ECG

Question 1

Unipolar leads measure the potential variation at a single point. Name the unipolar leads of an ECG

Answer 1

The augmented limb leads - aVR, aVL and aVF

Chest leads - V1-6

Question 2

There are three bipolar leads on an ECG. What do these measure?

Answer 2

The potential difference between two point

Question 3

The ‘lead’ of an E G refers to the electrical vector and not the wire. T/F?

Answer 3

True

Question 4

Which leads of the heart are used to visualise the heart in a coronary clock face?

Answer 4

Augmented limb leads and bipolar leads

Question 5

Which leads of the heart are used to visualise the heart in a transverse plane?

Answer 5

Chest leads V1-6

Question 6

If there is a positive deflection from the baseline on an ECG then the current is travelling in which direction in relation to the electrode?

Answer 6

Towards the electrode

Question 7

If there is a negative deflection from the baseline on an ECG then the current is travelling in which direction in relation to the electrode?

Answer 7

Away from the electrode

Question 8

If there is both positive and negative deflection from the baseline on an ECG then the current is travelling in which direction in relation to the electrode?

Answer 8

Parallel to the electrode

Question 9

How can the heart rate be measured by an ECG?

Answer 9

Divide 300 by the number of large squares between each QRS complex or use the number of QRS complexes across the ECG and multiply this by 6

Question 10

What is the QRS axis of an ECG?

Answer 10

The average vector of the ‘coronal clock face’ plane

Question 11

What is the normal range of values of a QRS axis of an ECG?

Answer 11

-30 to 90 degrees

Question 12

In a normal QRS axis the ARS complex is positive in which leads?

Answer 12

1 and 2

Question 13

In an ECG with a left QRS axis deviation in which lead(s) will the QRS complex be positive?

Answer 13

Lead one only

Question 14

What does a left QRS axis deviation indicate?

Answer 14

A problem with conduction on the left side

Question 15

What does an ECG with right QRS axis deviation indicate?

Answer 15

Rotation of the heart

Question 16

In an ECG with a right QRS axis deviation in which lead(s) will the QRS complex be positive?

Answer 16

aVF and lead 3

Question 17

An ECG with extreme QRS axis deviation where QRS is negative in leads one and two but positive in aVR could indicate?

Answer 17

Ventricular tachycardia

Question 18

The normal T wave has the same polarity as the QRS complex of an ECG. T/F?

Answer 18

True

Question 19

On an ECG what is the term given to any negative deflection after R?

Answer 19

S

Question 20

On an ECG if the first deflection of the QRS complex is negative then what is it called?

Answer 20

Q

Question 21

On an ECG, any further positive deflection after S is called…?

Answer 21

R’

Question 22

Bundle branch block will give a QRS complex greater than…?

Answer 22

120m seconds

Question 23

What sign on an ECG indicates MI?

Answer 23

Elevated ST segment