A 64-year-old man presents to the pacemaker clinic for routine assessment. He is asymptomatic:
Dual chamber pacemaker (as evidenced by two pacemaker spikes on 3rd QRS complex) with intermittent atrial undersensing
lead V1 is disconnected for first 2 seconds of recording
Poor R-wave progression and T-wave inversion in precordial leads suggests possible anterolateral infarct (see Comment)
Comment: In patients with intermittent ventricular pacing, the loss of ventricular pacing can occasionally cause the non-paced QRS complex to give the appearance of an anterolateral infarct because of cardiac memory.