Copyright 2003 Times Newspapers Limited
The Times (London)

November 3, 2003, Monday

SECTION: Features; Hospital Consultants Guide 8

LENGTH: 1443 words

HEADLINE: Conditions: Cardiomyopathy

BODY:


THIS IS the term used to describe any disease which affects the heart
muscle.

There are four main forms - dilated cardiomyopathy (DCM), hypertrophic
cardiomyopathy (HCM), arrhythmogenic right ventricular cardiomyopathy (ARVC) and
restrictive cardiomyopathy (RCM).

Dilated cardiomyopathy: The heart becomes enlarged and pumps less strongly.
The heart muscle becomes weak, thin or floppy and is unable to pump blood
efficiently, leading to heart failure (see page 6). The condition is often
genetic and is diagnosed when other causes of heart failure, such as coronary
artery disease, hypertension and valve disease, have been excluded.

Hypertrophic cardiomyopathy: This is characterised by an excessive
thickening of the heart muscle. The cardiac muscle cells are usually aligned in
parallel lines but here the cells become disorganised. These changes in the
structure of the heart may cause rhythm disturbances and sudden death.

Arrhythmogenic right ventricular cardiomyopathy: The heart muscle is
replaced by fibrous scar and fatty tissue. This is patchy in distribution, so
abnormal areas may be surrounded by normal ones. The right ventricle (lower
heart chamber) tends to be most affected. It is thought that abnormal genes lead
to heart muscle degeneration and that fibrous and fatty tissue replaces these
heart muscle cells in an attempt by the body to repair the damage. The
disorganised structure leads to abnormal electrical activity which causes rhythm
disturbances and sudden death.

Restrictive cardiomyopathy: This occurs when the walls of the ventricles are
stiff and prevent the normal filling with blood. The causes are unknown,
although it can be secondary to rare metabolic disorders.

Most cardiomyopathies are inherited - if either parent is affected you have
a 50 per cent chance of inheriting the abnormal gene implicated. "It used to be
thought that dilated cardiomyopathy could be caused by pregnancy and excessive
alcohol intake, but now it is recognised that putting extra stress on the heart
unmasks the underlying genetic defect," explains Bill McKenna, professor of
cardiology at the Heart Hospital, London.

Symptoms and severity of cardiomyopathy vary with the patient. Some have few
or no symptoms, while others develop problems such as heart failure (where the
muscle is not strong enough to pump blood around the body), abnormal rhythms,
and blood clots (from the slowing of blood flow). Common symptoms include
shortness of breath, chest pains - usually brought on by physical exertion -
palpitations and light-headedness or blackouts. But for some, the first
indication of a problem comes too late - unexpected sudden death in the young is
usually ascribed to abnormalities of the heart muscle (cardiomyopathy) or
premature coronary artery disease. When post-mortem examinations fail to reveal
such abnormalities, the term sudden arrhythmic death syndrome (SAD) is applied.

Diagnosis: Anyone who feels faint, giddy or has a blackout or palpitations
should have this investigated. An X-ray will show whether the heart has become
enlarged, or if fluid is accumulating in the lungs. An ECG, which records the
electrical activity of the heart and can reveal any muscle thickening or damage,
is needed for a firm diagnosis of cardiomyopathy. Sometimes an athlete's heart
may mimic cardiomyopathy because it is so developed - an ECG will help clarify
this.

Magnetic resonance imaging (MRI) is sometimes used to provide additional
information.

Other investigations may include cardiac catheterisation to measure pressure
in the different chambers of the heart and to obtain a biopsy of the heart
muscle (particularly in cases of restrictive cardiomyopathy): a catheter is
inserted into the vein in the groin or neck and threaded into the heart. For
people with serious rhythm disorders, electrophysiological studies may be
necessary. Here electrode catheters are inserted, which then emit electrical
impulses to provoke an arrythmia.

When someone is diagnosed with cardiomyopathy, non-invasive tests (ECG and
echo), should be offered to their relatives. Gene tests are being developed, but
no simple test exists at present.

