question: I saw a cardiologist today and when I walked fast on the treadmill the scan showed what the doctor called "laps" indicating my heart rate went faster while I was working harder.  I think I have been feeling more tired recently could this be the cause.  I will be 76 next month and in great health.  I will be getting an appointment to get a monitor and also a MPI test.  I'm interested in finding out more about this irregular heart beat.