An extra-cardiovascular medical device is configured to select a capacitor configuration from a capacitor array and deliver a low voltage, pacing pulse by discharging the selected capacitor configuration across an extra-cardiovascular pacing electrode vector. In some examples, the medical device is configured to determine the capacitor configuration based on a measured impedance of the extra-cardiovascular pacing electrode vector.

A method and implantable medical device system for delivering a cardiac pacing therapy that includes suspending delivery of the LV cardiac pacing therapy and sensing far-field cardiac signals via one or more far-field sensing vectors formed between a plurality of electrodes positioned on a single-pass coronary sinus lead. Far-field signal features are determined in response to the sensed far-field cardiac signals, a first offset interval and a second offset interval are determined in response to the determined far-field signal features, and an AV delay of the LV cardiac pacing therapy is adjusted in response to the determined first offset interval and second offset interval. Delivery of the LV cardiac pacing therapy having the adjusted AV delay is subsequently resumed.

Techniques for switching an implantable medical device (IMD) from a first mode to a second mode in relation to signals obtained from internal sensors are described. The internal sensors may include a temperature sensor and a biosensor. In some examples, processing circuitry of the IMD may make a first preliminary determination that the IMD is implanted based on a first signal from the temperature sensor. In response to the first preliminary determination being that the IMD is implanted, the processing circuitry may make a second preliminary determination that the IMD is implanted based on a second signal from the biosensor. The processing circuitry may switch the IMD from a first mode to a second mode based on both the first preliminary determination and the second preliminary determination being that the IMD is implanted.

A computing device includes a memory configured to store instructions. The computing device also includes a processor to execute the instructions to perform operations that include providing an alternating electrical signal to a patient through at least a pair of electrodes, and determining transthoracic impedance of the patient from a measurement associated with the applied alternating electrical signal. Operations also include identifying, from the transthoracic impedance, a sequence of resistance values for controlling the discharge of a charge storage device located external to the patient, and controlling the discharge of the charge storage device using the identified sequence of resistance values.

Techniques for using multiple physiological parameters to provide an early warning for worsening heart failure are described. A system is provided that monitors a multiple diagnostic parameters indicative of worsening heart failure. The parameters preferably include are least one parameter acquired from an implanted device, such as intrathoracic impedance. The system device derives an index of the likelihood of worsening heart failure based upon the parameters using a Bayesian approach and displays the resultant index for review by a physician.

Systems and methods for managing cardiac arrhythmias are discussed. A data management system receives a first detection algorithm including a detection criterion for detecting a cardiac arrhythmia. An arrhythmia detector detects arrhythmia episodes from a physiologic signal using a second detection algorithm that is different from and has a higher sensitivity for detecting the cardiac arrhythmia than the first detection algorithm. The arrhythmia detector assigns a detection indicator to each of the detected arrhythmia episodes. The detection indicator indicates a likelihood that the detected arrhythmia episode satisfies the detection criterion of the first detection algorithm. The system prioritizes the detected arrhythmia episodes according to the assigned detection indicators, and outputs the arrhythmia episodes to a user or a process according to the episode prioritization.

A medical apparatus for a patient comprises an external system and an implantable system. The external system is configured to transmit one or more transmission signals, each transmission signal comprising at least power or data. The implantable system is configured to receive the one or more transmission signals from the external system, and to deliver stimulation energy to the patient. Methods of delivering stimulation energy are also provided.

Systems and methods provide for assessing the heart failure status of a patient and, more particularly, to generating a trend parameter based on a distribution of the patient's respiration rate. Systems and methods provide for detecting, using an implantable device or a patient-external device, patient respiration and computing a respiration rate based on the detected patient respiration. A distribution of the respiration rate is calculated, and a trend parameter based on the respiration rate distribution is generated. The trend parameter is indicative of a patient's heart failure status. An output signal indicative of the patient's heart failure status may be generated based on the trend parameter.

A system and method are provided. The system includes a HIS electrode configured to be located proximate to a HIS bundle. A pulse generator is coupled to the HIS electrode and is configured to deliver HIS bundle pacing (HBP), a right atrial (RA) electrode is located in a right atrium, a sensing circuitry coupled to the RA electrode and defines an RA sensing channel that does not utilize the HIS electrode. The system includes a memory including program instructions. The system includes a processor is configured to collect cardiac activity (CA) signals over the RA sensing channel utilizing the RA electrode. The CA signals include a far field (FF) component associated with a ventricular event (VE). The processor analyzes the FF component to identify first and second FF component (FFC) characteristics of interest (COI) of the ventricular event and utilizes the first FFC COI to apply a first capture class (CC) discriminator to distinguish between first and second capture classes. The first capture class includes first and second capture types. The processor utilizes the second FFC COI to apply a second CC discriminator to distinguish between at least one of i) the first and second capture types within the first capture class, or ii) third and fourth capture classes and manages HIS bundle pacing based on distinctions by the first and second CC discriminators.

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.