Heart Palpitations: Causes,
When to Worry, and What Tests You Need

Heart palpitations are one of the most common reasons patients come to see me at Victoria Medical — and one of the most anxiety-provoking. That sudden awareness of your own heartbeat, the fluttering, the skipping, the pounding sensation in your chest or throat — it is difficult not to catastrophise. I understand that. But the clinical reality is more reassuring than most patients expect: in up to half of all cases, palpitations are not caused by a significant arrhythmia at all^[2].

That said, some palpitations do signal a rhythm disorder that requires prompt investigation and treatment. The challenge — for both patient and clinician — is distinguishing the benign from the significant. This article explains what palpitations are, what causes them, which symptoms should prompt urgent assessment, and which cardiac tests provide the clearest answers.

What Are Heart Palpitations?

Palpitations are defined as the awareness of an abnormal heartbeat — a rapid pulsation, an irregular rhythm, or a forceful beating that is not normally noticed^[1]. Patients describe them in different ways: a fluttering or racing in the chest, a "skipped beat" sensation, a pounding in the throat or neck, or a sudden awareness that the heart is beating too fast or too hard.

Palpitations are a symptom, not a diagnosis. They can reflect a cardiac cause, a non-cardiac systemic cause, a psychological cause, or simply a heightened awareness of normal cardiac activity during periods of stress, exercise, or anxiety. The sensation itself tells us relatively little about the underlying cause — which is why a structured clinical assessment is essential rather than reassurance based on the description alone.

They are also extremely common. Palpitations are one of the most frequent reasons for primary care consultations and represent the second most common reason for referrals from primary care to cardiology^[1]. If you are experiencing them, you are far from alone — and seeking assessment is the right response.

Common Causes of Heart Palpitations

Palpitations arise from changes in cardiac rate, rhythm, or contractility — but the trigger for those changes spans a wide spectrum, from entirely benign lifestyle factors to serious structural heart disease. The European Heart Rhythm Association classifies causes into four broad categories: cardiac arrhythmic, cardiac non-arrhythmic, systemic, and psychiatric^[5].

Of the cardiac arrhythmic causes, atrial fibrillation (AF) deserves particular attention. AF is the most common sustained cardiac arrhythmia worldwide, with a lifetime risk of 37% in people of European descent aged 55 and above^[4]. In England, an estimated 1.5 million people had AF in 2019, with a diagnosed prevalence of 1.6% in the general population — and the true figure is higher because AF is frequently asymptomatic and undetected^[4]. Untreated AF significantly increases the risk of stroke and heart failure, which is why palpitations that are irregular and sustained should always be investigated promptly.

Premature contractions — both atrial (PACs) and ventricular (PVCs) — are the most common arrhythmic cause of palpitations and are, in the vast majority of cases, benign. They produce the characteristic "skipped beat" or "thud" sensation that patients describe as the heart momentarily stopping before resuming. While alarming in the moment, isolated PACs and PVCs in a structurally normal heart rarely require treatment beyond lifestyle modification and reassurance.

When to Seek Medical Assessment

The clinical challenge with palpitations is that the subjective experience does not reliably predict the underlying cause. A patient with severe anxiety may describe terrifying palpitations that turn out to be benign PACs; a patient who barely notices their symptoms may have AF that has been present for months. For this reason, I recommend assessment for any palpitations that are new, recurrent, or associated with any of the following features.

I want to be clear about one thing: the presence of benign features does not mean palpitations should be dismissed without investigation. Even in patients with apparently low-risk presentations, a 12-lead ECG is the minimum appropriate first step — it takes less than five minutes, is entirely non-invasive, and can identify or exclude a significant arrhythmia with a high degree of accuracy. The clinical guideline from the BMJ's Rational Testing series is unambiguous: all patients presenting with palpitations should have a resting ECG and basic blood tests as part of their initial assessment^[3].

Which Tests Investigate Palpitations?

