I guess you have Xeralto for atrial fibrillation. The heart rate is hard to count in AF patient. Heart beat interval is used to evaluate the heart beat. You should be concered when your heart beat interval is longer than 3 seconds. My sugguestion is to follow up at the doctor who give you Xeralto. Holter is recommended.
If you do have long heart beat intervals you'll need a pacemaker. Let's take the tests first.