away causes of heart disease
Thanks to ongoing medical research in many different areas, heart
disease could soon be no more than a distant memory writes Vicki
recent years a great deal of research has been going into the
causes, prevention and treatment of coronary heart disease.
With the mapping of the human genome, more is being discovered
about the genetic roots of coronary
heart disease. Scientists are trying to pinpoint which genes
are involved and which environmental factors cause these genes
to be activated. Itís already widely accepted that some genes
affect the way cholesterol and fat behave in the blood and so
predispose to heart attacks.
Identifying these genes will help some people with these
characteristics limit any risk by taking specially tailored
drugs. If these are prescribed to a patient already adopting a
lifestyle designed to lower cholesterol, the likelihood of a
healthy life is greatly increased. In future, gene therapy may
even be used to replace faulty genes and so prevent coronary
heart disease in those at risk.
Researchers are currently looking at specific risk factors
such as homocysteine and high blood pressure, and trying to
identify how they may increase the risk of coronary heart
disease in different populations.
In the area of transplantation, work is being undertaken to
improve immunosuppressant drugs that should make heart
transplants safer and more effective. Other researchis
directed towards engineering an artificial heart, a quest
which has been going on since the 1950s, so far with only
limited success. But the latest research means it is only a
matter of time before the search to construct an effective
artificial heart is successful, opening a new era for people
who need a new heart.
Current treatment for coronary heart disease varies depending
on age, the state of arteries, the severity of symptoms, and a
variety of other factors, but in many cases coronary heart
disease can be treated with drugs. In others, surgery or a
procedure to open up blocked blood vessels may be necessary.
Coronary angioplasty or percutaneous transluminal coronary
angioplasty (PTCA) is a procedure performed under local
anaesthetic and is commonly used to treat angina when
condition canít be controlled with drugs. It involves
squashing the fatty build up in a blocked artery and
stretching the artery walls so more blood and oxygen can flow
to the heart muscle.
Balloon angioplasty, or balloon treatment, was the first type
of angioplasty used. In it, the surgeon passes a fine hollow
tube or catheter, on the end of which is a small balloon, into
an artery in the groin or arm - and directs it under x-ray
guidance to the blocked artery. The balloon is inflated,
compressing the fatty build up against the artery walls. The
surgeon then lets down the balloon and removes it.
Another common type of angioplasty involves inserting a short
stainless steel mesh tube, a stent, at the same
time as the balloon. As the balloon deflates, the stent
expands and is left in place to help keep the artery open.
This method helps to prevent the problem of reblockage (restenosis)
which affects around a third of people following conventional
Doctors are also trying out a number of newer ways to perform
angioplasty using a variety of devices to cut or drill out
fatty deposits, vapourise them with a laser, or blast them
with ultrasound. However, as yet, these are not routinely
available in most areas.
Coronary bypass surgery or coronary artery bypass graft (CABG),
allows a blood vessel from another part of the body
to be grafted between the aorta and coronary artery or
arteries to bypass blockages and restore blood flow to the
heart. A bypass can be done on each of the four coronary
arteries and the operation can be done using conventional
surgical techniques or by microsurgery.
In recent years, an experimental technique known as
transmyocardial laser revascularistion (TMR) has also been
developed, which uses a laser beam to create channels in the
wall of the left ventricle allowing oxygenrich blood to flow
to the heart muscle.
In the past, heart transplants sometimes failed because the
immune system rejected the transplanted heart. However, with
the use of drugs to prevent rejection, heart transplants are
now extremely successful. Unfortunately a shortage of donors
means itís usually only recommended for those with advanced
heart disease where the heart muscle has become wakend (cardiomyopathy)
or the heartís blood vessels are blocked and the heart muscle
Apart from heart problems, the patient should be in good
health, under 60 and prepared to adapt to lifestyle changes
after the transplant. But most importantly, owing to the
limited number, all other treatments should have been tried or
Recovery time after any procedure depends on the type of
surgery and anaesthetic and what kind, age, and overall state
of health. Itís extremely important that patients are able to
attend a Cardiac Rehabilitation programme to ensure they reach
the optimum level of health and understand how to modify
lifestyles tominimise chances of future
A large range of drugs exist to treat and control the symptoms
of coronary heart disease or risk factors, such as angina or
high blood pressure. Most drugs fall into a handful of types
which act in similar ways.
ACE angiotensin converting enzyme-inhibitors are used to treat
heart failure and lower blood pressure, blocking the activity
of the hormone, angiotensin II, which narrows the blood
vessels, improving blood flow and decreasing the amount of
work for the heart. Anti-arrhythmic drugs control the rhythm
of the heart, but their effectiveness depends on keeping
exactly the right amount in the bloodstream.
Anticoagulants inhibit blood clotting, preventing fibrin from
forming. They are also used to treat deep vein thromboses and
to prevent these from travelling to the lungs where they may
cause a pulmonary embolism.
Aspirin and anti-platelets prevent blood clotting by reducing
the stickiness of platelets. They can reduce the risk heart
attacks or strokes, as well as for angina and to prevent blood
clotting following bypass surgery and other procedures.
Beta blockers prevent angina and lower high blood pressure.
They work by blocking the effects of stress hormones which
make the heart beat faster and more forcefully. They can also
be used to lower the risk of subsequent heart attacks and help
Calcium channel blockers or calcium antagonists can be used to
treat angina, reduce high blood pressure and work by reducing
the amount of calcium entering the arteriesí muscle cells.
This relaxes and widens the arteries, increasing the blood
flow to the heart and lowering blood pressure.
Lipid-lowering drugs reduce the levels of blood fats or
lipids. They may work by raising levels of HDL cholesterol
and/or lower circulating amounts of LDL cholesterol.
The main type are Ďstatins,í a group of cholesterollowering
drugs that can inhibit the action of an enzyme involved in
cholesterol synthesis to lower LDL cholesterol levels. They
are intended to be used in alongside lifestyle measures to
lower cholesterol, such as increasing physical activity,
giving up smoking and eating a low-fat diet
However, while lowering cholesterol does help to combat
cardio-vascular disease, some research suggests that statins
could also be carcinogenic. Diuretics work on the kidneys to
increase excretion of water in the urine. They are useful for
treating heart failure, which causes an excess of water to
accumulate in tissues, and to reduce blood pressure.
Nitrates relax the muscles in the walls of blood vessels,
reducing the workload of the heartís left ventricle. They are
used to treat angina and may be prescribed as sublingual
tablets, as an aerosol spray, as tablets, or as skin patches.
Potassium channel activators act to relax the walls of the
coronary arteries and improve blood flow, and are used to
Thrombolytic drugs can dramatically reduce any risk of a fatal
heart attack, and can help minimise the damage of a heart
attack. They work by breaking up clots, restoring blood flow
through the narrowed artery, and reducing damage to the heart
While this array of medication and medical procedures are
already widely available and are effective in minimising the
risks associated with heart disease, the medical profession
continues to try groundbreaking procedures and researchers are
continually looking for the one breakthrough that could
eventually mean cure for all.