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Flashcards in Intro to EKG Deck (100):
1

What are the leads on a 12 Lead EKG

V1 - V6
RA
LA
RL
LL

*placement matters!

2

What does a positive wave of depolarization spreading towards a positive EKG lead result in on the EKG

an upward or positive deflection

3

What does a negative wave of depolarization (depolarization) spreading away from a positive lead result in on the EKG

upward or positive deflection on the EKG

4

What does a current of depolarization traveling away from a positive electrode result in on EKG

downward or negative deflection

5

Lead I
- what kind of lead
- what does it look at

- Bipolar limb lead
- across the heart from the side (left to right arm)
- lateral view

6

Lead II
- what kind of lead
- what does it look at

- bipolar limb lead
- negative to positive
- looks at inferior portion of heart (from feet to right arm)

7

Lead III
- what kind of lead
- what does it look at

- bipolar limb lead
- negative to positive
- looks at inferior part of the heart (from feet to left arm)

8

What type of leads are AVL, AVR, and AVF?

augmented vector leads
- unipolar
- use the same electrodes as the bipolar, just connect them in different ways

9

AVR
- what is positive and what is negative

- LA and LL negative
- RA positive

10

AVL
- what is positive and what is negative

- RA and LL negative
- LA positive

11

ARF
- what is positive and what is negative

- LA and RA negative
- LL positive

12

What are the precordial/chest leads

- horizontal plane
- rotating group of lines that run through the AV node in anterior-posterior plane

13

What do V1 and V2 look at

- anterior heart
- "right chest leads"

14

what do V3 and V4 look at

- the septum

15

what do V5 and V6 look at

- lateral wall
- "left chest leads"
- share a view with lead I

16

What leads look at the lateral wall

Lead I
V5
V6

17

Automaticity Foci

- focal areas of automaticity (spontaneously depolarize)
- located throughout the heart
- have inherent rates based on where in the heart they are located

18

Overdrive Suppression

- fastest are of automaticity paces the heart

19

what is the normal area that paces the heart

SA node

20

what happens when SA node fails

- other automaticity foci "escape" SA node overdrive and take over, act as backup
- "ectopic" foci

21

Inherent rates:
- SA node
- Atrial foci
- AV junctional foci
- Ventricular foci

- SA: 60 to 100 bpm
- Atrial: 60 to 80
- AV junctional: 40 to 60
- ventricular: 20 to 40

22

EKG paper
- how many seconds in each small box
- how many seconds in each big box

- small: 0.04 seconds
- big: 0.20 seconds

23

How many big box make 1.0 seconds

5 big boxes

24

EKG paper
- what does vertical axis measure
- what does horizontal axis measure

- vertical: amplitude
- horizontal: time

25

What is amplitude measurement of one small box

1 mm
0.1 mV

26

Sinus Rhythm
- what to look for

- distance should be the same between similar waves (R to R interval)
- P wave should be the same, don't want P' waves!
- Narrow QRS
- P before every QRS
- T after every QRS

27

In which leads should P wave be upright?
downward?

Upright in II, III, AVF

Downward in AVR

28

when is sinus arrhythmia common?

young people
not in old people!

29

P wave normal morphology

- sinus node depolarization
- before every QRS
- duration <0.12ms
- amplitude <2.5 mm

30

multiple P waves in a row suggest

P wave being blocked by AV node, not allowing to ventricles

31

lack of P wave with scribbly baseline suggests

atrial fibrillation

32

Multiple "shark fin" P waves suggests

atrial flutter

33

PR interval normal morphology

- pause in conduction at AV node
- if duration >0.20ms suggests AV nodal block Type I

34

QRS normal morphology

- ventricular depolarization
- duration <0.10 ms

35

what does wide and weird QRS without a P wave suggest

likely PVC
(premature ventricular contraction)

36

What does wide QRS suggest?

inter ventricular conduction delay

37

T wave normal morphology

- upright, rounded

38

ST segment normal morphology

- should be flat or upsloping

39

what does convex ST segment suggest

injury pattern

40

What does a concave ST segment suggest

- ischemia per guest lecturer
- normal per Dr. V.

