Interpreting ECG

Question 1

What do you first check on the ecg?

Answer 1

Name
Date
Age
Prev ecg to compare

Question 2

How do you determine if it is a full standard ecg?

Answer 2

Standardization mark 2 large blocks tall

Question 3

How do you calculate rate using ecg?

Answer 3

300 divide by no. of small blocks between R waves

Question 4

How do you determine if the rhythm is sinus?

Answer 4

1. P wave before every QRS complex
2. QRS complex after every P wave
3. P wave upright leads I, II, III
4. Constant PR interval

Question 5

What do you look at determine ecg axis?

Answer 5

QRS in lead I and AVF

Question 6

How does a normal axis appear on ecg?

Answer 6

I = +
AVF = +

Question 7

How does a right axis appear on ecg?

Answer 7

I = -
AVF = +

Right -> becoming positive

Question 8

How does a left axis appear on ecg?

Answer 8

I = +
AVF = -

Question 9

How does an extreme left axis appear on ecg?

Answer 9

I = - 
AVF = -

Question 10

What is a P pulmonale?

Answer 10

P wave taller than 2 blocks

Question 11

What is a P mitrale?

Answer 11

P wave wider than 2 blocks

Question 12

How long should the PR interval be?

Answer 12

0.08 - 0.12s

Question 13

How long should the QRS complex be?

Answer 13

3 small blocks (0.12s)

M pattern seen in:
V1 = RBBB (right is first!)
V6 = LBBB

Question 14

How long should the QT interval be?

Answer 14

<0.45 <6 months

< 0.44 > 6 months

Question 15

Name causes of peaked, pointed T waves

Answer 15

Hyperkalemia

LVH

Question 16

Name causes of flattened T waves

Answer 16

Hypokalemia

Hypothyroidism

Question 17

Where do you look to assess T waves?

Answer 17

VI and VII
<7d = +
7d - 7y = inverted
>7y = +

Question 18

How does RVH appear on ecg?

Answer 18

Tall R waves in V1/V2
Deep S waves in V5/V6
Predominent R/S wave in VI and VII< 6 months can be normal
Increased R/S ratio in V1 or decreased R/S ratio in V6
ST segment and asymmetric T wave inversion in VI and VII – strain
R wave in V1 > 7mm

Question 19

How does LVH appear on ecg?

Answer 19

Tall R waves in V5 & V6
Deep S waves in V1 & V2
Abnormal R wave progression
T wave inversion in V5 and V6
Left axis deviation

Question 20

How do SVT and VT differ on ecg?

Answer 20

SVT = narrow QRS
VT = broad QRS