Abi

Living with right ventricle outflow tract ventricular tachycardia (RVOT-VT)

My condition came to light at the end of 2008 when I was 34. I’d been to the doctors to discuss these strange palpitations and dizzy spells I’d been experiencing, but was sent away and told it was due to “stress”. This seems to be the usual response from a GP the first time you report these symptoms. I remember thinking, I didn’t even know I was stressed but perhaps I was and this was how my body was coping.

Fitness wise, I was reasonably active. I swam and ran every week and generally felt well, so wasn’t worried that this was anything more serious than stress related palpitations.

After a routine trip into hospital to have four wisdom teeth removed under a general anaesthetic, the nurses told me they had trouble stabilising my heart rhythm when I was in recovery. Once back in my hospital room, I was advised to see a cardiologist to ensure that everything was fine.

Again I wasn’t too concerned but thought I would mention it to my doctor when I was fully recovered.  The next evening I was home, in bed recuperating when my heart started to behave very strangely. It began flipping, jumping, and felt like it was falling over itself. A strange way to describe it but it’s how it felt. It would flip and felt like it was stalling. I felt dizzy, sick, scared, as if I was going to fall unconscious. I rang the emergency medical line and they told me to call for an ambulance who took me straight into hospital. From there they referred me to a cardiologist who over a period of weeks carried out a series of tests; a stress test, ECHO an MRI of my heart and I had to wear a 24 hour Holter monitor etc.

The results were in – the good news was that structurally my heart was fine, but the holter monitor found something. It was a run of tachycardia around 250bpm – it was then that I received the diagnosis of right ventricle outflow tract ventricular tachycardia (RVOT–VT), a benign heart arrhythmia, although sometimes frightening for the sufferer. I was sent home and told to see how things go and to try beta-blockers.

For some people beta-blockers are great and work wonders, but they made me feel dreadful, tired and depressed so I came off them. As time progressed the symptoms got worse and having felt like I’d exhausted all routes of medical help in my local area I went online and came across the London Bridge Hospital website and from there contacted an electrophysiologist who felt confident that they could help me.

After my consultation and more tests, my first ablation was booked. I’d read up a little about what was involved but I can still remember shaking when I was getting ready in the hospital room. All kinds of things were running through my head; will it be painful, will I survive, what if it doesn’t work, how long will it take?

I was given a huge gown to wear, one that has loads of pockets that can be pumped full of warm air to keep you comfortable when you’re in theatre. I looked pretty funny and my husband and I were joking about it, he even took a picture of my theatre outfit!

As I walked down to theatre I remember thinking I hope this is the end of all the problems and that my life will return to normal. I couldn’t believe that my quality of life had changed so much in such a short space of time. RVOT-VT had meant I was no longer able to run or exercise without feeling utterly drained and ill afterwards. My arrhythmia was daily and left me feeling weak, ill and unable to concentrate on anything. I had chest pains and sleeping had become a problem too. I couldn’t sleep on my left side and would suddenly wake gasping for air. So, despite my fears of going into theatre I focused on my future, one that would allow me to go on to start a family without being plagued with these symptoms.

Everyone involved in the procedure were amazing. They helped me onto the theatre bed and began attaching the leads, which they use to monitor your heart throughout the procedure. I was warm and comfortable. They gave me a sedative to relax me and I actually fell asleep a few times during the procedure. I also had an oxygen mask.

They made an incision in my right groin into the femoral artery which is how they get the wires up into the heart chamber. I didn’t feel any pain. They would stimulate the heart with electrical current so they could see the problematic areas on the monitor and know where to ablate. I could feel some pressure in my chest when they were stimulating the heart but after some more sedative I drifted off to sleep.

Two and half hours later I was back in the hospital room and was elated that it was all over.

