Implantable medical device for detecting atrial undersensing

Computer program product comprising computer-readable code that causes a processor to perform the following step when executed on the processor:

• evaluation of atrial events in an atrial electric signal detected by a first detection unit and/or ventricular events in a ventricular electric signal detected by the second detection unit of an implantable medical device for recognizing a condition of the implantable medical device in which atrial events in the atrial electric signal are detected only insufficiently, wherein the evaluation is carried out on the basis of at least one of the following criteria:
• i) morphology of the detected atrial electric signal,
• ii) lacking stability of atrial events,
• iii) absence of atrial events over a first period of time,
• iv) detection of an amplitude of the detected atrial electric signal being lower than a predefined threshold value,
• v) absence of atrial events during detection of ventricular events at the same time, and
• vi) comparison of atrial electric signals sensed with a first sensing profile of the first detection unit and atrial events sensed with a second sensing profile of the first detection unit, the second sensing profile being more sensitive than the first sensing profile.

Method of treatment of a human or animal patient in need of such treatment by means of an implantable medical device, wherein the implantable medical device comprises a processor, a memory unit, a first detection unit configured to detect an atrial electric signal of a human or animal heart, a second detection unit configured to detect a ventricular electric signal of the same heart, and a stimulation unit configured to stimulate a cardiac region of the same heart, the method comprising the following steps:

• evaluation of atrial events in the atrial electric signal detected by the first detection unit and/or ventricular events in the ventricular electric signal detected by the second detection unit for recognizing a condition of the implantable medical device in which atrial electric signals are detected only insufficiently, wherein the evaluation is carried out on the basis of at least one of the following criteria:
• i) morphology of the detected atrial electric signal,
• ii) lacking stability of atrial events,
• iii) absence of atrial events over a first period of time,
• iv) detection of an amplitude of the detected atrial electric signal being lower than a predefined threshold value,
• v) absence of atrial events during detection of ventricular electric signals at the same time, and
• vi) comparison of atrial events sensed with a first sensing profile of the first detection unit and atrial events sensed with a second sensing profile of the first detection unit, the second sensing profile being more sensitive than the first sensing profile,
• automatically adjusting a detection mode of the first detection unit if a condition of the implantable medical device has been recognized in which atrial events are only insufficiently detected, and
• stimulating a cardiac region of the of the human or animal heart by applying a stimulation pulse with the stimulation unit if such stimulation is deemed to be necessary upon an evaluation of a cardiac rhythm of the human or animal heart in the adjusted detection mode.