An apparatus comprises a stimulus circuit, a cardiac signal sensing circuit, and a control circuit. The stimulus circuit provides electrical pulse energy to a first pacing channel that includes a first left ventricular (LV) electrode as a cathode and a second pacing channel that includes a second LV electrode as a cathode. The cardiac signal sensing circuit senses cardiac signals using a first sensing channel that includes one of the first LV electrode or the second LV electrode. The control circuit includes a capture detection sub-circuit configured to: initiate delivery of electrical pulse energy to both the first pacing channel and the second pacing channel; sense cardiac depolarization of a ventricle using the first sensing channel; determine first and second cardiac capture pulse energy level thresholds for the first and second pacing channels respectively; and provide indications of the cardiac capture pulse energy level thresholds to a user or process.

Generally, the disclosure is directed one or more methods or systems of cardiac pacing employing a plurality of left ventricular electrodes. Pacing using a first one of the left ventricular electrodes and measuring activation times at other ones of the left and right ventricular electrodes. Pacing using a second one of the ventricular electrodes and measuring activation times at other ones of the left ventricular electrodes. Employing weighted sums of the measured activation times to measure a fusion index and select one of the left ventricular electrodes for delivery of subsequent pacing pulses based on comparing fusion indices during pacing from different LV electrodes. One or more embodiments use the same fusion index to select an optimal A-V delay by comparing fusion indices during pacing with different A-V delays at resting atrial rates as well as rates above the resting rate.

The invention relates to a device incorporating an endocardial acceleration (EA) sensor. A capture test circuit of the device collects a sampled EA signal and extracts a limited series of EA measurements during a duration of a predetermined temporal window opened after delivery of a pacing pulse. An indicator value based on an average of absolute values of successive EA measurements of the series of EA measurements is calculated at an end of the temporal window. The indicator value is compared to a predetermined discrimination threshold to determine the presence or absence of a capture according to whether the indicator value lies above or below the predetermined discrimination threshold. The indicator value is very robust to noise and particularly efficient in terms of computing, which reduces, in large proportions, consumption of the digital processor and thus of the capsule.

Techniques for delivering genetic material to a target tissue site of a patient via a leadless implantable medical device that includes a pump and a stimulation energy delivery element are described. In some examples, delivery of genetic material to the target tissue site causes transgene expression of tissue at the target tissue site, which may result in generation of new cells or modified properties of existing cells of the target tissue site, facilitating more effective and efficient treatment of a disorder of the patient.

In a medical device system, a computer apparatus is configured to receive body surface electrical signals from an electrode apparatus including multiple external electrodes. The computing apparatus generates electrical dyssynchrony data from the body surface electrical signals during delivery of His bundle pacing pulses and identifies effective His bundle capture based on the electrical dyssynchrony data. The computing apparatus generates an indication of His bundle capture in response to identifying the effective His bundle capture.

A computer implemented method and system for monitoring types of capture within a distributed implantable system having a leadless implantable medical device (LIMD) to be implanted entirely within a local chamber of the heart and having a subcutaneous implantable medical device (SIMD) to be located proximate the heart are provided. The method is under control of one or more processors of the SIMD configured with program instructions. The method collects far field (FF) evoked cardiac signals following the pacing pulses delivered by the LIMD for an event and analyzes the FF evoked cardiac signals to identify a type of HIS capture as loss of capture (LOC), selective capture, myocardial tissue-only (MT-only) capture, or a non-selective (NS) capture and records a label for the event based on the type of HIS capture identified.

A medical device comprises therapy delivery circuitry and processing circuitry. The therapy delivery circuitry is configured to deliver anti-tachycardia pacing (ATP) therapy to a heart of a patient. The ATP therapy includes one or more pulse trains and each of the one or more pulse trains includes a plurality of pacing pulses. The processing circuitry is configured to, for at least one of the plurality of pacing pulses of at least one of the one or more pulse trains, determine at least one latency metric of an evoked response of the heart to the pacing pulse. The processing circuitry is further configured to modify the ATP therapy based on the at least one latency metric.

According to various method embodiments, a person is indicated for a therapy to treat a cardiovascular disease, and the therapy is delivered to the person to treat the cardiovascular disease. Delivering the therapy includes delivering a vagal stimulation therapy (VST) to a vagus nerve of the person at a therapeutically-effective intensity for the cardiovascular disease that is below an upper boundary at which upper boundary the VST would lower an intrinsic heart rate during the VST.

Energy delivered from an implantable medical device to stimulate tissue within a patient's body is controlled. An electrical signal used to stimulate the tissue is changed from a first energy state to a second energy state during a magnetic resonance imaging (MRI) scan. The energy delivered is maintained at the second energy state after the MRI scan. A capture threshold of the tissue is then measured, and the energy delivered to the tissue is adjusted based on the measured capture threshold of the tissue.

A medical device and medical device system for delivering left ventricular pacing that includes a subcutaneous sensing device having a subcutaneous electrode to sense a subcutaneous cardiac signal and an emitting device to emit a trigger signal in response to the sensed cardiac signal, an intracardiac therapy delivery device to deliver the left ventricular pacing in response to the emitted trigger signal, and a processor configured to determine whether the medical device system is in one of a VVD pacing mode and a VVI pacing mode, determine whether the delivered left ventricular pacing captures the left ventricle, determine whether to adjust a pacing parameter in response to the determination of whether the device system is in one of a VVD pacing mode and a VVI pacing mode and the determination of whether the delivered left ventricular pacing captures the left ventricle, and deliver the left ventricular pacing in response to determining whether to adjust the pacing parameter.