I could write pages about this, but I'll just answer the question simple. The answer is YES! it's possible and very likely.
You can forget the "normal values" of 60-100 beats pr minute. They are just the definition on what is sinus rhythm, or if below; sinus bradycardia, and above, sinus tachycardia. When you exercise, it's "normal" to have a heart rate above 100, and if you rest or sleep, it's normal to have a heart rate below 60.