I run out of breath very quickly by just walking up a mild grade or walking at a faster pace. I have been on Tikosyn since the end of may. I am in sinus rhythm at all times. I had a stress test today and after my heart rate went over 115 it dropped to 59(took less than 2 minutes) and I was totally out of breath. According to the cardiogram I developed a 2 to 1 AV block. I see my regular cardiologist next week.