Systems and methods for monitoring and treating patients with heart failure are discussed. The system may receive patient atrioventricular (AV) conduction characteristic under different heart rates or patient conditions. Stimulation parameters including stimulation timing parameters may be stored in a memory. The system may include a stimulation control circuit configured to determine a parameter update schedule indicating a timing at which to update stimulation parameter using patient AV conduction characteristic, and dynamically update at least a portion of the stored set of stimulation parameters at the determined parameter update schedule. For a specified heart rate or heart rate range, a stimulation parameter may be selected from the set of the stimulation parameters for use during cardiac stimulation.

One embodiment provides a system for determination and utilization of cardiac electrical asynchrony data. The system includes an analysis circuitry including a processor and a memory, the analysis circuitry configured to: obtain a plurality of sets of cardiac signals collected in at least two locations of a heart of a patient, the signals comprising at least one of surface electrocardiography signals and pseudo-surface ECG signals; detect one or more QRS complexes for each of the sets based on the cardiac signals for that set; obtain one or more cross-correlation signals, each of the cross-correlation signals being between at least two of the signal sets and being obtained using the detected QRS complexes from the signal sets; and calculate one or more asynchrony indices using one or more of the cross-correlation signals, each of the asynchrony indices being indicative of a level of asynchrony between the at least two locations.

Pacing parameters may be adjusted to increase the cardiac output of a patient's heart while a patient is awake and/or active and the demand placed on the heart may be greatest, and to decrease or hemodynamic efficiency while a patient is at rest so that the heart itself has time to rest before the next period of higher demand for efficiency begins. This may aid in lessening the strain placed on the heart by making the heart work hard when needed such as when the patient is active, and by permitting the heart to “rest” when the patient is relatively inactive.

A method for identifying reversible cardiac dyssynchrony (RCD) of a patient and treating the RCD measures an event relating to a rapid increase in the rate of pressure increase within the left ventricle. The method calculates a first time delay between the event and a first reference time. If the first time delay is longer than a set fraction of electrical activation of the heart, then the presence of cardiac dyssynchrony in the patient is identified. Pacing is applied to the heart, and a second time delay between the event following pacing and a second reference time following pacing is calculated. If the second time delay is shorter than the first time delay, the method identifies a shortening of a delay to onset of myocardial synergy, OoS, thereby identifying the presence of RCD in the patient. Treatment of the RCD is performed.

Systems and methods for optimizing the stimulation of a heart of a patient are disclosed herein. The method comprises delivering pacing therapy to the patient according to a pacing therapy setting schedule, using specific pacing intervals via specific electrode configurations. Further, sinus rate values are recorded over at least one cardiac cycle at each pacing therapy setting and it is determined whether a sinus rate value satisfies predetermined measurement conditions, wherein sinus rate values are used for trending the sinus rate over time if the measurement conditions are satisfied. The accepted sinus rate values, i.e. values that satisfy the measurement conditions, are trended over time, wherein each trended sinus rate value is created based on recordings from at least one cardiac cycle. A preferred pacing therapy setting is determined to be the pacing therapy setting that provides a lowest sinus rate.

Systems and methods are described herein for assisting a user in identification of interventricular (V-V) delay for cardiac therapy. The systems and methods may monitor electrical activity of a patient using external electrode apparatus to provide electrical heterogeneity information for a plurality of different V-V intervals and may identify a V-V interval based on the electrical heterogeneity information.

Methods and/or devices may be configured to monitor ventricular activation times and modify an atrioventricular delay (AV delay) based on the monitored ventricular activation times. Further, the methods and/or devices may determine whether the AV delay should be modified based on the measured activation times before modifying the AV delay.

The disclosure relates to a device including a plurality of electrodes for stimulation of both ventricles with application of an atrioventricular delay and of an interventricular delay, a processor configured to multidimensionally measure an interventricular conduction delay, and monitor the evolution of a patient's condition. For the multidimensional measurement of the interventricular conduction delay, the device produces stimulation of one of the ventricles and collects, in the other ventricle, two endocardial electrogram signals on separate respective channels, giving two respective temporal components. Both temporal components are combined in one single parametric 2D characteristic representative of the cardiac cycle, and a comparison is made with reference descriptors for deriving an index representative of the evolution of the patient's condition.

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.

An apparatus for coupling to a plurality of electrodes implantable at a plurality of tissue sites of a heart chamber of a subject. The apparatus including a stimulus circuit configured to provide an electrical cardiac pacing stimulation to the plurality of electrodes, a switching circuit configured to select electrodes of the plurality of electrodes for electrical coupling to the stimulus circuit, and a control circuit including a heart rate sub-circuit configured to determine heart rate; and a pacing site activation sub-circuit configured to selectively change which electrodes of the plurality of electrodes are used to provide the electrical cardiac pacing stimulation therapy according to the determined heart rate.