The
Cardiomyopathy
Association

Figure 4 Echo machine

This is performed by standing in front of an X-ray machine. The results will show any inappropriate enlargement of the heart or accumulation of fluid in the lungs. Again, the findings on a chest x-ray are not specific for DCM.

Holter monitor or 24 hour tape

Figure 5 Holter monitor

This is a specially modified exercise test, similar to that used to assess patients with chest pains (angina). Breathing, blood pressure and ECG are monitored during an exercise test using a bicycle or a treadmill. It also measures your oxygen usage with a mouthpiece connected to the machine. This can be a little awkward while exercising. However, this test allows symptoms not obvious at rest to become apparent when the heart is stressed during exercise, and also allows an objective measurement of improvement or worsening of heart function over time.

Baseline blood tests are performed helping to create a health profile. These might include a blood count, kidney and thryoid function test and tests for rare causes of DCM such as haemochromatosis and sarcoidosis. Genetic testing is available only on a research basis in the UK but developments are expected in the next few years.

Other investigations which may be necessary

Cardiac catheterisation

This is to ensure that the coronary arteries are not narrowed, a condition which can sometimes mimic DCM. The test requires the patient to be admitted to a hospital, usually as a day case but sometimes a little longer. In this test a small tube is passed into a blood vessel in the arm or leg. A further, smaller tube (catheter), is then passed into the heart under x-ray control. Through it a harmless dye is then injected to outline the heart and the coronary heart arteries (angiography). An angiogram is an invasive test and thus has small risks attached to it which will be explained by your doctor. In general a light sedative and local anaesthetic are used when performing an angiogram.

Sometimes it is necessary to examine a small piece of heart tissue under a microscope. If this is required, the biopsy, which is performed as a day case, involves a small tube being passed via a vein into the heart from the patient's neck. A few tiny pieces of the heart are then taken and sent to the laboratory. In general a light sedative and local anaesthetic are used when carrying out this test.

Electrophysiological studies (EPS)

This is a special type of cardiac catheterisation used to study the electrical activity of the heart in detail. It is needed when more serious abnormalities of heart rhythm are suspected. This procedure would usually require the patient having a light sedative and local anaesthetic.

In this test a small, short-acting and safe amount of radioactivity in the form of a special dye is given by injection, and often the patient is then exercised on a bicycle or treadmill. A special camera (gamma camera) is then used to scan the heart and a computer assesses the heart’s ability to contract.

COMPLICATIONS

Some people have few or no symptoms in DCM while others develop problems that need medication:

This is a common feature of DCM. It occurs when the muscle of the heart is not strong enough to pump blood efficiently round the body, causing build up of fluid in the lungs and /or the tissues.

Some people have stable disease and there is little worsening of their condition. Others have fluctuating symptoms known as “heart failure”. This usually affects both left and right sides of the heart (congestive heart failure) causing symptoms of breathlessness, swelling of the ankles or legs, prominent visible veins in the neck and a sensation of fullness in the abdomen.

In DCM the blood flow through the heart is slower than normal. This may allow blood clots to form in the heart. If a blood clot dislodges from these sites and goes into circulation, it can cause damage to the brain (a stroke). Therefore, some people with DCM ,especially those with very enlarged hearts, may need to be treated with anticoagulant medication (warfarin), to prevent such clots from forming.

These generally cause dizziness, breathlessness, palpitations (awareness of the heartbeat), or may cause no symptoms. Some rhythm disorders that may occur in DCM are:

Occasional single extra heart beats. These usually require no treatment, are not dangerous on their own and can be found in normal healthy people.

Is a very fast heart beat. It is a more serious matter and occurs quite commonly in DCM. It is often associated with a fall in blood pressure and symptoms of dizziness, breathlessness or fainting. But it can be symptomless. It may respond to medication or an implantable cardioverter defibrllator (ICD). (see below).

Occurs rarely. A severe and serious disorder of the electrical activity of the heart rhythm. It will cause collapse, and can lead to death if uncorrected.

The risk of this happening is small but may occur with little or no warning. It is usually caused by a severe arrhythmia or large blood clot developing. Medication and/or an ICD may lessen this risk.

If the normal electrical conduction system within the heart fails to function properly, the heart may become too slow. Light headedness or blackouts may be experienced. If this occurs, a pacemaker may be necessary.

Currently, DCM is not curable although some patients improve spontaneously.

Treatment is usually with drugs and is aimed at minimising symptoms and preventing the development of complications and progression of the disease. A minority of patients deteriorate in spite of treatment and may need a heart transplant.

