Pacemaker Malfunction

HPI:
90 y/o woman h/o sick sinus syndrome, AF, and a pacemaker presents with atypical CP.  Troponins are negative, CTPA is negative for PE.  She denies palpitations, shock-like sensations, or chest wall contractions. Palpated HR corresponds with QRS complexes on the monitor.

EKG:

Question:
What's going on with this pacemaker? Is the malfunction the cause of her symptoms?