Systems and methods for multi-site cardiac stimulation are disclosed. The system includes an electrostimulation circuit to deliver electrostimulation to one or more candidate sites of at least one heart chamber. The system may sense a physiological signal including during electrostimulation of the heart, use the physiological signal to determine a first stimulation vector for electrostimulation at a first left ventricular (LV) site and a second stimulation vector for electrostimulation at a different second LV site, and determine a therapy mode including a first chronological order and a first timing offset between stimulations delivered according to the first and second stimulation vectors. The electrostimulation circuit may deliver electrostimulation to the heart in accordance with the first and second stimulation vectors and the therapy mode.

Various aspects of the present disclosure are directed toward apparatuses, systems, and methods that include a single pass implantable lead configured to be coupled to the implantable medical device and arranged to sense and pace the chambers of a patient's heart. The lead may include a proximal region having a plurality of electrodes, a distal region having at least one electrode, and an intermediate region therebetween. The system can sense and pace the right atrium, the left atrium, the right ventricle, and the left ventricle.

Cardiac resynchronization therapy (CRT) delivered to a heart of a patient may be adjusted based on detection of a surrogate indication of the intrinsic atrioventricular conduction of the heart. In some examples, the surrogate indication is determined to be a sense event of the first depolarizing ventricle of the heart within a predetermined period of time following the delivery of a fusion pacing stimulus to the later depolarizing ventricle. In some examples, the CRT is switched from a fusion pacing configuration to a biventricular pacing configuration if the surrogate indication is not detected, and the CRT is maintained in a fusion pacing configuration if the surrogate indication is detected.

A medical device for stimulating the heart using biventricular stimulation. The device includes a sensor for detecting an endocardial acceleration parameter and a processing circuit configured to receive the endocardial acceleration parameter. The device further includes stimulation electronics coupled to the processing circuit. The processing circuit is configured to use the EA parameter to evaluate the biventricular stimulation. The evaluation includes comparing the value of the EA parameter in biventricular mode to the value of the EA parameter in left only mode or right only mode, and using the comparison and an assessment of the variability of the EA parameter as a function of the AVD in the left or right mode to distinguish between cases comprising: (a) normal operation, (b) a loss of RV or LV capture, (c) possible anodal stimulation. The processing circuit is further configured to conduct at least one update to operational parameters of the device based on the determined case.

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.

Systems and methods are described herein for evaluation and adjustment of a left ventricular assist device (LVAD). The systems and methods may utilize at least a plurality of external electrodes to monitor cardiac electrical activity before and during LVAD therapy. The cardiac electrical activity as well as other information such cardiac sound information may be used to determine and adjust one or more LVAD output parameters such as pump speed.

VfA cardiac therapy uses an implantable medical device or system. The implantable medical device includes a tissue-piercing electrode implanted in the basal and/or septal region of the left ventricular myocardium of the patient's heart from the triangle of Koch region of the right atrium through the right atrial endocardium and central fibrous body. The device may include a right atrial electrode, a right atrial motion detector, or both. The device may be implanted completely within the patient's heart or may use one or more leads to implant electrodes in the patient's heart. The device may be used to provide cardiac therapy, including single or multiple chamber pacing, atrioventricular synchronous pacing, asynchronous pacing, triggered pacing, cardiac resynchronization pacing, or tachycardia-related therapy. A separate medical device may be used to provide some functionality for cardiac therapy, such as sensing, pacing, or shock therapy.

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 system for artificial stimulation of the heart of a subject is provided, the system comprising a controller comprising a receiver for receiving signal data, a processor for processing received signal data, and a transmitter for transmitting signal data; a sensing stent for location in the proximal coronary sinus of the subject, the sensing stent electrode comprising a sensing electrode assembly for sensing atrial and/or ventricular signals from the heart of the subject and a transmitting assembly for transmitting signal data to the receiver of the controller; and a stimulation stent for location in a vein of the subject distal of the sensing stent, the stimulation stent comprising a receiver for receiving signal data from the transmitter of the controller and an electrode assembly for providing a stimulating electrical signal to the heart of the subject in response to the data received.

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.