After about eight months it became apparent that my particular RVOT-VT would require a second ablation. So I was back in hospital again and this time the procedure took over four hours. I don’t remember this one as I was blissfully sleeping throughout, but was told afterwards that there were multiple sites that needed treatment. Recovery from ablation is very quick. I stayed in hospital overnight to ensure that my heart was happy and that the incision in the femoral artery had closed. The next day you’re home and on your way to a feeling better. I took a few weeks off work to rest.

It’s been over a year now since my last ablation and I’m very pleased with the results. My heart is so much better. It’s been a long emotional journey, not just for me but for my entire family. I’m due to have a check-up in the next two weeks but I feel confident about the future and know that I shouldn’t be frightened of this condition. I’m looking forward to starting a family and living a healthy happy life.

Louise Bees

Living with Wolff-Parkinson-White syndrome

Hi, I got diagnosed with Wolff-Parkinson-White syndrome (WPW) after nearly dying giving birth to my son.

I had suffered with palpitations for years, but nothing was done about it. Then, whilst I was pregnant, the attacks became more frequent and when I told my doctor I was given a 24-hour heart monitor to wear. After wearing the monitor, I was told that I was fine, so I just carried on.

27 hours into labour, my heart started racing. I couldn’t breathe and my lungs started filling with fluid. I was rushed for an emergency c-section and my son had to be resuscitated as his heartbeat had dropped because there wasn’t any oxygen getting to him.

The next thing I knew, I was waking up in intensive care on a ventilator, being told I had this condition WPW. What a shock that was.

I was put on verapamil for 3 months, and then I had a catheter ablation – which I might add was very painful.

That was 3 and a half years ago, I have been fine since and so is my son.

Lyndsay Morton

Living with Wolff-Parkinson-White syndrome

When I was 19 I was woken by a paramedic at 3am one morning. The paramedic had been called by my partner because I had stopped breathing and started fitting in my sleep.

Subsequently I was told that I was “stressed and its nothing to worry about”!

I kept getting severe palpitations – often out of the blue – which would make me pass out at times and feel quite sick.

I was still informed I was having severe panic attacks and learnt to deal with these symptoms.

On New Year’s Day in 2001, I collapsed with a severe chest pain and palpitations of 228 bpm. I was rushed in to hospital where they had to stop my heart beat and revive me. After several days of very frightening tests I was finally diagnosed as having what was then thought to be a very rare heart condition – Wolff-Parkinson-White syndrome (WPW). I was sent home to live ‘a normal life’ on two beta-blockers a day.

Two days later I was being revived by paramedics in my bed, as again I had turned blue with a heart rate going up to 200-240bpm and had started to fit. That night I was rushed into hospital and operated on within hours to undergo the cardiac ablation procedure.

After five hours in surgery and a week in hospital to recover I was informed how lucky I was to have gone through such a traumatic experience.

To this day I am grateful to still be here, and even more grateful to have had my daughter after being told that my heart may not be strong enough to go through pregnancy. I do still suffer palpitations and chest pains and continue to undergo tests and wear heart monitors several times a year.

Cardiomemo and event recorder

These are more sophisticated versions of the basic Holter. Whenever you have an attack of symptoms, you can activate the device to record your heart’s rhythm. (You can also do this with the digital Holter.) The advantage of the cardiomemo is that it doesn’t have any leads, so you can just place it on your chest when you get symptoms, without having to put any leads in position.

Arrhythmogenic right ventricular cardiomyopathy (ARVC)

Read personal stories from myheart members with ARVC here.

The incidence of arrhythmogenic right ventricular cardiomyopathy (ARVC) is now thought to be higher than previously believed (affecting 1 in every 1000 individuals), due to the availability of better diagnostic techniques and general awareness of the disorder amongst the medical profession. ARVC was first recognised in the late 1970’s. It is anticipated that even more information regarding ARVC will be available in the coming years, to help us understand the natural history of the condition.

What causes ARVC?

