Palpitations

Palpitations are an unpleasant awareness of the heartbeat, described as pounding, fluttering, racing, skipping or flip-flopping. They occur in healthy people with benign ectopy and sinus tachycardia, and in patients with arrhythmia or structural heart disease. The history usually points to the rhythm, but an ECG recorded during an event is needed for a definitive diagnosis.

Clinical relevance. Palpitations are the presenting complaint in about 15% of primary care cardiac consultations. Most causes are benign (sinus tachycardia from anxiety, caffeine, anaemia, thyrotoxicosis; premature atrial or ventricular beats). Dangerous causes include ventricular tachycardia, atrial fibrillation with rapid response in a patient with pre-excitation, long QT syndrome, and sick sinus syndrome. Palpitations with syncope, family history of sudden death, or structural disease need urgent assessment.

Classification by pattern.

• Isolated skipped or extra beat (premature atrial or ventricular contractions).
• Sustained regular fast rate with abrupt onset and offset (supraventricular tachycardia, atrial flutter, ventricular tachycardia).
• Sustained irregular rapid rhythm (atrial fibrillation, multifocal atrial tachycardia).
• Gradual onset and offset, linked to emotion or exertion (sinus tachycardia).
• Pounding of a regular, slow or normal rhythm (anxiety, hyperdynamic states, compensatory pause after ectopic, bradycardia with large stroke volume).
• Rapid fluttering in the neck (cannon A waves in atrioventricular dissociation).

Classification by cause. Cardiac (arrhythmia, structural disease, valve disease), non cardiac (anxiety, thyrotoxicosis, anaemia, fever, hypoglycaemia, phaeochromocytoma, pregnancy, medication), and psychiatric.

History.

• Description of the sensation (fast, slow, irregular, pounding), taps on the table to reproduce the rhythm, regularity, rate if measured.
• Onset and offset (abrupt suggests re-entrant tachycardia; gradual suggests sinus), duration, frequency, triggers (exertion, emotion, caffeine, alcohol, posture, lying on the left side, meals), relief with vagal manoeuvres (supraventricular tachycardia).
• Associated: chest pain, dyspnoea, dizziness, syncope, presyncope, sweating, polyuria after episode (atrial natriuretic peptide, supraventricular tachycardia or atrial fibrillation), tremor, weight loss, heat intolerance, headache, flushing.
• Past history: heart disease, rheumatic fever, congenital heart disease, myocarditis, thyroid disease, anaemia, diabetes, panic disorder, pregnancy, previous arrhythmia, surgery.
• Family history of sudden death, cardiomyopathy, long QT syndrome, Brugada syndrome, pre-excitation.
• Drugs and substances: caffeine, alcohol, nicotine, cocaine, amphetamines, energy drinks, decongestants (pseudoephedrine), salbutamol, theophylline, levothyroxine, thyroid hormone, digoxin, antiarrhythmics, tricyclics, antipsychotics, macrolides, fluoroquinolones, antihistamines, herbal products.
• Psychological: anxiety, panic attacks, stress, depression, trauma, sleep.

Examination.

• Pulse (rate, rhythm, volume), blood pressure, orthostatic change, temperature, oxygen saturation, weight.
• Thyroid size, eye signs, tremor, sweating.
• Cardiac: jugular venous pressure (cannon waves), apex, murmurs (mitral stenosis, mitral prolapse, aortic stenosis, hypertrophic cardiomyopathy), added sounds.
• Pallor, features of heart failure, signs of alcohol use, anaemia.
• Lung examination, abdominal examination.
• Anxiety signs, hyperventilation.

Red flags.

• Syncope or presyncope with palpitations, chest pain, severe breathlessness.
• Family history of sudden cardiac death under 50.
• Known structural heart disease, heart failure, prior myocardial infarction, cardiomyopathy.
• ECG abnormality: delta wave, long QT, short QT, Brugada pattern, epsilon wave, bundle branch block, left ventricular hypertrophy, Q waves.
• Palpitations during exercise or while swimming.
• Heart rate over 150 or irregular rapid rate with hypotension.
• Pregnancy with palpitations and dyspnoea.
• Pre-excitation with atrial fibrillation.

Cardiac arrhythmia. Premature atrial and ventricular beats, sinus tachycardia, atrial fibrillation, atrial flutter, atrioventricular nodal re-entrant tachycardia, atrioventricular re-entrant tachycardia (Wolff-Parkinson-White syndrome), atrial tachycardia, ventricular tachycardia, torsades de pointes, sick sinus syndrome (tachycardia bradycardia syndrome), bradycardia with compensatory beats, pacemaker related.

Structural and valvular heart disease. Mitral valve prolapse, mitral stenosis, aortic stenosis, aortic regurgitation, hypertrophic cardiomyopathy, dilated cardiomyopathy, arrhythmogenic right ventricular cardiomyopathy, congenital heart disease, myocarditis, ischaemic heart disease, heart failure.

Metabolic and endocrine. Thyrotoxicosis, anaemia, hypoglycaemia, hypokalaemia, hypomagnesaemia, hypocalcaemia, phaeochromocytoma, carcinoid, menopause, pregnancy, fever, hypovolaemia, hypoxia.

