Abstract: This document discusses, among other things, a cardiac mechanical alternans (MA) detector circuit. In an example, the mechanical alternans detector circuit is configured to determine a mechanical alternans (MA) condition. In an example, the MA detector circuit can include a physiologic impedance input configured to receive physiologic information indicative of mechanical alternans. In an example, the MA detector circuit can include an intravascular pressure input configured to receive physiologic information indicative of mechanical alternans.

Abstract: A method and device for treating myocardial ischemia are described in which the stress experienced by a myocardial region identified as vulnerable to becoming ischemic is varied with pre-excitation pacing. In an unloading mode, pacing is applied in proximity to the vulnerable region to reduce stress and the metabolic demand of the region. In a loading mode, pacing is applied to a region remote from the vulnerable region in order to produce a conditioning effect.

Abstract: A pacemaker initiates and times a monitoring interval in response to an event such as a therapy delivery to a patient. The monitoring interval is specified to include a duration of an anticipated acute response to the event, such as vagal surge. One or more physiological parameters indicative of the acute response are detected during the monitoring interval for analyzing therapeutic effect of the event. In various embodiments, one or more pacing parameters are adjusted for a response interval specified to include the duration of the anticipated acute response to allow for the analysis and maximization of the therapeutic effect. In various embodiments, the event includes a session of pacing therapy delivered according to an intermittent cardiac stress augmentation pacing protocol, and the therapeutic effect is analyzed to adjust that protocol.

Abstract: An implantable medical device detects a tachyarrhythmia of a heart. During the detected tachyarrhythmia, the device determines a local myocardial impedance. Using the local myocardial impedance, the device determines whether there is sufficient perfusion to the heart. The device can then either deliver a less aggressive device therapy in response to the detected tachyarrhythmia when there is sufficient perfusion to the heart, or deliver a more aggressive device therapy in response to the detected tachyarrhythmia when there is insufficient perfusion to the heart. The perfusion information can also be used to alter tachyarrhythmia detection or classification.

Abstract: An apparatus comprises an implantable sensor, a stimulation circuit, and a controller. The implantable sensor is configured to provide a sensor signal representative of hemodynamic function of a subject. The stimulation circuit is configured to provide electrical simulation energy to an implantable electrode. The controller is communicatively coupled to the stimulation circuit and the implantable sensor and includes a hemodynamic monitor module. The hemodynamic monitor module is configured to detect an episode of reduced hemodynamic capacity in a subject using the sensor signal. In response to the detected episode, the controller is configured to initiate delivery of the electrical stimulation energy to artificially induce at least one of deep ventilation or rapid ventilation in the subject. The hemodynamic monitor module is configured to obtain a measure of hemodynamic performance after delivery of the electrical stimulation energy.

Abstract: An apparatus comprises an implantable sensor and a signal analyzer circuit communicatively coupled to the implantable sensor. The implantable sensor is configured for coupling to an implantable lead and the implantable sensor provides an electrical vibration sensor signal representative of mechanical vibration of the implantable lead. The signal analyzer circuit is configured to determine a baseline of the vibration sensor signal, detect a change in the vibration sensor signal from the baseline vibration sensor signal, and provide an indication of the change to a user or process.

Abstract: A device and method are disclosed for treating chronic pain by delivering electrical stimulation to nervous tissue or smooth muscle fibers by means of electrodes disposed in the body's lymphatic system. An implanted pulse generator is connected to an electrode by a lead that may be intravenously introduced into the lymphatic system. The stimulation may be patient-controlled or be delivered in accordance with a programmed schedule.

Abstract: Methods and devices for treating a blockage in the coronary arterial system are provided. Some blockages in the coronary arterial system restrict the blood flow to a portion of the heart, causing ischemia or infarction. Such blockages may be treated by displacing, removing and/or breaking up the blockage, which allows blood to reperfuse into the infarcted portion of the heart. Before, during, and/or after the reperfusion, cardioprotective pacing is provided to the heart. The devices have multiple electrodes in order to provide multiple locations at which the cardioprotective pacing may be delivered. The devices are adapted to deliver cardioprotective pacing to the heart via the electrode that results in a relatively high level of dyssynchrony of the heart.

Abstract: A first fluid status indicator of a pulmonary fluid status associated with pulmonary edema and a second fluid status indicator of a non-pulmonary fluid status can be used to provide an alert or to control a therapy for pulmonary edema. Additionally, intermittent cardiac blood volume redistribution therapy can be used to provide cardiac conditioning in heart failure patients.

Abstract: A cardiac pacing system controls the progression of a cardiac disorder such as heart failure by delivering cardiac stress augmentation pacing to create or augment regional stress in the heart according to a delivery schedule programmed for a patient. Various events associated with the patient's conditions, activities, and other treatments may render the cardiac stress augmentation pacing risky or ineffective. The system detects such events before and during each cardiac stress augmentation pacing session and modifies the delivery schedule in response to the detection of each event to ensure patient safety and therapy efficiency.