ARVC is caused by a defect in the ‘glue’ that holds the muscle cells of the heart together, working as a unit. When stretched the ‘glue’ breaks down, the muscle cells separate and an inflammatory process begins to repair the break. In a way the heart muscle sustains an injury that the body attempts to repair. As this process is repeated there is a progressive replacement of the normal heart muscle cells by scar tissue and fat. Initially this may only involve small areas of the right heart but later on it becomes global and may even involve the left side.

ARVC is inherited, passed on in the genes from one generation to the next. The pattern of inheritance is such that the child of an affected parent has 50% chance of inheriting the condition. The disease affects men and women equally and has been recognised in people of diverse ethnic origin.

What are the symptoms?

Clinical presentation is usually with symptoms of palpitations (feeling the heart pounding) because of a fast and irregular heart rhythm. The irregular heart rhythm may be associated with light-headedness or fainting episodes. Unlike most cardiomyopathies, shortness of breath and chest pains are unusual symptoms and tend to occur at the later stages of the disease.

How is it diagnosed?

The diagnosis of ARVC can be extremely difficult and usually requires specialist expertise. Your doctor will usually start by asking you some questions and examining you. Most of the investigations are painless and non-invasive, similar to those performed in the diagnosis of hypertrophic and other cardiomyopathies. Initial investigations include a tracing of the electrical activity of the heart (ECG) and an ultrasound scan (echocardiogram). As with hypertrophic cardiomyopathy (HCM), the ECG is very sensitive in picking-up ARVC since up to 80% of individuals with the disease will have an ECG abnormality. The echocardiographic features, however, can be very subtle in the early stages of the condition, often confined only to the right ventricle and therefore further imaging of the right side of the heart is required in most cases with a magnetic resonance imaging scan (MRI). Further evaluation includes an exercise treadmill test and a 24-hour Holter monitor (tape) in an attempt to capture the irregular heart rhythms. In some specialist centres further invasive investigations are performed in an attempt to identify the electrical faults of the heart muscle associated with ARVC (electrophysiological studies) and to biopsy part of the heart muscle and examine it under the microscope. These investigations, however, are not widely accepted, they are still being developed, can still miss ARVC, which affects some areas of the heart but not others and can be associated with potentially serious complications.

Advances in molecular genetics (DNA) means that in some centres, the condition may be diagnosed using a blood test. This test, however, is not available in every hospital, it is expensive, the results may take up to several months and it is not always positive in ARVC patients (we are able to identify a defective gene in 60% of clinically confirmed ARVC patients). It can be used after the clinical evaluation to confirm the diagnosis or in the context of family screening.

Treatment and advice

The majority of patients with this condition have no symptoms for many years unless irregular heart rhythm develops. Treatment in the majority of cases aims to prevent or at least control the irregular heart rhythms.

If your tests prove positive your specialist will advise you on lifestyle modifications. You will most likely be advised not to participate in competitive, strenuous activities.

Watch CRY’s myheart cardiologist, Dr Michael Papadakis talk about things to avoid with cardiomyopathy below.

Drug treatment may also be used to control the irregular heart rhythms. Drugs may include beta-blockers, amiodarone or sotalol.

In cases where drug treatment is unsuccessful in controlling rapid heart beats, an implantable cardioverter defibrillator (ICD) may be fitted. This is similar to a pacemaker where a box is implanted under the skin in the chest. The box has a fine wire which is attached to the heart to record and deliver electrical impulses in the presence of an abnormal heart rhythm.

It will be necessary for you to have at least annual check-ups which usually will include a repeat of the initial investigations. Since the disease runs in families, all first degree relatives of the affected patients have to be screened with ECG and Echocardiogram.

Dilated cardiomyopathy (DCM)

In dilated cardiomyopathy (DCM) the main pumping chambers of the heart are dilated and contract poorly. This results in a reduced volume of blood (low output) pumped around the body which fails to meet the body’s demand and features of what is commonly known as heart failure. There is a build up of fluid in the lungs and under the skin, which manifests as breathlessness and swelling of the legs and abdomen, respectively.

