B4.011 Interpreting EKGs

Question 1

6 steps to EKG interpretation

Answer 1

rate
rhythm
axis
intervals
hypertrophy
ischemia/infarction

Question 2

2 ways to get rate

Answer 2

300/boxes between R intervals
OR
count total R-R intervals * 6

Question 3

how can you tell is a rhythm is sinus?

Answer 3

P waves present before QRS

Question 4

which 2 leads do you look at for axis

Answer 4

lead I

lead aVF

Question 5

what is a normal axis?

Answer 5

down and left
QRS + at lead I (left side 0 deg)
QRS + at lead aVF (down 90 deg)

Question 6

typical PR interval length

Answer 6

120-200 mS

3-5 small squares

Question 7

typical QRS length

Answer 7

80-120 mS

2-3 small squares

Question 8

ECG graph paper time intervals

Answer 8

1 small box 40 mS
1 big box 200 mS
5 big boxes 1 s

Question 9

typical QT length

Answer 9

300-440 mS

8-11 small squares

Question 10

what are 2 reasons for a widened QRS?

Answer 10

issue w Perkinje system

starting from ventricular origin in v-tac

Question 11

what type of evidence might there be for hypertrophy?

Answer 11

more voltage so deeper S waves, taller R waves (ventricle) or taller P waves (atrium)

Question 12

criteria for LVH

Answer 12

Romhilt Estes
Sokolov-Lyon
Cornell

Question 13

Cornell criteria

Answer 13

R wave in aVL + S wave in V3 = 28 mm in men or 20mm in women

Question 14

major indicator of MI

Answer 14

ST elevation

Question 15

which leads pick up ST elevation the best

Answer 15

V1-6

Question 16

QRS + in lead I

QRS - in lead aVF

Answer 16

LAD

Question 17

QRS - in lead I

QRS + in lead aVF

Answer 17

RAD

Question 18

QRS - in lead I

QRS - in lead aVF

Answer 18

extreme RAD

Question 19

which leads are often used as rhythm strips and why?

Answer 19

leads II or VI

good at picking up P waves

Question 20

why might you get an RAD?

Answer 20

damage in left heart

hypertrophy in right heart

Question 21

what does an inverted Q wave represent?

Answer 21

dead myocardial tissue