68 Harley Street London, W1G 7HE · Main Office
Also at Cromwell & Syon Bishops Wood · Multiple Locations
0203 9838 001 Call for Appointments
jessica@oneheartclinic.com Rapid Response to Enquiries
Heart palpitations — your questions answered
Feeling your own heartbeat can be unsettling, but the great majority of palpitations are harmless. The job of a cardiologist is to identify the small minority that signal something more serious — most often atrial fibrillation — and to give everyone else clear, genuine reassurance. On this page I answer the palpitations questions patients ask me most.
Palpitation assessment at One Heart Clinic
Palpitations are one of the most common reasons patients seek cardiology advice. Most causes are benign — but the key is distinguishing innocent ectopic beats from arrhythmias that carry real risk.
- Same-day ECG and echocardiogram
- 24-hour and 7-day ambulatory ECG monitoring
- Implantable loop recorder for infrequent episodes
- Smartwatch ECG review accepted in clinic
24-hour Holter monitoring captures heart rhythm during daily activity
When palpitations are an emergency — call 999
Call 999 if palpitations come with any of the following:
- Chest pain or pressure
- Severe breathlessness
- Fainting or near-fainting (blackout)
- A sustained very fast rate (above 140 bpm) that does not settle within a few minutes
A single fast or irregular episode that settles spontaneously usually does not need 999 — but it does deserve same-week cardiology assessment.
Questions on this page
- Why does my heart suddenly start racing for no reason?
- Are heart palpitations dangerous?
- When should I worry about palpitations?
- What does atrial fibrillation feel like?
- Can caffeine, alcohol or stress cause palpitations?
- Why do I feel my heart skip a beat?
- Are palpitations worse at night or when lying down?
- Can the menopause cause heart palpitations?
- What is a normal resting heart rate?
- What is the difference between AFib, SVT and ectopic beats?
- Will a Holter monitor detect my palpitations?
- Do palpitations mean I'll have a heart attack?
Why does my heart suddenly start racing for no reason?
A sudden episode of a fast, regular heartbeat that starts and stops abruptly is usually a supraventricular tachycardia (SVT) — an extra electrical circuit in the heart that fires off unpredictably. It feels alarming but is rarely dangerous.
Other causes include anxiety, dehydration, fever, an overactive thyroid, anaemia, and certain medications or stimulants. The pattern matters: SVT switches on and off like a light switch, while anxiety-driven tachycardia builds and fades more gradually. A captured ECG during an episode is the gold-standard diagnosis, which is why I often use wearable monitors in my clinic.
Are heart palpitations dangerous?
Most palpitations are not dangerous — particularly the very common "skipped beats" (ectopic beats) that almost everyone experiences from time to time. They become important when they are sustained, frequent, associated with chest pain, breathlessness or fainting, or occurring in someone with known heart disease.
Atrial fibrillation deserves special attention because, although the palpitations themselves are not life-threatening, untreated AFib significantly raises the risk of stroke. That is precisely why investigating palpitations properly matters — even when the outcome is reassuring.
"Palpitations are one of those symptoms that can sound alarming but are almost always benign. In my clinic I see everything from completely normal ectopic beats to atrial fibrillation that genuinely needs treatment. The important thing is to capture the rhythm during an episode — and modern monitoring makes that far more achievable than it used to be."
— Dr Sukhjinder Nijjer, Consultant Cardiologist, Harley Street
When should I worry about palpitations?
Palpitations warrant prompt assessment when they are accompanied by chest pain, breathlessness, dizziness, fainting or near-fainting, when they last more than a few minutes, when they happen during exercise, or when there is a family history of sudden cardiac death or inherited heart conditions.
Brief, occasional flutters with no associated symptoms — especially when triggered by stress, caffeine or tiredness — are usually benign. If you are uncertain, a single cardiology consultation with an ECG and an echocardiogram will almost always provide a definitive answer.
What does atrial fibrillation feel like?
Atrial fibrillation typically feels like an irregular, often fast, "fluttering" or chaotic sensation in the chest, sometimes with breathlessness, light-headedness or reduced exercise tolerance. Many patients describe it as their heart "running away with itself" in a way that feels neither steady nor predictable.
Importantly, around a third of people with AFib have no symptoms at all, which is why the first sign is sometimes a stroke. If you can take your own pulse during an episode and it feels completely chaotic and irregular, that is a strong clue. Smartwatches with single-lead ECGs (such as the Apple Watch) are increasingly useful for capturing AFib between clinic visits.
Dr Nijjer's clinical perspective Consultant Cardiologist · One Heart Clinic, 68 Harley Street
Palpitations are one of the most common reasons people come to see me, and the reassuring news is that the majority of cases are benign. The key question I always ask is: do you get them at rest or only on exertion? Are they brief or prolonged? Do they cause dizziness or near-blackout? These features point me toward the right investigation pathway.
Wearable ECG devices have genuinely changed palpitation investigation. I regularly review Apple Watch ECG strips in clinic that have captured the exact rhythm during a patient's symptoms — something that was almost impossible to achieve with traditional monitoring alone. If you have experienced palpitations, try to capture them on your device and bring the recording to your appointment. I also offer ambulatory ECG monitoring and, for very infrequent but concerning episodes, an implantable loop recorder.
Types of irregular heartbeat
Normal sinus rhythm
Regular beats at 60–100 per minute. Small flutters or missed beats that occur occasionally are usually innocent ectopics.
Ectopic beats
Extra beats arising from outside the normal pacemaker. Usually felt as a thud or missed beat. Common and usually benign.
