A leadless pacing device may include a housing having a proximal end and a distal end, and one or more electrodes supported by the housing. The housing may include a body portion and a header. A distal extension may extend distally from the header of the housing, the distal extension including one or more electrodes. The header may include a guide wire port and a guide wire lumen may extend from the guide wire port through the header of the housing and through the distal extension. A fixation member may extend from the header of the housing. The header may be formed from an over mold process.

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.

Techniques are disclosed for using feature delineation to reduce the impact of machine learning cardiac arrythmia detection on power consumption of medical devices. In one example, a medical device performs feature-based delineation of cardiac electrogram data sensed from a patient to obtain cardiac features indicative of an episode of arrythmia in the patient. The medical device determines whether the cardiac features satisfy threshold criteria for application of a machine learning model for verifying the feature-based delineation of the cardiac electrogram data. In response to determining that the cardiac features satisfy the threshold criteria, the medical device applies the machine learning model to the sensed cardiac electrogram data to verify that the episode of arrhythmia has occurred or determine a classification of the episode of arrythmia.

Systems, methods and devices for delivering stimulating energy with a lead are disclosed. One method includes inserting a lead for cardiac therapy into an intercostal space of a patient and proximate to a lateral margin of the patient's sternum (the lead having a distal end configured to transmit therapeutic electrical pulses from a pulse generator to the heart), advancing the distal end of the lead through the intercostal space, and coupling a proximal end of the lead to the pulse generator for delivery of therapeutic electrical pulses for pacing or defibrillation of the heart.

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.

An implantable medical device is configured to control a therapy module to couple a capacitor array comprising a plurality of capacitors to a plurality of extra-cardiovascular electrodes and control the therapy module to deliver a composite pacing pulse to a patient's heart via the plurality of extra-cardiovascular electrodes by sequentially discharging at least a portion of the plurality capacitors to produce a series of at least two individual pulses that define the composite pacing pulse.

An implantable medical device system capable of sensing cardiac electrical signals includes a sensing circuit, a therapy delivery circuit and a control circuit. The sensing circuit is configured to receive a cardiac electrical signal and sense a cardiac event in response to the signal crossing a cardiac event sensing threshold. The therapy delivery circuit is configured to deliver an electrical stimulation therapy to a patient's heart via the electrodes coupled to the implantable medical device. The control circuit is configured to control the sensing circuit to set a starting value of the cardiac event sensing threshold and hold the starting value constant for a sense delay interval. The control circuit is further configured to detect an arrhythmia based on cardiac events sensed by the sensing circuit and control the therapy delivery circuit to deliver the electrical stimulation therapy in response to detecting the arrhythmia.

A medical device that includes a power source, a therapy delivery interface, therapy electrodes, electrocardiogram (ECG) sensing electrodes to sense ECG signal of a heart of a patient, a sensor interface to receive and digitize the ECG signal, and a processor. The processor is configured to analyze the ECG signal to determine a cardiac rhythm and a transform value representing a magnitude of a frequency component of the cardiac rhythm, analyze the cardiac rhythm and the transform value to detect a shockable cardiac arrhythmia by classifying the cardiac rhythm as a noise rhythm or a shockable cardiac arrhythmia rhythm based on the transform value, and causing the processor to detect the cardiac arrhythmia if classifying the cardiac rhythm as a shockable cardiac arrhythmia rhythm, initiate a treatment alarm sequence, adjust the shock delivery parameter for a defibrillation shock, and provide the defibrillation shock via the therapy electrodes.

A cardiac net with at least one electrode enhances the pacing effect on a ventricle. The cardiac net with at least one electrode includes non-conductive portions formed by weaving non-conductive or conductive thread, defibrillation electrodes, and pacing electrodes, which are connected to one another. The defibrillation electrodes are configured to cover the circumference of the heart substantially horizontally, and are placed on an upper side and a lower side of the heart. The pacing electrodes are placed between the defibrillation electrodes and used for sensing the motions of the heart and pacing the ventricle. The pacing electrodes are configured to cover the circumference of the heart substantially horizontally so as to overlay the center of a spiral wave reentry. This configuration allows excitatory stimulus to be applied to the heart from the circumference thereof, thereby enabling the pacing electrodes to perform effective pacing.

A subcutaneously implantable device includes a housing, a clip attached to the housing, a prong, and an electrode. The clip is configured to anchor the device to a muscle, a bone, and/or a first tissue. The prong has a base portion attached to the housing, an arm portion extending from the base portion so as to define a first plane that includes opposite ends of the arm portion of the prong and is perpendicular to a horizontal plane of the housing, and a contact portion that is configured to contact an organ, a nerve, the first tissue, and/or a second tissue. The contact portion is angled away from the first plane. The electrode is at the contact portion of the prong. The electrode is configured to contact the organ, the nerve, the first tissue, and/or a second tissue. Circuitry in the housing is in electrical communication with the electrode and is configured to provide monitoring, therapeutic, and/or diagnostic capabilities with respect to the organ, the nerve, the first tissue, and/or the second tissue.