ECG

Question 1

interval vs segment

Answer 1

intervals INclude a wave/complex

segments don’t

Question 2

size: QRS

Answer 2

< 120 ms (1/2 box?)

Question 3

size: p wave

Answer 3

< 120 ms wide

< .25 mV heigh

Question 4

size: t wave

Answer 4

< 200 ms wide

< 0.5 mV tall

Question 5

non-pathologic Q waves

Answer 5

< 1 small block wide

< 1/3 height of R

Question 6

size: PR interval

Answer 6

< 200 ms

Question 7

J point

Answer 7

start of ST segment

Question 8

QTc

Answer 8

rate corrected QT interval

QTc = QT/sqrtRR

Question 9

size: QTc

Answer 9

males < 440 ms

females < 460 ms

Question 10

size: ECG paper sections

Answer 10

25 mm/s –> 25 small boxes/s –> 5 big boxes/s
1 big box = 0.2 s
1 small box = 0.04 s
height: 1 mm = 0.1 mV = 1 small block

Question 11

calculate rate

Answer 11

big boxes btwn QRS –> 300, 150, 100, 75, 60, 50 (300/#)
or
10 x # in 6 seconds

Question 12

signs of normal axis

Answer 12

I and aVF are both (+)
I (+), aVF (-) but II is (+)
– if II (-) –> LAD

Question 13

phase 0

Answer 13

Na influx, rapid depolarization

Question 14

phase 1

Answer 14

K outflow, early repolarization

Question 15

phase 2

Answer 15

Ca influx, Na influx, plateau phase

Question 16

phase 3

Answer 16

K outflow, repolarization

Question 17

phase 4

Answer 17

resting phase

Question 18

when is the effective refractory period (absolute)

Answer 18

0, 1, 2, early 3

Question 19

when is relative refractory period

Answer 19

late 3, 4

Question 20

what does a wife QRS show

Answer 20

usually a ventricular rhythm

ex: BBBs, WPW, HK, ventricular rhythms

Question 21

1st degree AV block EKG

Answer 21

long PR interval (> 0.20 s, 1 big block)

Question 22

1st degree AV block location

Answer 22

above AV node

Question 23

2nd degree AV block (type I) EKG

Answer 23

Wenckeback

PR gets longer and longer until the QRS is dropped

Question 24

2nd degree AV block (type I) location

Answer 24

in AV node

Question 25

2nd degree AV block (type II) EKG

Answer 25

more P waves than QRS

2:1 - 5:1, etc

Question 26

2nd degree AV block (type II) location

Answer 26

below bundle of His

Question 27

3rd degree AV block EKG

Answer 27

complete heart block
Ps and QRSs aren’t coordinated at all
regular P-P intervals and regular R-R intervals, but not together

Question 28

PACs: problem?

Answer 28

no problem if ASx

Question 29

atrial flutter EKG

Answer 29

ventricular rate regular, narrow QRS
atrial rate regular but FAST (250-300)
sawtooth Ps

Question 30

atrial fibrillation EKG

Answer 30

irregularly irregular
ventricular rate regular, narrow QRS
atrial rate regular but FAST (250-300)
may not see Ps, if can see = coarse

Question 31

causes of A flutter

Answer 31

HTN, valves, AMI, chronic angina, PE, chronic pulm dz

Question 32

causes of A fib

Answer 32

PIRATES
PE, Pericarditis
Ischemia
Rheumatic/Valve heart dz
Atrial enlargement
Thyroid dz
EtOH, electrolytes
Sick sinus synddrome

Question 33

junctional rhythm: pacemaker?

Answer 33

AV node

Question 34

junctional rhythm: P waves

Answer 34

if present 1:1 P:QRS

can be before but inverted, during or after

Question 35

junctional rhythms: QRS

Answer 35

narrow, regular (40 - 60)

Question 36

AV nodal reentry –>

Answer 36

SVT

regular, narrow, fast QRS

Question 37

rate of ventricular rhythms

Answer 37

20 - 40

Question 38

WPW EKG

Answer 38

short PR
wide QRS
delta waves (upsloping PR)