Lecture 5 Test 4

Question 1

What is the Mean Axis?

Answer 1

59 degrees

Question 2

Meaning of
Small arrow (Vector)?
Big Arrow?

Answer 2

• small electrical activity
• more electrical activity

Question 3

Looking at an EKG, if the vector is coming from a negative to positive? What is the deflection?

Answer 3

Positive deflection

Question 4

What is the deflection if the vector is up and down?

Answer 4

0 deflection

Question 5

What is the deflection if the vector is coming from positive to negative?

Answer 5

Negative deflection

Question 6

Where is the first part of the heart to be depolarized?

Answer 6

Left inner septum

Question 7

Meaning of aVR

Answer 7

augmented voltage right side go the body; other 2 leads of the triangle would be negative (RV + Basal septum)

Question 8

Meaning of aVL

Answer 8

Augmented voltage left side of the body; other 2 leads of the triangle would be negative (view: High lateral LV with Lead I)

Question 9

Meaning of aVF

Answer 9

augmented voltage foot lead (inferior); other 2 leads of the triangle would be negative (View: Inferior wall with Lead II, III)

Question 10

Which lead is used the least?

Answer 10

aVR

Question 11

What does it mean if the electrical current is moving from the anterior part of the heart towards the rear (away from V2)?

Answer 11

Anterior heart injury (negative deflection)

Question 12

What does it mean if the current is coming from the posterior part of the heart and towards V2?

Answer 12

Posterior heart injury (positive deflection)

Question 13

Where are lateral leads located?

Answer 13

V5 and V6

Question 14

What are anterior leads?

Answer 14

V1-V4

Question 15

V1 would show positive or negative deflections for P, QRS, T waves?

Answer 15

All negative deflections because its far away from the heart

Question 16

How would the deflections look on V4?

Answer 16

Large deflections because it’s right on top of the heart and in line with the Mean Axis

Question 17

Which lead is most helpful in 12 lead?

Answer 17

V2 (views posterior/anterior injury)

Question 18

Where are V1 and V2 placed?

Answer 18

Left/Right 4th intercostal space

Question 19

Where does V4-V6 get placed?

Answer 19

Along 5th intercostal space

Question 20

Where does V3 get placed?

Answer 20

Halfway between V2 and V4

Question 21

If the depolarization and repolarization of the QRS complex goes in the same direction, your deflection would be?

Answer 21

Positive with a negative T wave

Question 22

What is a biphasic T wave?

Answer 22

It’s half down and half up because its depolarizing in an abnormal way

Question 23

How do you figure out the Mean arterial axis?

Answer 23

Add Lead I and Lead III to get Lead II

Question 24

1 big box equals? (5mm x 5mm)

Answer 24

5mm height = 0.5 mV
5mm width = 0.2 secs

Question 25

What happens if you have a resistance at the left bundle branch?

Answer 25

Depolarization of the right ventricle is faster

Question 26

What does it mean if you have "rabbit ears" on your QRS?

Answer 26

There's a bundle branch block

Question 27

How do you know if it's a left/right bundle branch?

Answer 27

Figure out the Mean Axis of the heart

Question 28

How can you find the area of injury of the heart?

Answer 28

Find the area that's stuck in a depolarized state causing an abnormal current where there shouldn't be one.

Question 29

Based on 12 lead, R wave should look? S wave should look?

Answer 29

V1-V6 - small to big - big to small

Question 30

12 lead Shows the right ventricle current

Answer 30

V1-V3, aVR

Question 31

12 lead Views basal septum current

Answer 31

V2, V3, aVR

Question 32

12 lead Views anterior wall of the heart

Answer 32

V2-V4

Question 33

12 lead views lateral wall

Answer 33

V5, V6, Lead I, aVL

Question 34

small boxes in the EKG strip

Answer 34

1mm height = 0.1 mV 1mm width = 0.04 secs

Question 35

Normal QRS size

Answer 35

< 0.12 secs (3 small boxes)

Question 36

Normal PR interval

Answer 36

< 0.2 secs (5 small boxes)