According to some embodiments, a device operates by comparative morphological analysis of depolarization signals collected in spontaneous rhythm on separate respective channels, with two temporal components combined into a single 2D parametric VGM vectogram characteristic. Similarity quantification methods evaluate a variation over time of a descriptor parameter of a current VGM compared to a stored previous reference VGM. This variation is compared with predetermined thresholds to diagnose an occurrence of remodeling or reverse remodeling in a patient, and/or to detect a lead failure or an occurrence of ischemia. The descriptor parameter is a function of a velocity vector of the VGM, a comparison relating to a correlation coefficient between respective magnitudes of a current VGM velocity vector and of a reference VGM velocity vector, and an average angle between these respective velocity vectors.

A medical device for treating cardiac arrhythmia includes a microprocessor. A MCU configures the medical device to operate in a modified DVI (R) mode in which: when receiving a signal indicating the sensing of an atrial event, the MCU sets a PANP interval and sends to a time control unit a signal; if a scheduled post-ventricular atrial escaping interval is to end at a time not within the PANP internal, the MCU sends respective signals to a pacing control/generation unit and the time control unit to dictate the pacing control/generation unit and control a second timing unit to use a PAVI as a next ventricular escape interval; and if the scheduled post-ventricular atrial escaping interval is to end within the PANP interval, the MCU sends a signal to the time control unit, controlling the second timing unit to use the PAVI as the next ventricular escape interval.

Devices and methods for improving device therapy such as cardiac resynchronization therapy by determining a value for a device parameter are described. An ambulatory medical device (AMD) can include a sensor circuit to sense a physiological signal and generate two or more signal metrics, and detect an event of worsening cardiac condition using the two or more signal metrics. In response to the detection of worsening cardiac condition, the AMD can determine, for a stimulator, a value of at least one stimulation parameter based on temporal responses of two or more signal metrics. The temporal responses include near-term and long-term responses to the stimulation. The AMD can program the stimulator with the determined parameter value, and generate stimulation according to the determined parameter value to stimulate target tissue.

Systems and methods for pacing cardiac conductive tissue are described. A medical system includes an electrostimulation circuit to generate His-bundle pacing (HBP) pulses. A sensing circuit senses a physiologic signal, and detect a local His-bundle activation discrete from a pacing artifact of the HBP pulse. A control circuit verifies capture status in response to the HBP pulses. Based on the capture status, the control circuit determines one or more pacing thresholds including a selective HBP threshold representing a threshold strength to capture only the His bundle but not the local myocardium, and a non-selective HBP threshold representing a threshold strength to capture both the His bundle and the local myocardium. The electrostimulation circuit may deliver HBP pulses based on the selective and non-selective HBP thresholds.

Systems and methods for controlling blood pressure by controlling atrial pressure and atrial stretch are disclosed. In some embodiments, a stimulation circuit may be configured to deliver a stimulation pulse to at least one cardiac chamber of a heart of a patient, and at least one controller may be configured to execute delivery of one or more stimulation patterns of stimulation pulses to the at least one cardiac chamber, wherein at least one of the stimulation pulses stimulates the heart such that an atrial pressure resulting from atrial contraction of an atrium overlaps in time a passive pressure build-up of the atrium, such that an atrial pressure of the atrium resulting from the stimulation is a combination of the atrial pressure resulting from atrial contraction and the passive pressure build-up and is higher than an atrial pressure of the atrium would be without the stimulation, and such that the blood pressure of the patient is reduced.

A method and system for delivering cardiac pacing therapy that includes sensing electrical activity of tissue of a patient from a plurality of external electrodes during delivery of a non-ambulatory pacing therapy from a pacing device and determining an optimal electromechanical (EM) response time from an optimal electrical activation determined from electrical heterogeneity information obtained during non-ambulatory pacing therapy. During delivery of subsequent ambulatory pacing, the pacing sensing an EM signal from an EM sensor of the pacing device, determines a current EM response time in response to the sensed EM signal, and adjusting a pacing parameter setting of the ambulatory pacing therapy in response to comparing the current EM response time to the optimal EM response time.

A medical device system and associated method predict a patient response to a cardiac therapy. The system includes for delivering cardiac pacing pulses to a patient's heart coupled to a cardiac sensing module and a cardiac pacing module for generating cardiac pacing pulses and controlling delivery of the pacing pulses at multiple pace parameter settings. An acoustical sensor obtains heart sound signals. A processor is enabled to receive the heart sound signals, derive a plurality of heart sound signal parameters from the heart sound signals, and determine a trend of each of the plurality of heart sound signal parameters with respect to the plurality of pace parameter settings. An external display is configured to present the trend of at least one heart sound parameter with respect to the plurality of pace parameter settings.

A medical device and medical device system for determining capture during delivery of a ventricular pacing therapy that includes a subcutaneous sensing device comprising a subcutaneous electrode to sense a subcutaneous cardiac signal and to emit a trigger signal in response to the sensed cardiac signal, an intracardiac therapy delivery device capable of being implanted within a left ventricle of a heart to receive the trigger signal and deliver the ventricular pacing therapy to the left ventricle in response to the emitted trigger signal, and a processor positioned within the subcutaneous sensing device, the processor configured to compare a beat of the subcutaneous cardiac signal sensed by the sensing device subsequent to the ventricular pacing therapy being delivered to a baseline template associated with a non-paced beat, and determine whether the delivered ventricular pacing therapy captures the left ventricle in response to the comparing.

Methods and devices for reducing ventricle filling volume are disclosed. In some embodiments, an electrical stimulator may be used to stimulate a patient's heart to reduce ventricle filling volume or even blood pressure. When the heart is stimulated in a consistent way to reduce blood pressure, the cardiovascular system may over time adapt to the stimulation and revert back to the higher blood pressure. In some embodiments, the stimulation pattern may be configured to be inconsistent such that the adaptation response of the heart is reduced or even prevented. In some embodiments, an electrical stimulator may be used to stimulate a patient's heart to cause at least a portion of an atrial contraction to occur while the atrioventricular valve is closed. Such an atrial contraction may deposit less blood into the corresponding ventricle than when the atrioventricular valve is opened throughout an atrial contraction.

Brugada syndrome and related forms of ion channelopathies, including ventricular asynchrony of contraction, originate in the region near the His bundle or para-Hisian regions of the heart. Manifestations of Brugada syndrome can be corrected by delivering endocardial electrical stimulation coincident to the activation wave front propagated from the atrioventricular (AV) node early enough to compensate for the conduction problems that start in those regions. The stimulation can include waveforms of the same polarity delivered to a site within the region near the His bundle or para-Hisian regions of the heart associated with a low cardiac electrical asynchrony level or can include at least two single-phased superimposed waveforms of opposite polarity delivered through a pair of pacing electrodes relative to a reference electrode, which can be delivered to any site within the region near the His bundle or para-Hisian regions. Defibrillation can also be used to terminate an arrhythmia.