Premature ventricular contractions (PVCs): extra heartbeats explained

The heart's normal rhythm is set by electrical signals that start in the upper chambers. An ectopic beat is an additional heartbeat. A factsheet from the AF Association, hosted by the Heart Rhythm Alliance, explains that it can arise either in the upper chamber (the atrium) or the lower chamber (the ventricle), and these are called premature atrial contractions (PACs) or premature ventricular contractions (PVCs). The beat occurs just before the normal heartbeat.

The NHS includes skipped or extra beats (ectopic beats) among the ways heart palpitations feel, alongside racing, pounding and fluttering. Palpitations can last seconds, minutes or longer. The British Heart Foundation says early or extra heartbeats are among the causes of palpitations, which are common and in most cases harmless.

The AF Association factsheet says ectopics can be felt either as an extra beat in the rhythm, or as a thud following a short pause. In the second case the additional beat has occurred in the pause and the thud is the heart catching up. It adds that ectopics tend to occur when the heart rate is slower, such as when relaxing in the evening or sleeping at night, which is why many people become aware of them in bed.

The NHS says you may feel palpitations in your chest, neck or throat. Although symptoms can be unpleasant or cause anxiety, the factsheet notes that they do not necessarily indicate any problem with the heart and that the extra beats will not usually cause any damage.

The NHS lists common causes of palpitations: strenuous exercise, lack of sleep, stress and anxiety, medicines, and alcohol, caffeine, nicotine and recreational drugs. Hormonal changes in pregnancy or menopause can contribute. Palpitations can also reflect iron deficiency anaemia, an overactive thyroid, a heart rhythm problem or other heart disease such as valve disease.

The British Heart Foundation adds smoking or vaping, triggering foods such as spicy or rich food, and over-the-counter medicines. The AF Association factsheet notes that some cold and flu remedies contain decongestants and other stimulating drugs that are probably best avoided.

• Caffeine, alcohol and nicotine.

• Stress, anxiety and lack of sleep.

• Some prescription and over-the-counter medicines.

• An overactive thyroid or anaemia.

• Underlying heart conditions, which are the reason evaluation matters.

The AF Association factsheet says a clinician will normally diagnose an ectopic beat from what you describe, and a heart tracing (ECG) may be recorded. If ectopics are less frequent they may not appear on a short ECG, so a portable monitor may be more likely to capture them, and in people with frequent symptoms a 24-hour ECG may be done to clarify the pattern and frequency and their relation to symptoms.

The NHS says an ECG, where small pads are stuck to the skin to check the heart's electrical signals, helps find the cause, and referral to a cardiologist may follow. It advises seeing a GP if palpitations keep coming back or happen more often, last longer than a few minutes, or if you have a heart condition or a family history of heart problems. The factsheet notes that in those with structural heart disease, ectopic beats may need closer assessment.

The NHS advises calling 999 or going to A&E if you currently have palpitations that do not go away, or you have them with chest pain, shortness of breath, or feeling faint or fainting. If these symptoms have stopped, it advises asking the GP surgery for an urgent appointment, calling 111 or using 111 online. The British Heart Foundation gives a similar list, including severe breathlessness, chest tightness, dizziness and blackouts.

The NHS arrhythmia page stresses that having these symptoms does not necessarily mean a heart rhythm problem, but that persistent or worsening palpitations should be checked.

Most people need reassurance and advice. The AF Association factsheet suggests cutting down on stimulants. If symptoms are persistent and uncomfortable, medical therapy may be appropriate, generally a beta blocker such as bisoprolol first; a calcium channel blocker such as diltiazem may be considered where beta blockers cannot be used, for example in asthma. The NHS says palpitations often do not need treatment, and that avoiding triggers such as stress, smoking, caffeine and alcohol can help when no health condition is responsible.

The British Heart Foundation suggests keeping a symptom diary to recognise triggers, drinking less caffeine, keeping alcohol within the recommended 14 units a week, managing stress and not smoking. If tests show an underlying heart condition, treatment depends on that condition. The factsheet summarises that ectopic beats are nearly always harmless but it is best to see a doctor for evaluation.