Premature heartbeats in a structurally normal heart: what is checked, when they matter, and what treatment has been shown to do

A skipped or "extra" heartbeat is one of the most common reasons people ask a doctor about their heart. In most cases the cause is a premature beat: an impulse that starts earlier than the normal one, either in the upper chambers (a premature atrial contraction, PAC) or in the lower chambers (a premature ventricular contraction, PVC). This article covers what is usually checked, which findings change the picture, and what the trials show about treatment.

What a premature beat is, and why it can feel like a pause

A premature beat is often followed by a pause, and the next beat can feel stronger. That is why people describe the same event as a "skip", a "flutter" or a "thump".

The feeling does not say which chamber the beat came from, how often it happens, or whether the heart is otherwise healthy. Only a recording of the heart's electrical activity at the moment of the symptom can answer those questions.

How common premature beats are in healthy people

• In a 1981 study of 101 adults (mean age about 49) in whom a full cardiac workup, including coronary angiography, was normal, 39 had at least one PVC on a 24-hour recording. Only four had more than 100 PVCs in 24 hours. The chance of having PVCs rose with age.

• On a short resting ECG they are much rarer. In a 1962 study, routine 12-lead ECGs lasting about 48 seconds were read in 122,043 apparently healthy men in the US Air Force flying population, aged 16 to over 50. Ventricular premature beats were present in 952 of them, 7.8 per thousand.

In other words, finding some premature beats on a 24-hour recording is common. The questions that matter are how many there are and what the heart around them looks like.

What is usually checked

The 2017 US guideline (American Heart Association, American College of Cardiology and Heart Rhythm Society) and the 2022 European Society of Cardiology guideline on ventricular arrhythmias describe the following checks:

• A 12-lead ECG, in the US guideline for suspected or documented ventricular arrhythmia, and in the European guideline as part of the first evaluation when frequent premature ventricular beats are newly documented.

• Ambulatory monitoring, often a Holter recorder for 24 hours or longer, to see whether symptoms such as palpitations happen at the same time as the beats and to count them. The count is often given as a burden: the share of all heartbeats that are premature.

• An echocardiogram in that first European evaluation, and, in the US guideline, when the beats may be linked to structural heart disease or to a risk of sudden cardiac arrest.

• An exercise test when symptoms come on with effort, when ischaemic heart disease is suspected, or when an adrenaline-triggered arrhythmia is possible.

• Cardiac MRI when the ECG, the echocardiogram or the history still leave structural heart disease as a real possibility, including when the pattern is not typical of a benign source.

A practical point: a recording helps only if it covers the time when symptoms happen. If the beats are felt mainly at night or during a particular activity, it makes sense to tell the doctor, so that the monitoring period includes it.

Which findings change the picture

Structural heart disease

The same number of premature beats means different things in a structurally normal heart and in a heart with scarring, a weak pump or another disease. Most of the reassuring data below come from people whose hearts were examined and found normal.

• In a 1985 follow-up of 73 people without symptoms whose healthy status had been confirmed by extensive non-invasive testing and who had frequent and complex ventricular ectopy (a mean of 566 ectopic beats per hour), two deaths occurred over a mean of 6.5 years, fewer than the 7.4 expected for the general US population. Invasive testing in a subsample did find serious coronary disease in 19%, which is a reminder that "no symptoms" and "normal heart" are not the same thing.

A high burden

Very frequent PVCs can, in some people, weaken the heart muscle over time. This is called PVC-induced cardiomyopathy.

• In a 2010 study of 174 patients referred for ablation of frequent PVCs with no other identified cause, 57 (33%) had a reduced ejection fraction. A burden above 24% best separated patients with and without reduced pump function, and the lowest burden linked to a reversible cardiomyopathy was 10%. This was a group of patients already referred for treatment, not the general population.

This is the main reason the burden is measured: it identifies the minority of people in whom the beats themselves may be a problem for the heart.

