I Am A Healthy 33 Year Old Female (healthy Weight,

I am a healthy 33 year old female (healthy weight, exercise, very little caffeine, do not smoke, eat healthy, etc.) who began waking in the early morning ( usually between 4:00 and 7:00) with what felt like an adrenaline rush. Some mornings I would wake and simply feel shaky. I have also had an increase in my resting heart rate. I finally made an appointment with the doctor after one morning of in my sleep feeling two stronger beats followed by a pause and then a very strong almost electric like heart beat that put me into what would be described as a panic attack, though I had never had one before. The cardiologist had me do an EKG, echo, and wear a monitor for a week. The EKG and echo came back normal apart from some slightly leaky valves which he wasn't concerned about. The monitor had recorded two pvc runs, one which was five beats long, one which was six beats long. He prescribed for me a low dose beta blocker which he said would slow down my heart rate and hopefully prevent these pvc episodes. I have not begun taking it as I am unsure it is necessary. The early morning adrenaline / shakiness has been going on for over six months now. I am not anxious about it although I would like to address any underlying causes. My magnesium showed up .1 under the normal range. Could such a minor difference cause these pvc runs? Also, although I am not experiencing anxiety now, I did go through a prolonged time of stress and anxiety for about a year just preceding the onset of this early morning adrenaline. Could that have been a trigger? Should I take the medication because of the length of the pvcs (5 and 6 beats long) even though they are not very frequent? Thank you for your time.