiac ischemia. By selectively comparing changes detected along different unipolar sensing vectors, the device distinguishes or discriminates stroke from cardiac ischemia within the patient. The discrimination may be corroborated using various physiological and hemodynamic parameters. In some examples, the device further identifies the location of the ischemia within the heart.

Abstract: Diastolic function is monitored within a patient using a pacemaker or other implantable medical device. In one example, the implantable device uses morphological parameters derived from the T-wave evoked response waveform as proxies for ventricular relaxation rate and ventricular compliance. In particular, the magnitude of the peak of the T-wave evoked response is employed as a proxy for ventricular compliance. The maximum slew rate of the T-wave evoked response following its peak is employed as a proxy for ventricular relaxation. A metric is derived from these proxy values to represent diastolic function. The metric is tracked over time to evaluate changes in diastolic function. In other examples, specific values for ventricular compliance and ventricular relaxation are derived for the patient based on the T-wave evoked response parameters.

Abstract: Methods for monitoring a patient's level of B-type natriuretic peptide (BNP), and implantable cardiac systems capable of performing such methods, are provided. A ventricle is paced for a period of time to provoke a ventricular evoked response, and a ventricular intracardiac electrogram (IEGM) indicative of the ventricular evoked response is obtained. Based on the ventricular IEGM, there is a determination of at least one ventricular evoked response metric (e.g., ventricular evoked response peak-to-peak amplitude, ventricular evoked response area and/or ventricular evoked response maximum slope), and the patient's level of BNP is monitored based on determined ventricular evoked response metric(s). Based on the monitored level's of BNP, the patients heart failure (HF) condition and/or risks and/or occurrences of certain events (e.g., an acute HF exacerbation and/or an acute myocardial infarction) can be monitored.

Abstract: An exemplary includes acquiring an electroneurogram of the right carotid sinus nerve or the left carotid sinus nerve, analyzing the electroneurogram for at least one of chemosensory information and barosensory information and calling for one or more therapeutic actions based at least in part on the analyzing. Therapeutic actions may aim to treat conditions such as sleep apnea, an increase in metabolic demand, hypoglycemia, hypertension, renal failure, and congestive heart failure. Other exemplary methods, devices, systems, etc., are also disclosed.

Abstract: An exemplary includes acquiring an electroneurogram of the right carotid sinus nerve or the left carotid sinus nerve, analyzing the electroneurogram for at least one of chemosensory information and barosensory information and calling for one or more therapeutic actions based at least in part on the analyzing. Therapeutic actions may aim to treat conditions such as sleep apnea, an increase in metabolic demand, hypoglycemia, hypertension, renal failure, and congestive heart failure. Other exemplary methods, devices, systems, etc., are also disclosed.

Abstract: Implantable systems, and methods for use therewith, enable the monitoring of a patient's electromechanical delay (EMD) and arterial blood pressure. Paced cardiac events are caused by delivering sufficient pacing stimulation to cause capture. A cardiogenic impedance (CI) signal, indicative of cardiac contractile activity in response to the pacing stimulation being delivered, is obtained. One or more predetermined features of the CI signal are detected, and a value indicative of the patient's EMD is determined by determining a time between a delivered pacing stimulation and at least one of the detected one or more features of the CI signal. The value indicative of EMD can be used to more accurately determine metrics indicative of pulse arrival time (PAT), which can be used to estimate arterial blood pressure.

Abstract: Provided herein are implantable systems, and methods for use therewith, for characterizing a tachycardia and/or selecting treatment for a tachycardia using results of a fractionation analysis. One or more electrogram (EGM) signal(s) indicative of cardiac electrical activity are obtained. At least one of the EGM signal(s) is analyzed to determine whether the EGM signal is fractionated, and the results of the analyzing are used to characterize a tachycardia and/or to select treatment for a tachycardia.

Abstract: Provided herein are implantable systems, and methods for use therewith, for characterizing a tachycardia and/or selecting treatment for a tachycardia using results of a dominant frequency analysis. One or more electrogram (EGM) signal(s) indicative of cardiac electrical activity are obtained. For at least one of the EGM signal(s) a dominant frequency (DF) analysis is performed, and the results of the DF analysis are used to characterize a tachycardia and/or to select treatment for a tachycardia.

Abstract: Diastolic function is monitored within a patient using a pacemaker or other implantable medical device. In one example, the implantable device uses morphological parameters derived from the T-wave evoked response waveform as proxies for ventricular relaxation rate and ventricular compliance. In particular, the magnitude of the peak of the T-wave evoked response is employed as a proxy for ventricular compliance. The maximum slew rate of the T-wave evoked response following its peak is employed as a proxy for ventricular relaxation. A metric is derived from these proxy values to represent diastolic function. The metric is tracked over time to evaluate changes in diastolic function. In other examples, specific values for ventricular compliance and ventricular relaxation are derived for the patient based on the T-wave evoked response parameters.

