I Am 62 Yrs.old And In Stage 4 COPD, But

I am 62 yrs.old and in stage 4 COPD, but in the last month when I am just sitting and am calm sometimes my pulse rate will jump to 180 and I get very light headed feeling like I might pass out. My blood pressure is always pretty good when I check it .I feel like my heart is pounding when this is happening.