Common ECG Abnormalities Flashcards Preview

ESA 2- Cardiovascular System > Common ECG Abnormalities > Flashcards

Flashcards in Common ECG Abnormalities Deck (107)
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1

Viewing from lead II, what does atrial depolarisation produce?

A small upwards deflection

2

Why is atrial depolarisation a small deflection?

Because there is only a small amount of muscle

3

What is the deflection from atrial depolarisation upwards (viewing from lead II)?

Because its moving towards the electrode

4

What is deflection caused by atrial depolarisation called?

The P wave

5

What does presence of the P wave show?

Atrial activity, at that the activity starts at the SAN

6

What is conduction from the atrium to ventricle via?

The AV node and bundle of His

7

How quick is conduction from atrium to ventricle?

Slow

8

Why is conduction from atrium to ventricle slow?

To allow time for atrial contraction to fill ventricle

9

What does conduction from the atrium to the ventricle produce on the ECG?

A isoelectric (flat) segment

10

How does electrical activity spread in the interventricular septum?

Down the left and right branches of the bundle of His, faster down the left bundle

11

What is the result of depolarisation being faster down the left bundle?

The muscle in the interventricular septum depolarises from right to left

12

What does depolarisation down the interventricular septum produce in the ECG wave?

A small downwards deflection

13

Why does spread down the interventricular septum produce a small downwards deflection (viewing from lead II)?

Downwards because moving away
Small because not moving directly away

14

What is the downwards deflection caused by the spread in the interventricular septum called?

Q wave

15

What does spread through the ventricle cause in the ECG (viewing from lead II)?

A large upwards deflection

16

Why does spread through the ventricle cause a large upwards deflection (viewing from lead II)?

Upwards because moving towards 
Large because lots of muscle, and moving directly towards the lead

17

What is the large upwards deflection caused by spread through the ventricle called?

The R peak

18

What happens at the end of depolarisation?

Depolarisation spreads towards the base of the ventricles

19

What is produced in the ECG when depolarisation spreads upwards to the base of depolarisation (viewing from lead II)?

A small downwards deflection

20

Why is a small downwards deflection produced at the end of depolarisation (viewing from lead II)?

Downwards because moving way 
Small because not moving directly away

21

What is the downwards deflection at the end of depolarisation called?

S wave

22

Where does ventricular repolarisation begin?

Epicardial surface

23

How does ventricular repolarisation?

In the opposite way to depolarisation

24

What does ventricular repolarisation produce in the ECG (viewing from lead II)?

Medium upwards deflection

25

Why does ventricular repolarisation cause an upwards deflection?

Because its moving away

26

What is the deflection caused by ventricular repolarisation called?

T wave

27

What is the first step in reading an ECG?

Assess rhythm

28

What do you need know to assess rhythm?

What it looks like in lead 2- don’t need to look at all 12 leads

29

What do you look at to assess rhythm?

The long rhythm strip

30

What do all ECG machines run at?

25m/sec