Learn ECG lessons

Each lesson teaches a few patterns, then quizzes you over everything so far. Simulator · Free quiz · Progress

🚨 Emergencies drill A quiz over the can't-miss patterns. No lessons to unlock, jump straight in. →

The learning path unlocks in order: finish one lesson to open the next.

Foundations · How to read any ECG

  1. 1 Part 1 · Orientation: the paper & the rate 3 reads + quiz
  2. 🔒 Part 2 · Rhythm: regular, sinus, linked? Locked
  3. 🔒 Part 3 · Axis & the intervals Locked
  4. 🔒 Part 4 · The waves I: depolarisation (P·Q·R·S) Locked
  5. 🔒 Part 5 · The waves II: repolarisation (ST·T·U) Locked
  6. 🔒 Part 6 · Chambers & synthesis Locked

Rate & the sinus node

  1. 🔒 The normal beat & sinus rate Locked
  2. 🔒 Sinus node dysfunction Locked

The atria (P wave)

  1. 🔒 Atrial enlargement: reading the P wave Locked
  2. 🔒 Atrial ectopy, fibrillation & flutter Locked
  3. 🔒 Multiple-P rhythms Locked

The AV junction (PR)

  1. 🔒 AV block I: the PR interval & Wenckebach Locked
  2. 🔒 AV block II: dropped beats & escape Locked
  3. 🔒 AV-nodal re-entry (SVT) Locked

Accessory pathways

  1. 🔒 Pre-excitation & AVRT Locked

Ventricular conduction (QRS)

  1. 🔒 Fascicular block & the axis Locked
  2. 🔒 Bundle branch blocks Locked
  3. 🔒 Pacemakers & device malfunction Locked

Ventricular voltage

  1. 🔒 Hypertrophy: QRS voltage Locked
  2. 🔒 Low voltage & infiltration Locked

Ventricular arrhythmias

  1. 🔒 Ventricular ectopy & tachycardia Locked

Ischemia (ST/T)

  1. 🔒 The earliest ischemia Locked
  2. 🔒 Territorial STEMI I: the anterior wall Locked
  3. 🔒 Territorial STEMI II: inferior, posterior & RV Locked
  4. 🔒 Hard ST calls Locked

ST/T mimics

  1. 🔒 ST-elevation mimics Locked
  2. 🔒 Other repolarization patterns Locked

The QT interval

  1. 🔒 The QT interval & Torsades Locked

Systemic & metabolic

  1. 🔒 Electrolytes Locked
  2. 🔒 Drug effects & toxicity Locked
  3. 🔒 Systemic & environmental clues Locked

Structural & congenital

  1. 🔒 Congenital heart disease Locked
  2. 🔒 Structural & positional oddities Locked

Reference · The 12 leads

A lead atlas you can open any time, no need to unlock it.

  1. 34 Lead II: the rhythm strip 1 leads
  2. 35 Einthoven's triangle: I, II, III 3 leads
  3. 36 Augmented leads & the frontal axis: aVR, aVL, aVF 3 leads
  4. 37 Septal precordials: V1–V2 2 leads
  5. 38 Anterior precordials & the transition zone: V3–V4 2 leads
  6. 39 Lateral precordials: V5–V6 2 leads
  7. 40 Putting it together: one dipole, twelve views 12 leads