ECG

Question 1

What does the p wave represent?

Answer 1

Atrial depolarisation

Question 2

What does the QRS wave represent and why is the R so tall?

Answer 2

Ventricular depolarisation

R wave- ventricular depolarisation directly toward the apex of a large amount of muscle

Question 3

What does LV hypertrophy show on ECG?

Answer 3

Taller R wave

Question 4

Which way is the IV depolarisation and which ECG wave depicts it?

Answer 4

Left to right

Q wave

Question 5

Why is the S wave a small downward defection?

Answer 5

Down ward because electrical activity moving away from apex and small because not directly away- oblique.

Question 6

Why is the T wave upright when viewed from the apex?

Answer 6

Depolarisation moving away from apex

Question 7

12 lead ECG has how many leads?

Answer 7

10=
6 chest
+
4 limb

Question 8

Which three leads look at the inferior heart?

Answer 8

II, aVF, III

Question 9

Which lead looks from the right shoulder obliquely?

Answer 9

aVR

Question 10

Which leads looks across the heart horizonatlly heart from the left limb?

Answer 10

I

Question 11

The oblique view of the heart from the shoulder is given by lead….

Answer 11

aVL

Question 12

The limb leads look at the heart in the ….. plane

Answer 12

vertical

Question 13

Which leads look at the left side of the heart?

Answer 13

I and aVL

Question 14

Which chest leads look at the right ventricle and septum?

Answer 14

V1 and V2

Question 15

Which chest leads are looking at the apex and ant wall of heart?

Answer 15

V3 and V4

Question 16

Which chest leads look at the LV?

Answer 16

V5 and V6

Question 17

Name the 4 lateral leads.

Answer 17

aVL, I, V5 and V6

Question 18

What time scale does one small square equate to on an ECG?

Answer 18

0.04 s

Question 19

0.2s is depicted by what on an ECG

Answer 19

A big square

Question 20

Why do we look at 30 large squares to get a rate in irregular rhythms?

Answer 20

30 large squares is 6 seconds so can times by 10 to get bpm

Question 21

How do we count the beats?

Answer 21

R-R cycles

Question 22

In a regular rhythm how do you get a rate?

Answer 22

Look at R-R interval
eg 4 big boxes
300 big boxes is a minute so how many lots of 4 boxes could you fit in 300 and thats your HR

Question 23

How do you measure a PR interval?

Answer 23

Start of P wave to start of Q wave.

Question 24

If a PR wave is >3-5 small boxes it signals….

Answer 24

ischaemia

Question 25

The QRS interval is the …. of the QRS complex and should be less than….s which is … boxes

Answer 25

width
0.12s
3 small boxes

Question 26

What ECG element varies with heart rate?

Answer 26

QT interval so we correct for it

Question 27

How do you measure a QT interval and whats the upper limit of normal?

Answer 27

Starts of Q to the end of T

0.45s in men 0.47s in women

Question 28

What must you check to confirm sinus rhythm?

Answer 28

Rhythm regular 
P wave present 
P wave upright in leads I and II
PR interval 3-5 small boxes 
P wave always followed by QRS
QRS not wider than 3 small boxes.

Question 29

Can you be in sinus rhythm but have tachycardia or bradycardia?

Answer 29

Yes sinus tachycardia and sinus bradycardia can happen