ACE Inhibitors (such as Captopril, Enalapril, Lisinopril, Enalapril and others).

ACE (Angiotensin - converting - enzyme) inhibitor drugs are proven to prevent progressive dilation of the heart, and so are of benefit to patients with DCM. Most users feel less breathless and experience improved well being on these drugs. However, it is beneficial in the long term in DCM to take these drugs even if there is no apparent improvement in symptoms in the short term.

Side-effects occur in a minority of patients and include a dry cough, rash, metallic taste and rarely swelling of the tongue.

A related group of drugs, the Angiotensin Receptor Blockers (ARB) seem to be just as beneficial, and may be used as a substitute for ACE inhibitors if side effects such as dry cough occur on ACE inhibitors.

Beta-blockers (such as Metoprolol, Carvedilol, Bisoprolol and others)

If heart failure is present, the body overproduces adrenaline which can cause further damage to the heart. This can be prevented with beta-blockers. With a long-term use these drugs will improve the outcome of patients with DCM. Therefore, like ACE inhibitors, beta-blockers are used very commonly even when symptoms have been controlled. Side-effects occur in a minority of patients and include worsening fatigue, cold hands and wheezing. Patients should be started on a low dose and given more slowly.

This is commonly used to control the heart rate if atrial fibrillation develops. However, even when the heart rhythm is normal, digoxin may be given to help the the heart muscle contract better, but is usually only used when symptoms are not controlled by ACE inhibitors and beta-blockers.

Diuretics (such as Frusemide, Bumetamide, Amiloride and others)

These drugs are also known as water tablets and are used to reduce excess fluid in the body by increasing urine production. It may be possible to reduce these drugs when symptoms are controlled.

A type of diuretic that may also reduce scarring in the ventricle, and unlike other water tablets has been shown to improve long term outcome.

An anticoagulant drug which is used to prevent the formation of blood clots. This medication thins the blood and works very well at preventing stroke. However, too much warfarin will lead to excessive bleeding and levels must be watched on a regular basis.

Amiodarone is used for the treatment of heart rhythm disorders. However, it has several side effects that require close monitoring. Common side effects are sensitivity to the sun, sleep disturbances, thyroid hormone abnormalities and occasionally liver, lung and eye problems. It is unusual for a patient to have severe or permanent problems.

Other therapies

Cardioversion

Some rhythm disturbances need to be corrected by the delivery of a controlled electric shock to the chest. This is performed under a short general anaesthetic, and may be done as an emergency (if the patient is very ill) or as a planned procedure when the patients attends as a day case.

Some patients with DCM do not respond to medical treatment and deteriorate to such an extent that their quality of life is very poor. At this stage, the individual may be referred to a specialist hospital where an assessment will be made to see if a heart transplant is appropriate. Patients who have few symptoms are not usually considered for transplant.

Occasionally, patients with DCM develop a heart rhythm that is too slow. In these circumstances a pacemaker may be necessary to monitor the heart’s rhythm and take over control if it becomes too slow. The pacemaker is implanted just under the skin on the front of the chest (Figure 6) and connected to the heart by wires through a vein down to the heart. It is implanted as a day case or overnight procedure with local anaesthetic just below the collar bone, and often with light sedation.

More recently, new pacemakers with three leads (biventricular pacemakers) have been inserted into patients with heart failure to co-ordinate the right and left ventricles. This has some benefit in particular patients and may ease their symptoms, and reduce the need for hospital stays.

Figure 6 Pacemaker

Patients with pacemakers need to have regular checks of the pacemaker function at least once a year to ensure the battery is functioning normally.

Implantable cardioverter defibrillator (ICD)

A few patients suffer serious rhythm disturbances which cannot be controlled by medications but can be treated by a controlled small electric shock from a device known as an ICD. The ICD is a device similar to a pacemaker that can deliver a small internal shock when dangerous rhythms occur. An ICD can prevent sudden death in high-risk patients.

Left ventricular assist device (LVAD)

When a patient develops severe heart failure, newer surgical techniques such as artificial metal pumps are occasionally used to help the heart to pump. At present, they are only used in extreme circumstances, e.g. while waiting for a transplant (bridge-to-transplant).

After the initial diagnosis has been made, all patients must be seen for regular checkups. This is necessary to monitor an individual’s progress and adjust treatment as necessary. Follow-up is important as any complications that may arise can be identified and treatment started when it is most beneficial.