We are able to identify a specific cause for dilated cardiomyopathy in about 50% of patients. In the other 50%, however, the cause remains uncertain. The commonest causes of DCM in western societies includes coronary artery disease (narrowed coronary arteries) which may lead to reduced blood flow to the heart muscle and a heart attack resulting in ‘death’ of part of the muscle and a weak heart. Other common causes include longstanding high blood pressure, excessive alcohol intake and heart valve disease. Less common causes include viral infections, autoimmune diseases i.e. the body’s own defences mistakenly attack the heart muscle cells resulting in damage to the heart muscle, deficiency of several vitamins and other rare conditions.

In dilated cardiomyopathy, antibodies against the heart are found in approximately 30% of patients and in a similar proportion of the asymptomatic relatives. This and other evidence suggests that an autoimmune component may play an important part in the development and progression of dilated cardiomyopathy. The significance of the cardiac antibody in individuals without symptoms is under study.

CRY Consultant Cardiologist Professor Sanjay Sharma talks about dilated cardiomyopathy (DCM) below. This video was published in 2011 – please note that life expectancy following a diagnosis of DCM is now (July 2017) much better than in 2011.

Pregnancy

There is a form of dilated cardiomyopathy which develops during late pregnancy and in the period shortly following childbirth. The cause is uncertain but it is believed that the additional demand of pregnancy on the heart may be triggering factor in the development of the condition.

Genetics

Recently it has become apparent that dilated cardiomyopathy is inherited in at least 25% of cases. All first-degree relatives of patients diagnosed with DCM of unknown cause (idiopathic) should be screened to exclude the condition. Evaluation of the family has potential to clarify the genetic contribution to the development of the condition within individual families.

What are the symptoms?

Symptoms depend on the stage and evolution of the condition.

  • Shortness of breath– This is a common symptom which becomes worse with exertion.  It is caused by the build-up of fluid and elevated pressure in the lungs. When severe, there may be marked breathlessness at rest or even when the patient lies in bed. Patients may feel more comfortable sitting-up in bed by adding extra pillows or may experience sudden bouts of breathlessness which wake them up at night.
  • Lack of energy – If the heart is not pumping well and the body is not getting enough blood the muscles are unable to contract normally and easily become tired.
  • Ankle swelling– When the right side of the heart fails to expel the blood it receives, the fluid builds up in the body tissues. This is called oedema and usually presents initially with swelling of the ankles which can then extend up to the thighs, back and abdomen.
  • Chest pain– This may occur at rest or during exercise. Though the cause of the pain is usually not clear, it is important to exclude significant coronary artery disease i.e. angina.
  • Irregular heart rhythm– Irregular heart rhythms are a common complication. The heart can either beat irregularly, too rapidly (tachycardia) or too slowly (bradycardia). Such arrhythmias are often asoociated with an uncomfortable awareness of the heart beat (palpitations) and/or accompanied by dizziness and fainting.

How is it diagnosed?

Your doctor will usually start by asking you some questions and examining you. An electrocardiogram (ECG) should be performed followed by an echocardiogram. The echocardiogram provides images of the heart with measurements of the size of the chambers as well as determination of how well they contract. It may also provide evidence of the cause of dilated cardiomyopathy. Exercise testing, either on a treadmill or a bicycle, should be performed to stress the heart. This test is particularly useful as symptoms and abnormal heart rhythms may not be obvious at rest and only become apparent during exertion. Monitoring the heart rhythm with a continuous tape recording is also important to detect arrhythmias which may not be symptomatic. It might be necessary for you to have further investigations.

Treatment and advice

Treatment aims to improve the symptoms of heart failure, prevent complications, particularly those arising from the development of arrhythmias, improve the heart function and prolong life.

Lifestyle modification plays a pivotal role to DCM treatment. Your doctor may discuss the following things with you.

