Abstract: The present invention is related to implantable cardiac devices such as pacemakers and defibrillators that deliver cardiac resynchronization therapy (CRT), and to a method of optimizing acquisition of impedance signals between electrodes present on implanted lead systems. This system then automatically determines which electrodes or electrode combinations acquire impedance waveforms that have the best signal to noise ratio (highest fidelity) and characterize data most representative of dysynchronous electro-mechanical events. Using closed loop algorithms which provide electrograms and a variety of impedance data reflective of the patient's clinical status, the system autonomously modifies interval timing within the CRT device.

Abstract: An exemplary method includes passing a lead through a wall of an epicardial vein, an epicardial venous structure and/or a cardiac chamber wherein the lead includes an electrode portion; positioning the electrode portion proximate to an autonomic nerve and/or other tissue region; and delivering an electrical signal to the electrode portion to stimulate the autonomic nerve and/or other tissue region and thereby change cardiac function.

Abstract: A cardiac rhythm management apparatus includes a proximal housing, a distal housing and a lead. The proximal housing includes a first energy storage device. The distal module is implantable within a patient's heart, and includes a second energy storage device, at least one electrode, and a control module. The control module controls the delivery of at least one electrical stimulus from the second energy storage device to a location in communication with the patient's heart. The lead connects the proximal housing to the distal module and is configured to communicate one or more digital signals between the proximal housing and the distal module.

Abstract: In one embodiment, an ICD is provided which includes a case having a connector block and a conductor post integrally formed with the connector block and extending through a dielectric feedthrough extending through the case. A capacitor is located within the dielectric. In some embodiments, the conductor post is a straight conductor post extending from a side of the connector block facing the feedthrough directly toward the feedthrough. The conductor post and the connector block may be formed of the same material, such as titanium. In some embodiments, a plurality of straight conductor posts and connector blocks are integrally formed. In some embodiments, the dielectric may be a single matrix dielectric, such that each of the straight conductor posts extends through the single matrix dielectric. In other embodiments, each of the straight conductor posts extends through a separate dielectric portion.

Abstract: An implantable medical device comprises a hermetically sealed casing enclosing electrical stimulation and/or sensing circuitry. A header on the casing comprises a longitudinal receptacle for receiving the electrical connector assembly of an electrical medical lead that senses cardiac blood pressure. The receptacle has electrical contacts engageable by corresponding electrical terminals on the connector assembly. A telemetry circuit assembly, mounted vertically within the confines of the header adjacent to the receptacle, comprises a winding having ends connected across the electrical contacts of the receptacle.

Abstract: An exemplary method includes calling for delivery of energy to one or more electrodes positionable proximate to an autonomic pathway to alter tone of the geniglossus muscle. Such a method may maintain or alter upper airway patency and, in turn, prevent or alleviate obstructive apnea. Other exemplary methods, devices, systems, etc., are also disclosed.

Abstract: Methods and systems are presented for using an ICD to detect myocardial ischemia. In one embodiment, a method includes sensing a signal indicative of cardiac pressure, measuring a height of the sensed signal at a peak amplitude of the sensed signal, and measuring a duration of the sensed signal. The method further includes indicating an ischemia based on a comparison of a ratio of the height to the duration with a predetermined value. In another embodiment, a method includes sensing a signal indicative of cardiac pressure, determining a derivative signal that is a first derivative of the sensed signal, measuring a maximum positive value of the derivative signal, and measuring a maximum negative value of the derivative signal. The method further includes indicating an ischemia based on a comparison of a ratio of the maximum positive value to the maximum negative value with a predetermined value.

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 anograde 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 and apparatus for analyzing IEGM waveforms is disclosed. The method includes generating a long term ensemble average of a plurality of baseline IEGM waveforms and generating a short term ensemble average of at least a portion of the plurality of baseline IEGM waveforms. The method further includes determining a short term absolute point value as a function of the absolute value of the difference of the amplitude of the short term ensemble average and a test IEGM waveform and a long term absolute point value as a function of the difference of the amplitude of the long term ensemble average and the test waveform at a plurality of sample points. The disclosed method further includes detecting ischemia if the difference between the short term absolute point value and the long term absolute point value is greater than an ischemia detection threshold.

Abstract: Techniques are provided for detecting heart failure or other medical conditions within a patient using an implantable medical device, such as pacemaker or implantable cardioverter/defibrillator, or external system. In one example, physiological signals, such as immittance-based signals, are sensed within the patient along a plurality of different vectors, and the amount of independent informational content among the physiological signals of the different vectors is determined. Heart failure is then detected by the implantable device based on a significant increase in the amount of independent informational content among the physiological signals. In response, therapy may be controlled, diagnostic information stored, and/or warning signals generated. In other examples, at least some of these functions are performed by an external system.

