Ecg

Question 1

Where the positions of the limb electrodes

Answer 1

The right arm
Left arm
Left leg (Positive)

Question 2

What are the positions of the precordial chest leads

Answer 2

V1 - 4th intercostal space Right
V2 - 4th intercostal space left
V4- 5th intercostal space, midclavicular line
V5 - 5th intercostal space, anterior axillary line
V6 - 5th intercostal space, mid axillary line
V3- goes between 2 and 4

Question 3

What are the three unipolar limb leads

Answer 3

aVR (from the right side so would have the inverted ECG)
aVL (from the left arm so would have the smaller amp of the ECG, as would miss some of the signal)
aVF (from the left foot, would show the normal ECG)

Question 4

How can you test if you have put the limb leads in the right place

Answer 4

Add the voltage of lead 1 and 3 and this should equal that of lead 2

Question 5

What area of the heart does lead 1 and aVL cover

Answer 5

The high lateral side of the left ventricle

Question 6

What area of the heart does leads 2 and 3 and aVF cover

Answer 6

The inferior areas of the right and left ventricles

Question 7

What area of the heart would be covered by V1 AND 2

Answer 7

Right ventricle + normal septum

Question 8

What area of the heart does V2 AND 3 cover

Answer 8

The ventricular septum (basal septum)

Question 9

What area of the heart does V2 to V4 cover

Answer 9

The anterior wall of the heart
Mainly 3-4

Question 10

What side of the heart does V5 and V6 cover

Answer 10

The lateral wall of the heart

Question 11

What is the reason for the p wave

Answer 11

Atrial systole
Postitive ions moving to the postitive electrode
Positive deflect on the ecg

Question 12

What is the reason for the PR space

Answer 12

Would have the depolarisation at the AVN as the left atrium would need to empty
No ions move
Straight line

Question 13

What is the reason for the Q wave

Answer 13

Left ventricle would contract first and fast
This would move the ions across the inter-ventricular septum to the right side
This would not be moving to the positive node
Would have a negative deflect

Question 14

What is the reason for the QRS wave

Answer 14

The positive ions moving through the walls of the ventricles
Would move directly towards the electrode
Large positive deflect

Question 15

What is the reason for the S wave

Answer 15

The ions would be moving back up the walls of the ventricles away from the node
Would have a negative deflect

Question 16

What is the reason for ST space

Answer 16

The ions would need to depolarise before the ventricles can repolarise
Would have no ion movement
Straight line

Question 17

What is the reason for the T wave

Answer 17

The ventricles repolarise
The ions would be negative and would be moving to the negative electrode
negative to negative leads to a positive deflect

Question 18

When does atrial repolarisation occur and why can’t it be seen

Answer 18

Happens when the QRS (R) wave occurs
The repolarisation would be hidden under this big R Wave

Question 19

What part of the heart does aVR cover

Answer 19

The right ventricle and the basal septum

Question 20

What parts of the heart would be covered by the unipolar limb leads

Answer 20

aVR: right ventricle and the basal septum
aVL: the lateral wall of the heart
aVF: the inferior wall of the heart

Question 21

What leads cover the right coronary artery

Answer 21

Anterior lead (v3 and v4)
Inferior lead (2,3 and aVF)

Question 22

What leads would cover the left anterior descending artery

Answer 22

Septal leads
(V2 and v3)