A method and system for use with an implantable medical device for subcutaneous implant within a patient to determine a likelihood of the patient experiencing a cardiac event that includes sensing a cardiac signal along a plurality of different sensing vectors, determining state information of each vector of the plurality of sensing vectors, determining a cross correlation of the determined state information of each vector of the plurality of sensing vectors, comparing the cross correlation of the determined state information of each vector of the plurality of sensing vectors to a threshold, and detecting the cardiac event in response to the comparing.

Systems, devices, and techniques that enable medical devices to integrate and interoperate with one another are provided. In some examples, a wearable cardiac defibrillator (WCD) advantageously interoperates with an implanted pacemaker to provide a variety of benefits. For instance, in some examples, the WCD oversees execution of an antitachycardia (ATP) protocol by the implanted pacemaker and intervenes as needed. In other examples, the WCD drives an ATP protocol in which internal pacing pulses are provided by the implanted pacemaker under the control of the WCD. In other examples, the WCD monitors the activity of the implanted pacemaker to identify potential maintenance issues affecting the implanted pacemaker. The WCD and the implanted pacemaker may also interoperate to classify and act upon particular arrhythmia conditions.

An implantable system for stimulating a human/animal heart, comprising a processor, a memory unit, a stimulation unit for stimulating a His bundle of a human/animal heart, and a detection unit for detecting an electrical signal of the heart. The memory unit includes a computer-readable program that prompts the processor to perform the following steps when the program is executed on the processor: a) detecting by way of the detection unit whether a tachycardia is present in a human/animal heart; and b) when a tachycardia is present, carrying out a His bundle stimulation by way of the stimulation unit using at least one stimulation pulse having an amplitude in a range of 7.5 V to 30 V, and having a pulse width in a range of 1 ms to 15 ms. The program prompts the processor to classify a detected tachycardia into one of at least two classes.

A computer implemented method for detecting pocket stability for an implantable cardiac monitor, including under control of one or more processors in the ICM, collecting impedance data over at least one cardiac cycle. The impedance data is processed to separate an impedance waveform that varies over the at least one cardiac cycle in a manner representative of cardiac functionality over the at least one cardiac cycle. A characteristic of interest is analyzed from the impedance waveform over the at least one cardiac cycle. A pocket stability state of the ICM is identified and recorded based on the analyzing operation.

Systems and methods for detecting an arrhythmic event and storing physiological information associated with the detected arrhythmic event are described. A system may include a first detector to detect an arrhythmic event from a physiological signal sensed from a subject, and generate a confidence indicator indicating a confidence level of the detection of the arrhythmic event. If the confidence indicator indicates a relatively high confidence of arrhythmia detection, the system may provide the detected arrhythmic event to a first process for storing the detected arrhythmic event or generating an alert. If the confidence indicator indicates a relatively low confidence of arrhythmia detection, the system may provide the detected arrhythmic event to at least a second process including confirming or rejecting the detected arrhythmic event.

A pacemaker has a housing and a therapy delivery circuit enclosed by the housing for generating pacing pulses for delivery to a patient's heart. An electrically insulative distal member is coupled directly to the housing and at least one non-tissue piercing cathode electrode is coupled directly to the insulative distal member. A tissue piercing electrode extends away from the housing.

An implantable system for stimulating a human/animal heart, comprising a processor, a memory unit, a stimulation unit for stimulating a His bundle of a heart, and a detection unit for detecting an electrical signal of the heart. The memory unit includes a computer-readable program prompting the processor to perform the following steps when the program is executed on the processor: a) carrying out a cardiac stimulation via the stimulation unit; b) detecting a cardiac electrical signal, which was generated by a cardiac excitation as a result of the cardiac stimulation carried out beforehand, via the detection unit; c) ascertaining an excitation state of a heart stimulated by the cardiac stimulation based on the electrical signal; d) classifying the excitation state into one of at least three classes; and e) automatically adapting at least one control parameter of the system as a function of the classification that was carried out.

A medical device is configured to generate an acceleration signal and a temperature signal. The device is configured to determine an activity metric from the acceleration signal that is representative of patient physical activity. In response to determining that the activity metric is equal to or greater than a previously determined activity metric, the device is configured to adjust a target cardiac pacing rate based at least on a temperature change determined from the temperature signal. The device may include a pulse generator for generating cardiac pacing pulses based on the target cardiac pacing rate.

A method of controlling discomfort of a patient during external pacing by an external medical device includes detecting a cardiac condition of the patient; receiving, via a user interface, discomfort information descriptive of the discomfort experienced by the patient; determining from the discomfort information whether the patient is conscious or unconscious; responsive to determining from the discomfort information that the patient is unconscious, executing, via at least one therapy electrode disposed on the patient, at least one pacing routine, the at least one pacing routine being associated with the cardiac condition; and responsive to determining from the discomfort information that the patient is conscious, adjusting at least one characteristic of the at least one pacing routine.

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 an R-wave of the cardiac signal and determine a previous RR interval of the cardiac signal and a current RR interval of the cardiac signal based on the determined R-wave. The processing circuitry is further configured to determine a search window based on one or more of the current RR interval or the previous RR interval, determine a T-wave of the cardiac signal in the search window, and determine a QT interval based on the determined T-wave and the determined R-wave.