Systems and methods are described herein related to the evaluation and adjustment of left bundle branch (LBB) pacing therapy. Evaluation of the LBB pacing therapy may utilize electrical activity monitored from a plurality of external electrodes. The electrical activity may be used to provided one or more metrics of dispersion of surrogate cardiac electrical activation times, which may then be used to evaluate, and potentially adjust the LBB pacing therapy.

A medical device is configured to sense an acceleration signal and determine at least one frequency metric from the acceleration signal that is correlated to a frequency of oscillations of the acceleration signal. The medial device is configured to determine that the at least one frequency metric meets atrial tachyarrhythmia criteria and detect an atrial tachyarrhythmia in response to at least the frequency metric meeting the atrial tachyarrhythmia criteria.

A medical device system, such as an extra-cardiovascular implantable cardioverter defibrillator ICD, senses R-waves from a first cardiac electrical signal by a first sensing channel and stores a time segment of a second cardiac electrical signal in response to each sensed R-wave. The medical device system determines a morphology parameter correlated to signal noise from time segments of the second cardiac electrical signal, detects a noisy signal segment based on the signal morphology parameter; and withholds detection of a tachyarrhythmia episode in response to detecting a threshold number of noisy signal segments.

A system is provided for controlling a left univentricular (LUV) pacing therapy using an implantable medical device (IMD). The system also includes one or more processors configured to determine an atrial-ventricular (AV) conduction interval (AR.sub.RV) between the A site and a first RV sensed event at the RV site, determine an inter-ventricular (VV) conduction interval (R.sub.LV-R.sub.RV) between a paced event at the LV site and a second RV sensed event at the RV site, and set a ventricular refractory period (VRP) based on at least one of the AV conduction interval or the VV conduction interval and a predetermined offset. The one or more processors are also configured to blank signals over the RV sensing channel during the VRP.

A medical device is configured to sense event signals from a cardiac electrical signal and determine maximum amplitudes of cardiac electrical signal segments associated with sensed event signals. The medical device is configured to determine at least one tachyarrhythmia metric based on at least a greatest one of the determined maximum amplitudes. The medical device may determine when the at least one tachyarrhythmia metric does not meet true tachyarrhythmia evidence and, in response, determine when the maximum amplitudes meet suspected noise criteria. The medical device may withhold a tachyarrhythmia detection and tachyarrhythmia therapy when suspected noise criteria are met.

A method of selecting a patient for cardiac contractility modulation therapy, comprising: selecting a patient meeting a criteria for cardiac resynchronization therapy (CRT); detecting a potential difficulty in effective delivery of CRT to the patient; and determining that the patient can benefit from cardiac contractility modulation therapy in spite of said potential difficulty.

A medical device is configured to deliver an electrical stimulation pulse to a heart of a patient, determine a pre-stimulation cardiac event amplitude prior to delivering the electrical stimulation pulse and adjust a cardiac event sensing threshold according to a first post-stimulation decay sequence in response to the electrical stimulation pulse delivery. The first post-stimulation decay sequence is controlled by a sensing module of the medical device according to a first set of sensing control parameters including at least one sensing control parameter based on the pre-stimulation cardiac event amplitude.

An example device for detecting one or more parameters of a cardiac signal is disclosed herein. The device includes one or more electrodes and sensing circuitry configured to sense a cardiac signal via the one or more electrodes. The device further includes processing circuitry configured to determine a representative signal based on the cardiac signal, the representative signal having a single polarity, and determine an end of a T-wave of the cardiac signal based on an area under the representative signal.

An analysis device for supporting the implantation of a system for stimulating the human heart or animal heart, comprising a processor and a memory unit. The memory unit includes a computer-readable program, which prompts the processor to carry out the following steps when the program is being executed on the processor: a) receiving an electrocardiogram of a human heart or an animal heart into which a system for stimulating this heart is being implanted; b) automatically identifying signals of the electrocardiogram caused by a His bundle stimulation, a signal being identified which appears between an atrial signal and a ventricular signal; c) marking the previously identified signals in the received electrocardiogram; and d) outputting the electrocardiogram thus marked on an output device. The analysis device comprises a detection unit having a sensitivity of at least 0.25 mV.

Method and system embodiments for operating a device implantable in a subject using ultrasonic waves are described. In some embodiments, a method is performed at the implantable device to receive ultrasonic waves including an operating mode command. Then, the implantable device sets an operating mode of the implantable device to one operating mode from a plurality of predetermined operating modes based on the operating mode command.