QRS and Axis

Question 1

how should the QRS look in leads AVF, II, III

Answer 1

mostly positive deflections; vectors coming toward these leads

Question 2

how should the QRS look in lead AVR

Answer 2

mostly negative; stimulus traveling away

Question 3

how should the QRS look in lead I and AVL

Answer 3

q wave is normal. mostly positive deflection because stimulus travels away

Question 4

in the precordial leads V1 is mostly

Answer 4

negative deflection

Question 5

as you move across the chest in the precordial leads from right to left the QRS deflection becomes

Answer 5

increasingly positive

Question 6

what is the criteria for low voltage

Answer 6

<10mm in the precordial leads

Question 7

an example of a situation that would have low voltage

Answer 7

pericardial effusion

Question 8

an example of a situation with high amplitude/height of the QRS

Answer 8

hypertrophy

Question 9

what is a normal QRS duration

Answer 9

< 0.12 seconds

Question 10

name some causes of a wide QRS

Answer 10

hyperkalemia**: not as fast as vtach <125 bpm
BBB
idioventricular rhythms
VPCs
vtach
WPW
abberancy
meds (tricyclics)
pacemaker
IVCD

Question 11

how would you know a wide QRS is from a pacemaker

Answer 11

pacer spikes lines

Question 12

what does multifocal PVCs look like

Answer 12

multiple PVCs in the same lead of different shape; coming from different foci in the ventricle

Question 13

a QRS notch at the end of the complex ( j point)

Answer 13

benign, common in precordial leads

Question 14

if you saw a QRS notch with a benign ST segment elevation what should you consider

Answer 14

pericarditis

early repolarization

Question 15

what is an osborn wave

Answer 15

a large hump right after the QRS complex that is NOT the t wave

Question 16

what condition does an osborn wave signify

Answer 16

hypothermia

Question 17

in what conditions is a q wave considered benign/insignificant

Answer 17

1. small q waves in leads AVL and I
2. QS in V1 ONLY
3. isolated q wave in lead III only
4. Q wave in AVR

Question 18

what classifies as a pathologic Q wave

Answer 18

height > 1/2 height of the R wave

width > or equal to 0.04 seconds or 1 small box

Question 19

True or false: 1 lead in a region that has a q wave is concerning

Answer 19

false; 1+ leads in a region is where you get concerned for pathologic q waves

Question 20

if you saw a q wave in leads V1, V2, V3 with no upward notching what is this

Answer 20

pathologic- MI

Question 21

where is the normal transition zone of the precordial leads

Answer 21

between V3 and V4

Question 22

what classifies as an early transition

Answer 22

before V3

Question 23

what classifies as a late transition

Answer 23

after V4

Question 24

what is the normal QT interval measured from

Answer 24

the beginning of the QRS complex until the end of the t wave

Question 25

what is the normal duration of the QT interval

Answer 25

< 1/2 RR interval

Question 26

a prolonged QT interval can lead to...

Answer 26

torasades de point

Question 27

what can the ventricular axis help you diagnose

Answer 27

``` hemiblock- definitively R/L hypertrophy PE dextrocardia lead misplacement ```

Question 28

what is the normal axis

Answer 28

0-90 degres

Question 29

what is LAD

Answer 29

left axis deviation -1 to -90 degrees

Question 30

what is RAD

Answer 30

right axis deviation 91 to 180 degree

Question 31

if QRS is + in lead I, and + in AVF what is the axis

Answer 31

NORMAL

Question 32

if QRS is + in lead I and - and AVF

Answer 32

LAD

Question 33

if QRS is - in lead I and + in AVF

Answer 33

RAD

Question 34

calculating normal axis: | if lead I > lead AVF what is the axis in degrees

Answer 34

0-40 degrees

Question 35

calculating normal axis: | if lead I < AVF what is the axis in degrees

Answer 35

40-90 degrees

Question 36

calculating normal axis: | if lead I = lead AVF

Answer 36

45 degrees

Question 37

calculating normal axis | if lead I is isoelectric

Answer 37

90 degrees

Question 38

calculating normal axis | if lead AVF is isoelectric

Answer 38

0 degrees

Question 39

causes of left axis deviation

Answer 39

normal variant with aging | left anterior hemiblock

Question 40

causes of right axis deviation

Answer 40

``` normal variant in kids/teens right ventricle hypertrophy left posterior hemlock dextrocardia pulm pathology ```

Question 41

at what degree is LAD considered pathologic

Answer 41

greater than 30 degrees | < 30 is normal variant with aging

Question 42

if you have LAD and you look to lead II and see an isoelectric QRS deflection what degree could you assume

Answer 42

-30 degrees; borderline pathologic

Question 43

if you have an LAD and you look to lead II and see a negative deflection you know that the degree is

Answer 43

> -30 degrees; pathologic

Question 44

where is a left anterior hemiblock located

Answer 44

left anterior fasicle

Question 45

where is a left posterior hemiblock located

Answer 45

left posterior fasicle

Question 46

which is more common, LAH or LPH

Answer 46

LAH

Question 47

T or F: diagnosis with an EKG is definitive for LAH

Answer 47

true

Question 48

T/F: diagnosis with an EKG is definitive for LPH

Answer 48

false; dx of exclusion

Question 49

how does a LAH present

Answer 49

LAD: lead I is + lead AVF is - | lead II is negative

Question 50

what is a bifasicular block

Answer 50

RBBB + LAH/LPH

Question 51

RBBB + LPH ok or bad

Answer 51

BAD; concern for complete heart block and anterior MI

Question 52

RBBB + LAH

Answer 52

ok, common fin dinging | only not ok if ischemic