Abstract: In specific embodiments, a method for estimating a patient's central arterial blood pressure (CBP) for use with an implantable system, comprises (a) using an implanted sensor at a first site to obtain a first signal indicative of changes in arterial blood volume at the first site, the first site being along one or more peripheral arterial structures of the patient, (b) using an implanted sensor at a second site to obtain a second signal indicative of changes in arterial blood volume at the second site, the second site being a distance from the first site downstream along an arterial path of the peripheral arterial structure of the patient, and (c) using implanted electrodes to obtain a signal indicative of electrical activity of the patient's heart.

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 implantable medical device includes a lead configured to be located proximate to the left ventricle (LV) of the heart, the lead including multiple LV electrodes to sense cardiac activity at multiple LV sensing sites. The a detection module to detect an arrhythmia that represents at least one of a tachycardia and fibrillation based at least in part on the cardiac activity sensed at the multiple LV sensing sites. The ATP therapy module to identify at least one of an ATP configuration or an ATP therapy site based on the cardiac sensed activity at the LV sensing sites, the ATP therapy module to control delivery of antitachycardia pacing (ATP) therapy at the ATP therapy site.

Abstract: Specific embodiments provided herein relate to diagnosing, with improved specificity, occurrences of episodes relating to disorders that are known to affect T-wave morphology. One or more propensity metric is obtained, each of which is indicative of a patient's propensity for a specific disorder that is known to affect T-wave morphology. T-wave variability is monitored. Additionally, there is monitoring for a specific change in T-wave morphology that is known to be indicative of episodes relating to a disorder. When the specific change in T-wave morphology is detected, a diagnosis is determined for detecting the specific change in T-wave morphology, taking into account the propensity metric(s) and the T-wave variability.

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: An intravenous implantable optical sensor assesses the relative absorbance of multiple wavelengths of light in order to determine oxygen saturation. The calculation of oxygen saturation is enhanced by use of a function of hematocrit which is derived from the relative absorbance of light of an isobestic wavelength along two different length paths through the blood. The use of the hematocrit-dependent term and multiple wavelengths of light to calculate oxygen saturation provides results that are less susceptible to noise and variation in hematocrit and thus provides a more accurate measure of oxygen saturation over a wider range of conditions than previously possible. The optical sensor may form part of an implantable system which performs the calculation of oxygen saturation and uses the results for a diagnostic or therapeutic purpose.

Abstract: Specific embodiments of the present invention use an implanted sensor, during a period of time, to measure a physiologic property when the patient's heart is not stressed, and when the patient's heart is stressed. A slope is determined, where the slope is indicative of a change in the physiologic property during the period of time. Heart disease is monitored based on a magnitude of the slope. In further embodiments of the present invention, a slope indicative of a change in a physiologic property during a period of time is determined, for each of a plurality of periods of time. Changes in the patient's heart disease are monitored based on changes in the slope.

Abstract: Specific embodiments provided herein relate to diagnosing, with improved specificity, occurrences of episodes relating to disorders that are known to affect T-wave morphology. One or more propensity metric is obtained, each of which is indicative of a patient's propensity for a specific disorder that is known to affect T-wave morphology. T-wave variability is monitored. Additionally, there is monitoring for a specific change in T-wave morphology that is known to be indicative of episodes relating to a disorder. When the specific change in T-wave morphology is detected, a diagnosis is determined for detecting the specific change in T-wave morphology, taking into account the propensity metric(s) and the T-wave variability.

Abstract: Certain embodiments of the present invention are related to an implantable monitoring device to monitor a patient's arterial blood pressure, where the device is configured to be implanted subcutaneously. The device includes subcutaneous (SubQ) electrodes and a plethysmography sensor. Additionally, the device includes an arterial blood pressure monitor configured to determine at least one value indicative of the patient's arterial blood pressure based on at least one detected predetermined feature of a SubQ ECG and at least one detected predetermined feature of a plethysmography signal. Alternative embodiments of the present invention are directed to a non-implantable monitoring device to monitor a patient's arterial blood pressure based on features of a surface ECG and a plethysmography signal obtained from a non-implanted sensor.

Abstract: Implantable systems, and methods for use therein, perform at least one of a cardiac assessment and an autonomic assessment. Short-term fluctuations in PR intervals, that follow the premature contractions in the ventricles, are monitored. At least one of a cardiac assessment and an autonomic assessment is performed based on the monitored fluctuations in PR intervals that follow the premature contractions in the ventricles. This can include assessing a patient's risk of sudden cardiac death (SCD), assessing a patient's autonomic tone and/or detecting myocardial ischemic events based on the monitored fluctuations in PR intervals that follow the premature contractions in the ventricles.

Abstract: In various embodiments of the present invention, lower amplitude high frequency burst stimulation of cardiac fat pad(s) innervating the AV node and/or ventricle tissue performed in conjunction with ventricular pacing during refractory period is used to reduce the ventricular rate in order to terminate arrhythmias such as supraventricular tachycardia. In an embodiment of the present invention, one or more pace pulse delivered during a ventricular refractory period can be used to further extend the duration of the refractory period followed by a short burst of cardiac fat pad stimulation to temporarily slow AV conduction. In an embodiment of the present invention, this therapy slows the ventricular rate by altering conduction speed in both the AV node and the ventricles.