ECG Changes

Question 1

Hyperkalaemia

Answer 1

• Tall tented T waves
• Absent P waves
• Prolonged PR
• Wide QRS

Question 2

Hypokalaemia

Answer 2

• Flat T wave
• U wave present
• ST depression
• PR prolongation

Question 3

Hypercalcaemia

Answer 3

• Short QT
• j waves possible

Question 4

Hypocalcaemia

Answer 4

• Long QT

Question 5

NSTEMI

Answer 5

• ST depression
• T wave inversion
• Pathological Q waves

Question 6

STEMI

Answer 6

• ST elevation
• T wave inversion
• New left bundle branch block

Question 7

Pericarditis

Answer 7

PeRicardiTiS

• Widespread saddle shaped ST elevation
• PR depression, followed by T wave flattening and eventual inversion

Question 8

Pericardial Effusions

Answer 8

• Low QRS complex voltage

Question 9

Atrial fibrillation

Answer 9

• Irregularly irregular rhythm/QRS complexes
• Absent P waves
• Absent isoelectric baseline
• QRS complex <120ms
• Fibrillatory waves

Question 10

Heart failure

Answer 10

• Broad QRS

Question 11

Pulmonary Embolism

Answer 11

S1Q3T3
- Large S wave in lead 1
- Large Q wave in lead 3
- Inverted T wave lead 3

Question 12

Leads showing change, site of heart and coronary artery affected

Answer 12

Septal - V1, V2 - Left anterior descending
Anterior - V3, V4 - Left anterior descending
Inferior - II,III, aVF - Right coronary
Lateral- I, aVL, aVR, V5, V6 - Lateral circumflex

Question 13

Left Bundle Branch Block

Answer 13

WiLLiaM
- QRS looks like W in V1 and V2, looks like an M in V4-V6
- Deep S wave in V1, tall late R wave in V6

Question 14

Right Bundle Branch Block

Answer 14

MaRRoW
- QRS looks like a M in V1 and V2, looks like an W in V4-V6
- Tall late R wave V1, Slurred S wave V6

Question 15

All 4 heart blocks

Answer 15

• First degree AV block: PR >0.2s
• Mobitz type 1: increasing PR until QRS drops. PR resets and cycle repeats
• Mobitz type 2: PR remains constant, QRS drops intermittently
• Third degree: P waves and QRS completely dissociated

Question 16

Atrial flutter

Answer 16

Sawtooth-like F waves (p wave after p wave)

Question 17

AVRT (Wolff Parkinson White)

Answer 17

• Short PR
• Slurred delta wave
• Wide QRS

Question 18

ventricular ectopic tachycardia

Answer 18

random abnormal QRS on background of normal ECG

Question 19

Prolonged QT syndrome

Answer 19

> 430 in men
450 in women

Question 20

Torsades de Pointes

Answer 20

Twisting/oscillating of QRS complexes
Long QT