25/09/2026
A 72-year-old man who is known to have had a cardiac pacemaker inserted some years ago is admitted for
overnight monitoring to the Medical Admissions Ward following a collapse at home. He suffers a vacant
period while being monitored and the rhythm strip is shown below:
Which of the following most accurately describes what is shown on the rhythm strip?
A. Failure of atrial capture
B. Failure of atrial inhibition
C. Failure of ventricular capture
D. Retrograde atrial activation
E. Ventricular undersensing