11.29 A

Question 1

The P wave of an EKG is generated by what event?

Answer 1

atrial contraction

Question 2

The QRS complex is generated by what event?

Answer 2

ventricular depolarization

Question 3

The T wave is generated by what event?

Answer 3

ventricular repolarization

Question 4

Which ventricle contributes more to the magnitude of the QRS complex?

Answer 4

the left because it has a greater mass

Question 5

The ST interval is representative of what?

Answer 5

phase II of the ventricular action potential

Question 6

Where on an EKG would AV node depolarization fall if it was strong enough to show up?

Answer 6

in the PR interval

Question 7

An EKG has leads in what two planes?

Answer 7

frontal and horizontal

Question 8

The horizontal leads of an EKG are which ones?

Answer 8

V1 - V6

Question 9

The frontal leads of an EKG are which ones?

Answer 9

I, II, III, aVR, aVL, aVF

Question 10

Which frontal lead measures the vector directly downward?

Answer 10

the aVF lead

Question 11

ST segment elevation seen on an EKG is indicative of what?

Answer 11

infarcted tissue

Question 12

ST segment depression on an EKG is indicative of what?

Answer 12

ischemia

Question 13

What six things should you look for on an EKG?

Answer 13

• rate
• rhythm
• axis
• intervals
• hypertrophy
• ischemia/infarction

Question 14

Which leads will shows an axis deviation if one is present?

Answer 14

I and aVF

Question 15

What does it mean to check for sinus on an EKG?

Answer 15

confirm that each p wave have an associated QRS complex and vice versa

Question 16

How can one determine heart rate from a standard EKG?

Answer 16

divide 300 by the number of large boxes between beats

Question 17

Should the EKG be positive or negative in leads I and aVF?

Answer 17

they should both be positive

Question 18

How will afib show up on an EKG?

Answer 18

• irregular beat
• tachycardia
• lots of microdepolarizations in the p wave

Question 19

How should one treat atrial fibrillation?

Answer 19

with anticoagulants to reduce the risk of stoke

Question 20

Atrial fibrillation most commonly arises due to what?

Answer 20

chronic hypertension causes stretching of the heart which creates electrical disturbances

Question 21

What are the four possible characterizations for EKG axis?

Answer 21

• left deviation
• normal
• right deviation
• extreme right deviation

Question 22

When would one expect to see an extreme right axis deviation on an EKG?

Answer 22

in someone with situs inversus

Question 23

What are some possible causes of left ventricular hypertrophy?

Answer 23

• chronic hypertension is most common

- aortic stenosis, HOCM are also possible

Question 24

How does hypertension show up on an EKG?

Answer 24

as a larger QRS complex in the aVL and V3 leads

Question 25

Describe the EKG of a 1st degree AV block.

Answer 25

prolonged PR interval

Question 26

Describe the EKG of a 2nd degree AV block, Mobitz I.

Answer 26

sequential prolonging of the PR interval followed by a dropped beat and then the pattern restarts

Question 27

Describe the EKG of a 2nd degree AV block, Mobitz II.

Answer 27

• normal PR interval and then a non-conducted P wave

- so beats are occassionally skipped

Question 28

Describe the EKG of a 3rd degree AV block.

Answer 28

complete dissociation between atrial depolarization and ventricular depolarization

Question 29

How would one treat a 2nd degree AV block, Mobitz I?

Answer 29

avoid other AV nodal blocking agents or maneuvers

Question 30

How would one treat a 1st degree AV block?

Answer 30

by avoiding other blocking agents or maneuvers

Question 31

How would one treat a 2nd degree AV block, Mobitz II?

Answer 31

with a pacemaker

Question 32

Which AV blocks are benign?

Answer 32

1st degree and 2nd degree Mobitz I