Introduction
Palpitations is a common OSCE station that requires you to characterise the symptom precisely, systematically exclude life-threatening arrhythmias, and identify the most likely diagnosis. Most palpitations are benign, but missing a serious cause is a safety-critical error.
💎 Clinical Pearl
Ask the patient to tap out the rhythm of their palpitations. A patient demonstrating a regular fast rhythm vs irregular beats is more diagnostically useful than any verbal description.
Characterising the Palpitations
Speed and Regularity
| Description | Likely arrhythmia |
|---|---|
| Fast and regular | SVT (AVNRT), sinus tachycardia, atrial flutter (regular ventricular response) |
| Fast and irregular | Atrial fibrillation |
| Occasional single skipped beats | Ectopic beats (atrial or ventricular) — most common and benign |
| Sudden onset and offset | SVT (AVNRT, WPW) |
| Gradual onset and offset | Sinus tachycardia (anxiety, anaemia, thyrotoxicosis) |
Onset and Termination
- Sudden onset and sudden offset: SVT (AVNRT) — classic; ask if patient has learned vagal manoeuvres to terminate it
- Gradual onset: sinus tachycardia (anxiety, exertion, thyrotoxicosis)
- Ectopic beats: felt as a "missed beat" followed by a thump (post-ectopic beat)
Duration and Frequency
- How long does each episode last?
- How often do they occur?
- First episode or recurrent?
Associated Symptoms — Critical Questions
| Symptom | Significance |
|---|---|
| Chest pain or tightness | ACS, pericarditis, ischaemia-provoked arrhythmia |
| Syncope or presyncope | High-risk arrhythmia (VT, complete heart block, WPW) |
| Dyspnoea | AF with fast ventricular response, cardiac failure |
| Dizziness | Reduced cardiac output — haemodynamic compromise |
| Polyuria after episode | SVT (AVNRT) — characteristic feature (release of ANP) |
| Neck pounding | SVT — retrograde P waves causing pounding in neck |
Red Flags for Serious Arrhythmia
⚠️ Red Flag
Any of these features requires urgent cardiology assessment and cardiac monitoring:
- Syncope or near-syncope during palpitations
- Palpitations on exertion
- Family history of sudden cardiac death under 40
- Known structural heart disease (HCM, cardiomyopathy, valvular disease)
- Palpitations in a patient with ischaemic heart disease
- Irregular fast palpitations with dyspnoea (AF)
- Abnormal ECG between episodes
Causes of Palpitations
Cardiac Arrhythmias
- AF: irregular, associated dyspnoea in fast AF; ask about stroke risk factors (CHADS2-VASc)
- SVT (AVNRT): young adults, sudden onset-offset, regular, terminated by vagal manoeuvres
- WPW (Wolff-Parkinson-White): young, may present with fast irregular AF (dangerous)
- Ventricular ectopics: most common cause of palpitations; benign in a normal heart
- VT: wide complex tachycardia; usually in structural heart disease; haemodynamically compromising
Non-Cardiac Causes
- Anxiety and panic attacks: gradual onset, associated hyperventilation, somatic symptoms
- Thyrotoxicosis: tremor, weight loss, heat intolerance, goitre
- Anaemia: pallor, fatigue, dyspnoea on exertion
- Caffeine, alcohol, recreational drugs (cocaine, amphetamines)
- Medications: salbutamol, thyroxine, digoxin toxicity, antidepressants
- Fever
- Hypoglycaemia
Drug and Social History
- Caffeine intake (cups of coffee per day)
- Alcohol (units per week): AF trigger
- Recreational drugs: cocaine and amphetamines cause SVT and VT
- Medications: thyroxine overdose, excessive beta-agonist use (salbutamol), digoxin, antidepressants
- OCP (increases VTE risk in AF patients on anticoagulation)
DVLA Driving
⚠️ Red Flag
- Simple ectopics with normal heart and ECG: no restriction.
- Established AF: Group 1 — inform DVLA; may drive if symptoms controlled. Group 2 (HGV/bus) — off until successfully treated.
- SVT: Group 1 — off until controlled for 4 weeks. Group 2 — may be permanently barred depending on investigation.
- VT: Group 1 — off 6 months after ICD implantation or treatment. Group 2 — usually permanently barred.
How to Present
"This is a 26-year-old woman presenting with recurrent episodes of fast regular palpitations with sudden onset and sudden offset, lasting around 5 minutes each, associated with neck pounding and polyuria after the episode. There is no syncope, chest pain, or family history of cardiac death. The ECG between episodes is normal. This presentation is most consistent with SVT, likely AVNRT. I would arrange an ECG during an episode (event recorder), refer to cardiology for electrophysiology study, and advise the patient on vagal manoeuvres."
"How do you differentiate SVT from AF in the history?"
SVT (most commonly AVNRT) presents with sudden onset and sudden termination of fast, regular palpitations in a young adult. There may be neck pounding (retrograde P waves) and polyuria after the episode (ANP release). AF presents with fast, irregular palpitations that may be associated with dyspnoea and are more common in older patients with cardiovascular risk factors. AF does not have sudden offset and is not terminated by vagal manoeuvres.
"What features in a palpitations history suggest a serious arrhythmia?"
Red flags include: syncope or near-syncope during palpitations, palpitations provoked by exertion, family history of sudden cardiac death under 40, known structural heart disease or cardiomyopathy, irregular palpitations with dyspnoea (AF), and an abnormal ECG between episodes. These features require urgent cardiology assessment and prolonged cardiac monitoring.
"What non-cardiac causes of palpitations should you always ask about?"
Thyrotoxicosis (ask about weight loss, heat intolerance, tremor, goitre), anaemia (pallor, fatigue, dyspnoea), anxiety and panic disorder (gradual onset, associated hyperventilation, situational triggers), caffeine and alcohol excess, and medications including salbutamol, thyroxine, and recreational drugs such as cocaine and amphetamines.
"What is the clinical significance of polyuria after an SVT episode?"
During SVT, retrograde atrial activation causes atrial distension. This stimulates release of atrial natriuretic peptide (ANP), which causes a brisk diuresis after the episode terminates. Polyuria following palpitations is therefore a characteristic feature of SVT (particularly AVNRT) and helps distinguish it from other arrhythmias.
Related guides: Chest Pain History OSCE | ECG Interpretation OSCE | Syncope and Collapse History OSCE | How to Take a Cardiology History OSCE