41

What does inverted T wave suggest

ischemia

42

what does a tall, peaked T wave suggest

hyperkalemia

43

Premature atrial contraction
- define

- site outside normal conduction pattern fires erratically
- usually asymptomatic

44

how know if premature atrial contraction is ectopic and not sinus node?

- will have some normal P waves and then a few that don't fit in

45

Atrial fibrillation
- how common?
- increased risk for what
- outcome

- most common irregular rhythm >65 yo
- increased risk for stroke
- not malignant or fatal (unless stroke I guess)

46

Atrial fibrillation
- what happens

- Atria don't contract rhythmically from single discharge of sinus node
- depolarize more like 4th of July sparkler
- rate might be as high as 300 bpm

47

Why is there pretty normal ventricular contraction during atrial fibrillation

- the AV node protects the ventricles
- if AV node doesn't protect well enough CAN have a rapid ventricular response

48

Key characteristics of atrial fibrillation

- no distinct P before QRS
- complex, scribbly, erratic baseline (sparker)
- R to R interval is irregular
- broad variability between R waves
- correct number of ventricular beats but not at a normal rate

49

cause of atrial fibrillation

- structural heart disease or chronic HTN irritates area where pulmonary veins dump back into atria

50

treatment of atrial fibrillation

pulmonary vein isolation - scar the pulmonary veins

51

Atrial flutter
- describe

- Isthmus between inferior vena cava and tricuspid valve becomes irritable
- fires at rapid rate, 300 bpm typically

52

How to determine atrial flutter rate

- don't count, do math!
- calculate ventricular rate
- divide 300 by ventricular rate

ex. if ventricular rate is 100, ratio is 3:1 (300 atrial / 100 ventricular)

53

What be suspicious of if have tachycardia locked in at a rate

suspect atrial flutter! don't get fooled!

54

Issues associated with atrial flutter

- stroke risk less than atrial fibrillation
- less dangerous but can still cause issues, should be fixed

55

What see on lead II during atrial flutter

negative SOMETHING (not sure what?!?!)
- because the electrical signal is kicked back at the AV node so it moves in a counter clockwise motion
- because moving backwards, causes negative line (positive wave of depolarization heading towards negative right arm)

56

AV nodal block types

- 1st degree
- 2nd degree type 1
- 2nd degree type 2
- 3rd degree

57

AV nodal block 1st degree

- AV node holds conduction longer
- lengthen PRI
- PRI will be longer than 5 boxes on EKG

58

PRI

PR interval

59

AV nodal block 2nd degree type 1

- normal first beat
- second beat held at AV node
- third beat held longer at AV node
- fourth beat held even longer and not passed on to ventricles
- lengthening PRI and finally dropped QRS

- not a bad arrhythmia, might be caused by a beta blocker, just need to take pt off med

60

AV nodal block 2nd degree type 2

- normal sinus rhythm
- then pause at AV node
- then a few dropped QRS in a row
- PRI length same each time
- AV node gets snippy, ignores ventricles

61

AV nodal block type 3

- Total heart block at AV node
- no ventricular contractions
- ectopic sites kick in at 20 to 40 bpm in ventricles
- will die if not fixed
- "AV disassociation"

62

what does it mean if the P wave is inverted?

- "Junctional rhythm"
- tells you P wave is coming from lower in atrium
- retrograde conduction

63

what does it mean if there is not a P wave

- "Idioventricular rhythm"
- ventricle is pacing itself without input from AV node
- QRS will be weird and wide
- very bad

64

Types of ventricular ectopy

- PVCs
- Bigeminal PVCs
- Trigeminal PVS
- NSVT

65

what is a PVC

- ventricle "sneezes"
- can have all the time and not know it, rarely symptomatic
- often see when heart is overstimulated or during hypoxia
- if isolated, not a problem

66

What if PVCs are not isolated but are instead in patterns and runs

very bad
- Bigeminal
- Trigeminal
- Quadrageminal
etc
- could be sign of heart disease

67

What does the width and height of a PVC tell you?

where the PVC is coming from!

