A 75-year-old woman is on the cardiac surgery ward two days after coronary artery bypass surgery:

• Atrial fibrillation with a junctional  escape rhythm (rate 46/min). Consider the possibility of complete heart block.
• Septal infarction, age undetermined
• T wave abnormality, possible anterior ischemia

Digoxin was stopped, and the serum digoxin level was checked to rule out digitalis toxicity, however it was within desirable therapeutic levels. The patient was monitored, and the following ECG was obtained two days later:

• Sinus rhythm, 91/min
• Complete heart block, with escape junctional rhythm, 46/min
• Poor R wave progression from V1 to V3, consider septal infarction
• Non-specific T wave abnormality

A therapeutic procedure was performed, and the following ECG was obtained:

• DDD pacemaker (Atrial sensed, ventricular paced)
• Sinus tachycardia, 100/min
• Ventricular paced rhythm