Dilated Cardiomyopathy

dilated cardiomyopathy

The heart has four chambers - two atria and two ventricles. The walls of these chambers are mainly made of specialised heart muscle called the myocardium. During each heartbeat both of the atria contract, first to pump blood into the ventricles. Then both ventricles contract to pump blood out of the heart into the arteries. There are one-way valves between the atria and ventricles and also between the ventricles and the large arteries coming from the heart. The valves make sure that when the atria or ventricles contract, the blood flows in the correct direction.

What is cardiomyopathy?

Cardiomyopathy is a disorder of the heart muscle. There are four main types:

  • Dilated cardiomyopathy (DCM) - where the heart dilates (enlarges).
  • Hypertrophic cardiomyopathy - where the heart muscle becomes thickened (hypertrophied).
  • Restrictive cardiomyopathy - where the heart muscle cannot relax properly between heartbeats.
  • Arrhythmogenic right ventricular cardiomyopathy - a rare type which mainly affects the right side of the heart.

What happens in dilated cardiomyopathy?

In this condition the heart muscle is weakened. The ventricles then dilate (enlarge) because their muscular walls are weaker and more floppy than normal. This means the heart does not pump blood as strongly as normal.

 How common is dilated cardiomyopathy?

DCM is the most common type of cardiomyopathy. It can affect both children and adults. It is most common in middle-aged men.

What causes dilated cardiomyopathy?

Unknown cause

For most people the cause is not known. This is sometimes called idiopathic DCM.

Other causes

  • Alcohol, drugs and other poisons. Up to 3 in 10 cases of DCM can be linked to alcohol.
  • Poor diet. If you do not get enough of certain vitamins and minerals, especially vitamin B1 (thiamine), this can weaken the heart muscle and lead to DCM.
  • Inflammation of the heart muscle (myocarditis) is a rare condition which can be caused by various infections.
  • Pregnancy and childbirth. This is called peripartum cardiomyopathy.

DCM sometimes occurs with: sarcoidosis, amyloidosis, haemochromatosis, some forms of muscular dystrophy, vasculitis, systemic lupus erythematosus (SLE), polyarteritis nodosa, and Wegener's granulomatosis.

What are the symptoms of dilated cardiomyopathy?

Symptoms of heart failure

Symptoms of heart failure are mainly due to fluid building up in tissues of the lungs and body. This happens because your heart does not pump effectively. Symptoms include the following:

  • Shortness of breath.
  • Fluid retention in the legs.
  • Tiredness.
  • Palpitations sometimes occur.

How is dilated cardiomyopathy diagnosed?

  • Your symptoms.
  • Changes on your electrocardiogram (ECG).
  • Changes on your chest X-ray. This may show your heart is large or that there is some fluid in your lungs.
  • An ultrasound scan of the heart, called an echocardiogram.

How does the condition progress?

This can be difficult to predict. In some cases, the condition remains stable or does not get much worse. Medication may keep the symptoms of heart failure away and your lifestyle may be little affected. In some people, the function of the heart gradually deteriorates.

What are the complications of dilated cardiomyopathy?

  • Arrhythmias: An arrhythmia is an abnormal rate or rhythm of the heartbeat.
  • Blood clots: The blood flow through the heart is slower than normal, especially when the heart is very dilated. This can lead to small blood clots developing within the chambers of the heart. These may travel in the bloodstream and get stuck in arteries of the body. This may lead to a stroke if a clot gets stuck in an artery in the brain, or to other problems.
  • Sudden death: Sudden collapse and death without any warning occurs rarely in people with DCM.

What is the treatment for dilated cardiomyopathy?

Treatment aims to ease symptoms if they occur and to prevent complications. If you do not have any symptoms, or only mild symptoms, you may not need any treatment.

Medication to treat heart failure

  • Angiotensin-converting enzyme (ACE) inhibitors. These medicines prevent a build-up of fluid by interfering with the enzyme angiotensin (a body chemical). This is involved in regulating body fluid.
  • A diuretic (water tablet) is commonly needed in addition to an ACE inhibitor. Diuretics work on the kidneys and make you pass out extra urine. This helps to clear excess fluid that builds up in the body.
  • A beta-blocker, such as bisoprolol or carvedilol, may be prescribed in addition to an ACE inhibitor and diuretic. Beta-blockers have a protective effect on the heart muscle.

Medication to treat arrhythmias which may develop

There are various anti-arrhythmic medicines (for example, amiodarone) which are used to treat and to prevent arrhythmias.

Anticoagulants such as warfarin

An anticoagulant is a medicine which helps to prevent blood clotting so easily. An anticoagulant may be advised if you develop atrial fibrillation or have a very dilated heart.
Cardioversion is an option for some types of arrhythmia. Artificial pacemakers are used in certain types of arrhythmia where the heart beats abnormally slowly (complete heart block) and in certain other situations. An artificial pacemaker is a small device which is inserted just under the skin on the upper chest. Wires from the pacemaker are passed through veins into the heart chambers. The pacemaker can then stimulate the heart to maintain a regular normal heartbeat.

Implantable cardioverter defibrillators (ICDs) are sometimes used in certain situations - especially if you are at risk of developing serious and life-threatening arrhythmias. They are small devices which are similar to pacemakers and are inserted under the skin in the upper chest. Wires are passed through a vein to the heart. The device monitors the heartbeat. If it detects an abnormal rhythm, the device can send a small electrical shock to the heart to change it back to normal.

Cardiac resynchronisation

Cardiac resynchronisation tries to improve how the electrical impulses in your heart make it pump. This makes it pump more efficiently. This is done by using a pacing device.


Heart transplant or Artificial Heart

In some cases the condition progresses and severe heart failure develops. If this cannot be treated by the methods mentioned here, the only option for treatment is a heart transplant or a artificial heart.

What is the outlook?

The outlook with DCM varies and depends on the severity of the condition. However, the the outlook for many people with DCM has improved a lot in the last ten years. This is due to new medical and surgical treatments.

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