ECG's

Question 1

Hypokalaemia? (5)

Answer 1

• Prominent U-waves (esp in praecordial leads)
• T waves have a ‘sine wave’ appearance
• ST depression
• Prolonged QTc
• Prolonged PR

Question 2

Acute STEMI changes?

Answer 2

Hyperacute T waves for first few mins

ST elevation after this

T wave inversion after around 24 hours and can last days -months

Pathological Q waves after hours-days and persist forever

Question 3

Digoxin toxicity?

Answer 3

Downsloping ST depression (reverse tick)
Flattened/inverted T waves
Short QT interval
Arrhythmias (AV block, bradycardia)

Question 4

LBBB?

Causes of it?

Answer 4

Widened QRS and notched QRS in lateral leads

Widened NEGATIVE QRS in V1

Causes:

• ischaemia
• hypertension
• aortic stenosis
• cardiomyopathy

Question 5

RBBB?

Causes?

Answer 5

Widened QRS complexes
Positive V1

rSR waves and T inversion V1
qRs waves lateral leads

Causes:

• normal variant
• RVH
• Chronically increased RV pressure (e.g. cor pulmonale)
• PE
• MI
• ASD (osmium secundum)
• Cardiomyopathy/myocarditis

Question 6

Bi-fascicular block?

Answer 6

RBBB with left axis deviation

Question 7

Tri-fascicular block?

Answer 7

Bi-fascicluar block + 1st degree heart block

RBBB
Left axis deviation
PR prolongation

Question 8

Hypothermia?

Answer 8

Bradycardia
J wave - hump at end of QRS
Slowed PR and QT
Arrhythmias

Question 9

Normal variants in an athlete?

Answer 9

Sinus bradycardia
Junctional rhythm (bradycardia, narrow QRS, no relation with P waves)
1st degree heart block
Wenkebach (mobitz type I)

Question 10

Hyperkalaemia?

Answer 10

Peaked T waves (first to appear)
Loss of P waves
Broad QRS
Sinosoidal wave pattern
VF

Question 11

2 causes of peaked T waves?

Answer 11

Peaked:

• hyperkalaemia
• MI

Inverted:

• MI
• Digoxin toxicity
• SAH
• Arrhythmogenic RV cardiomyopathy
• PE
• Brugada

Question 12

1 cause of P wave amplitude?

Answer 12

Increased:
Cor pulmonale

Broad, notched (bifid) P waves:
Left atrial enlargement (usually MS)
Most pronounced in lead II

Question 13

4 causes of ST depression?

Answer 13

Secondary to abnormal QRS (LVH, LBBB, RBBB)
Ischaemia
Digoxin
Hypokalaemia

Question 14

4 main causes of PR prolongation?

Others?

Answer 14

• idiopathic (normal in athletes)
• IHD
• digoxin toxicity
• hypokalaemia

Others:

• aortic root pathology
• lyme disease
• rheumatic fever
• Sarcoidosis
• myotonic dystrophy

Question 15

1 cause of short PR interval?

Answer 15

WPW

Question 16

7 causes of left axis deviation?

Answer 16

• left anterior hemiblocl
• LBBB
• inferior MI
• WPW (right-sided accessory)
• hyperkalaemia
• congenital (ostium primum ASD, tricuspid atresia)
• obesity (minor)

Question 17

9 causes of right axis deviation?

Answer 17

• RV hypertrophy
• left posterior hemiblock
• lateral MI
• cor pulmonale
• PE
• ostium secundum ASD
• WPW (left-sided accessory)
• normal in infant <1y/o
• normal in tall people (minor)

Question 18

WPW?

Answer 18

• short PR interval
• slurred upstroke QRS (delta)
• Right/Left axis deviation depending on side of accessory

Question 19

Dextrocardia?

Answer 19

Inverted P wave lead I
Right axis deviation
Loss of R wave progression

Question 20

Hypercalcaemia?

Answer 20

Short QT interval

Question 21

Pericardial effusion?

Answer 21

Electrical alternans