if my father had a heart attack due to cigarette smoking and my grandfather had a few due to cigar smoking and unhealthydoes this mean they would be diagnossed with heart disease and now it would be heritary onto me even though l dont smoke and live a healthy lifestyle

No. Lifestyle health issues r not passed on to the next generation - unless they choose the same lifestyle. So the fact that ur father & ur grandfather smoked would not affect u - but the fact that they both had heart attacks might mean there was a weakness there that could be inherited. There is not a 100% correlation between smoking & heart attacks. Some people who never smoke still have heart attacks, & some people who smoke do not have heart attacks. So there could be underlying causes that were exaceebated by smoking. But good for u for making sure u remove as many unhealthy issues from ur life as possible.

It has not yet been established that Heart attack is hereditary. You may forget about the matter and be relaxed.

Yes, u need to be 'screeened' for gentic tendencies to heart disease. The 'smoking' did not CAUSE the heart attacks in either ur father or grandfather . it only 'contributed' to them. Because u do not smoke & live a healthy lifestyle u should have less chance of having a heart attack, but not as much less as u think . if there is any 'smog' in the air in ur city, if u live in an area where there r a lot of cars running, ur 'chances' of having a heart attack r actually HIGHER than those of ur fahter & grandfather . so GET CHECKED & do what the doctor tells you. And one other thing . cholesterol. Bad cholesterol is involved in 85% of heart attacks . those 'blood clots' that r formed r made up mostly of 'cholesterol' & since u know of at least two generations with heart disease u NEED TO HAVE YOUR CHOLESTEROL CHECKED. Get it done now, & have it done AT LEAST every six months, & FOLLOW YOUR DOCTOR'S DIRECTIONS if u want to live that 'healthy lifestyle' until u r very old.