An 82-year-old woman is in the cardiac ICU after replacement of her aortic valve due to severe aortic stenosis:

• Sinus rhythm with complete heart block
• Escape rhythm has wide QRS with ventricular rate 66/min (likely junctional rhythm with non-specific intraventricular block)

An electronic ventricular pacemaker is implanted, and the following ECG is recorded four days later:

• Sinus rhythm with second degree AV block and ventricular paced complexes (VVI pacing)
  
• Ventricular rate 69/min
• The A-V conducted QRS complexes have a left bundle branch block pattern