Final answer:
The abnormal ECG finding that can be normal for an athlete like Sam without symptoms is a heart rate of 42 bpm, a condition known as athletic bradycardia.
Step-by-step explanation:
The nurse observes an abnormal finding on Sam's ECG that can be normal in the absence of symptoms. When considering the options provided, a heart rate of 42 beats per minute (bpm) is likely the abnormal finding that can be considered normal, especially in a retired professional athlete like Sam. Trained athletes typically exhibit lower resting heart rates due to increased cardiac efficiency and vagal tone. This condition is known as athletic bradycardia and is not typically a cause for concern unless accompanied by symptoms like dizziness or fainting.