The prognosis is different for every patient, and statistics about DCM as a whole cannot be applied to the individual. Some patients improve spontaneously with treatment.

Others remain stable with some adjustments to their lifestyle. However, a small proportion of patients continue to deteriorate despite treatment and may need to be considered for a heart transplant.

In some cases, DCM seems to run in families. This suggests that there may be a genetic basis to the disease, although it is uncommon for all members of one family to have the condition. This means that some people may have no symptoms, or even no features of the disease but may still carry the abnormal gene(s) that determine the disease.

Once someone has been diagnosed with DCM, it is usual for first-degree relatives to be offered the chance to be screened for the disease. These people will undergo a similar series of tests, such as an echocardiogram and ECG, as well as being seen and assessed by a specialist doctor.

Approximately 30% of family members will be found to have a mild or early form of DCM even when they are free of symptoms. This early form of the condition is termed left ventricular enlargement (LVE). Some people with LVE will develop symptoms, and eventually develop DCM.

It is as yet unknown what treatment is appropriate for people with LVE, but they are advised to be followed up with further investigations and repeat medical assessments approximately once a year.

Psychological adjustment in cardiomyopathy

by Dr John Morgan

Finding out that you have a diagnosis of cardiomyopathy can be distressing, but most people come to terms with the diagnosis. We all have different ways of adjusting, and there is no right or wrong way. In the early stages it is normal to feel shock, anger and disbelief. Stress, fear and anxiety can sometimes help us to re-examine and to change our lifestyles, and the idea that all stress is bad for us is simply nonsense. Nonetheless, when emotions like this persist for months on end or begin to overwhelm us, they can merge into treatable medical diagnoses such as anxiety and depression.

A study at St. George’s Hospital in London found that two fifths of patients with cardiomyopathy had a current anxiety disorder and one fifth had depression. This was more than just distress, sadness or grief. Many patients also experienced problems with physical intimacy, but had difficulty in discussing those problems with health care professionals.

Anxiety combines physical and psychological symptoms. You may feel worried all the time, constantly fatigued and unable to concentrate, irritable or unable to sleep well. Anxious people experience bodily symptoms such as palpitations, sweating, rapid shallow breathing, dizziness, fainting, muscular tension, indigestion and diarrhoea.

All of these symptoms may be wrongly interpreted as symptoms of cardiomyopathy, and worrying about this can make the emotions spiral out of control. Sufferers may avoid talking about their feelings for fear that other people may think that they are ‘mad’.

Irritability can cause conflict with those who love you, and people with severe chronic anxiety often hold the world at arms' length.

What to do about anxiety?

Talking to someone is the first stage in finding a solution. Friends and relatives can be ideal, but sometimes it is easier to talk to a stranger. Talking to other people with cardiomyopathy can break down barriers of isolation. Self-help groups can be useful if enough people commit themselves to the group.

Relaxation techniques can help us to control anxiety. Learning to relax, like learning to play the piano, is a slow process and needs to be practised regularly, rather than to just relied on in a crisis. Health care professionals can teach relaxation techniques, but it is possible to use a variety of books and tapes. In a few, rare cases the roots of anxiety may be deeper and may need to be teased apart through psychotherapy, which may take weeks or months.

Doctors sometimes prescribe medication for anxiety, and this can be helpful in some cases. Sleeping tablets (tranquillisers) like valium (benzodiazepines) are highly effective but can also become addictive after only four weeks of regular use. As a short-term measure they can be very useful but should not be used for longer-term treatment. Sometimes anti-depressants can be useful for chronic anxiety.

What is depression?

Feeling fed up or miserable is normal, and feelings like this usually doesn’t last for long or interfere significantly with our lives. We say that someone has ‘clinical depression’ when these feelings persist and severely interfere with our lives. Feelings of clinical depression can last for months and affect a range of physical and psychological functions, including sleep disturbance, loss of appetite and frequent thoughts that life is not worth living. Depression comes on gradually and we do not recognise how depressed we are. Sometimes we pay more attention to our physical symptoms than our psychological state. Physical symptoms such as chest pain can actually be signs of a depressive episode. Depression is different to the normal grief that one would expect in being told you have a diagnosis of cardiomyopathy, in so far as grief pass through stages of acceptance and reconciliation, whereas depression hangs over us for months at a time.

What to do about depression?

