Systems and methods for monitoring chronic over-pacing (COP) to the heart are discussed herein. In an embodiment, a system includes a receiver circuit to receive information about pacing rates of a plurality of paced heart beats, and a pacing analyzer circuit to generate a pacing rate distribution using pacing rates of the plurality of the paced heart beats. The pacing rate distribution includes a pacing rate histogram. The pacing analyzer circuit may recognize a morphological pattern from the pacing rate distribution, and detect a COP indication using the extracted feature. A programmer circuit adjusts one or more therapy parameters in response to the detected. COP indication.

An intracardiac ventricular pacemaker includes a pulse generator for delivering ventricular pacing pulses, an impedance sensing circuit, and a control circuit in communication with the pulse generator and the impedance sensing circuit. The pacemaker is configured to produce an intraventricular impedance signal, detect an atrial systolic event using the intraventricular impedance signal, set an atrioventricular pacing interval in response to detecting the atrial systolic event, and deliver a ventricular pacing pulse in response to the atrioventricular pacing interval expiring.

Techniques are disclosed for detecting arrhythmia episodes for a patient. A medical device may receive one or more sensor values indicative of motion of a patient. The medical device may determine, based at least in part on the one or more sensor values, an activity level of the patient. The medical device may determine a heart rate threshold for triggering detection of an arrhythmia episode based at least in part on the activity level of the patient. The medical device may determine whether to trigger detection of the arrhythmia episode for the patient based at least in part on comparing a heart rate of the patient with the heart rate threshold. The medical device may, in response to triggering detection of the arrhythmia episode, collect information associated with the arrhythmia episode.

A wearable medical includes a walking detector module with a motion sensor that is configured to detect when the patient is walking or running. In embodiments, a parameter (referred to herein as a “Bouncy” parameter) is determined from Y-axis acceleration measurements. In some embodiments, the Bouncy parameter is a measurement of the AC component of the Y-axis accelerometer signal. This detection can be used by the medical device to determine how and/or whether to provide treatment to the patient wearing the medical device. For example, when used in a WCD, the walking detector can prevent “false alarms” because a walking patient is generally conscious and not in need of a shock.

Systems and methods for monitoring and treating patients with heart failure (HF) are discussed. The system may sense cardiac signals, and receives information about patient physiological or functional conditions. A stimulation parameter table that includes recommended values of atrioventricular delay (AVD) or other timing parameters maybe created at a multitude of patient physiological or functional conditions. The system may periodically reassess patient physiological or functional conditions. A therapy programmer circuit may dynamically switch between left ventricular-only pacing and biventricular pacing, or switch between single site pacing and multisite pacing based on the patient condition. The therapy programmer circuit may adjust AVD and other timing parameters using the cardiac signal input and the stored stimulation parameter table. A HF therapy may be delivered according to the determined stimulation site, stimulation mode, and the stimulation timing.

Devices, systems and methods provide forms of asymptomatic diaphragmatic stimulation (ADS) therapy that affect pressures within the intrathoracic cavity, including: 1) dual-pulse ADS therapy, during which a first ADS pulse is delivered during a diastolic phase of a cardiac cycle and a second ADS pulse is delivered during a systolic phase, 2) paired-pulse ADS therapy, during which a first ADS pulse is delivered, closely followed by a second ADS pulse, with the second ADS pulse functioning to extend or enhance a phase of a transient, partial contraction of the diaphragm, and 3) multiple-pulse ADS therapy, during which a stream of ADS pulses is delivered, wherein the time between pulses is based on heart rate. Devices, systems and methods also monitor electromyography (EMG) activity of the diaphragm relative to baseline activity to assess the health of a diaphragm subject to ADS therapy and to adjust ADS therapy parameters or sensing parameters.

Systems and methods for monitoring and treating patients with heart failure (HF) are discussed. The system may sense cardiac signals, and receives information about patient physiological or functional conditions. A stimulation parameter table that includes recommended values of atrioventricular delay (AVD) or other timing parameters may be created at a multitude of patient physiological or functional conditions. The system may periodically reassess patient physiological or functional conditions. A therapy programmer circuit may dynamically switch between left ventricular-only pacing and biventricular pacing, or switch between single site pacing and multisite pacing based on the patient condition. The therapy programmer circuit may adjust AVD and other timing parameters using the cardiac signal input and the stored stimulation parameter table. A HF therapy may be delivered according to the determined stimulation site, stimulation mode, and the stimulation timing.

A system is provided that includes electrodes configured to be implanted in a body, and a pulse generator (PG) circuitry to deliver a stimulus to one or more of the electrodes. The system also includes sensing circuitry configured to define a sensing channel between one or more of the electrodes to sense signals indicative of a physiologic activity of interest, and the sensing circuitry further configured to collect a calibration signal over the sensing channel. The sensing circuitry and PG circuitry are housed within an implantable medical device (IMD). The system also includes one or more processors configured to determine a signal characteristic of interest (COI) of the calibration signal. The one or more processors are also configured to compare a signal COI of the stimulus to the signal COI of the calibration signal, and adjust a parameter of the sensing circuitry or PG circuitry based on the comparison.

An example of a system includes an implantable medical device (IMD) for implantation in a patient, where the IMD includes a cardiac pace generator, phrenic nerve stimulation (PS) sensor, a memory, and a controller, and where the controller is operably connected to the cardiac pace generator to generate cardiac paces. The controller is configured to provide a trigger for conducting a PS detection procedure and perform the PS detection procedure in response to the trigger. In performing the PS detection procedure the controller is configured to receive a signal from the sensor, detect PS using the signal from the sensor, and record the PS detection in storage within the IMD.

A medical device is configured to determine a rate smoothing pacing interval based on at a ventricular cycle length ending with a ventricular pacing pulse and determine a post-sense ventricular pacing interval based on a ventricular cycle length ending with a sensed ventricular event signal. The medical device may be configured to start a ventricular pacing interval set to the post-sense ventricular pacing interval in response to the sensed ventricular event signal and generate a ventricular pacing pulse in response to the expiration of the post-sense ventricular pacing interval.