Abstract: Techniques are provided for estimating optimal atrioventricular pacing delay values for use in pacing the ventricles based on features of an intracardiac electrogram (IEGM) signal. Briefly, atrioventricular pacing delay pacing values are set based upon the location of atrial repolarization events within the IEGM. In one example, the end of an atrial repolarization is identified, then the interval from the atrial depolarization to the end of the atrial repolarization is measured. The atrioventricular pacing delay is then set by subtracting an offset value from that interval so as to time delivery of V-pulses prior the end of atrial repolarization. In this manner, atrioventricular pacing delay values are set based only IEGM signals and hence can be set to optimal/preferred values by the device itself without requiring surface electrocardiogram (EKG) signals and Doppler echocardiography or other cardiac performance monitoring techniques.

Abstract: A technique is provided for detecting episodes of cardiac ischemia based on an examination of the total energy of T-waves. Since cardiac ischemia is often a precursor to acute myocardial infarction (AMI) or ventricular fibrillation (VF), the technique thereby provides a method for predicting the possible onset of AMI or VF. Briefly, the technique integrates internal electrical cardiac signals occurring during T-waves and then compares the result against a running average. If the result exceeds the average by some predetermined amount, ischemia is thereby detected and a warning signal is provided to the patient. The maximum slope of the T-wave is also exploited. Techniques are also set forth herein for reliably detecting T-waves, which help prevent P-waves from being misinterpreted as T-waves on unipolar sensing channels. The T-wave detection technique may be used in conjunction with ischemia detection or for other purposes.

Abstract: A method of forming a tubular body for a catheter, sheath or lead comprises extruding a polymer core having an integrally formed core wall, first lumen, and second lumen, placing a first layer over an outer circumferential surface of the extruded polymer core, and bonding the first layer to the circumferential surface of the extruded polymer cover via a reflow process. The first and second lumens are mandrel free during the reflow process, and a temperature of the reflow process is below a softening point of the polymer core to maintain a collapse free first and second lumen.

Abstract: A system or appliance to treat heart failure (HF) conditions. The appliance includes a structural support or cardiac constraint to limit further distension of weakened heart tissue. The appliance also includes an implantable stimulation pulse generator and controller such that the appliance can automatically monitor cardiac activity and provide therapeutic stimulations for detected arrhythmias. The appliance can also include one or more surface electrodes. The surface electrodes can be arranged on opposite sides of the heart to apply relatively spatially uniform stimulation potentials across the heart with reduced shunting around the target tissue. A surface electrode can also be arranged to wrap substantially about a periphery of the patient's heart and used with an internal electrode to apply a relatively homogeneous shock while facilitating lower voltage and smaller shocking capacitors.

Abstract: An exemplary method includes detecting arrhythmia, detecting myocardial ischemia, determining whether the myocardial ischemia comprises local ischemia or global ischemia and, in response to the determining, calling for delivery of either a local ischemic anti-arrhythmia therapy or a global ischemic anti-arrhythmia therapy. Various other exemplary methods, devices, systems, etc., are also disclosed.

Abstract: System and methods for assessing sensed signals for determining a reliability measure of their accuracy with respect to a patient's true physiological status. As one example, the signals can include multiple, independently obtained signals, such as an electro-chemically based measure of cardiac activity and a plethysmography based measure of hemodynamic output which typically exhibit different morphologies and varying phase shifts with respect to each other. One manner of assessing the signals is to transform them into the frequency domain, such as via a Fast Fourier Transform (FFT), and evaluate them, such as by a coherence determination, to determine the degree of their mutual agreement. This can be used to assess the reliability of the sensing. Therapy can be delivered under certain observed conditions, such as a condition of hemodynamic insufficiency where anti-tachycardia pacing and/or shocking therapy can be delivered.

Abstract: Embodiments of the present invention relate to implantable systems, and methods for use therein, that can detect T-wave alternans and analyze the detected alternans to provide information regarding cardiac instabilities and predict impending arrhythmias.

Abstract: Therapy optimization includes tracking electrode motion using an electroanatomic mapping system and generating, based on tracked electrode motion, one or more mechanical dyssynchrony metrics to thereby guide a clinician in therapy optimization (e.g., via optimal electrode sites, optimal therapy parameters, etc.). Such a method may include a vector analysis of electrode motion with respect to factors such as times in cardiac cycle, phases of a cardiac cycle, and therapy conditions, e.g., pacing sites, pacing parameters and pacing or no pacing. Differences in position-with-respect-to-time data for electrodes may also be used to provide measurements of mechanical dyssynchrony.

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.