Reducing all cardiovascular risk factors:

Stop smoking with the help of smoking cessation clinics.
To improve dietary habits in order to lose weight, reduce the cholesterol and the salt in the diet. An expert dietician’s review can be very helpful.
Good control of the blood sugar if the patients is a diabetic.
To monitor and aggressively treat high blood pressure.
Regular exercise. The NHS provides exercise clinics run by expert nurses.
Limiting alcohol intake to the minimum possible. Current evidence suggest that no more than a small glass, preferably of red wine, should be consumed in a day.
Limiting fluid intake according to the physicians/specialist nurse advice.
Daily weighings using a reliable scale. Sudden, excessive increase in weight may be a sign of fluid built-up and may predate clinical signs by several days, acting as a warning sign.

Watch CRY’s myheart cardiologist, Dr Michael Papadakis talk about things to avoid with cardiomyopathy below.

The mainstay of heart failure treatment is drugs. It includes water tablets (diuretics) to get rid of excess fluid, angiotensin converting enzyme inhibitors (ACE-i) and beta-blockers. Other drugs may be necessary should symptoms persist on first-line treatment. Please note that ACE-i and beta-blockers have an abundance of evidence supporting their use in DCM and every patient should be on them unless contraindicated or significant side-effects arise.

When medical treatment fails device therapy may be necessary. This includes the insertion of specialised pacemakers under the skin that help the heart beat more efficiently. A small number of patients with dilated cardiomyopathy who do not respond to the above treatments may be referred to a specialist centre for assessment of the potential for cardiac transplantation. Strict criteria apply to the selection of patients in order to assure a successful transplantation.

Read myheart member, Paul Cowling’s story of living with dilated cardiomyopathy here.

Hypertrophic cardiomyopathy (HCM)

Read personal stories from myheart members with hypertrophic cardiomyopathy here.

Hypertrophic cardiomyopathy (HCM) is a condition where the heart muscle becomes thickened.

Traditionally, the term HCM was used for disease caused by abnormalities in genes which make the proteins responsible for contraction of the heart (sarcomeric contractile proteins). More recently the definition of HCM has been broadened to include a number of other conditions that result in thickened heart muscle. It is a hereditary disease i.e. it is passed on from parents. In the majority of cases the condition is inherited from a defective gene of one of the parents in such a way, that if a parent has an abnormal gene then each child has a 50% chance of inheriting the disease.

It is a disease that can affect both men and women of any ethnic origin. The condition is present from conception and excessive growth of the muscle may begin before birth when the foetal heart is developing. In a healthy adult heart, the muscle fibres are arranged in an organised fashion and their thickness does not exceed 12mm. In the HCM heart, however, the muscle becomes excessively thick and the fibres are arranged haphazardly making the heart vulnerable to some dangerous heart rhythms (ventricular fibrillation or ventricular tachycardia). The heart muscle also may thicken in individuals who have high blood pressure or who participate in prolonged athletic training, but in HCM patients the muscle thickens without an obvious cause.

What are the symptoms?

Symptoms and severity can vary from person to person.  They may begin in infancy, childhood, middle or elderly life.  No particular symptom or complaint is unique to HCM sufferers.  Most patients never experience any symptoms, thus affected individuals are often diagnosed during ECG screening or family screening.

The most common symptoms of HCM are:

shortness of breath
chest pains (usually brought on by physical exertion)
palpitations (rapid, irregular heart beat)
light-headedness, blackouts.

If you suffer from any of these symptoms it does not mean that you necessarily have HCM but if you visit your GP, he or she may suggest that you undertake some tests or may refer you to a cardiologist (a heart specialist).

How is it diagnosed?

Diagnosis involves having an ECG and an ultrasound scan of the heart (echocardiogram). The great majority (up to 98%) of individuals with HCM have an abnormal ECG, alerting the physician to the possibility of underlying heart disease. Although the echocardiogram is the gold standard test in the diagnosis of this condition, occasionally the ECG may become abnormal long before the excessive thickening of the heart can be observed in the echocardiogram. In individuals with a diagnosis of HCM or high index of suspicion, further tests with an exercise treadmill test and a 24-Holter is required. In some cases further imaging of the heart may be necessary using a magnetic resonance imaging scan (MRI).