The diagnostic pathway for palpitations is built around one fundamental challenge: palpitations are usually intermittent, and the patient is typically in normal sinus rhythm by the time they are assessed. This means the initial resting ECG — while essential — may be normal even in patients with a significant underlying arrhythmia. Understanding the role of each test helps you understand what your doctor is looking for and why further investigation may be recommended even after a normal ECG.

The ECG: First-Line Investigation

A 12-lead resting ECG is the gold standard first-line investigation for palpitations^[1]. It records the electrical activity of the heart across twelve different perspectives, allowing identification of arrhythmias, conduction abnormalities, QT interval prolongation (which predisposes to dangerous ventricular arrhythmias), and signs of structural heart disease such as left ventricular hypertrophy.

If you are experiencing palpitations at the time of the ECG, the diagnosis is often straightforward. The limitation is that most patients are in normal sinus rhythm when they attend — which is why a normal resting ECG does not exclude an arrhythmia. It does, however, exclude several important diagnoses (pre-excitation syndromes, long QT, Brugada pattern) and provides a baseline for comparison if further monitoring is needed. At Victoria Medical, our private ECG test is available same-day, with results reviewed immediately by our clinical team.

The Echocardiogram: Assessing Heart Structure

An echocardiogram is an ultrasound scan of the heart. While an ECG measures electrical activity, an echocardiogram images the heart's physical structure — its chambers, valves, wall motion, and pumping function. It is the investigation of choice when palpitations may be caused by or associated with structural heart disease: hypertrophic cardiomyopathy, valvular disease, dilated cardiomyopathy, or reduced ejection fraction.

For patients with AF, an echocardiogram is a routine part of the workup — it assesses left atrial size (enlarged in long-standing AF), left ventricular function, and valve disease that may be contributing to the arrhythmia. For patients with ventricular ectopics or ventricular tachycardia, it is essential to exclude hypertrophic cardiomyopathy and other structural causes before reassurance can be given. Our private echocardiogram service is performed by a consultant cardiologist and provides a comprehensive assessment of cardiac structure and function.

Ambulatory Monitoring: Capturing Intermittent Arrhythmias

When the resting ECG is normal but palpitations continue, ambulatory cardiac monitoring extends the recording window to capture arrhythmias that occur intermittently. The 24–48 hour Holter monitor is the most widely used device, but its diagnostic yield for palpitations is relatively modest — approximately 16.5% — because most patients do not have a symptomatic episode during the recording period^[2].

For patients with less frequent symptoms, longer monitoring periods dramatically improve diagnostic yield. External loop recorders worn for up to four weeks, and automatically triggered recording devices, achieve diagnostic yields of 72–80% in patients with palpitations^[2]. The BMJ's guidance on investigating palpitations recommends adapting monitoring duration to the frequency of symptoms: daily symptoms warrant a 24–48h Holter; weekly symptoms warrant 7–14 day monitoring; monthly or less frequent symptoms warrant an external loop recorder^[3].

The key principle is this: a negative 24-hour Holter does not mean your palpitations are benign — it means the arrhythmia was not captured during that 24-hour window. If your symptoms are recurrent and the initial investigations are inconclusive, further monitoring is clinically appropriate and should be pursued rather than accepted as a dead end.

What to Do Next

If you are experiencing palpitations — whether for the first time or as a recurrent symptom — the appropriate first step is a clinical assessment that includes a thorough history, physical examination, resting ECG, and basic blood tests. This combination identifies the majority of significant underlying causes and guides the need for further investigation.

Dr George Xynopoulos — Consultant Physician & Cardiologist

"The patients who concern me most are not those who come in anxious about palpitations — they are the ones who dismiss them for months because they feel intermittent. Atrial fibrillation, in particular, can be entirely asymptomatic in some patients and dramatically symptomatic in others. The only way to know what you are dealing with is to capture it on an ECG. That is why I always say: if you have noticed your heart doing something unusual, even once, it is worth getting it checked. A five-minute ECG can provide enormous reassurance — or catch something important before it causes harm."

Frequently Asked Questions