- more normal looking QRS means from higher in ventricle (more like normal electrical conduction)
- weirder QRS means lower in ventricle, more odd electrical conduction

68

How to name runs of ventricular tachycardia

two is couplet
three is triplet
etc i assume

69

how to treat sustained ventricular contraction

electrical shock

70

Torsades de pointes

TSD
- twisting of points - polymorphic ventricular tachycardia (like twisting crepe paper)
- no P waves before QRS
- QRS all wide and weird
- rapid rate
- potentially deadly, can easily descent to ventricular fibrillation - dead

71

how to treat Torsades de pointes

magnesium STAT

72

can you shock systole back to a normal rhythm?

nope, only on TV

73

which type of bundle branch block is more dangerous

Left
- results in ventricular dys-symmetry from repeated depolarization from the right ventricle which is kind of like driving a car for a long time on the spare tire...

74

EKG signs of RBBB

- rabbit ears on V1
- broad, deep S-wave on V6

75

EKG signs of LBBB

- deep QRS on V1
- two R waves but both small and above baseline (small right ventricle)

76

Hemiblock
- which branch most likely to be affected
- typical EKG pattern

- Left anterior fascicle
- negative R in II, III, & AVF

77

Prolonged QT

- represents depolarization and beginning of depolarization
- lots of drugs prolong QT

78

what is dangerous about prolonged QT

incoming and outgoing wave crash into each other analogy
- if depolarize before finished repolarizing = chaos
- prolong QT creates more opportunity for the two to overlap
- can be fatal

79

QT measurement

- varies with rate, use corrected QT based on patient's weight
- prolonged if corrected is >440 for men >470 for women

80

causes of prolonged QT

drugs
hypocalcemia
hypothermia
etc.

81

EKG signs of atrial enlargement

* p wave is actually two atrial waves on top of each other.
- right atrium enlarged = tall witch hat, sums early
- left atrium enlarged = shift out of phase with each other "diphasic", left will creep out from behind and create two humps (camel hump)

82

Right ventricular hypertrophy
- EKG signs

- large R in V1
- R wave amplitude progressively smaller V2-V4

83

Left ventricular hypertrophy (LVH)
- EKG

- large S in V1
- large R in V5
- amplitude of S in V1 + R in V5 >35 mm, there is a voltage criteria for LVH

84

Quick glance to check for LVH

how tall is AVL
how deep is V2
how tall is V5

85

ST segment depression indicates what

- ischemia
- can be pattern associated with LVH
- look like left handed checkmarks

86

what is best next step after signs of LVH

echocardiogram - easiest, cheapest way to look for heart disease.
- measures cardiac output, valve function, dimensions of walls/chambers

87

What is elevated in acute MI

ST segment
- if in contiguous leads is a problem

88

V1 and AVL look at

high lateral wall of heart

89

V5 and V6 look at

low lateral wall of heart

90

V2, V3, AVF look at

inferior wall of heart (right ventricle)

91

V1 and V2 look at

anterior heart

92

V3 and V4 look at

septum of heart

93

How many members of "group" of leads is needed to claim significant change

the whole family, not just isolated leads

94

What is a reciprocal change

ST change elevation in one location and depression in another

95

STEMI

ST segment elevation MI
- do something right away!!
*don't know for sure is MI until further testing

96

special signs

- Wellen's sign
- WPW
- Dig effect
- Brugada

97

Wellen's sign

- ST elevation
- biphasic T wave in V2 and V3
- sign of large LAD lesion

98

Wolff-Parkinson-White Syndrome

- Short PR interval <0.12 sec
- prolonged QRS >0.10 sec
- delta wave
- can simulate ventricular hypertrophy, BBB, previous MI

99

Digitalis on EKG

ST looks like Dali mustache

100

Brugada syndrome

- autosomal dominant genetic mutation of Na channels
- syncope, v-fib, self terminating VT, sudden cardiac death
- can be intermittent on EKG
- middle-aged males
- need ICD (implanted defibrillator)