A regular active routine can be effective for mild depression. Having cardiomyopathy restricts vigorous exercise and you should consult your doctor if you are uncertain about activity, but that shouldn’t stop you being active. People with depression may stop looking after the body, losing weight and ignoring essential nutrients. Many people with depression have difficulty sleeping. Sleep disturbance does not kill you, so try not to worry too much about sleep difficulties. Nonetheless, establishing regular habits of eating and sleeping can help your mood. Alcohol seems to make us happy but is actually a depressant. Studies suggest a small minority of people with cardiomyopathy are driven to drink, giving transient relief of symptoms. But this will only make things worse.

When depression starts to significantly affect your hobbies, social relations and occupation, when you start to believe that life is not worth living, or when the feelings are persisting for a long time, then is the time to seek help. You should approach your family doctor. Professional help is often necessary, usually treated by family doctors who may recommend some sort of talking treatment, anti-depressants tablets or a combination of the two. Talking to a trained counsellor or therapist can be easier than talking to people you know. There are many different forms of psychotherapy. Cognitive therapy looks at the structure of your thoughts, and helps to overcome the automatic thoughts at the root of depression. Dynamic and inter-personal therapies can help look at relations with others. Talking therapies take time to work, and you may need to see a counsellor for many sessions over several weeks before you gradually experience an improvement.

Severe or chronic depression may benefit from a course of anti-depressants. Having cardiomyopathy may limit the choice of anti-depressant, but will not stop you getting a prescription if you need one. It can take several weeks to experience beneficial effects from anti-depressants. Anti-depressants act on chemical substances in the brain called neuro-transmitters. This is not to suggest that depression is nothing but a chemical event, but sometimes modest improvements in brain chemistry can have substantial benefits for overall functioning. A minority of patients may need more specialist help from a psychiatrist or member of a mental health team.

Specific help for cardiomyopathy

All chronic medical conditions like cardiomyopathy require the patient to become the expert, and many patients will know more about the condition than some doctors. This applies as much to emotional as to physical sequelae. Chatting to other people with the diagnosis can be invaluable. Nurses and doctors working in dedicated clinics have a tremendous range of expertise and understanding. Accessing more specialist psychological treatments can be difficult but if you need help you should ask for it. Most people come to terms with cardiomyopathy, but some people will require extra assistance. If one of those people is you, you should ask your family doctor for more support.

In general, drinking alcohol is not recommended for patients with DCM as it has a toxic and depressant effect on the heart muscle. Any individual diagnosed with the condition who wishes to drink is advised to spread the number of recommended units consumed over a week and to attempt to stay significantly inside the suggested number. Low alcohol and alcohol free wine, beers and lagers are useful substitutes.

Allowances are available for those people whose symptoms cause severe restrictions. Disability Living Allowance is a state benefit for those with an illness or disability who need help getting around or help with personal care. Disability Working Allowance is a benefit to help with getting a job for those who are disadvantaged at work by their condition.

Details of these benefits can be obtained by calling freephone 0800 882200            (benefit Enquiry Line) or by visiting the local office of the Social Security or Citizens Advice Bureau or at the Social Services Department of a local hospital.

If an individual is overweight, it places extra strain on the heart. Sensible eating habits are encouraged to maintain weight within the normal range for height and age. As rapid increase in weight may be due to fluid retention, it should always be notified to a doctor.

Individuals with DCM in whom the condition is stable are generally allowed to drive a private motor vehicle, although each case is individually assessed. Any patient developing serious complications - arrhythmia, blackouts or symptomatic heart failure may be advised not to drive. A diagnosis of DCM will bar the patient from holding a vocational licence, ie PSV or HGV.

Once over the initial diagnosis and having started treatment, many patients get back to a normal quality of life. Patients with DCM may undertake physical exercise as long as it does not produce undue symptoms. So exertion should be discontinued if symptoms persist. By staying inside exercise limits individuals should not find any difficulty in taking a moderate degree of exercise, albeit at a slower pace than other people. Everyone is different!

Moderate exercise in the form of regular walks is beneficial to patients with heart failure by improving cardiovascular fitness.

Medical advice should always be sought before taking part in any competitive sports or strenuous physical exercise, as these should be largely avoided by patients with DCM.

When a person is diagnosed with DCM, it is advised that their family members should be assessed for the same condition. Usually this means first degree relatives - parents, brothers and sisters and children.

Each family member will undergo ECG, echocardiogram, blood tests, and physical examination. Sometimes, early forms of DCM can be identified (see Families and DCM).

This may be recommended by a doctor to prevent a severe bout of flu which can place an extra stain on the heart.

Travel

It is advisable to see a GP for medical approval before travelling. If travelling abroad, it is also recommended that information be obtained from travel agents regarding insurance and the health care policy of the country visited.

