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)