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: 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: An exemplary method includes selecting multiple electrodes located in a patient; acquiring position information during one or more cardiac cycles for the multiple electrodes where the acquiring includes using each of the electrodes for measuring one or more electrical potentials in an electrical localization field established in the patient; calculating one or more vector metrics based on the acquired position information for one or more vectors, each vector defined by two of the multiple electrodes; and analyzing the one or more vector metrics to assess cardiac performance during the one or more cardiac cycles. Various other methods, devices, systems, etc., are also disclosed.

Abstract: An exemplary controller includes an input for receiving information related to a signal of supraventricular origin, control logic to determine a control signal and an output to deliver the control signal to thereby actively filter the signal of supraventricular origin in the His bundle. Other exemplary methods, devices, systems, etc., are also disclosed.

Abstract: The invention relates to an apparatus and method to assess the fluid level in lungs. An implantable medical device or external monitor is used to sense or monitor the patient's respiratory patterns to identify the presence of periodic breathing or Cheyne-Stokes Respiration (CSR) which is common in patients with congestive heart failure. A fluid index is used to assess the severity of congestive heart failure in a patient. A ratio of ? blood gas/?total lung volume can be used to determine the lung fluid index.

Abstract: Techniques are provided for monitoring thoracic fluid levels based on thoracic impedance (ZT) and cardiogenic impedance (ZC). In one example, the implantable device tracks the maximum time rate of change in cardiogenic impedance (i.e. max(dZC/dt)) to detect trends toward hypervolemic or hypovolemic states within the patient based on changes in heart contractility. The detection of these trends in combination with trends in thoracic impedance allows for a determination of whether the thoracic cavity of the patient is generally “too wet” or “too dry,” and thus allows for the titration of diuretics to avoid such extremes. In particular, a decrease in thoracic impedance (ZT) in combination with a decrease in max (dZC/dt) is indicative of the thorax being “too wet” (i.e. a fluid overload). Conversely, an increase in thoracic impedance (ZT) in combination with a decrease in max (dZC/dt) is indicative of the thorax being “too dry” (i.e. a fluid underload).

Abstract: An implantable cardiac stimulation device monitors the progression and/or regression of heart disease. The device comprises a sensing circuit that senses activity of a heart and provides an electrogram for each one of a plurality of cardiac cycles, an averaging circuit that averages a number of the plurality of electrograms at spaced apart intervals to provide averaged trend electrograms, and a data generator that provides a metric reflective of progression or regression of heart failure responsive to a difference between a current averaged trend electrogram and a previous averaged trend electrogram.

Abstract: An exemplary method includes delivering stimulation according to one or more stimulation parameters to cause contraction of the diaphragm, monitoring chest activity related to respiration and, in response to the monitoring, adjusting one or more of the one or more stimulation parameters during contraction of the diaphragm and continuing the delivering. Various other exemplary methods, devices, systems, etc., are also disclosed.

Abstract: Techniques are provided for detecting dilated cardiomyopathy within a patient using a pacemaker or other implantable medical device. Briefly, values representative of QT duration and QT dispersion are detected within the patient and then the risk of dilated cardiomyopathy is evaluated based on the values of QT duration and QT dispersion. In one particular example, the implanted device calculates an index representative of the extent to which individual QT duration and QT dispersion values deviate from a daily mean. The device then compares the index against a threshold indicative of a substantial likelihood of the presence of dilated cardiomyopathy within the patient. Additional techniques described herein relate to distinguishing dilated cardiomyopathy from heart failure within patients that may have one or both conditions.

Abstract: An exemplary method for multi-tier pacing includes delivering single site, left ventricular pacing, sensing patient activity; comparing the sensed patient activity to a patient activity threshold and, if the sensed patient activity exceeds the patient activity threshold, then delivering multi-site, left ventricular pacing for a predetermined period of time and, after the predetermined period of time, delivering single, site left ventricular pacing. In such a method, the period of time may be determined based on cardio-pulmonary demand. Other exemplary technologies are also disclosed.

Abstract: An exemplary method includes determining an intramural pressure based on one or more in vivo pressure measurements, based on the intramural pressure, deciding whether apnea exists and, if apnea exists, calling for one or more types of stimulation selected from a group consisting of autonomic nerve stimulation, phrenic nerve stimulation, diaphragm stimulation and cardiac stimulation. Other exemplary methods, devices, systems, etc., are also disclosed.