Beats around exercise

• In 29,244 patients (mean age 56) referred for an exercise test and without a history of heart failure, valve disease or arrhythmia, frequent ventricular ectopy during the recovery phase after exercise was associated with higher mortality over a mean of 5.3 years (adjusted hazard ratio 1.5). Frequent ectopy during exercise alone was not, after adjustment. This is an observational association in a clinical population referred for testing.

Population studies

• A 2013 meta-analysis of 11 observational studies with 106,195 people from general populations found that frequent PVCs were associated with a higher risk of sudden cardiac death (relative risk 2.64). Most of these studies did not test participants for underlying structural heart disease, so the authors could not separate the association with the beats from the association with undetected disease.

• For atrial premature beats, the Copenhagen Holter Study followed 678 people aged 55–75 without cardiovascular disease. Those with 30 or more supraventricular ectopic beats per hour, or runs of 20 or more, had more admissions for atrial fibrillation and more strokes over a median of 6.3 years. In 1,260 older adults from the Cardiovascular Health Study, each doubling of the hourly PAC count was associated with a 17% higher risk of atrial fibrillation. Both are observational associations.

What treatment has been shown to do

When the heart is normal and the beats are not bothersome

The 2017 US guideline does not recommend treating the beats in this situation. The 2022 European guideline states that there are no data showing a benefit from treating asymptomatic beats when pump function is preserved, and that pump function should be rechecked when the burden is high. It also says catheter ablation may be considered if premature ventricular beats are repeatedly more than 20% of all beats on follow-up recordings. Where the guidelines support treatment, it is for symptoms, or for a high burden together with reduced pump function.

Medicines and ablation

• For symptomatic PVCs in an otherwise normal heart, the 2017 US guideline says a beta-blocker or a non-dihydropyridine calcium-channel blocker is useful. For symptomatic outflow-tract beats in an otherwise normal heart, it says catheter ablation is useful when antiarrhythmic medicines are ineffective, not tolerated, or not the patient's preference.

• The 2022 European guideline recommends catheter ablation as first-line treatment for symptomatic PVCs, or ventricular tachycardia, from the right ventricular outflow tract or the left fascicles.

• In a randomized trial of 330 patients in China with frequent PVCs from the right ventricular outflow tract, PVCs recurred within a year in 19.4% after ablation and in 88.6% on antiarrhythmic drugs.

That trial measured how well the beats were suppressed. No randomized trial has shown that suppressing premature beats in a structurally normal heart changes survival.

Why suppression is not the goal in itself

The Cardiac Arrhythmia Suppression Trial (CAST) tested whether suppressing PVCs with encainide or flecainide would reduce sudden death after a heart attack in people who had at least six ventricular premature beats an hour and few or no symptoms. Over an average of 10 months, total mortality was 7.7% (56 of 730) on the drugs and 3.0% (22 of 725) on placebo. The trial was not in people with normal hearts. Its report says it is unknown whether the result applies to other patients.

Coffee

In a randomized trial published in 2023, 100 adults (mean age 39) were told by daily text message on which days to drink caffeinated coffee and on which to avoid caffeine, while wearing a continuous ECG recorder. The number of premature atrial beats did not differ significantly (58 vs 53 per day). The number of premature ventricular beats was higher on coffee days (154 vs 102 per day). The trial measured beats, not symptoms or heart health, over two weeks.

What these studies do not tell you

• They do not tell you whether your own beats matter. That depends on a recording, on the burden and on the structure of your heart.

• Most outcome data are observational. They show who is at higher risk, not that reducing the number of beats changes that risk.

• The cardiomyopathy thresholds come from patients referred for ablation. How often a burden of 10–24% causes problems in the general population is not established.

• A wrist device that estimates pulse from light can suggest an irregular pulse, but it is not a reliable way to tell what kind of beat it was. An ECG recording at the moment of the symptom is what a doctor can interpret.

What to do with the symptom

If you feel skipped or extra beats, the useful step is a conversation with a doctor about recording them: an ECG, a longer monitor that covers the times when you feel them, and an assessment of heart structure. Symptoms that need urgent care are different: fainting, chest pain, severe shortness of breath, or a fast heartbeat that does not settle.

This material is for information only and does not replace a consultation with a doctor.

Sources

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