Genetic testing can identify carriers of the HCM gene. Unfortunately, this form of testing is limited at the moment, as 3 in every 10 people who are known to have HCM do not have mutations of the genes known to be associated with HCM. An additional problem is that many families who do have the mutations appear to have a specific change to the DNA code which is not found in other families (known as a ‘private’ mutation). This sometimes makes it difficult to decide whether a mutation is causing the disease or not. Things are further complicated because people with the same mutation can have effects of varying severity. However, when a well known HCM gene is identified, it can be used after the clinical evaluation to confirm the diagnosis or in the context of family screening

Treatment and advice

There is no cure at present for HCM. Treatment is aimed at preventing complications and improving symptoms. Treatment can be obtained through lifestyle modification advice, drugs, specialised pacemakers, or in some cases, surgery.

If your tests prove positive your specialist will advise you on lifestyle modifications. You will probably be advised not to participate in competitive sport and strenuous activities.

Watch CRY’s myheart cardiologist, Dr Michael Papadakis talk about things to avoid with cardiomyopathy below.

For many people the condition should not significantly interfere with their lifestyle and can be controlled by drugs. Drugs are given initially when a patient presents with symptoms. A variety of drugs are used in the treatment of HCM and the choice of treatment will vary from patient to patient. However, in patients with severe symptoms, who do not respond to medical treatment, surgery may be suggested. A surgical myomectomy, where muscle is removed, is usually successful in the relief of symptoms. The operation involves removing a portion of the thickened muscle, which relieves the obstruction.

There are other forms of treatment, which are occasionally recommended for people with HCM.

  • Electrical cardioversion– This is for sufferers of atrial fibrillation (irregular heart beat), which is quite common in HCM patients.  It is carried out under general anaesthetic and involves the patient being given a small electric shock to the chest which restores the normal heartbeat.
  • Pacemaker– In HCM sufferers the normal electric signal may fail, and if so a pacemaker can be fitted.  This is a small box containing a battery which is placed in the chest under the skin and ensures the heart receives the necessary electrical signals.
  • Implantable cardiac defibrillator (ICD) – In cases where a rapid heart beat is seen that could potentially cause cardiac arrest, and cannot be controlled by drugs, an ICD may be fitted. This is similar to a pacemaker where a box is implanted under the skin in the chest. The box has a fine wire which is attached to the heart to record and deliver electrical impulses in the presence of an abnormal heart rhythm.

What should you do if you are diagnosed with HCM?

If your tests prove positive your specialist will advise you on lifestyle modifications.  You will probably be advised not to participate in continuous strenuous activities e.g. competitive sports.  For many people the condition should not significantly interfere with their lifestyle and can be controlled by drugs.  It will be necessary for you to have at least annual check-ups.  However, the severity of the disease varies from person to person and even if you have been diagnosed with HCM you may not necessarily present any symptoms and can live a fairly normal life.  Since the disease runs in families, all first degree relatives of the affected patients have to be screened with ECG and an echocardiogram.

Long QT syndrome (LQTS)

Read personal stories from myheart members with long QT syndrome here.

Download our LQTS information leaflet

Long QT syndrome (LQTS) is an ion channelopathy. Ion channelopathies (also sometimes referred to as arrhythmia syndromes or cardiac channelopathies)affect the electrical functioning of the heart without affecting the heart’s structure. They are a group of rare genetic conditions that are caused by abnormalities of the DNA known as mutations. They are usually inherited from parents although they can occur for the first time in a person. (If they occur for the first time they are described as sporadic.)