Abstract: Exemplary techniques for determining patient posture from cardiac data sensed by an implantable medical device (IMD) are described. One technique involves sensing intracardiac electrogram (IEGM) data from a patient and determining a posture of the patient from the sensed IEGM data. The technique then considers the posture in formulating patient therapy.

Abstract: Techniques are provided for detecting pulmonary edema based on a comparison of impedance-based respiratory patterns and impedance-based cardiac patterns, i.e. patterns derived from thoracic impedance signals. In one example, a numerical ratio is calculated between average peak-to-peak amplitudes of the respiratory patterns and average peak-to-peak amplitudes of the cardiac patterns. Pulmonary edema is detected if the amplitude ratio falls below a pulmonary edema detection threshold. Techniques are also provided for controlling operation of an impedance-based reduced respiration detector, i.e. a detector which seeks to detect apnea, hypopnea, or the like, based on analysis of respiratory patterns derived from a thoracic impedance signal.

Abstract: An exemplary method includes selecting a cross-correlation frequency having an associated cross-correlation period, detecting and binning a heart rate in a heart rate bin, detecting and binning an activity state in an activity state bin, repeating the detecting and binning a heart rate and the detecting and binning an activity state during a cross-correlation period, and summing the products a bin count of the heart rate bins and a bin count of the activity state bins to provide a cross-correlation index for the cross-correlation period. Other exemplary algorithms, methods, devices, systems, etc., are also disclosed.

Abstract: Techniques for reducing orthostatic hypotension are described. One technique detects an incident of orthostatic hypotension in a patient, and in response, increases cardiac stroke volume, at least in part, by stimulating the patient's phrenic nerve.

Abstract: An exemplary implantable microarray device includes an inlet for a body fluid, a plurality of individual reaction cell arrays where each reaction cell array includes a series of reaction cells configured to receive the body fluid, a sensor array to sense a reaction result for an individual reaction cell array where the reaction result corresponds to a reaction between the body fluid and at least one reagent in each of the reaction cells of the individual reaction cell array and a positioning mechanism to position an individual reaction cell array with respect to the sensor array. Various other exemplary technologies are also disclosed.

Abstract: A monitoring and/or stimulation device to receive a signal from a lead sensor positioned in the heart of patient. The monitoring and/or stimulation device processes the blood pressure data received from the sensor to determine an augmentation pressure for each heart beat. The augmentation pressure may be tracked over time or compared to a template to determine the circadian state of the patient. The augmentation pressure may be tracked or analyzed over a longer time period to detect other heart conditions such as hypertension.

Abstract: An exemplary method includes providing a filling pressure parameter, providing a perfusion parameter, determining a hemodynamic profile based at least in part on the filling pressure parameter and the perfusion parameter and adjusting a stimulation parameter of an implantable cardiac therapy device based at least in part on the hemodynamic profile. Other exemplary methods, devices, systems, etc., are also disclosed.

Abstract: Techniques are provided for measuring ventricular evoked response within the heart of a patient during atrial fibrillation. An intrinsic ventricular depolarization (i.e. a QRS complex) is sensed within the right ventricle and then a pacing pulse is applied to the left ventricle prior to intrinsic depolarization thereof. In this manner, the left ventricle contracts solely in response to the pacing pulse and possible fusion between the pacing pulse and a conducted P-wave/A-pulse from the atria is avoided. The evoked response generated in the left ventricle is then measured by the pacemaker. The technique permits reliable detection of left ventricular evoked response, even during atrial fibrillation when atrial contractions are frequent and erratic, but the technique may also be employed during normal sinus rhythm. Features of the evoked response are analyzed to detect heart failure, evaluate its severity and track its progression. Appropriate therapy is then automatically delivered to the patient.

Abstract: Subject matter includes methods and devices for detecting and quantifying apnea. One exemplary implementation includes deriving a ventilation related parameter in real-time from a patient, deriving apneic intervals based on the parameter, distributing the apneic intervals as counts on a histogram, and calculating a single data point, such as a centroid, for clustered counts on the histogram. Centroids can be calculated at regular intervals and stored for lengthy periods, such as months, because they occupy very little storage space. A position of a centroid on the histogram can indicate an aspect of the patient's health and changes in the centroid positions over time can be used to detect trend changes in the patient's condition.