Methods and devices herein are provided for managing atrial (A) pacing in connection with premature atrial contracts (PAC). The methods and devices obtain an atrial pace-on-PAC (APAC) interval and cardiac activity (CA) signals. The methods and devices are configured to: i) during a first cardiac beat; following a ventricular paced (VP) or ventricular sensed (VS) event, activate a timer for a post ventricular-atrial refractory period (PVARP) interval; and determine whether a first atrial refractory (AR) event occurs during the PVARP interval; ii) during a second cardiac beat; in response to the detecting that the first AR event occurred, initiate an APAC interval; during the APAC interval for the second cardiac beat, determine whether a second AR event occurs; and update a count of APAC events when the second AR event occurs; and iii) repeat i) and ii) for multiple cardiac beats, to track the count of APAC events.

An implantable medical device system delivers a pacing pulse to a patient's heart and starts a first pacing interval corresponding to a pacing rate in response to the delivered pacing pulse. The system charges a holding capacitor to a pacing voltage amplitude during the first pacing interval. The system detects an increased intrinsic heart rate that is at least a threshold rate faster than the current pacing rate from a cardiac electrical signal received by a sensing circuit of the implantable medical device. The system starts a second pacing interval in response to an intrinsic cardiac event sensed from the cardiac electrical signal and withholds charging of the holding capacitor for at least a portion of the second pacing interval in response to detecting the increased intrinsic heart rate.

Systems and methods are described herein for evaluation and adjustment cardiac therapy. The systems and methods may initially evaluate a first pacing parameter while other pacing parameters are fixed to, for example, nominal values, and determine an effective setting for the first pacing parameter. Then, a second pacing parameter may be evaluated while the first pacing parameter is fixed to the previously-determined effective setting. Each evaluation may not test every possible setting for the pacing parameters, and instead, may utilize various processes to limit the settings to a subset of settings to test.

An implantable leadless pacemaker (iLP) for a human or animal heart, wherein the iLP includes a housing, at least two electrode poles for picking up electrical potentials and/or delivering electrical stimulation, a stimulation control unit in connection with the electrode poles, a sensing unit that is in connection with at least one electrode pole, a signal processing unit in connection with the sensing unit, a signal evaluation unit in connection with the signal processing unit and/or the sensing unit, and an energy source. The sensing unit is configured to sense a first signal associated with an activity of the first heart chamber, and the stimulation control unit is configured to deliver electrical stimulation in the first heart chamber via the at least two electrode poles. wherein the sensing unit is configured to sense a second signal associated with an activity of a second heart chamber.

Systems, methods and implantable devices configured to provide cardiac resynchronization therapy and/or bradycardia pacing therapy. A first device located in the heart of the patient is configured to receive a communication from a second device and deliver a pacing therapy in response to or in accordance with the received communication. A second device located elsewhere is configured to determine an atrial event has occurred and communicate to the first device to trigger the pacing therapy. The second device may be configured for sensing the atrial event by the use of vector selection and atrial event windowing, among other enhancements. Exception cases are discussed and handled as well.

A lead-in-lead system may include a first implantable lead having a first electrode and a second implantable lead having a second electrode guided by the first implantable lead to an implantation site. The second electrode may be implanted in a patient's heart distal to the first electrode at the same implantation site or at a second implantation site. Various methods may be used to deliver the lead-in-lead system to one or more implantation sites including at the triangle of Koch for ventricle-from-atrium (VfA) therapy, at the right ventricular septal wall for dual bundle-branch pacing, or in the coronary vasculature for left side sensing and pacing.

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.

In some examples, controlling delivery of CRT includes delivering ventricular pacing according to a sequence of different values of at least one of A-V delay or V-V delay, and acquiring one or more electrograms from respective vectors. For each of the different values of the at least one of A-V delay or V-V delay, at least one of a QRS amplitude or a QRS area may be determined based on the one or more electrograms, and a target change in QRS amplitude or QRS area between adjacent ones of the values of the at least one of A-V delay or V-V delay of the sequence may be identified. In response to the identification of the target change, the implantable medical device may deliver the ventricular pacing at a value of the at least one of A-V delay or V-V delay determined based on the identification to provide CRT.

The present invention relates to an implantable device for stimulating a heart and lowering blood pressure, comprising: a stimulation unit configured to stimulate the His bundle or the left-bundle branch of the heart, and a sensing unit for detecting atrial activity of the heart. According to the present invention the stimulation unit is configured to stimulate the His bundle or the left bundle branch immediately before or immediately after detection of an atrial activity.

An implanted device for an organ of a patient including a housing. The device includes a detector having electrodes that have a varying distance over time between them which produces a detector signal based on electrical signals derived from the organ. The device includes a signal processor disposed in the housing in communication with the detector which determines admittance from the detector signal based on the varying distance over time between the electrodes. The device includes a drive circuit disposed in the housing to cause the electrodes to generate emitted electrical signals. A method for monitoring a patient's organ.