Cardiomyopathy is a general term for diseases of the heart muscle, where the walls of the heart chambers have become stretched, thickened or stiff. This affects the heart's ability to pump blood around the body. Some types of cardiomyopathy are inherited and are seen in children and younger people.
Dilated cardiomyopathy
In dilated cardiomyopathy the muscle walls of the heart have become stretched and thin, so they can't contract (squeeze) properly to pump blood around the body.
How serious is it?
If you have dilated cardiomyopathy, you're at greater risk of heart failure, where the heart fails to pump enough blood around the body at the right pressure. Heart failure typically causes shortness of breath, extreme tiredness and ankle swelling.
There's also a risk of heart valve problems,
an irregular heartbeat and blood clots. You'll need to have regular
appointments with your doctor/ GP so the disease can be monitored.
Who is affected?
Dilated cardiomyopathy can affect both children and adults.
The heart muscle can become stretched if you
have an unhealthy lifestyle or an underlying medical condition, or both.
The following can all play a role in the disease:
- uncontrolled high blood pressure
- an
unhealthy lifestyle – such as a lack of vitamins and minerals in the
diet, heavy drinking and recreational drug use
- a
viral infection that causes inflammation of the heart muscle
- a
heart valve problem
- a
disease of the body tissues or vessels – such as Wegener's granulomatosis, sarcoidosis, amyloidosis, lupus, polyarteritis nodosa,
vasculitis or muscular dystrophy
- inheriting
a mutated (changed) gene that makes you more vulnerable to the disease
- pregnancy –
cardiomyopathy can sometimes develop as a complication of pregnancy.
But for many people, the cause is unknown.
Schematic diagram of the heart and the different types of cardiomyopathy.
Hypertrophic cardiomyopathy
In hypertrophic cardiomyopathy, the heart
muscle cells have enlarged and the walls of the heart chambers thicken. The chambers are reduced in size so they can't
hold much blood, and the walls can't relax properly and may stiffen.
How
serious is it?
Most people with hypertrophic cardiomyopathy will be able to live a full, normal life. Some people don't even have symptoms and don't need treatment.
But that doesn't mean the condition can't
be serious. Hypertrophic cardiomyopathy is the most common
cause of sudden unexpected death in childhood and in young athletes.
The main heart chambers can become
stiff, leading to back pressure on the smaller collecting
chambers. This can sometimes worsen the symptoms of heart failure and lead
to abnormal heart rhythms (atrial fibrillation).
Blood flow from the heart may become reduced or restricted (known as obstructive hypertrophic cardiomyopathy). Also, the mitral heart valve can become leaky, causing blood to leak backwards. Read more about mitral regurgitation.
These heart changes can cause dizziness,
chest pain, shortness of breath and temporary loss of consciousness. You'll also be at greater risk of developing endocarditis (a heart infection).
If you have severe hypertrophic cardiomyopathy, you'll need to see your doctor regularly so your condition can be monitored. Your doctor will advise about the level and amount of exercise you can do and sensible lifestyle changes to make.
Table showing the different causes of cardiomyopathy.
Who is
affected?
Hypertrophic cardiomyopathy is thought to affect 1 in 500 people in the UK. Most people inherit the disease from their parents.
Restrictive cardiomyopathy
Restrictive cardiomyopathy is rare and mostly affects older adults. The walls of the main heart chambers become stiffened and rigid and can't relax properly after contracting. This means the heart can't fill up properly with blood.
It results in reduced blood flow from the
heart and can lead to symptoms of heart failure, such as
breathlessness, tiredness and ankle swelling, as well as heart rhythm
problems. In many cases the cause is unknown, although
sometimes it can be inherited.
Arrhythmogenic right ventricular cardiomyopathy
In arrhythmogenic right ventricular cardiomyopathy
(ARVC), the proteins that normally hold the heart muscle cells together
are abnormal. Muscle cells can die and the dead muscle tissue is replaced with
fatty and fibrous tissue.
The walls of the main heart chambers become thin
and stretched, and can't pump blood around the body properly. People with ARVC typically have heart rhythm
problems. Reduced blood flow from the heart can also lead to symptoms of heart failure.
ARVC is an uncommon inherited condition caused
by a mutation (change) in one or more genes. It can affect teenagers or
young adults and has been the reason for some sudden unexplained
deaths in young athletes.
There's increasing evidence that prolonged,
strenuous exercise worsens the symptoms of ARVC. It's important that people
with or at risk of ARVC have a careful discussion about this with their
cardiologist.
Diagnosing cardiomyopathy
Some cases of cardiomyopathy can be diagnosed after various heart scans and tests, such as an electrocardiogram (ECG) and an echocardiogram.
Cardiomyopathy that runs in the family can be
diagnosed after a genetic test. If you've been diagnosed with
cardiomyopathy, you may be advised to have a genetic test to identify the
mutation (faulty gene) that caused this.
Your relatives can then be tested for the same
mutation and, if they have it, their condition can be monitored and
managed early.
Treating cardiomyopathy
There's no cure for cardiomyopathy, but the treatments described below are usually effective at controlling symptoms and preventing complications.
Not everyone with cardiomyopathy will need
treatment. Some people only have a mild form of the disease that they
can control after making a few lifestyle changes.
Lifestyle changes
If the cause of your cardiomyopathy isn't
genetic, it should generally help to:
- follow
a healthy diet and take gentle exercise
- quit smoking (if you smoke)
- lose weight (if you're
overweight)
- avoid
or reduce your intake of alcohol
- get
plenty of sleep
- manage stress
- make
sure any underlying condition, such as diabetes, is well controlled.
Medication
Medication may be needed to control blood pressure,
correct an abnormal heart rhythm, remove excess fluid or prevent blood
clots. These include:
- medication for high blood pressure
- beta-blockers to treat an
irregular heartbeat or heart failure
- diuretics to remove excess fluid
from your body if this has caused swelling
- anticoagulants such as warfarin
to prevent blood clots
- medication to treat heart failure.
Hospital
procedures
In some people with obstructive hypertrophic
cardiomyopathy, the septum (the wall dividing the left and right side of the
heart) is thickened and bulges into the main heart chamber. They may need to
have either:
- an
injection of alcohol into their heart – this is to reduce part of the
muscle in the septum
- a
septal myectomy – heart surgery to remove part of the thickened
septum (the mitral valve may be repaired at the same time, if
necessary).
Those with heart rhythm problems may need to have a
pacemaker, or a similar device, implanted to control their abnormal
heart rhythm. As a last resort, a heart transplant may be necessary.
Information about you
If you have cardiomyopathy, your clinical team may pass information about you on to the National Congenital Anomaly and Rare Diseases Registration Service (NCARDRS). This helps scientists look for better ways to prevent and treat this condition. You can opt out of the register at any time.
Broken heart syndrome
Some people who sustain significant emotional
or physical stress, such as bereavement or major surgery, go on to experience a
temporary heart problem.
The heart muscle becomes suddenly weakened or
"stunned", causing the left ventricle (one of the heart's main
chambers) to change shape. It may be caused by a surge of hormones,
particularly adrenaline, during this period of stress.
The main symptoms are chest pain and breathlessness, similar to those of a heart attack – always call 999 if you or someone else experiences these.
The condition – known medically as Takotsubo cardiomyopathy, or acute stress cardiomyopathy – is temporary and reversible. It's unusual for it to happen again.
