ECG basics

Question 1

Rate if regular rhythm?

Answer 1

300/R-R

Question 2

Rate if irregular rhythm?

Answer 2

Count R waves in 10 seconds, multiply by 6.

Question 3

Axis Deviation?

Answer 3

Line up left thumb with I, Right with aVF.

Question 4

Normal Axis

Answer 4

L + R thumbs line up (+ve deflections)

Question 5

Left Axis Deviation?

Answer 5

L thumb lines up (+ve), R doesn’t (-ve)

Question 6

Right Axis Deviation?

Answer 6

L thumb doesn’t (-ve), R does (+ve)

Question 7

What do V1, V2 show?

Answer 7

R ventricle

Question 8

What do V3, 4 show?

Answer 8

Septum

Question 9

What to do V5, 6 show?

Answer 9

L side of heart

Question 10

QRS normal length?

Answer 10

≤ 0.12 seconds (2-3 small squares)

Question 11

Bundle Branch Block?

Answer 11

QRS in V1 + V6.
LBBB: ‘W’ in V1, ‘M’ in V6.
RBBB: ‘M’ in V1, ‘W’ in V6.

Question 12

Heart Block?

Answer 12

PR interval: ‘‘Deterioration of romantic relationship between P and QRS’’
Type 1: consistently prolonged.
Morbitz Type 1: progressively gets longer
Morbitz Type 2: normal, occasionally missing QRS
Complete: No association between P + QRS

Question 13

Ventricular Hypertrophy?

Answer 13

V1 + V5/6
RVH: V1 dominant R wave (+other signs covered later)
LVH: V5/6 >5 big big squares tall

Question 14

ST elevation basics?

Answer 14

Elevation, Depression + leads
Elevated in a few leads: MI
Depressed: Ischaemia OR posterior MI
Elevated in every lead: Pericarditis/Tamponade

Question 15

What do II, III and aVF show?

Answer 15

Inferior side of heart.

Question 16

Hyperkalaemia?

Answer 16

Generalized tall tented T-waves