ANGINA - a patient's guide
Dr Guy Armstrong - Cardiologist
What is angina? (other names, angina pectoris, effort
The heart, like other organs, requires blood to supply it with
oxygen and other nutrients. Blood vessels called arteries carry blood
from the pumping chamber of the heart around the body. The arteries
supplying blood to the heart are the coronary arteries.
A process named 'atherosclerosis' causes damage and narrowing to
the arteries, limiting the amount of blood flow. When this occurs in
the coronary arteries ("coronary artery disease" or CAD for short),
it may cause angina. Usually angina is brought on by physical
exertion, which increases the blood required by the heart. If the
arterial narrowings are severe enough, angina may be brought on by
minimal exertion, emotion or even when resting (unstable angina).
Usually at least a 70% narrowing of an artery is needed to cause
Men are at greater risk, increasing age, high blood levels of
cholesterol, smoking, high blood pressure, diabetes, obesity, stress
and family history of ischaemic heart disease (angina or myocardial
Some people are predisposed to developing coronary disease despite
lacking any of the accepted risk factors. The reason for this is
uncertain, but these people may have as yet unrecognised risk
factors. Possibilities currently under investigation include
lipoprotein (a), homocysteine, ferritin, inflammation (caused by
infection with a micro-organism Chlamydia pneumoniae) and cholesterol
Premenopausal women have a lower risk of angina than men, probably
due to the favourable effect of natural oestrogen on the blood lipid
profile. After menopause this advantage is lost and the female risk
of CAD rapidly approaches that of men of similar age.
What symptoms may I expect?
Angina is typically is brought on by exercise and is a sensation
of tightness or pressure behind your breast bone (sternum). It may
also be felt in the arm, between the shoulder blades, neck or jaw.
Resting relieves it as does medicine (GTN or anginine) placed under
the tongue. Other activities that can trigger angina include large
meals, becoming excited, or walking into a cold head wind.
What will the doctor look for?
The key feature of angina is that it is usually brought on by
increased heart rate with exercise and relieved by rest when the
heart slows down.
Indigestion (peptic disease or acid reflux) can also mimic angina
but is not typically brought on by exertion.
Causes of chest discomfort that may be difficult to distinguish
from angina include rupture of the aorta (the main artery
distributing blood from the heart to various parts of the body). In
this case the chest pain is usually severe and sudden onset. It is
often felt through to between the shoulder blades as well as in the
front of the chest.
What investigations will the doctor consider?
Tests & shortcomings
Your doctor will probably ask for an exercise electrocardiograph
(treadmill test), where your heart rhythm is recorded before and
after walking on a treadmill. This gives an indication whether
significant coronary artery narrowings are present.
If your performance on the treadmill is not satisfactory, your
doctor may suggest an angiogram. You are lightly sedated for this
test which involves passing a thin tube, via a nick in the groin, up
near the heart and into the coronary arteries. Dye is then injected
to take x-ray pictures of any narrowings and blockages in your
What treatment options are available?
All the lifestyle measures will help lessen your angina symptoms
and also decrease your risk of having a heart attack:
You must give up smoking. Happily, your risk of a heart attack
drops down to the level of a lifelong non-smoker within 2-5 years of
you giving up.
Losing weight will directly improve your angina. It will also help
reduce your cholesterol level.
A dietician should be consulted to try to help achieve a low fat
weight-loss diet. Support and motivation are needed.
Getting fit by regular exercise (do 30 minutes of aerobic exercise
such as walking at least three times a week).
Cholesterol, blood pressure and diabetes need to be
You should avoid heavy lifting. Tasks that bring on angina should
be attempted more slowly.
When the coronary artery wall is damaged by atherosclerosis, clots
may form, blocking the artery completely and causing a heart attack.
Aspirin thins the blood and helps prevent heart attacks. The usual
dose is 75-325 mg each day. Side effects are uncommon but it may
cause stomach irritation or bleeding. The benefits usually far
outweigh the risks, but you should always discuss starting aspirin
with your doctor.
Glyceryl trinitrate (GTN) is taken under the tongue as a pill or a
spray. It works in minutes to relax blood vessels and decrease the
heart's workload. It can also be taken before doing activities that
cause angina, to prevent an attack. The main side effect is headache.
It may also drop your blood pressure, causing you to feel faint (if
so you should sit or lie down promptly). If the angina is not
relieved by GTN within 20 minutes you should call an ambulance (check
this with your doctor).
Beta-blockers relieve angina by slowing the heart and making it
pump less forcefully. They allow you to do more physical activity
before getting angina. People with asthma should not take
beta-blockers. Possible side effects include tiredness and sleep
Long-acting nitrates' effectiveness are reduced if your body is
exposed to them constantly. Therefore they are usually taken as a
once-a-day tablet or a skin-patch applied for only 16 hours each day.
They relieve angina. A possible side-effect is headache.
These also relieve angina, allowing you to be more active. They
work by relaxing the arteries the heart to pump more efficiently.
Possible side-effects include headaches, ankle swelling and
Surgery or other intervention
If your angina is not satisfactorily controlled through medicines
and lifestyle changes, your symptoms may be improved by mechanically
unblocking a narrowed artery (angioplasty) or bypassing the blockage
Angioplasty (percutanous transluminal angioplasty,
This procedure is similar to an angiogram. It is done by passing
thin tubes up from the groin whilst you are lightly sedated. A tiny
balloon is passed down the narrowed vessel and inflated to clear the
blockage. Usually you can leave hospital the following day, however
over the next six months there is a significant chance the opened
artery will close again (approximately 30 percent risk).
Increasingly, stents (little tubes), may be blown up and left in
the artery to reduce the risk of re-occlusion occurring.
Different drugs are also being researched, which may reduce the
risks of occlusions reoccurring.
Cardiac surgery (coronary artery bypass grafting, CABG)
This is open heart surgery where the narrowed and blocked arteries
are bypassed with other vessels. You will be in hospital for about
one week. It takes some weeks for the chest scar to heal and full
recovery to occur.
Angina needs to be taken seriously because it can lead to a heart
attack (myocardial infarction) where some of the heart muscle dies.
However, we now have very powerful medicines that substantially
reduce the risk of this happening (aspirin and statins).
Controversies and uncertainties
It is not known whether hormonal replacement therapy for women
will reduce the risk of CAD. The current studies are
Elevated homocysteine levels can be reduced by taking folate
(sometimes together with vitamin B12 and B6). Whether this reduces
the risk of CAD is not known yet.
Vitamins A and C have no role in reducing CAD, they may even
increase the risk of CAD. Vitamin E may reduce the risk of heart
attack but there still exists some concern over whether it may be
harmful. Three further studies are pending.
Your doctor, cardiologist or local hospital will be able to
The National Heart Foundation of New Zealand, 9 Katrina St,
Ellerslie, PO Box 17160, Greenlane Auckland. Ph 571 9191.
Dr Guy Armstrong
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