Have you had any other testing done? For some, a slower heart rate isn't a concern, and it would depend on your history, etc. Have you always had a slower heart rate?
Is it your primary care doctor that isn't worried? Have you asked to see a cardiologist?
This can absolutely be abnormal. It can also be normal. Do you faint? Do you feel like you’re about to faint? Under what conditions do you faint if applicable.
It's worth noting resting heart rate decreases with age.