ECG 2_arrhythmias

Question 1

Changes on ECG seen in hypokalaemia

Answer 1

Question 2

Changes on ECG seen in Hyperkalaemia

Answer 2

Question 3

What’s Torsades de Pointes?

Answer 3

Polymorphic VT = VT with varying amplitude

Question 4

What’s characteristic of asystole?

Answer 4

No pulse, flat line

Question 5

Pathological changes in infraction

Answer 5

• ST elevation (fisrt change)
• T wave inversion
• pathological Q wave (full thickness MI, develop 8-12 hrs after full-thickness MI not re-perfused)

Question 6

What’s the significance of pathological Q wave?

Answer 6

pathological Q wave (full thickness MI, develop 8-12 hrs after full-thickness MI not re-perfused)

Question 7

(3) STEMI criteria

Answer 7

• ST elevation in >2 small squares in 2 adjacent chest leads

OR

• ST elevation in >1 square in 2 adjacent limb leads

OR

• new LBBB

Question 8

(2) ischaemic changes on ECG

Answer 8

• ST depression
• new T wave inversion

Question 9

(2) signs on ECG of the previous infarct

Answer 9

• T wave inversion (persists weeks to months)
• pathological Q wave (permanent)

Question 10

Signs on ECG of posterior wall (LV) infraction

Answer 10

• dominant R wave in V1/V2
• horizontal ST depression V1-V3

*Q waves only seen if chest leads are placed on pt’s back

Question 11

Signs of L ventricular hypertrophy on ECG (4)

Answer 11

• L axis deviation
• dominant S wave in V1
• tall R wave in V5/V6 (>big squares)
• T wave inversion in lateral leads

Question 12

Signs of R ventricular hypertrophy on ECG

Answer 12

• R axis deviation
• dominant R wave in V1
• dominant S wave in V5/V6
• T wave inversion in V1-3, II, III, aVF (right inferior)

Question 13

What can be seen in Right bundle branch block?

Answer 13

RBBB pattern

Question 15

What can be seen on ECG in ‘left anterior hemiblock’?

Answer 15

L anterior hemiblock = anterior fascicle of L bundle brunch

ECG: marked L axis deviation

Question 16

What can be seen in left posterior hemiblock?

Answer 16

left posterior hemiblock* = posterior fascicle of left bundle branch

*it is rare

ECG appearance: marked R axis deviation

Question 17

What’s bifasicular block

How does it appear on ECG?

Answer 17

Bifasicular block = RBBB + left anterior/posterior hemiblock

Appearance: RBBB + left/right axis deviaiton

Question 18

What’s trifascicular block?

Answer 18

Trifascicular = RBBB + left anterior hemiblock + left posterior hemiblock

Question 19

Signs on ECG of hyperkalaemia (3)

Answer 19

• wide, flat P waves
• wide, bizarre QRS
• tall tented T waves

Question 20

ECG changes in hypokalaemia (4)

Answer 20

• prolonged PR
• depressed ST
• flattened/inverted T wave
• prominent U wave

Question 21

Sign of hypercalcaemia on ECG (1)

Answer 21

short QT interval

Question 22

signs of hypocalcaemia on ECG (1)

Answer 22

prolong QT

Question 23

Signs of Wolf-Parkinson White on ECG (6)

Answer 23

• slurred upstroke into QRS complex = delta wave
• short PR interval
• wide QRS
• dominant R wave in lead V1 (if L sided accessory pathway)
• dominant S wave in V1 (if R sided accessory pathway)

Question 24

Possible ECG changes (common ones) in PE

Answer 24

• tachycardia
• R axis deviation
• RA enlargement (peaked P waves)
• RBBB
• RV dilatation (R dominant in V1)
• RV strain (T wave inversion in R chest and inferior leads)

Question 25

Possible classical/textbook changes on ECG in PE

Answer 25

S1 Q3 T3 pattern

(prominent S wave in lead I, Q wave and inverted T wave in lead III)

Question 26

Pericarditis pattern on ECG

Answer 26

• PR depression
• saddle-shaped ST elevation