Most palpitations are harmless, some are not, and the features that separate them are specific. What to notice, and what a cardiologist will ask you.
A palpitation is simply being aware of your own heartbeat. That awareness can take several forms — racing, pounding, fluttering, or the sensation of a skipped beat followed by a thump. The experience is unpleasant and often frightening, and the frightening quality is unfortunately a poor guide to whether it is dangerous.
The commonest cause is a normal heart
Extra beats — ectopics — occur in almost everyone. What people usually feel is not the extra beat itself but the pause after it and the unusually forceful beat that follows, because the ventricle has had longer to fill. In a structurally normal heart these are generally harmless, even when frequent enough to be distressing.
Fast rhythms are also often driven by something outside the heart entirely. Fever, dehydration, anaemia, an overactive thyroid, caffeine, alcohol, nicotine, some inhalers and decongestants, and anxiety all raise heart rate. Treating the driver treats the palpitations.
The features that change the assessment
- Fainting or near-fainting during an episode. This always warrants assessment.
- Chest pain, or breathlessness at rest, alongside the palpitations.
- An episode that carries on for many minutes and will not settle.
- A pulse that is irregular with no discernible pattern, which raises the question of atrial fibrillation.
- Palpitations in someone with a previous heart attack, known weak heart muscle, or valve disease.
- A family history of sudden unexplained death at a young age.
Atrial fibrillation deserves separate mention
Atrial fibrillation is an irregular rhythm of the upper chambers. It matters not primarily because of how it feels but because blood can pool and clot in the atrium, and that clot can travel to the brain. It is a leading cause of stroke.
Many people with it have no symptoms at all, which is why an irregular pulse found incidentally is worth an ECG rather than being dismissed. Where stroke risk assessment supports it, anticoagulation substantially reduces that risk — and aspirin is not an adequate substitute in this setting.
How to make the appointment more useful
The single most valuable thing is a recording made during an episode. If palpitations last long enough for you to reach a clinic or hospital, an ECG taken at that moment answers in one minute what weeks of monitoring may fail to capture.
Short of that, learn to feel your own pulse at the wrist and note whether it is fast or slow, regular or irregular, during an episode. Write down the date, the time, how long it lasted, what you were doing, and anything you had eaten or drunk. Many modern watches can record a single-lead ECG; those recordings are not definitive but they are genuinely useful to bring.