Drugs and substances. Caffeine, nicotine, alcohol (holiday heart), cocaine, amphetamines, stimulants, decongestants, bronchodilators, thyroid hormone, digoxin toxicity, antiarrhythmics, QT prolonging drugs, vasodilators with reflex tachycardia.

Psychiatric. Panic disorder, anxiety, somatic symptom disorder, depression, post traumatic stress, health anxiety.

Others. Postural orthostatic tachycardia syndrome, inappropriate sinus tachycardia, autonomic dysfunction, chronic obstructive pulmonary disease, pulmonary embolism, sleep apnoea, vagal reflexes, high output states (arteriovenous fistula, Paget disease, beriberi).

1. 12 lead ECG for all patients (also while symptomatic if possible): rhythm, rate, PR interval, delta wave, QRS width, QTc, ST and T wave changes, left ventricular hypertrophy, Brugada pattern, epsilon waves.
2. Blood tests: full blood count, ferritin, urea, creatinine, electrolytes (potassium, magnesium, calcium), glucose, thyroid stimulating hormone and free thyroxine, liver function tests, troponin if chest pain, pregnancy test, natriuretic peptide if heart failure suspected, drug levels (digoxin), toxicology screen as indicated.
3. Echocardiography for murmurs, abnormal ECG, heart failure, family history, suspected structural disease or before ablation.
4. Rhythm documentation:

• Holter monitor (24 to 48 hours) for daily symptoms.
• Event recorder or patch monitor (7 to 30 days) for weekly symptoms.
• Implantable loop recorder (up to 3 years) for rare events with syncope.
• Smartphone or smartwatch ECG for documentation by the patient.

1. Exercise testing for exertional palpitations (catecholaminergic polymorphic ventricular tachycardia, long QT, ischaemia).
2. Electrophysiology study for suspected pre-excitation, recurrent supraventricular tachycardia, or unexplained syncope with structural disease.
3. Cardiac MRI for cardiomyopathy, myocarditis, scar.
4. Genetic testing and family screening for channelopathies and cardiomyopathies.
5. Screening for anxiety, panic disorder and depression (GAD-7, PHQ-9) when cardiac evaluation is negative. Sleep study if apnoea suspected.
6. Plasma or urine metanephrines if episodic hypertension, sweating and headache.

Limits. Short monitors miss infrequent episodes. A normal ECG between episodes does not exclude paroxysmal arrhythmia. Electrophysiology study is invasive. Premature ventricular beat burden over 10% to 15% of beats can cause cardiomyopathy and needs follow up.

Unstable patient (hypotension, chest pain, syncope, heart failure, altered consciousness) with tachycardia: synchronised direct current cardioversion under sedation (broad complex 100 to 200 J biphasic; narrow complex regular 70 to 120 J; atrial fibrillation 120 to 200 J). Pulseless: cardiac arrest management.

Narrow complex regular tachycardia (suspected supraventricular tachycardia), stable.

• Vagal manoeuvres: modified Valsalva (blow into a 10 mL syringe for 15 seconds in semi recumbent position, then lie flat with legs raised for 15 seconds), carotid sinus massage (not with bruit), cold water face immersion.
• Adenosine 6 mg rapid intravenous bolus into a large vein with 20 mL saline flush. Give 12 mg after 1 to 2 minutes if no response, and a further 12 mg.
• Adenosine cautions: give 3 mg through a central line; avoid in asthma, 2nd or 3rd degree block, and with dipyridamole or carbamazepine; reduce to 3 mg with cardiac transplant. Warn of brief chest tightness and impending doom.
• If adenosine fails or is contraindicated: verapamil 2.5 to 5 mg intravenously over 2 minutes (repeat 5 to 10 mg after 15 to 30 minutes, maximum 20 mg), or diltiazem 0.25 mg/kg intravenously over 2 minutes. Avoid these in heart failure, hypotension, or pre-excitation with atrial fibrillation. Alternatively metoprolol 2.5 to 5 mg intravenously over 2 minutes.
• Recurrent supraventricular tachycardia: catheter ablation (success over 95%) is first line for patients preferring cure.
• Oral prophylaxis with bisoprolol 2.5 to 10 mg daily, verapamil 40 to 120 mg three times daily or diltiazem 60 mg three times daily.
• Pill in the pocket (flecainide 100 to 200 mg, or diltiazem 120 mg with propranolol 80 mg once at onset) for infrequent episodes after documented safety.

Atrial fibrillation.

