Tag pacemaker failure

ECG Case 107

86 yr old male referred by his General Practitioner with worsening renal failure. Describe and interpret this ECG. LITFL Top 100 ECG
ECG-Exigency-LITFL-Clinical-Cases-340 2

Pacemaker Panic #2

An ECG case of pacemaker failure. Can you guess the underlying cause of the Pacemaker Panic?