EKG Conference

Question 1

What are the 3 bipolar leads of heart?

Answer 1

Lead I
Lead II
Lead III

Question 2

What are the unipolar leads of the heart?

Answer 2

aVR
aVF
aVL

Question 3

What are the precordial unipolar leads of the heart?

Answer 3

V1
V2
V3
V4
V5
V6

Question 4

What direction is the mean frontal plane vector and what is its range?

Answer 4

It goes down and to the left.

The normal angle of the MFP vector is from -30 degrees to 105 degrees.

Question 5

Of all the leads, which one has the largest deflection and why?

Answer 5

Lead II. It is parallel with the to the MFP vector.

Question 6

What is the PR interval of the EKG?

Answer 6

It is when the SA node activates the atria and then activates the AV node and the His bundle and Purkinje fibers after that.

Question 7

What is the normal time range of the PR interval?

Answer 7

120 - 200 ms

Question 8

What is the QRS complex of the EKG?

Answer 8

It is the activation of the ventricles.

Question 9

What is the normal time range of the QRS complex?

Answer 9

70 - 100 ms

Question 10

What is the QT interval?

Answer 10

It is the duration of the action potential OR the refractory period

Question 11

What is the normal time range of the QT interval?

Answer 11

250 - 430 ms

Question 12

What is the ST segment?

Answer 12

It corresponds with the plateau of the action potential and shifts up or down can indicate ischemia or infarction.

Question 13

What is the U wave of the EKG?

Answer 13

It is thought to be the repolarization of the Purkinje fibers.

Question 14

What makes the U wave more prominent?

Answer 14

Hypokalemia

Question 15

What is the probable cause if all the EKG reading show very high amplitude?

Answer 15

Hypertrophy of the heart

Question 16

What part of the cardiac cycle is lost more and more with increasing heart rate?

Answer 16

The diastole of the T wave to the R wave is lost more and more with increasing heart rate.

Question 17

Where is lead aVR connected? What is its detection region?

Answer 17

Right Arm - Indetermined

Question 18

Where is lead aVF connected?

What is its detection region?

Answer 18

Left Leg - Inferior

Question 19

Where is lead aVL connected?

What is its detection region?

Answer 19

Left Arm - Lateral

Question 20

Where is V1 connected and what is its detection region?

Answer 20

4th intercostal space on right - Septal

Question 21

Where is V2 connected and what is its detection region?

Answer 21

4th intercostal space on left - Septal

Question 22

Where is V3 connected and what is its detection region?

Answer 22

Midway between V2 and V4 - Anterior

Question 23

Where is V4 connected and what is its detection region?

Answer 23

Left mid-clavicular line in 5th intercostal space - Anterior

Question 24

Where is V5 connected and what is its detection region?

Answer 24

Left anterior axillary line at the level of V4 - Lateral

Question 25

Where is V6 connected and what is its detection region?

Answer 25

Left midaxillary line at the level of V4 - Lateral

Question 26

Where are the positive and negative ends of Lead I connected? What area does it detect?

Answer 26

Positive - Left Arm Negative - Right Arm Lateral

Question 27

Where are the positive and negative ends of Lead II connected? What area does it detect?

Answer 27

Positive - Left Leg Negative - Right Arm Inferior

Question 28

Where are the positive and negative ends of Lead III connected? What area does it detect?

Answer 28

Positive - Left Leg Negative - Left Arm Inferior

Question 29

Why does repolarization appear as positive on the EKG?

Answer 29

It is positive because depolarization occurs where depolarization ends and goes backwards from epicardium to endocardium.

Question 30

What is a right MFP vector shift?

Answer 30

Greater than 105 degrees

Question 31

What is a left MFP vector shift?

Answer 31

Less than -30 degrees

Question 32

In terms of vector summation, what is the equivalent of Lead II?

Answer 32

Lead I + Lead III