The coronary arteries are the heart’s own blood supply and they carry
the fuel and oxygen needed for its efficient working. When these arteries
are diseased, their lining becomes thickened by fatty and other materials, so
that the flow of blood may be reduced, especially when the heart has to work
harder during exercise or excitement. When this happens, chest pain called
angina may result. If there is a more complete obstruction and a prolonged
reduction of blood flow, part of the heart muscle becomes injured or
damaged. This is what occurs in a coronary heart attack.
Facts
1. Coronary heart disease is the leading cause of premature death in
this country (89,000 in 1984) and smoking contributes to a large proportion
of these deaths.
2. The risk of a heart attack rises with the amount smoked. In general,
people who smoke cigarettes have about twice the risk of a heart attack than
those who do not. However, this increased risk is particularly large in
smokers aged under about 50, their heart attack death rates are up to ten
times greater than those for non-smokers of the same age.
3. You are more likely to have heart attack not only if you smoke
cigarettes, but also if you have raised blood pressure, raised blood
cholesterol levels or take little exercise. Being male, getting older or having
parents with heart disease also increase the risk of heart attacks and these
risks you cannot alter. The factors you can control are even more important
if you have risks which you cannot affect.
4. People who have always been pipe or cigar smokers have a smaller
increased risk of heart attacks, probably because they do not inhale; but cigarette smokers who change to pipes or cigars usually continue to inhale
and as a result they may not reduce their risk.
5. Carbon monoxide and nicotine are probably the most important
substances in tobacco smoke which affect the heart, Nicotine stimulates the
body to produce adrenaline which makes the heart-beat faster and raises the
blood pressure. Carbon monoxide joins on to the red pigment of the blood,
called haemoglobin, and reduces its power to carry oxygen to the heart and
all other parts of the body. Both nicotine and carbon monoxide may
encourage thrombosis (blood clotting).
6. Cigarette smoking is a very important cause of diseases of the leg
arteries which lead to pains in the leg on walking (intermittent claudication).
This condition is very rare in non-smokers. It may lead to loss of a leg by
amputation; but this rarely occurs in those who have stopped smoking.
7. There is no evidence that filter cigarettes are less dangerous than
plain cigarettes and they may even increase the amount of carbon monoxide
inhaled and thus be more harmful to the heart. Smokers who change to low
tar/nicotine cigarettes in the belief that they may be less dangerous tend to
inhale more deeply.
8. Passive or involuntary smoking is when non-smokers inhale other
people’s smoke. This often causes smarting of the eyes, a sore throat or
headaches and it may carry an increased risk of lung cancer. Heavy passive
smoking may be harmful to those who suffer angina or heart disease and
exposure should be avoided as far as possible.
For these reasons, it is especially important that anyone who has
angina, who has had a heart attack, has disease of the leg arteries or raised
blood pressure should stop smoking. It is particularly important for those
who have just had a heart attack as, by doing so, this will halve their risk of
another attack, which could be fatal.