Intro to EKG

Question 1

What is the normal axis for an EKG?

Answer 1

-30 to +90

Question 2

How many seconds are in one small box on EKG?

Answer 2

40 ms

Question 3

How many seconds are in one big box EKG?

Answer 3

200 ms

Question 4

How can you determine HR for normal rhythm?

Answer 4

count the number of big boxes between 2 RR waves

divide 300 by # of big boxes

Question 5

How can you determine HR for irregular rhythm?

Answer 5

count the number of QRS complexes on bottom strip and multiply by 6

we were multiplying by 6 in class

Question 6

What are limits for tachycardia and bradycardia?

Answer 6

Tachy : >100 bpm

Brady : < 60 bpm

Question 7

If lead I is positive and lead aVF is positive, what is your axis?

Answer 7

0 - +90º (normal)

(remember that positive 90 is downwards for lead aVF)

Question 8

If lead I is positive and lead aVF is negative, what is your axis?

Answer 8

axis between (-) 30º - (-) 90º

this is a left shift!

Question 9

If lead I is negative and lead aVF is positive, what is your axis?

Answer 9

axis between +90º - +180º

this is a right shift

Question 10

How big is PR interval normally?

Answer 10

normally 1 big box

120-200 ms

Question 11

How big is QRS duration normally?

Answer 11

normally < 3 small boxes

< 120 ms

Question 12

How long is QT interval normally?

Answer 12

T wave is < halfway between RR interval

QT should be < 440 ms

Question 13

How can you determine if there is a ST segment elevation or depression?

Answer 13

compare to PR line for reference

Question 14

Which leads are left sided?

Answer 14

leads 4-6

Question 15

Which leads are right sided?

Answer 15

leads 1-3

Question 16

What are the lateral leads?

Answer 16

I, aVL, V5-V6

Question 17

What do the lateral leads give us information about?

Answer 17

LCx or diagonal of LAD

Question 18

What are the inferior leads?

Answer 18

II, III and aVF

Question 19

What do the inferior leads give us information about?

Answer 19

RCA and/or LCx

Question 20

What are the anterior/septal leads?

Answer 20

VI-V4

Question 21

What do the anterior/septal leads give us information about?

Answer 21

LAD

Question 22

If you have an inferior block on EKG (leads II, III and aVf) what are we concerned about?

Answer 22

the posterior wall could be hiding on EKG and there could be a block there (perhaps coming off the RCA)

Question 23

How do you check for a posterior block?

Answer 23

look at if there are deep depressions on VI-V4

Question 24

What are the 3 stages of a worsening MI that pop up on the EKG?

Answer 24

1) ST depression / T-wave inversion

2) ST elevation

3) Q-waves

Question 25

ST depression / T-wave inversion indicates (in setting of MI) ...

Answer 25

ischemia (some area is not getting enough blood, but there isn't true cell death yet)

Question 26

ST elevation indicates (in setting of MI) ...

Answer 26

cell injury (not necessarily infarct / cell death yet)

Question 27

Q waves indicate (in setting of MI) ...

Answer 27

cell death / infarct Q-waves get worse if MI is untreated

Question 28

How many boxes from baseline = an ST elevation?

Answer 28

2 small boxes above baseline

Question 29

What is your flow for reading an EKG? 5 steps

Answer 29

1) look at P-waves (are they there? is PR interval normal?) 2) look at QRS (are they normal intervals? are they wide?) 3) look at ST (is there elevation / depression) 4) look at QT (is there lengthening) 5) look at rate!!

Question 30

What does VT look like on EKG?

Answer 30

p-waves embedded in QT wave AV dissociation is hallmark of VT (type 3 AV block) also tachycardia and wide QRS

Question 31

1st degree AV block

Answer 31

prolonged PR interval with conducting p-wave

Question 32

Mobitz I AV block

Answer 32

progressively prolonged PR interval with eventually nonconduction irregular RR grouped beating

Question 33

Mobitz II AV block

Answer 33

equal PR interval (may not be prolonged) with eventual nonconduction indicates a His-Purkinje block

Question 34

Which blocks do we treat with pacemakers?

Answer 34

Mobitz II 3rd degree AV block

Question 35

3rd degree AV block

Answer 35

no p-wave conduction, QRS complex is coming from another pacemaker (escape rhythm) RR interval is normal!! But it is detached from p-wave

Question 36

RBBB

Answer 36

wide QRS complex with VI positive also can see T-wave inversion (don't freak)

Question 37

LBBB

Answer 37

wide QRS complex with VI negative also can see T-wave inversion (don't freak)

Question 38

RVH

Answer 38

enlarged Right sided lead (VI) and right axis deviation

Question 39

LVH

Answer 39

enlarged Left sided lead (aVl, 1, V5, and V6) large S wave in V1

Question 40

Atrial fibrillation

Answer 40

absent P-waves irregularly, irregular RR interval

Question 41

Digoxin effect on EKG

Answer 41

peaked T-wave, scooped out ST interval, shortened QT interval

Question 42

Hypokalemia

Answer 42

T wave inversion, ST depression, and prominent U wave

Question 43

Hyperkalemia

Answer 43

Peaked T-wave, P wave flattening, PR prolongation, wide QRS

Question 44

EKG of AVRNT

Answer 44

no p-waves before QRS see retrograde p-waves also narrow QRS

Question 45

EKG of WPW

Answer 45

very short PR interval QRS is widened delta wave is present in QRS complex!