The mutations affect certain genes – specific segments of the DNA that are responsible for the production of cardiac ion channels. An ion is a chemical substance – such as sodium, potassium or calcium – that carries an electrical charge and forms the basis of the movement of electricity through the heart muscle. Each heart muscle cell is surrounded by a membrane that separates the inside from the outside of the cell . An ion channel is the route (the gate) that the ions take in and out of the heart muscle cells to allow the movement of electricity. The ion channels regulate the flow of electrical charge. If these channels do not behave normally, the electrical function of the heart becomes abnormal. The person can then be prone to arrhythmias (disturbances in the heart’s rhythm) that may cause blackouts or a cardiac arrest.

LQTS is the most common and best understood type of channelopathy.
It occurs in about 1 in 2,000 people. In 70% of people with LQTS, gene testing can identify the ion channels involved. In most cases two of the potassium channels that regulate the movement of potassium ions from the inside to the outside of the cell are affected. In a small proportion of people with LQTS, a sodium channel that regulates the flow of sodium ions from the outside to the inside of cells is affected.

In people with potassium channel associated LQTS, the channels do not behave as efficiently as normal. They let potassium ions into the cell too slowly. If the sodium channel is affected, too many sodium ions are allowed into the cell.

This results in an electrical disturbance in the cells of the heart called prolonged repolarisation. This can be seen on an ECG recording as a lengthening of the time period known as the QT interval.

What are the symptoms?

LQTS varies greatly in severity. Symptoms vary according to the type of channel involved, whether the person is male or female, their age, and the length of the QT interval on the ECG. Males are more likely to have symptoms before puberty, while females are more likely to have them in adolescence and early adulthood. Relatives from the same family who have inherited the same mutation may have very different experiences. For example, some may have a normal QT interval and not have any symptoms; some may have a very abnormal QT interval but no symptoms; and some may have a very abnormal QT interval and have many symptoms that put them at risk.

The most common symptom of LQTS is blackouts. Sometimes palpitations due to extra or ectopic heartbeats can be a problem.

Are there any physical signs?

There are usually no physical signs of LQTS. However, certain rare forms of LQTS may be associated with muscle weakness, minor abnormalities of the skull, chin, fingers and toes or reduced hearing.

How is it diagnosed?

Diagnosis involves having an ECG. Sometimes it is possible to tell which ion channel has been affected just by looking at the ECG recording. Unfortunately, in a proportion of people who might be carriers, the ECG may not show any sign of the condition. Repeated ECGs, exercise tests and 24-48 hour tape monitoring may be needed before the diagnosis is established. More recently some doctors have used slow injections of the hormone adrenaline (epinephrine) via a drip to try and improve the diagnosis of some potassium channel LQTS. There is no evidence however that this is any better than an exercise test.

Genetic testing can identify carriers of the LQTS gene. Unfortunately, this form of testing is limited at the moment, as 3 in every 10 people who are known to have LQTS do not have mutations of the genes known to be associated with LQTS. An additional problem is that many families who do have the mutations appear to have a specific change to the DNA code which is not found in other families (known as a ‘private’ mutation). This sometimes makes it difficult to decide whether a mutation is causing the disease or not. Things are further complicated because people with the same mutation can have effects of varying severity.

Treatment and advice

If you have LQTS, your doctor will advise you to avoid excessive exercise or strenuous athletic activities. He or she will also advise you to avoid certain drugs that can make the condition worse and which could increase the risk of blackouts and cardiac arrest.

Watch CRY’s myheart cardiologist, Dr Michael Papadakis, talk about things to avoid if you have an ion-channel disease below.

Other treatment options will vary depending on the severity of the condition. Those with one or more of the following features will likely need more intervention than those without:

a previous cardiac arrest
blackouts
a very long QT interval on the ECG
sodium channel mutations
some potassium channel mutations
young, adult women.

Drugs

The most commonly used drugs for LQTS are beta-blockers. These block the effects of adrenaline and associated natural chemicals in the body that make the heart pump harder and faster. They therefore also block the effects of exercise on the heart. They are effective in the most common forms of LQTS as they reduce symptoms and the risk of cardiac arrest. However, they are less effective in people with the sodium channel form of LQTS.

