Regulating cardiac activity may include pacing the patient's heart at a starting pacing rate and instigating an intrinsic heart beat search algorithm that includes pacing at a reduced rate for a period of time and capturing electrical signals representative of cardiac electrical activity while pacing at the reduced rate in order to determine a presence or absence of intrinsic heart beats. If intrinsic heart beats are not detected, the heart may be paced at a further reduced rate for a period of time. If intrinsic beats are detected, the heart may be paced again at the starting pacing rate. This may continue until intrinsic heart beats are detected or until a lower search rate limit is reached. Diagnostic data may be collected at each stage and transmitted to a display device for analysis by a physician or the like.

A cardiac pacemaker is disclosed for pacing cardiac tissue to improve synchrony between the atria and ventricles and/or between the left and right ventricles. A pulse generator is configured to deliver a pacing pulse to a patient's ventricle at an atrioventricular (AV) delay following a preceding atrial event. A sensing circuitry configured to sense a signal from the patient's ventricle following delivery of a said pacing pulse. A processing circuitry coupled to the pulse generator and the sensing circuitry and configured to control the pulse generator, the processing circuitry further configured to: (1) acquire from the sensed signal a set of features; (2) determine whether the ventricular pacing pulse effectively captures the patient's ventricle using the set of features; (3) determine whether one or more tissue latency conditions are present. The one or more pacing pulse parameters are adjusted, in response to determining that tissue latency is present.

The disclosure relates to a device including a circuit for adjusting the energy of the stimulation pulses, independently controlling the pulse width and the voltage of each stimulation pulse. An iterative search algorithm for determining the optimum energy includes changing both the pulse width and voltage at each new pulse delivered, by setting a high energy value and a low energy value, and delivering a stimulation pulse with the low energy value. A capture test is then carried out. In the presence of a capture, a current iteration is complete and a new iteration is done with the current low energy as a new high energy value. In the absence of capture, the algorithm is terminated with selection of the last energy value that produced the capture as the value of optimum energy.

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.

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.

A biostimulator, such as a leadless pacemaker, having electrode(s) coated with low-polarization coating(s), is described. A low-polarization coating including titanium nitride can be disposed on an anode, and a low-polarization coating including a first layer of titanium nitride and a second layer of platinum black can be disposed on a cathode. The anode can be an attachment feature used to transmit torque to the biostimulator. The cathode can be a fixation element used to affix the biostimulator to a target tissue. The low-polarization coating(s) impart low-polarization to the electrode(s) to enable an atrial evoked response to be detected and used to effect automatic output regulation of the biostimulator. Other embodiments are also described and claimed.

The disclosure describes implantable medical systems that respond to occurrence of a lead-related condition by utilizing an elongated coil electrode in defining an alternative pacing therapy vector to maintain optimal drain of an IMD power supply. An exemplary system includes a medical electrical lead having an elongated electrode and an improved sensing and therapy delivery circuitry to provide the alternative pacing therapy vector responsive to the lead-related conditions. The system reconfigures the operation of the sensing and therapy delivery circuitry triggered by the switch to the alternative pacing therapy vector.

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.

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 medical device including a control unit, at least a right ventricular sensing unit and/or a right atrial sensing unit, wherein the right ventricular sensing unit is connected or can be connected to a right ventricular stimulation electrode lead having at least one electrode pole and a stimulation unit that is connected or can be connected to a multipolar left ventricular stimulation electrode lead having a plurality of electrode poles. The control unit is adapted to determine right atrioventricular conduction state and to cause selection of one of the plurality of electrode poles of the multipolar left ventricular stimulation electrode lead depending a respective determined right atrioventricular conduction state.