• Rate control (target resting heart rate under 110): bisoprolol 2.5 to 10 mg daily, metoprolol 25 to 100 mg twice daily, diltiazem 60 to 120 mg three times daily or slow release 120 to 360 mg daily (not in heart failure with reduced ejection fraction).
• Or digoxin 0.125 to 0.25 mg daily (loading 0.5 mg intravenously/orally then 0.25 mg every 6 hours for two doses, adjusting for kidney function and age).
• Rhythm control (symptomatic, younger, new onset, heart failure): cardioversion (synchronised 120 to 200 J) after 3 weeks of anticoagulation or exclusion of atrial thrombus by transoesophageal echocardiography, within 48 hours of onset with immediate anticoagulation.
• Flecainide 300 mg orally once (pill in the pocket 200 to 300 mg) or 2 mg/kg intravenously over 10 minutes in structurally normal hearts.
• Amiodarone 300 mg intravenously over 1 hour (or 5 mg/kg) then 900 mg over 24 hours, then 200 mg orally three times daily for 1 week, 200 mg twice daily for 1 week, then 200 mg daily, with thyroid, liver, lung and eye monitoring.
• Catheter ablation.
• Stroke prevention: CHA2DS2-VASc score (heart failure 1, hypertension 1, age 75 or older 2, diabetes 1, stroke or thromboembolism 2, vascular disease 1, age 65 to 74 1, female sex 1).
• Anticoagulate men with score 2 or more, women 3 or more, and consider at 1 (men) or 2 (women).
• Choose apixaban 5 mg twice daily (2.5 mg twice daily if two of age 80 or more, weight 60 kg or less, creatinine 133 micromol/L or more), rivaroxaban 20 mg daily with food (15 mg if creatinine clearance 15 to 49 mL/min), edoxaban 60 mg daily (30 mg if creatinine clearance 15 to 50 mL/min or weight 60 kg or less), or dabigatran 150 mg twice daily (110 mg if age 80 or more).
• Warfarin (INR 2 to 3) is required in moderate to severe mitral stenosis or mechanical valve. Assess bleeding risk (HAS-BLED) and address modifiable factors.
• Treat precipitants: thyrotoxicosis, alcohol, hypoxia, sepsis, hypokalaemia, valve disease, sleep apnoea.

Ventricular arrhythmias. Stable monomorphic ventricular tachycardia: amiodarone 300 mg intravenously over 20 to 60 minutes then 900 mg over 24 hours, or procainamide 10 to 17 mg/kg at 20 to 50 mg/minute, or synchronised cardioversion; treat the underlying disease; implantable cardioverter defibrillator; ablation.

Torsades de pointes: magnesium sulphate 2 g intravenously over 10 minutes, correct potassium to over 4.5 mmol/L, stop QT prolonging drugs, overdrive pacing or isoprenaline. Premature ventricular beats: reassurance if burden low and no structural disease; beta blocker or calcium channel blocker for symptoms; ablation for burden over 10% with falling ejection fraction.

Bradycardia related. Atropine 500 micrograms intravenously repeated every 3 to 5 minutes to a maximum of 3 mg, and transcutaneous pacing if ineffective.

Non cardiac causes. Thyrotoxicosis: propranolol 10 to 40 mg three times daily, carbimazole 20 to 40 mg daily (maximum 60 mg) and specialist management. Anaemia: treat the cause (ferrous sulphate 200 mg daily). Caffeine, alcohol, nicotine, stimulants: reduce or avoid. Anxiety and panic: explanation, breathing retraining, cognitive behavioural therapy, sertraline 50 mg daily or propranolol 10 to 40 mg as needed.

Phaeochromocytoma: alpha blockade (phenoxybenzamine 10 mg twice daily increasing to 1 mg/kg daily) then beta blockade, and surgery. Postural orthostatic tachycardia syndrome: fluids 2 to 3 litres, salt 6 to 10 g daily, compression, exercise reconditioning, and specialist drugs. Pregnancy: reassure for benign palpitations; manage arrhythmias with metoprolol, adenosine, and electrical cardioversion when needed.

Lifestyle. Reduce caffeine, alcohol, tobacco, energy drinks and stimulants; maintain sleep, hydration, regular exercise; keep a symptom diary.

Monitoring. Review results of ambulatory monitoring in 2 to 4 weeks. For antiarrhythmic and anticoagulant therapy check ECG, renal function, liver function, thyroid function, and INR as appropriate.

Referral and escalation. Cardiology or electrophysiology for documented arrhythmia, structural heart disease, family history, abnormal ECG, or palpitations with syncope. Endocrinology for thyroid disease. Psychology for anxiety. Obstetrics for pregnant women.

Admission. Haemodynamic instability, syncope, ventricular tachycardia, pre-excitation with atrial fibrillation, new onset atrial fibrillation with heart failure or ischaemia, drug toxicity, severe electrolyte abnormality, or unexplained palpitations with high risk features.

Safety netting. Return urgently for fainting, chest pain, breathlessness, a heart rate over 150 that does not settle, or palpitations lasting over 30 minutes with symptoms.

Special groups. Children and young adults: supraventricular tachycardia, pre-excitation and channelopathies. Athletes: bradycardia is physiological but exertional palpitations need evaluation. Pregnancy: benign ectopy common; exclude anaemia, thyroid disease and peripartum cardiomyopathy. Older adults: atrial fibrillation, sick sinus syndrome, drug interaction. Endemic regions: rheumatic mitral stenosis, Chagas disease, thyrotoxicosis and anaemia.