There are other more recent trends in drug treatment that look promising, but their long-term benefits are unknown. These involve using antiarrhythmic drugs. These drugs block disturbances in the heart rhythm. Potassium supplement pills have also been tried with occasional success.

Pacemaker or implantable cardioverter defibrillator (ICD)

If you are at high risk (for example if you have already had a cardiac arrest), or if drugs have failed to control your symptoms, your doctor may advise you to have a pacemaker or an implantable cardioverter defibrillator (ICD) fitted, as well as taking your medication. A pacemaker and an ICD both consist of an electronic box that is inserted under the skin and attached to the heart by special electrical ‘leads’. A pacemaker controls the heart rate and stops any excessive slowing of the heart that could trigger an arrhythmia. An ICD acts in the same way as a pacemaker but it can also identify any dangerous arrhythmias and deliver an electrical shock to reset the heart.

Surgery

Another option for high risk patients is to perform surgery to disrupt the nerves that release adrenaline and related chemicals at the heart. This is performed in only a small minority of individuals and is known as cervical sympathectomy and involves operating on the left side of the neck.

 

Progressive cardiac conduction defect (PCCD)

Progressive cardiac conduction defect (PCCD) is a rare condition. In people with PCCD, the heart’s electrical impulses are conducted very slowly and this results in the gradual development over time of heart block. (Heart block is a failure of the heart’s electrical impulse to conduct properly from the top chambers [the atria] to the bottom chambers [the ventricles]). The severity of the condition and its associated risk can vary. PCCD can cause arrhythmias – either because the heart’s rhythm is too sluggish (bradycardia and asystole), or because of rapid rhythm disturbances (tachycardia) arising from parts of the heart that have escaped normal regulation. In some people PCCD has been associated with sodium channel mutations that cause changes in channel behaviour similar to those found in people with Brugada syndrome.

What are the symptoms?

Dizziness and blackouts are the usual symptoms, cardiac arrest may also occur.

Are there any physical signs?

There are no physical signs usually except if there is heart block when the doctor may feel a slow pulse.

How is PCCD diagnosed?

The ECG abnormalities may be detected either on a standard ECG or with Holter monitoring. An electrophysiological study may also help the doctor make a diagnosis.  If a sodium channel mutation is identified in affected members of a family then it may also be found in other relatives.

Treatment and advice

If you have PCCD you will need to have a pacemaker fitted in order to stop dangerous bradycardia from occurring. You may also need to take antiarrhythmic drugs. Some people may need to have an implantable cardioverter defibrillator (ICD) fitted instead of a pacemaker. Medication alone does not help.

Short QT syndrome (SQTS)

This rare condition is similar to but distinct from long QT syndrome (LQTS). As the name suggests the QT interval in carriers is shorter than in normal people. This means that the heart takes a shorter time to repolarise or reset itself,making it prone to ventricular arrhythmias. There is also an increased risk of a less dangerous arrhythmia from the top chambers of the heart (the atria) called atrial fibrillation. This is an irregular and rapid heart rhythm that may go unnoticed or causes breathlessness and palpitations. As in LQTS, potassium channel genes are affected but instead of allowing less potassium through they allow through too much too quickly.

What are the symptoms?

Palpitations, blackouts and cardiac arrest.

Are there any physical signs?

There are no physical signs usually except if there is atrial fibrillation when an irregular rapid pulse may be felt by the doctor.

How is it diagnosed?

The ECG abnormalities are usually detected either on a standard ECG or a 24-hour Holter. An electrophysiological study may also help the doctor make a diagnosis. Genetic testing may find a potassium channel mutation in affected members of a family that may then also be found in other relatives.

Treatment and advice

If you have short QT syndrome (SQTS) it is likely that an implantable cardioverter defibrillator (ICD) will need to be fitted in order to treat dangerous arrhythmias. Quinidine has been used in some patients but it is unclear whether it is safe to rely on medication alone. Tablets may also be used to treat atrial fibrillation.