Some aspects relate to systems, devices, and methods of assessing heart rate recovery. A heart rate of a patient may be measured during a plurality of heart rate recovery events. Each of the plurality of heart rate recovery events comprises a duration of time after an activity resulting in an elevated heart rate. Heart rate recovery information may be determined based on the measured heart rate during each of the plurality of heart rate recovery events and a cardiac status of the patient may be generated from the determined heart rate recovery information over the plurality of heart rate recovery events.

Systems and methods are described herein for configuration of cardiac therapy. The systems and methods may select, or determine, a plurality of different configuration parameters based electrical activity monitored or measured using a plurality of external electrodes. For example, the systems and methods may select, or determine, a left ventricular pacing vector, adaptive or non-adaptive pacing therapy, an interventricular pacing delay, and a atrioventricular pacing delay.

An implantable system, and methodology, for improving a heart's hemodynamic performance featuring (a) bimodal electrodes placeable on the diaphragm, out of contact with the heart, possessing one mode for sensing cardiac electrical activity, and another for applying cardiac-cycle-synchronized, asymptomatic electrical stimulation to the diaphragm to trigger biphasic, diaphragmatic motion, (b) an accelerometer adjacent the electrodes for sensing both heart sounds, and stimulation-induced diaphragmatic motion, and (c) circuit structure, connected both to the electrodes and the accelerometer, operable, in predetermined timed relationships to the presences of valid V-events noted in one of sensed electrical and sensed mechanical, cardiac activity, to deliver diaphragmatic stimulation. The circuit structure includes accelerometer-linked computer structure for enabling selective review, for later operational modifications, of stimulation-produced diaphragmatic motions, and in a modified form, may additionally include timing-adjustment substructure capable of making adjustments in the mentioned timed relationships.

An implantable medical device includes an activity sensor, a pulse generator, and a control module. The control module is configured to determine activity metrics from the activity signal and determine an activity metric value at a predetermined percentile of the activity metrics. The control module sets a lower pacing rate set point based on the activity metric value at the predetermined percentile.

Systems and methods for monitoring patient vasoactivity are discussed. An exemplary patient monitor system includes a sensor circuit configured to generate a heart sound (HS) metric using a HS signal sensed from a patient, and a vasoactivity monitor configured to monitor vasoactivity, such as degree of vasoconstriction or vasodilation, using the HS metric. The system can provide the monitored vasoactivity to a user to alert patient hemodynamic responses to vasoactive drugs, or initiate or adjust a vasoactive therapy according to the vasoactivity. The system may use the monitored vasoactivity to detect a medical condition such as worsening heart failure, pulmonary edema, or syncope.

A medical device senses cardiac electrical signals including T-waves attendant to ventricular myocardial repolarizations and detects a T-wave template condition associated with non-pathological changes in T-wave morphology. The device generates a T-wave template from T-waves sensed by the sensing circuit during the T-wave template condition. After generating the T-wave template, the device acquires a T-wave signal from the cardiac electrical signal and compares the acquired T-wave signal to the T-wave template. The device detects a pathological event in response to the acquired T-wave signal not matching the T-wave template.

A method of distinguishing a non-epileptic seizure from an epileptic seizure in a patient, comprising: detecting a seizure in a patient based on at least one first body signal of the patient selected from an autonomic signal, a neurologic signal, a metabolic signal, an endocrine signal, and a tissue stress marker signal; analyzing at least one second body signal of the patient selected from an autonomic signal, a neurologic signal, a metabolic signal, an endocrine signal, and a tissue stress marker signal; determining, based on the analyzing, at least a first classification index comprising at least one of an epileptic seizure index and a non-epileptic seizure index; and classifying the seizure as one of a non-epileptic seizure or an epileptic seizure based on the at least a first classification index. A medical device system capable of implementing the method. A computer-readable device for storing data that, when executed, perform the method.

Systems and methods are provided for using stored physiologic information about a subject to detect a previous treatment event. Physiologic information can be sensed from a subject using one or more sensors. Using a detection circuit, a change in the sensed physiologic information, such as a change from reference physiologic information, can be used to identify a candidate previous treatment event. An alert or other information about the candidate treatment event can be provided to a patient or clinician. In an example, a candidate treatment event can include a heart failure or diuresis treatment that is identified using information about a change in one or more of a subject's circadian pattern, a subject's thoracic impedance, or a subject's respiration status.

Systems and methods for detecting cardiac arrhythmias such as atrial tachyarrhythmia (AT) are discussed. An exemplary system includes an arrhythmia detector circuit that can receive physiologic information sensed from a patient over time, detect an arrhythmia onset when the physiologic information during a first time period satisfies an onset condition, and in response to the detected arrhythmia onset, detect an arrhythmia termination when the physiologic information during a second time period, subsequent to and longer than the first time period, satisfies an exit condition. An arrhythmia episode can be detected based on an arrhythmia duration between the detected onset and termination. The detected sustained arrhythmia episode can be provided to a user or a processor for further processing.

Hemodynamic performance of a heart may be improved by determining, from a location associated with a diaphragm, an occurrence of a valid cardiac event; and then delivering asymptomatic electrical stimulation therapy directly to the diaphragm at termination of a diaphragmatic stimulation delay period that is timed relative to the occurrence of the valid cardiac event. The diaphragmatic stimulation delay period may be automatically established by sensing a plurality of cardiac events directly from a diaphragm; and for each of the sensed cardia events, determining whether the sensed cardiac event represents a valid cardiac event or a non-valid cardiac event. The diaphragmatic stimulation delay period is then calculated based on a plurality of sensed cardia events that are determined to be valid.