If travelling in Europe it is recommended that you have a European Health Insurance Card (EHIC) which has replaced the E111 form. You can apply online at www.ehic.org.uk, call 0845 6062030       or pick up an application form from a Post Office.

Further information on travel insurance contact the Cardiomyopathy Association on freephone 0800 018 1024     or email info@cardiomyopathy.org

Clearly, as with many heart conditions, difficulties may be encountered in acquiring insurance cover and/or premiums may be high. If you are having problems contact the CMA on freephone 0800 018 1024     or email info@cardiomyopathy.org

Pregnancy and childbirth

Occasionally, DCM can develop for the first time during a pregnancy and then regress; this is termed peripartum cardiomyopathy (see causes of DCM), and can recur during subsequent pregnancies.

Women with pre-existing DCM are prone to more problems during pregnancy and delivery. Sometimes, heart failure due to DCM can worsen during pregnancy. It is advised that a woman with DCM who plans to become pregnant is supervised jointly by an obstetrician and a specialist cardiologist.

Although cigarette smoking is not directly associated with DCM, in all cases of heart disease it is advisable not to smoke as it is likely shorten your life.

Frequently asked questions

1. What is an ejection fraction? And what do the numbers mean?

Ejection fraction is a measure from the Echo test of the strength of the heart pump. Normal EF is greater than 50%, and levels less than this diagnose DCM. It does not mean breathlessness, and some people have very low ejection fractions but are not breathless. Another measure of pump function is the fractional shortening (%FS), which is roughly half the EF, so FS greater than 25% is normal.

2. Are there dangers associated with fluid overload? (Do I have to be careful about how much I drink?)

This is most important. In DCM, your ability to deal with excess fluid is less (your reserve is less) and so lots of fluid can lead to sudden overload, ankle swelling and breathlessness. Most doctors encourage their patients to weigh themselves once a week (on the same scales!). An increase of more than 3 kg signifies fluid overload so m more diuretics (water tablets) to deal with it.

Alcohol in excess is dangerous both because of fluid overload and because it can be directly toxic to the heart. Moderate intake is permitted when you have stable DCM.

3. Should I have children?

Although some DCM is genetic/familial, not all those who inherit the gene will develop the condition (i.e the disease does not appear). In any case, many patients with DCM do not develop the problem until well into adult life. Treatment has got much better in the last 10 years. This decision depends on how aggressive the disease is in your family and on your own personal experience. You need to discuss this in detail with your doctor.

4. I’m afraid that my GP doesn’t know enough about my condition to help me. What can I do to help him help me?

Some doctors do not know a lot about DCM. The Cardiomyopathy Association provides CD-Roms for the medical profession. If you want a copy for your doctor, contact the CMA.

5. Will DCM affect my sex life?

Usually only in the acute phase when there are significant symptoms of heart failure. If this is controlled by medication, most people tend to settle down to a normal quality of life. Some medications in some people (beta-blockers and spironolactone) can cause impotence (failure to maintain an erection), and this can interfere with your sex life. If this happens talk to your doctor.

6. I have thought about taking Viagra. Are there any risks specifically for patients with DCM?

In stable heart failure there is no problem reported with Viagra, but it is to be avoided if you are breathless at rest or on minimal exertion. Also it is contraindicated if you are taking nitrate medication or have active angina (chest pain from coronary arteries).

7. What effect will drinking alcohol have on someone with DCM?

Some people’s DCM is due directly to alcohol excess and may resolve on abstaining. For people with unexplained DCM, alcohol in excess is dangerous both because of fluid overload and because it can be directly toxic to the heart. Moderate intake is permitted when you have stable DCM.

8. What effect will recreational drugs (marijuana, cocaine, ecstasy) have on someone with DCM?

Any drugs with an excitatory effect on the heart are a very bad idea, and may provoke dangerous extra beats and arrhthymias. As these drugs are illegal there are no safety data available.

9. Do I need to have antibiotics before dental procedures?

Not unless you have a murmur when the doctor listens to your heart or evidence of a valve leak on the Echo test. Check with your doctor.

10. Can I go on holiday?

DCM patients usually have no problem with travel or air flights unless they are very symptomatic from heart failure (short of breath at rest or on minimal exertion) in which case distance travel is best avoided. Be sensible. Avoid lifting heavy bags. There is no special need for oxygen on air flights in DCM.

