A method includes determining whether electrical activity is indicative of atrial fibrillation, determining whether mechanical activity is indicative of atrial fibrillation, and adjusting a pacing parameter or mode based on whether the electrical activity and the mechanical activity are indicative of atrial fibrillation. The electrical activity may be detected based on a far-field measurement. The method may be performed using a leadless implantable medical device.

Systems and methods for controlling blood pressure by controlling atrial pressure and atrial stretch are disclosed. In some embodiments, a stimulation circuit may be configured to deliver a stimulation pulse to at least one cardiac chamber of a heart of a patient, and at least one controller may be configured to execute delivery of one or more stimulation patterns of stimulation pulses to the at least one cardiac chamber, wherein at least one of the stimulation pulses stimulates the heart such that an atrial pressure resulting from atrial contraction of an atrium overlaps in time a passive pressure build-up of the atrium, such that an atrial pressure of the atrium resulting from the stimulation is a combination of the atrial pressure resulting from atrial contraction and the passive pressure build-up and is higher than an atrial pressure of the atrium would be without the stimulation, and such that the blood pressure of the patient is reduced.

The present invention involves approaches for selecting one or more electrode combinations. Various method embodiments can include implanting a plurality of cardiac electrodes supported by one or more leads in a patient, attaching the one or more leads to a patient external analyzer circuit, delivering electrical stimulation to the patient's heart using the plurality of cardiac electrodes and the analyzer circuit, evaluating, for each electrode combination of a plurality of electrode combinations of the plurality of cardiac electrodes, one or more first parameters and one or more second parameters produced by the electrical stimulation delivered using the electrode combination, the first parameters supportive of cardiac function consistent with a prescribed therapy and the second parameters not supportive of cardiac function consistent with the prescribed therapy, selecting one or more electrode combinations of the plurality of cardiac electrodes based on the evaluation, the one or more electrode combinations selected as being associated with the one or more first parameters and less associated with the one or more second parameters relative to other electrode combinations of the plurality of cardiac electrodes, programming an implantable pacing circuit to deliver a cardiac pacing therapy that preferentially uses the selected one or more electrode combinations relative to other electrode combinations of the plurality of cardiac electrodes, detaching the one or more leads from the analyzer circuit, attaching the one or more leads to the implantable pacing circuit, and implanting the implantable pacing circuit.

A method of cardiac signal processing including: receiving measurements from at least two electrodes positioned within the heart; determining, using the measurements, relative positioning of the at least two electrodes relative to each other; evaluating suitability of the relative positioning of the at least two electrodes for measurement of cardiac activity to determine which cardiac cycles should receive cardiac contractility modulation stimulation.

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.

Methods and systems for use of the Q-wave to R-wave interval to guide placement of a leadless cardiac pacemaker are disclosed. An implant delivery device is equipped with sensing electrodes to sense R-wave onset in a ventricle of a patient's heart to allow placement at a location of last or latest onset of the R-wave. Guidance tools are provided to assist in determination of the Q-wave to R-wave interval during implantation. For a chronic system, a cooperative approach is disclosed in which an implantable medical device and a leadless cardiac pacemaker exchange data to determine Q-wave to R-wave intervals and enhance cardiac resynchronization therapy delivery by the leadless cardiac pacemaker.

Techniques and systems for monitoring cardiac arrhythmias and delivering electrical stimulation therapy using a subcutaneous device (e.g. subcutaneous implantable (SD)) is described. In one or more other embodiments, SD is implanted into a patient's heart. Electrical signals are then sensed which includes moderately lengthened QRS duration data from the patient's heart. A determination is made as to whether cardiac resynchronization pacing therapy (CRT pacing) is appropriate based upon the moderately lengthened QRS duration in the sensed electrical signals. The CRT pacing pulses are delivered to the heart using electrodes. In one or more embodiments, the SD can switch between fusion pacing and biventricular pacing based upon data (e.g. moderately lengthened QRS, etc.) sensed from the heart.

A system for cardiac monitoring and therapy includes a mother device configured to receive signals indicative of cardiac electrical activity in a patient's heart. The mother device includes a mother wireless communications module configured to transmit and receive information to and from the mother device. The system also includes a satellite device configured to receive the signals indicative of the cardiac electrical activity in the patient's heart from a remote location relative to the mother device and includes a satellite wireless communications module configured to transmit from and receive communications sent to the satellite device to at least communicate with the mother wireless communications module. The system also includes a processor configured to receive the signals indicative of the cardiac electrical activity in the heart received by the mother device and the satellite device and, based thereon, control delivery of electrical therapy to the patient's heart.

An implantable system for stimulating a human heart or an animal heart contains a processor, a memory unit, an atrial stimulation unit, and a detection unit for detecting atrial tachycardia. The system is characterized in that the memory unit stores a computer-readable program, which prompts the processor to carry out the following steps when the program is being executed on the processor: a) detecting by way of the detection unit whether atrial tachycardia to be treated is present in a human heart or an animal heart; b) when atrial tachycardia to be treated is present, applying atrial antitachycardia pacing by way of the atrial stimulation unit; and c) after the atrial antitachycardia pacing has been applied, carrying out an atrial post-treatment stimulation, the post-treatment stimulation being configured to be within a range of 1 minute up to 7 days.

Systems and methods for reducing ventricle filling volume are disclosed. In some embodiments, a stimulation circuit may be used to stimulate a patient's heart to reduce ventricle filling volume or even blood pressure. When the heart is stimulated at a consistent rate to reduce blood pressure, the cardiovascular system may over time adapt to the stimulation and revert back to the higher blood pressure. In some embodiments, the stimulation pattern may be configured to be inconsistent such that the adaptation response of the heart is reduced or even prevented. In some embodiments, a stimulation circuit may be used to stimulate a patient's heart to cause at least a portion of an atrial contraction to occur while the atrioventricular valve is closed. Such an atrial contraction may deposit less blood into the corresponding ventricle than when the atrioventricular valve is opened throughout an atrial contraction.