Treatment: There is no cure for cardiomyopathy and treatment is aimed at
preventing complications and improving symptoms. For the majority who have few

or no symptoms treatment is not given.

Drug treatments for cardiomyopathy include beta-blockers, ACE inhibitors and
anticoagulants. Beta-blockers block the stimulating effect of adrenaline,
slowing the heart rate and reducing the demands on the heart. Beta-blockers
cannot be given to patients with bronchitis or asthma because they make
breathing more difficult. Other possible side-effects include cold hands and
feet, aching leg muscles when walking, tiredness and occasionally impotence.

ACE inhibitors work by dilating the blood vessels, which leads to a fall in
blood pressure. This helps in cases of cardiomyopathy as it reduces the work the
heart has to do to pump blood around the body (and prevents the heart from
getting progressively bigger). Some patients on ACE inhibitors develop a
troublesome cough, which may mean they have to stop taking medication. However,
a newer class of drugs - Angiotensin II antagonists - may help in such cases.
Anticoagulants are given to prevent blood clots forming in the chambers and then
causing a stroke or pulmonary embolism.

For people with hypertrophic cardiomyopathy, surgery can help relieve
symptoms by removing some of the excess muscle.

For patients at high risk of sudden death, implantable carrdioverter
defibrillators may be used to monitor the heart's electrical activity. If a
serious arrhythmia is detected, an electric shock will be delivered to the heart
(see

page 10). Pacemakers are indicated in people with slow heart rates or heart
block (see

page 10). In very advanced cases when medical therapy is ineffective the
patient may be referred for transplantation.

Incidence and mortality: Around one in 500 people is affected by
hypertrophic cardiomyopathy; one in 1,000 has arrhythmogenic right ventricular
cardiomyopathy and one in 1,000 has dilated cardiomyopathy, the Cardiomyopathy
Association reports.

New research/developments: The genes linked to various cardiomyopathies are
now being identified, including 11 for hypertrophic cardiomyopathy, 15 for
dilated cardiomyopathy and two for arrhythmogenic right ventricular
cardiomyopathy. Once

the pathways which cause muscle cell damage are identified, scientists will
be

able to produce drugs that can interfere or prevent the disease developing
and progressing. "Once we understand the genetic basis of cardiomyopathy we can
begin to offer clinical DNA testing," McKenna says. "This would make it much
easier to evaluate families."

In the US and Italy it is mandatory for all competitive athletes to be
screened for cardiomyopathy, and in the UK the organisation Cardiac Risk in the
Young (CRY)

is campaigning for all people involved in sport to be offered a cardiac
evaluation. The widespread availability of genetic tests would make screening
easier to implement in the UK.

Recognising that it can be difficult for patients in different parts of the
country to get to see cardiologists with a special interest in cardiomyopathy,
the Cardiomyopathy Association is leading a project to set up regional clinics
to give cardiologists and their patients access to specialists at the Heart
Hospital in London through telemedicine links. "This facility will provide
support not only for echo cardiographic assessment, but also for genetic
counselling and clinical management of patients," McKenna says.

European comparisons: The incidence of cardiomyopathy is the same for most
European countries, although it appears that more people are affected by
arrhythmogenic right ventricular cardiomyopathy in Venice and parts of Greece
than in other parts of Europe.

Links:

www.cardiomyopathy.org

Cardiomyopathy Association,

helpline 0800-0181 024, provides information and support to people affected
by cardiomyopathy

www.c-r-y.org.uk

Cardiac Risk in the Young. Offers screening for young people and counselling
for loss of a family member, 01737 363222 www.sadsuk.org

Sudden Adult Death Trust provides information and support to families who
have experienced the sudden unexpected death of a relation or friend from a
cardiac problem.

WHAT TO ASK YOUR DOCTOR

Will I need exercise tests or monitoring?

What sort of anaesthetic will be given for electrical cardioversion?

Is there a risk of heart block in my case?


LOAD-DATE: November 11, 2003