11. What is the survival rate in DCM?

Everyone is different. Survival has improved a lot in the last ten years due to new drug treatments and some people recover normal heart function and lead a normal, long life. Old figures which suggest half of patients will die within five years are simply not true anymore.

AMBULATORY: Refers to tests performed when a person is walking around or going about their normal activities.

ANGINA: A chest pain or discomfort usually brought on by exertion and relieved by rest. Angina results from insufficient oxygen supply to the heart muscle.

ANGIOGRAPHY: An internal x-ray of the heart and blood vessels which may be taken at the time of cardiac catheterisation (see below). In particular, this test assesses the coronary arteries (the blood vessels which supply the heart muscle).

ANTICOAGULATION: Treatment (eg heparin or warfarin) to reduce the clotting ability of the blood. Such treatment is used when there is a risk of clot formation in the heart eg due to atrial fibrillation (see below).

ARRHYTHMIA: An abnormal rhythm or irregularity of the heart beat. The heart beat may be either too fast (tachycardia) or too slow (bradycardia). Arrhythmias may cause symptoms such as palpitation or light-headedness.

ATRIA: The filling chambers of the heart, one on the right side and one on the left. Blood is collected in the atria while the ventricles are contracting. This blood is then released into the ventricles when they are ready to fill.

ATRIAL FIBRILLATION: A common type of arrhythmia. It begins in the atria and may be transient, (paroxysmal), or persistent. The heart rhythm is irregular.

CARDIOMYOPATHY: Any disease of the heart muscle; cardia refers to the heart and myopathy means an abnormality of muscle.

CONGESTIVE HEART FAILURE: see HEART FAILURE.

DIURETICS: Occasionally patients may develop fluid retention and they may be given tablets, called diuretics, which increase the production of urine by the kidneys.

ELECTRICAL CARDIOVERSION: An arrhythmia, such as atrial fibrillation, may be stopped by the application of an electric shock to the chest. If this procedure is necessary, it is carried out under general anaesthesia.

ELECTROPHYSIOLOGICAL STUDY or EPS: In this test catheters are introduced into the heart as in cardiac catheterisation, (see above). These catheters can record and stimulate the electrical activity of the heart.

EXERCISE (STRESS) TESTING: Exercise capability may be tested using either a treadmill or a stationary bicycle. During an exercise test a doctor and technician will monitor a patient's symptoms, ECG, blood pressure and, sometimes, breathing.

GENES AND CHROMOSOMES: Genes are the code or blueprint, which build all the tissues in the body. Each individual has thousands of genes and they are all present in every cell of the body. Genes come in pairs, one inherited from one's mother and the other from one's father. In each cell the genes are grouped together in tiny, thread like structures called chromosomes. Each individual has 23 pairs of chromosomes.

HEART BLOCK: Occasionally the normal electrical signal does not travel down to the ventricles resulting in an abnormally slow heart rate. This situation can be diagnosed on ECG. If it occurs, a pacemaker is implanted.

HEART FAILURE (CONGESTIVE CARDIAC FAILURE): A condition where weakness of the beating action of the heart causes fluid retention and symptoms of shortness of breath and tiredness on exercise. It can be associated with heart beat irregularities, fluid in the lungs or swollen lungs.

HOLTER MONITOR: A continuous recording of the heart beat over 24 to 48 hours. Adhesive electrodes are placed on the chest, wires from these go to a special cassette recorder which is worn on a belt. A Holter monitor detects irregularity of the heart beat, otherwise known as arrhythmia.

 IMPLANTABLE CARDIOVERTER DEFIBRILLATOR (commonly abbreviated to ICD): A specialized pacemaker which recognises when a heart rate is excessively fast and responds by either pacing the heart or delivering a small electrical shock to restore the normal heart rhythm. The ICD can also serve as a conventional pacemaker to deliver the necessary impulses when the heart rate is too slow.

 MURMUR: A murmur is a noise, audible using a stethoscope, caused by turbulent blood flow within the heart.

PACEMAKER: When the normal electrical impulse fails to be transmitted to the ventricles a pacemaker is implanted. This involves inserting a small box containing a battery under the skin of the chest, with a fine wire going through the veins to the heart, to deliver the necessary impulses.

PALPITATION: An uncomfortable awareness of the heart beat. Palpitation may be due to a normal heart beat made more prominent by anxiety or exercise, or may be caused by an arrhythmia.

VENTRICLES: The main pumping chambers of the heart, one on the right side and one on the left.

VENTRICULAR TACHYCARDIA: A type of arrhythmia, which takes the form of a fast heart beat arising in the ventricles.