An implantable device and associated method for delivering multi-site pacing therapy is disclosed. The device comprises a set of electrodes including a first and second left ventricular electrodes spatially separated from one another and a right ventricular electrode, all coupled to an implantable pulse generator. The processing circuit coupled to the implantable pulse generator, the processing circuit configured to determine whether a prospective heart failure condition has occurred and if so to trigger the pulse generator to switch from a first pacing mode to a second pacing mode, the first pacing mode comprising delivering only a first pacing pulse to a left ventricle (LV) and thereafter delivering an RV pacing pulse to the right ventricular electrode within a single cardiac cycle and the second pacing mode comprising delivering first and a second pacing pulses to the LV and thereafter delivering an RV pacing pulse to the right ventricular electrode within a single cardiac cycle.

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.

A ventricularly implantable medical device that includes a sensing module that is configured to identify a search window of time within a cardiac cycle to search for an atrial artifact. Control circuitry in the ventricular implantable medical device is configured to deliver a ventricular pacing therapy to a patient's heart, wherein the ventricular pacing therapy is time dependent, at least in part, on an atrial event identified in the search window of time.

Methods, systems and devices for providing cardiac resynchronization therapy (CRT) to a patient using a leadless cardiac pacemaker (LCP) implanted in or proximate the left ventricle of a patient. A setup phase is used to establish parameters in the therapy delivery. In operation, the method and/or device will sense at least one non-paced cardiac cycle to determine a native R-R interval, and then delivers a synchronization pace at an interval less than the native R-R interval followed by a plurality of pace therapies delivered at the R-R interval or a modification thereof.

A leadless cardiac pacemaker (LCP) is configured to sense cardiac activity and to pace a patient's heart and is disposable within a ventricle of the patient's heart. The LCP MAY include a housing, a first electrode and a second electrode that are secured relative to the housing and are spaced apart. A controller is disposed within the housing and is operably coupled to the first electrode and the second electrode such that the controller is capable of receiving, via the first electrode and the second electrode, electrical cardiac signals of the heart. The LCP may include a pressure sensor and/or an accelerometer. The controller may determine a pace time within a cardiac cycle based at least in part upon an indication of metabolic demand.

Methods, systems and devices for providing cardiac resynchronization therapy (CRT) to a patient using a leadless cardiac pacemaker and an extracardiac device. The extracardiac device is configured to analyze one or more QRS complexes of the patient's heart, determine whether fusion pacing is taking place, and, if not, to communicate with the leadless cardiac pacemaker to adjust intervals used in the CRT in order to generate desirable fusion of the pace and intrinsic signals. The extracardiac device may take the form of a subcutaneous implantable monitor, a subcutaneous implantable defibrillator, or other devices including wearable devices.

Systems and methods for dynamically controlling His-bundle pacing (HBP) according to an indication of a rate-related or intermittent atrioventricular (AV) block in a subject are disclosed. An exemplary medical system includes an AV conduction monitor to detect an indication of either a presence or an absence of intermittent or rate-related AV conduction disturbance using physiologic information of the subject. In the event that an intermittent or rate-related AV conduction disturbance is present, a control circuit provides a control signal to an electrostimulation circuit to deliver HBP pulses. If there is no indication of intermittent or rate-related AV conduction disturbance, or a previously detected intermittent or rate-related AV conduction disturbance has been terminated, the control circuit withholds or discontinues delivery of the HBP pulses to promote intrinsic ventricular conduction and activation.

Some aspects relate to systems, devices, and methods of delivering rate responsive pacing therapy. The method includes monitoring activity information related to an activity level of a patient and delivering rate responsive pacing (RRP) to the patient at a pacing rate corresponding to a RRP profile. The RRP profile may be used to generate the pacing rate based on the activity information and may be adjusted based on the monitored activity information.

A computer implemented method and device for providing dual chamber sensing with a single chamber leadless implantable medical device (LIMD) are provided. The method is under control of one or more processors in the LIMD configured with specific executable instructions. The method obtains a far field (FF) cardiac activity (CA) signals for activity in a remote chamber of a heart and compares the far field CA signals to a P-wave template to identify an event of interest associated with the remote chamber. The method sets an atrial-ventricular (AV) delay based on the P-wave identified and delivers pacing pulses at a pacing site of interest to a local chamber based on the AV delay,

Embodiments of the present technology described herein are directed to implantable systems for performing cardiac resynchronization therapy (CRT), methods for use therewith, and leadless pacemakers for use therewith. Such a system can include a first leadless pacemaker configured to be implanted in or on the right atrial (RA) chamber and selectively pace the RA chamber, a second leadless pacemaker configured to be implanted in or on the right ventricular (RV) chamber and selectively pace the RV chamber, and a third leadless pacemaker configured to be implanted in or on the left ventricular (LV) chamber and selectively pace the LV chamber, wherein one of the leadless pacemaker is designated a master leadless pacemaker. In certain embodiments, the master leadless pacemaker determines a VV delay and an AV delay and coordinates CRT using such delays.