Abstract: A system and method for controlling cardiac ventricular tachyarrhythmias by acquiring a pressure signal representative of coronary venous pressure (CVP) from a pressure sensor implanted within a coronary vein of the patient. A CVP index is derived based on the pressure signal. The onset of a ventricular tachyarrhythmia episode is detected based on a cardiac rates signal. The CVP index and the rate signal are monitored and, responsive to the rate signal indicating a sustained tachycardia episode during the episode monitoring period, anti-tachycardia therapy selectively withheld and the episode monitoring period is extended based on the CVP index.

Abstract: An apparatus comprises a first impedance sensing circuit, a second sensing circuit, and an impedance-based cardiac dyssynchrony detector. The impedance sensing circuit senses an intracardiac local impedance signal that is indicative of a cardiac local wall motion of a first cardiac region from an implantable first bipolar pair of impedance sensing electrodes. The second sensing circuit is configured to produce a second sensor signal indicative of cardiovascular activity. The impedance-based cardiac dyssynchrony detector is configured for detecting cardiac dyssynchrony using a relationship between the first intracardiac local impedance signal and the second sensor signal. Other apparatuses and methods are disclosed.

Abstract: A cardiac pacing system introduces a transitional period when pacing mode changes, such as when pacing starts and stops, or when one or more pacing parameter values change substantially. For each pacing parameter that changes substantially when the pacing mode changes, its value is adjusted incrementally over the transitional period to protect the heart from potentially harmful conditions associated with an abrupt change in the value of that pacing parameter.

Abstract: Renal function may be modulated by an implantable device having one or more leads or catheters disposed near the kidney via the lymphatic system. In one embodiment, lymphatic drainage from the kidney is modulated to increase or decrease tubular reabsorption of salt and water. The renal function modulation therapy may be delivered in an open-loop or closed-loop fashion, with the latter dependent upon a physiological variable such as blood pressure or cardiac output.

Abstract: A method and device are described for delivering cardiac therapy in which an implantable device for delivering such cardiac therapy is additionally configured to detect the presence of inflammation. Upon detection of inflammation, the device may be configured to modify its delivery of therapy in various ways and/or to communicate the information to an external agent for other types of interventions.

Abstract: An external cardiac stimulation patch integrates a transcutaneous cardiac stimulation device and body-surface electrodes with a skin patch. The skin patch is to be attached onto a patient to provide for electrical contacts between the body-surface electrodes and a patient. The transcutaneous cardiac stimulation device delivers pacing pulses to the heart of the patient through pacing electrodes selected from the body-surface electrodes.

Abstract: According to various embodiments of a method for modulating autonomic neural activity in a body having a spinal cord, a subclavian vein and thoracic lymphatic vessels that include a thoracic duct and a right lymphatic duct, at least one programmed therapy is implemented using an implanted medical device to modulate autonomic neural activity. Implementing the therapy includes increasing or decreasing sympathetic activity in sympathetic nerves branching from a first region of the spinal cord using a first electrode in the thoracic duct, and further includes increasing or decreasing parasympathetic activity in parasympathetic nerves adjacent to the desired thoracic lymphatic vessel or sympathetic activity in sympathetic nerves branching from a second region of the spinal cord using a second electrode in the desired thoracic lymphatic vessel.

Abstract: An implantable gastrointestinal (GI) stimulation system includes an implantable medical device and at least one stimulus delivery device configured to be placed in one or more lymphatic vessels of a patient, such as the patient's thoracic duct and/or vessels branching from the thoracic duct. In one embodiment, the implantable medical device includes a GI stimulation circuit to deliver electrical stimulation pulses to one or more target regions adjacent to a lymphatic vessel through the stimulus delivery device. In one embodiment, to control obesity, the electrical stimulation pulses are delivered to the organs and/or nerves of the GI tract to create a sensation of satiety and/or to expedite food movement through the GI tract.

Abstract: Systems and methods for deploying a sensor assembly onto a cardiac lead are disclosed. The sensor assembly can include a resilient cuff having one or more sensor modules for sensing physiological parameters within the body. The resilient cuff may have a substantially cylindrical shape having an inner diameter that is smaller than an outer diameter of the lead body onto which the cuff is deployed such that the cuff is retained on the lead body by frictional forces. The sensor assembly may be deployed in conjunction with a new lead to be implanted within a chamber of the patient's heart or a body vessel, or may be deployed onto an existing, implanted lead implanted within the patient's body.

Abstract: Methods and devices are described for delivering electrical stimulation to the heart in a manner that advantageously redistributes myocardial stress during systole for therapeutic purposes in the treatment of, for example, post-MI and HF patients. Pre-excitation pacing may be applied to deliberately de-stress a particular myocardial region that may be expected to undergo deleterious remodeling, such as the area around a myocardial infarct or a hypertrophying region or to deliberately stress a region remote from the pre-excitation pacing site in order to exert a cardioprotective conditioning effect, similar to the beneficial effects of exercise. Pre-excitation pacing may be advantageously combined with inotropic electrical stimulation applied to the stressed region.