Atrial fibrillation
Chaotic irregular rhythm with no pattern. Requires anticoagulation assessment and specialist management. Learn about AFib →
Can caffeine, alcohol or stress cause palpitations?
Yes — all three are well-recognised triggers. Caffeine and stress drive up adrenaline and can both cause ectopic beats and trigger SVT or AFib in susceptible people. Alcohol is particularly potent: a binge can provoke AFib in otherwise healthy people ("holiday heart"), and regular heavy drinking is an independent risk factor for chronic AFib.
Other common triggers include poor sleep, dehydration, large or late meals, decongestants and energy drinks. Keeping a brief symptom diary linking episodes to potential triggers is one of the most useful things a patient can do before their consultation — it often reveals patterns that change how the condition is managed.
"I regularly see patients who've been worried about their palpitations for months, sometimes years. In the majority of cases, a 7-day heart monitor and an echocardiogram give us a completely clear picture within two weeks. That clarity — knowing exactly what rhythm you're in and that your heart structure is normal — is genuinely reassuring in a way that repeated A&E visits cannot provide."
— Dr Sukhjinder Nijjer
Why do I feel my heart skip a beat?
The sensation of a "skipped beat" is almost always an ectopic beat — an extra beat fired early, followed by a slightly longer pause and then a forceful "thump" as the heart resets. It is the pause and the next beat you feel, not the skip itself.
Ectopic beats are extremely common and usually entirely benign. They become a concern when they are very frequent (more than 10% of all beats over 24 hours), when they trigger fainting, or when an underlying structural heart problem is present. A simple 24-hour Holter monitor can quantify them and put the question to rest.
Are palpitations worse at night or when lying down?
Yes — many people notice palpitations more in bed, particularly lying on the left side. This is partly because the chest wall is closer to the heart in that position, and partly because, with no other distractions, you become more aware of every beat.
Reflux can also trigger palpitations at night, and sleep apnoea is a well-recognised cause of nocturnal AFib. If your palpitations are clustered around sleep and you snore heavily or wake unrefreshed, a sleep study may be worth considering alongside cardiac investigations.
Can the menopause cause heart palpitations?
Yes — palpitations are reported by roughly half of women going through the menopause and perimenopause, driven by fluctuating oestrogen levels and an increased sensitivity to adrenaline. They are typically brief, irregular and not associated with other cardiac symptoms.
That said, the menopause is also a time when underlying heart disease begins to declare itself, so menopausal palpitations should not be dismissed without an ECG and a clinical review. There is more about women-specific heart risks on the women and heart disease FAQ page.
"In my clinic, I often start with a 7-day patch monitor rather than a 24-hour Holter because the diagnostic yield is substantially higher and the device is unobtrusive enough to wear normally — including in the shower. A captured ECG during a symptomatic episode is what turns a guess into a diagnosis, and that changes everything."
— Dr Sukhjinder Nijjer
What is a normal resting heart rate?
A normal resting heart rate for adults is 60–100 beats per minute, although well-trained athletes can sit comfortably in the 40s or 50s without any cause for concern. Heart rate naturally varies through the day, with lower rates during sleep and higher rates after activity, caffeine or stress.
Consistently above 100 bpm at rest (tachycardia) or below 50 bpm with symptoms (bradycardia) warrants assessment. Smartwatch data is genuinely useful here — a record of overnight resting heart rate trends is often more informative than a single clinic reading taken on an anxious afternoon.
What is the difference between AFib, SVT and ectopic beats?
The three commonest rhythm problems behave very differently. Ectopic beats are single early beats experienced as skips or thumps — usually harmless. SVT (supraventricular tachycardia) is a sustained, very fast but regular rhythm — typically 150–220 bpm — that starts and stops abruptly. Atrial fibrillation is a sustained, irregular and often fast rhythm caused by chaotic electrical activity in the upper chambers.
The treatment and risk profile of each is quite different. Ectopics usually need reassurance only. SVT can often be cured with a one-off ablation procedure. AFib requires stroke-risk assessment, rate or rhythm control and, in most cases, an anticoagulant.
Will a Holter monitor or ECG patch detect my palpitations?
A monitor can only diagnose what it captures, so timing matters. For daily symptoms, a 24-hour Holter monitor is usually sufficient. For weekly symptoms, a 7-day patch monitor is better. For rare but worrying episodes, an implantable loop recorder can monitor for up to three years.
A captured ECG during a symptomatic episode is what turns a guess into a diagnosis. Modern smartwatches (Apple Watch, Fitbit, Withings ScanWatch) with built-in single-lead ECG can also produce useful tracings that I am happy to review in clinic.
Do palpitations mean I'll have a heart attack?
No — palpitations and heart attacks are different problems. Palpitations are an electrical rhythm symptom; heart attacks are a "plumbing" problem caused by a blocked coronary artery. Having palpitations does not raise your risk of a heart attack.
The exception is if palpitations come alongside exertional chest pain, in which case both may be driven by the same underlying coronary disease. If you have palpitations alongside any chest discomfort, breathlessness or fainting, please seek a prompt cardiology review.
Related conditions and investigations
See Dr Nijjer for a palpitations assessment
Dr Nijjer offers same-week palpitations clinics with on-site ECG, echocardiography and rapid access to 7-day patch monitoring. Most patients leave with a clear diagnosis and a firm plan within a fortnight.
Book a ConsultationTrusted external resources
This page provides general information for educational purposes and is not a substitute for personalised medical advice, diagnosis or treatment. Always seek the advice of your GP or a qualified medical professional with any questions about a medical condition. In a medical emergency, call 999. Last reviewed ; next review due .