I Am A 55 Year Old Woman, 5'9", 165 Pounds.

I am a 55 year old woman, 5'9", 165 pounds. I have always had rather low BP and heart rate (120/65 and 55-60), but recently I've been averaging a BP of about 135/85 and my heart rate goes as high as 125 without physical stress. These changes seem to have started suddenly a few months ago. During these times I also feel "shaky". I also occasionally feel as though I can't catch my breath and that my lungs are being squeezed. My mother began suffering from high BP about my age, and my father had a heart attack at 64. Should I be worried about heart problems, or is there something else I should look into?