Methods and/or devices may be configured to estimate right ventricular-timings from left ventricular (LV) sensing times for adaptive cardiac therapy using DDD/VDD LV pacing without using a right ventricular (RV) lead. One embodiment employs a subcutaneous device (SD) in a patient and a leadless pacing device (LPD) coupled to a patient's heart. Heart activity including atrial and ventricular events are sensed from the patient's heart using the SD. Left ventricular events (LVS) are sensed using the LPD. The SD is used to determine whether cardiac resynchronization pacing therapy (CRT pacing) is appropriate based upon the heart activity sensed by the SD. The SD is further configured to determine timing of CRT pacing pulses for delivery to cardiac tissue through the LPD.

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.

A medical device and medical device system for controlling delivery of therapeutic stimulation pulses that includes a sensing device to sense a cardiac signal and emit a trigger signal in response to the sensed cardiac signal, a therapy delivery device to receive the trigger signal and deliver therapy to the patient in response to the emitted trigger signal, and a processor positioned within the sensing device, the processor configured to determine whether the sensed cardiac signal exceeds a possible P-wave threshold, compare a portion of the sensed cardiac signal to a P-wave template having a sensing window having a length less than a width of the P-wave, confirm an occurrence of a P-wave signal in response to the comparing, emit the trigger signal in response to the occurrence of a P-wave signal being confirmed, and inhibit delivery of the emitting signal in response to the occurrence of a P-wave signal not being confirmed.

An implantable medical device is provided that comprises a pulse generator circuit that times delivery of ventricular pacing pulses based on a base intracardiac interval (ICI). A processor is provided that has memory storing program instructions and storing atrial and ventricular events over multiple cardiac cycles and that is responsive to execution of the program instructions. The processor adjusts the base ICI by an ICI adjustment, during one or more of the multiple cardiac cycles, to promote intrinsic heart activity. The processor further counts a number of the cardiac cycles in which the ICI adjustments occurred in conjunction with arrhythmias to identify an excessive adjustment count and modifies the ICI adjustment to utilize a new ICI adjustment based on the excessive adjustment count.

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. By performing the start of the activation of the HIS bundle or para-Hisian region early enough, electrical stimulation can be delivered fast enough to compensate for the conduction problems that start in those region, such that the activation wave front, as stimulated, transitions from the AV node to the His bundle in a normal, albeit electrically-supplemented, fashion. This stimulation not only helps resolve the conditions that trigger Brugada syndrome, but also resolves the asynchrony of the contraction of the heart.

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) nodeearly enough to compensate for the conduction problems that start in those region. 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 of the heart.

Techniques and systems for monitoring cardiac arrhythmias and delivering electrical stimulation therapy using a subcutaneous device (e.g. subcutaneous implantable (SD)) and a leadless pacing device (LPD) are described. In one or more embodiments, a computer-implemented method includes sensing a first electrical signal from a heart of a patient through a SD. The first signal is stored into memory and serves as a baseline rhythm for a patient. Subsequently, a second signal is sensed from the heart through the SD. A cardiac condition can be detected within the sensed second electrical signal through the SD. A determination is made as to whether cardiac resynchronization therapy (CRT) is appropriate to treat the detected cardiac condition. A determination can then be made as to the timing of pacing pulse delivery to cardiac tissue through a leadless pacing device (LPD).

The present disclosure relates generally to pacing of cardiac tissue, and more particularly to adjusting delivery of His bundle or bundle branch pacing in a cardiac pacing system to achieve synchronized ventricular activation. A left bundle branch (LBB) cathode electrode may be implanted a left side of the septum of the patient's heart proximate to the LBB, and a right bundle branch (RBB) cathode electrode may be implanted on a right side of the septum of the patient's heart proximate to the RBB. One or both cathode electrodes may be used to deliver synchronized left and right bundle-branch pacing based on one or both of an atrial event and a ventricular event. A device for bundle branch pacing may be implanted based on determining whether an LBB block pattern or an RBB block pattern is present in monitored electrical activity.

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.

Systems and methods for controlling blood pressure via electrical stimulation of the heart are disclosed. Embodiments may include at least two different stimulation patterns, each configured to reduce blood pressure to a different degree, and may alternate between stimulation patterns based on the need of a patient, for example, alternating between day and night or between periods of strenuous and light activity. Some embodiments may take advantage of a slow baroreflex response that occurs after treatment is stopped, suspending treatment for extended periods, and then resuming treatment before blood pressure levels reach pretreatment values. Embodiments may control blood pressure by controlling atrial pressure and atrial stretch.