Paroxysmal atrial fibrillation: when the irregular rhythm comes and goes

Atrial fibrillation (AF) is a heart rhythm problem in which the heartbeat is not steady. The British Heart Foundation explains that the electrical signals in the top chambers of the heart, the atria, do not get sent out properly. They should be steady and regular, but instead they quiver or twitch, which makes the heart beat randomly and means it does not pump blood as well as it should.

The word paroxysmal refers to the pattern, not to how severe each episode is. In paroxysmal AF the rhythm goes in and out of AF. The British Heart Foundation sets the pattern out as one or more episodes within 7 days, which start and stop and can last from a few minutes to a few days. Episodes usually settle on their own without treatment, although the charity says they sometimes need treatment if they happen often.

The British Heart Foundation describes four patterns, and the NHS uses the same ideas in simpler terms. Where a person sits among them can change over time, and the NHS notes that over time you may always have symptoms, which it calls permanent AF.

The NHS lists the main symptoms as an irregular heartbeat where the pulse is not steady, a sudden feeling that the heart is pounding, racing, fluttering, skipping or missing a beat, a heartbeat faster than 100 beats per minute, feeling very tired, finding it harder to exercise, chest pain or tightness, and feeling short of breath, lightheaded, dizzy or like you might faint.

Because the heart returns to a normal rhythm between episodes, a pulse check or ECG done at an appointment can be normal. This is a practical problem rather than a reason to doubt your experience. The British Heart Foundation says AF usually gets noticed when a healthcare professional checks your pulse during an examination or check-up, and that devices such as smart watches can help notice AF, but only a healthcare professional can diagnose it.

• Note the date and time of episodes, how long they last and what you were doing.

• Check your pulse at the wrist during an episode: the British Heart Foundation says a normal resting rate is steady and usually between 60 and 100 beats a minute, while in AF the pulse has no set pattern.

• Tell the GP if palpitations keep happening or are getting worse. The NHS lists this as a reason to see a GP.

The NHS says to call 999 if you currently have a fast or irregular heartbeat and any of these symptoms: chest pain, shortness of breath, sweating, feeling or being sick, fainting, feeling dizzy or falling over, a severe headache, weakness or numbness on one side of the face or body, blurred vision or loss of sight, or confusion or difficulty speaking. It adds that you should not drive yourself to A&E.

The stroke-type symptoms in that list matter because AF can allow blood clots to form in the heart. The NHS says treatment should help lower the risk of complications such as blood clots, stroke and heart failure.

The NHS says AF is caused by a problem with the electrical system that makes the heart beat. Anyone can get it, but you may be more likely to if you are aged 55 or older, are a man, live with obesity or overweight, smoke, take certain medicines such as levothyroxine, lithium or some asthma medicines like salbutamol, or do endurance sports such as long-distance running, cycling or skiing.

Other conditions can lead to it: high blood pressure, heart conditions such as heart failure or mitral valve problems, a heart attack, chronic kidney disease, an overactive thyroid, diabetes and sleep apnoea. The British Heart Foundation adds that it can be triggered by alcohol, caffeine, smoking, recreational drugs, emotional stress and spicy food, and that many people have no known condition or risk factor. When no cause can be found it is sometimes called lone AF.

The NHS notes that sometimes AF is caused by another health condition or medicine, and in those cases treating the condition or stopping the medicine can improve symptoms. That is a decision for the doctor, not something to do alone.

If a GP thinks you could have AF, the NHS says they will refer you to a heart specialist (cardiologist), who will ask about your symptoms, check your heart rate, and arrange tests to see if anything else could be causing your symptoms and to check your heart rhythm. Tests may include an electrocardiogram (ECG), an echocardiogram, a chest X-ray and blood tests.

An ECG records the rhythm, rate and electrical activity of the heart, according to the British Heart Foundation. For paroxysmal AF, which may not be present during a short recording, the NHS and BHF pages read for this guide list an ECG and do not describe longer monitors. The cardiology team will decide whether more extended rhythm monitoring is needed for you.

The NHS says people diagnosed with AF will have regular check-ups to make sure symptoms are under control, and may be given medicine to control the rate and rhythm of the heart, such as beta blockers, and to lower the risk of blood clots or stroke (anticoagulants). Other possible treatments are ablation (burning, freezing or using high-energy electrical pulses to destroy a section of the heart), electrical cardioversion to reset the rhythm, and a pacemaker or implantable cardioverter defibrillator (ICD).

The British Heart Foundation emphasises that anticoagulants and DOACs are the most effective treatments to reduce stroke risk. Anticoagulation is about the risk of stroke, not about how often episodes happen, so it is usually discussed even when episodes are short and infrequent.

The NHS says there is currently no cure for AF but treatment should help manage symptoms and lower the risk of complications, and that you should be able to carry on doing most things as usual, including exercise. It advises avoiding intense exercise and not exercising when you have symptoms. If you drive you may need to tell the DVLA, and there may be practical matters such as travel with medicine and insurance.

Self-help advice from the NHS includes avoiding triggers such as caffeine, spicy food, stress, dehydration and lack of sleep, keeping to a healthy weight, eating a balanced diet, aiming for at least 150 minutes of moderate exercise a week, not smoking and not drinking too much alcohol. The British Heart Foundation notes that stress and anxiety are common after a heart condition diagnosis and offers emotional support through its helpline and online community.

On the NHS the route normally runs from the GP to a cardiology or arrhythmia clinic for tests, followed by medicines and, if needed, a procedure such as ablation. Private cardiology can offer quicker access to tests and consultations, and some private providers offer extended rhythm monitoring, but the principles of treatment, including stroke prevention, are the same. If you move between settings, take your ECG results and medicine list with you.