I Have For Years, Had This Fluttering I Get In

i have for years, had this fluttering i get in my chest....sometimes i can feel the pulse speed up for usually 7 beats, slamming rapid and hard, then the rhythm goes back to a regular beat. this had been happening for 20 yrs. i'm 63 yrs, wgt 135, walk dog 2 miles/day, eat only organic, avoid all grains esp gluten due to diverticuliosis....i do not ever eat fast food, which is a poison to me. lately the fluttering has increased, but i've had a lot of crisis in the last 5 months (buried mother, then 4 days later found partner of 31 yrs dead in chair, ...2wks later dog diagnosed with cancer etc).......i expected more fluttering and i try yoga and meditation, but the fluttering is more pronounced and seems to be getting worse.... worth noting...i do not qualify for health care under the current system. i also worry about the 4 CT scans and the PET scan including 2 more CT scans for the nodule in my chest which is small.....since these tests(they told the DR to stop ordering these) i have been having sensations in my chest, like a tightness.....should i be taking something for the radiation,...? my health history includes my mother who died from type 1 diabetes complications and had a lot of heart attacks, until the last one which was massive, killed her finally.....thank you ,
roxanne