Wolff-Parkinson-White syndrome: symptoms, tests and treatment

The heart beats because of electrical signals that travel between its upper and lower chambers in an organised way. The British Heart Foundation (BHF) explains that in WPW syndrome there is an extra electrical pathway between the upper and lower chambers. It can create a loop that lets signals travel round and round, causing the heart to beat very fast. This is called tachycardia.

The NHS describes it as a heart condition that can cause a very fast heartbeat and says it is usually due to a problem with electrical connections that you are born with. The BHF says symptoms may not appear until later in life, and that many healthy young adults and children are diagnosed.

Some people have the extra pathway but never have a fast heartbeat. The BHF calls this a WPW pattern, noting that such people probably will not need treatment and that for some young people it improves as they grow up.

The main symptom, according to the NHS, is suddenly getting a very fast heartbeat that can last from a few seconds to several hours and usually stops by itself. How often it happens varies, from every day to a few times a year or less. Symptoms usually start in adults aged between 30 and 50 but can happen at any age.

• A fluttering feeling in the chest, or a heartbeat that is pounding, racing or going too slowly (palpitations).

• Feeling dizzy, lightheaded or faint.

• Shortness of breath.

• Chest pain or discomfort.

• Feeling anxious or sweaty, which the BHF also lists.

The BHF says WPW may show up differently in babies and small children. Signs can include not feeding well, acting restless or unsettled, a blue or grey tint to the skin, lips or nails, and fast breathing or difficulty breathing. Fainting is rare and usually only happens if the heart has been racing for over 30 minutes. It advises booking a GP appointment if you see such symptoms in a child, and, as with any child who is struggling to breathe or looks very unwell, using emergency help.

The NHS says to call 999 or go to A&E if you or someone else gets a fast heartbeat and it keeps happening or is getting worse, does not go back to normal after a few minutes, or comes with dizziness, sickness, faintness, shortness of breath or chest pain, if someone faints and cannot be woken, or if you have been diagnosed and the techniques you have been shown to stop a fast heartbeat are not working.

The BHF gives similar advice and adds chest, neck, jaw, arm or back pain lasting more than 15 minutes. It says to see your GP if you keep getting a fast or noticeable heartbeat, to make sure it is not something else serious. The NHS advises that you should not drive yourself to A&E and should bring any medicines you take.

If a GP thinks you could have a heart problem such as WPW, the NHS says they will refer you to a cardiologist for tests. The condition is usually diagnosed with an ECG, in which sensors on the chest record the heart's electrical activity. The BHF says it may be picked up during or after an episode needing medical attention, or during routine tests for palpitations when a WPW pattern is seen.

Other tests listed by the NHS include an exercise ECG on a treadmill or bike, wearing a small heart monitor for 24 hours or longer, an echocardiogram (ultrasound of the heart) and an electrophysiological (EP) study, in which thin tubes are passed through a vein to the heart to look at its electrical function in more detail. The BHF also mentions an adenosine test.

The NHS says treatment depends on your symptoms and whether your cardiologist thinks you are at high risk of serious problems. You may not need any treatment if you have no symptoms or only mild, rare ones. The BHF says people in high-risk jobs, such as pilots or professional athletes, sometimes have extra tests.

The NHS says the condition is not usually serious. In rare cases it can cause a fast heartbeat that is life-threatening, but treatment is offered if doctors think you are at risk. The BHF adds that some people with WPW also have atrial fibrillation, which can increase the chance of a very fast heartbeat, although this is rare.

The NHS says WPW is passed on from a parent to a child only in rare cases. The BHF says it is not known as an inherited condition but is sometimes found to run in families, and offers a genetic information service for questions.

Even if you do not need treatment, the BHF stresses the importance of attending appointments so your specialist can check your heart regularly. Learn the techniques you have been shown and keep a note of what triggers your episodes.

On the NHS, WPW is usually diagnosed after GP referral to a cardiologist, with ECG-based tests and, if ablation is needed, referral to a specialist heart rhythm (electrophysiology) service. Ablation is carried out by specialist heart rhythm teams.

Private cardiologists also see people with palpitations and WPW, mostly offering quicker appointments or a second opinion. The tests and treatments are the same, and whichever route you take, ask who will follow you up and how to get help if an episode does not settle.