CardiologyTier 1Approach to a presentation

Palpitations

Red flags

  • Palpitations + syncope/pre-syncope - haemodynamically significant arrhythmia
  • Palpitations + chest pain - consider ischaemia-driven arrhythmia
  • Family history of sudden cardiac death <40 years, or personal history of unexplained syncope - inherited arrhythmia syndrome (Long QT, Brugada, HCM, ARVC)
  • Known structural heart disease (prior MI, cardiomyopathy, severe valve disease) presenting with new palpitations - higher risk of VT
  • Irregular palpitations with a rate >150 in a young, otherwise well patient with pre-excitation on ECG - WPW with pre-excited AF is a medical emergency (avoid AV-nodal blockers)

Differential by mechanism

By mechanism
  • Ectopic beats (atrial or ventricular) - commonest cause overall, benign in a structurally normal heart, felt as a "skipped beat" or thump
  • Supraventricular tachycardia - AVNRT, AVRT (WPW), atrial tachycardia - abrupt onset/offset, regular, fast
  • Atrial fibrillation/flutter - irregularly irregular (AF) or regular fast (flutter)
  • Ventricular tachycardia - more concerning, associated with structural heart disease, may be haemodynamically unstable
  • Sinus tachycardia - physiological/secondary - anxiety, fever, anaemia, thyrotoxicosis, dehydration, PE, caffeine/stimulants, pregnancy
  • Non-cardiac - anxiety/panic disorder (very common), hypoglycaemia, phaeochromocytoma (rare)

Focused history

Characterise the sensation
  • Fast/slow, regular/irregular (ask the patient to tap it out), onset/offset abrupt or gradual, duration
  • Triggers - exertion, caffeine/alcohol/stimulants, posture change, specific movements (self-terminating with Valsalva suggests SVT)
  • Associated syncope/pre-syncope, chest pain, dyspnoea
Background
  • Structural heart disease, prior MI, cardiomyopathy
  • Family history of sudden death, inherited arrhythmia syndromes, cardiomyopathy
  • Medications (stimulants, thyroxine, QT-prolonging drugs), recreational drugs, caffeine intake
  • Thyroid symptoms, anaemia symptoms, anxiety/panic history

Focused examination

  • Pulse rate and rhythm, BP
  • Signs of structural heart disease - murmurs, displaced apex, signs of heart failure
  • Thyroid exam (goitre, tremor, lid lag)
  • Signs of anaemia
  • 12-lead ECG in everyone, even if asymptomatic at the time - look for pre-excitation (delta wave), QT interval, LVH, Brugada pattern, prior infarct

Investigation strategy

First-line
  • 12-lead ECG - during symptoms if possible (diagnostic), otherwise baseline for structural clues
  • FBE, TFT, UEC, glucose
Rhythm capture - matched to symptom frequency
  • Frequent (daily) - Holter monitor 24-48h
  • Less frequent - extended patch monitor (1-2 weeks), external loop recorder, or smartphone-based ECG
  • Rare but concerning (esp. with syncope) - implantable loop recorder
Further work-up if structural disease suspected or red flags present
  • Echocardiogram - structure/function
  • Exercise stress test - exertional or catecholamine-sensitive arrhythmia
  • Electrophysiology study if VT/inherited syndrome suspected

Management

By likely cause
  • Isolated ectopics, structurally normal heart, no red flags - reassurance, reduce stimulants/caffeine/alcohol; beta-blocker only if symptomatically troublesome
  • SVT - vagal manoeuvres/adenosine for acute termination; catheter ablation is first-line definitive therapy for recurrent symptomatic SVT (more effective and durable than long-term drug therapy)
  • AF/flutter - rate vs rhythm control strategy, anticoagulation per CHA2DS2-VASc regardless of symptom burden
  • VT or structural heart disease - urgent cardiology referral, consider ICD per guideline criteria, treat underlying cardiomyopathy/ischaemia
  • Secondary causes (thyrotoxicosis, anaemia, PE) - treat the underlying condition
  • Anxiety-driven palpitations - after cardiac causes excluded, psychological support/CBT; avoid over-investigation once reassured

Traps

  • Reassuring a patient based on a normal ECG taken between episodes - the ECG is only diagnostic if captured during symptoms
  • Missing pre-excitation (delta wave) on a resting ECG and later using an AV-nodal blocking drug (verapamil, adenosine relatively, digoxin) in pre-excited AF - can accelerate conduction down the accessory pathway to VF
  • Attributing palpitations to anxiety without checking TFT/FBE and a baseline ECG first
  • Under-investigating palpitations with syncope or a concerning family history - these need rhythm capture and structural assessment, not reassurance
  • Forgetting anticoagulation because AF is "just palpitations" and asymptomatic between episodes

Talk track

1. Characterise the rhythm before naming a cause

  • "Fast or slow, regular or irregular, abrupt or gradual onset - that alone narrows the differential substantially."

2. Always get a resting ECG

  • "Even asymptomatic, it can show pre-excitation, QT prolongation, or a Brugada pattern that changes everything."

3. Match monitoring to frequency

  • "Daily symptoms get a Holter; rare symptoms need a loop recorder - the tool has to be able to actually catch the event."

4. Red flags change the pace of work-up

  • "Syncope, a family history of sudden death, or known structural disease moves this from reassurance to urgent referral."

5. Don't forget the systemic causes

  • "Thyroid, anaemia, and the medication list are part of every palpitations work-up."

Study aid only. These notes are written with the help of AI. Not for guiding clinical decisions.