In some examples, an implantable medical device determines that another medical device delivered an anti-tachyarrhythmia shock, and delivers post-shock pacing in response to the determination. The implantable medical device may be configured to both detect the delivery of the shock in a sensed electrical signal and, if delivery of the shock is not detected, determine that the shock was delivered based on detection of asystole of the heart. The asystole may be detected based on the sensed electrical signal. In some examples, an implantable medical device is configured to revert from a post-shock pacing mode to a baseline pacing mode by iteratively testing a plurality of decreasing values of pacing pulse magnitude until loss of capture is detected. The implantable medical device may update a baseline value of the pacing pulse magnitude for the baseline mode based on the detection of loss of capture.

According to various method embodiments, a person is indicated for a therapy to treat a cardiovascular disease, and the therapy is delivered to the person to treat the cardiovascular disease. Delivering the therapy includes delivering a vagal stimulation therapy (VST) to a vagus nerve of the person at a therapeutically-effective intensity for the cardiovascular disease that is below an upper boundary at which upper boundary the VST would lower an intrinsic heart rate during the VST.

An extra-cardiovascular implantable cardioverter defibrillator (ICD) having a low voltage therapy module and a high voltage therapy module is configured to select, by a control module of the ICD, a pacing output configuration from at least a low-voltage pacing output configuration of the low voltage therapy module and a high-voltage pacing output configuration of the high voltage therapy module. The high voltage therapy module includes a high voltage capacitor having a first capacitance and the low voltage therapy module includes a plurality of low voltage capacitors each having up to a second capacitance that is less than the first capacitance. The ICD control module controls a respective one of the low voltage therapy module or the high voltage therapy module to deliver extra-cardiovascular pacing pulses in the selected pacing output configuration via extra-cardiovascular electrodes coupled to the ICD.

A medical device and medical device system for delivering left ventricular pacing that includes a subcutaneous sensing device having a subcutaneous electrode to sense a subcutaneous cardiac signal and an emitting device to emit a trigger signal in response to the sensed cardiac signal, an intracardiac therapy delivery device to deliver the left ventricular pacing in response to the emitted trigger signal, and a processor configured to determine whether the medical device system is in one of a VVD pacing mode and a VVI pacing mode, determine whether the delivered left ventricular pacing captures the left ventricle, determine whether to adjust a pacing parameter in response to the determination of whether the device system is in one of a VVD pacing mode and a VVI pacing mode and the determination of whether the delivered left ventricular pacing captures the left ventricle, and deliver the left ventricular pacing in response to determining whether to adjust the pacing parameter.

Systems and methods are provided for managing patient activated capture of transient data by an implantable medical device (IMD). The systems and methods collect transient data using the IMD. The collected transient data is stored in a temporary memory section of the IMD. The IMD receives a patient activated storage request including activation information related to a patient designated trigger point from an external device. The IMD transfers a segment of the transient data from the temporary memory section to a long-term memory, wherein the segment of transferred transient data is based on the trigger point. The activation information includes an elapsed time corresponding to a duration of time between entry of the trigger point and issuance of the patient activated storage request by an external activation device.

An implantable device and associated method for delivering multi-site pacing therapy is disclosed. The device comprises a set of electrodes including a first ventricular electrode and a second ventricular electrode, spatially separated from one another and all coupled to an implantable pulse generator. The device comprises a processor configured for selecting a first cathode and a first anode from the set of electrodes to form a first pacing vector at a first pacing site along a heart chamber and selecting a second cathode and a second anode from the set of electrodes to form a second pacing vector at a second pacing site along the same heart chamber. The pulse generator is configured to deliver first pacing pulses to the first pacing vector and delivering second pacing pulses to the second pacing vector. The pulse generator generates a recharging current for recharging a first coupling capacitor over a first recharge time period in response to the first pacing pulses. The pulse generator for generating a recharging current for recharging a second coupling capacitor over a second recharge time period in response to the second pacing pulses. An order of recharging the first and second coupling capacitors is dependent upon one of ventricular pacing mode, left ventricle to right ventricle delay (V-V) pace delay, multiple point LV delay and latest delivered pacing pulses to one of the first and second pacing vectors.

Systems and methods for pacing cardiac conductive tissue are described. In an embodiment, a medical system includes an electrostimulation circuit to generate pacing pulses to stimulate a His bundle or a bunch branch. A sensing circuit senses a far-field ventricular activation, determines a cardiac synchrony indicator using the far-field ventricular activation in response to His bundle or bundle branch pacing, and verifies His-bundle capture status using the determined cardiac synchrony indicator. The system can determine a pacing threshold using the capture status under different stimulation strength values. The electrostimulation circuit can deliver stimulation pulses in accordance with the determined pacing threshold.

Systems, devices, and methods for pacing a heart of a patient are disclosed. A device may include a leadless cardiac pacemaker (LCP) that includes a power supply, a pair of electrodes, and a controller operably connected to the electrodes and the power supply. The controller may identify a capture threshold by setting a pace amplitude at a power supply voltage of the power supply and deliver pacing stimulation pulses with different pulse widths to identify the capture threshold. The LCP may then deliver pacing stimulation pulses based, at least in part, on a pulse amplitude and pulse width associated with the capture threshold, and also adding a capture margin. In some cases, the pulse amplitude may change over time and the LCP may adjust a pulse width along a strength-duration curve to account for the pulse amplitude change and maintain a capture threshold and capture margin.

This document discusses, among other things, systems and methods for programming a neuromodulation therapy to treat neurological or cardiovascular diseases. A system includes an ambulatory medical device (AMD) and at least one computer-readable storage medium including instructions executable on an external system. The instructions, when executed by the external system, causes a user interface in the external system to receive a waveform function and one or more modulation parameter values. The waveform function includes one or more modulation programs characterized by one or more modulation parameters. The instructions causes a compiler to translate the waveform function into virtual machine (VM) instructions, which can be transmitted to the AMD. The AMD includes a VM that executes the VM instructions, and generates one or more modulation waveform datasets. The AMD may generate and deliver electrostimulation therapy in accordance with the one or more modulation waveform datasets.

Ventricle-from-atrium (VfA) cardiac therapy may utilize a tissue-piercing electrode implanted in the left ventricular myocardium of the patient's heart from the right atrium through the right atrial endocardium and central fibrous body. The exemplary devices and methods may determine whether the tissue-piercing electrode is achieving effective left ventricular capture. Additionally, one or more pacing parameters, or paced settings, may be adjusted in view of the effective left ventricular capture determination.