DMS EKG I

Question 1

What are the anterior leads?

Answer 1

V2
V3
V4

Question 2

What are the inferior leads?

Answer 2

II
III
aVF

Question 3

What are the left lateral leads?

Answer 3

I
aVL
V5
V6

Question 4

What are the right leads?

Answer 4

aVR

V1

Question 5

What happens when the wave of depolarization meets the myocardial cell?

Answer 5

releases Ca causing it to contract

Question 6

Which leads should you look at for atrial enlargement?

Answer 6

II & V1

Question 7

R atrial enlargement

Answer 7

look at II & V1

inc. height of 1st portion of P wave

possible R axis deviation of P wave

Question 8

L atrial enlargement

Answer 8

look at II & V1

sometimes have inc. height of last portion of P wave

inc. P wave duration

aka P mitrale

Question 9

R vent. hypertrophy

Answer 9

R axis dev

ratio of R:S height >1 in V1
<1 in V6

Question 10

L vent. hypertrophy

Answer 10

1. R wave in V5/V6 + S wave in V1/V2 >35
2. R wave in V5 > 26
3. R wave in V6 > 18
4. R wave in V6 > V5
5. R wave in aVL > 13
6. R wave in aVF > 21
7. R wave in I > 14
8. R wave in I + S wave in III > 25

Question 11

4 questions to ask about arrhythmias

Answer 11

1. Are normal P waves present?
2. Are the QRS complexes narrow or wide? (0.12s normal)
3. What is the relationship btwn the P waves & the QRS complexes?
4. Is the rhythm regular or irregular?

Question 12

Paroxysmal Supraventricular Tachycardia (PSVT)

Answer 12

P waves retrograde if visible in II/III

150-250 bpm

Carotid massage - slows or terminates

Question 13

A Flutter

Answer 13

Saw-toothed
2:1, 3:1, 4:1
Best seen in II & III

atrial rate: 250-350 bpm
vent. rate slower

Carotid massage inc. block

Question 14

A Fib

Answer 14

irregularly irregular
undulating baseline
atrial rate 350-500 bpm
vent. rate variable
best seen in V1

Carotid massage may slow vent. rate

Question 15

Multifocal Atrial Tachycardia (MAT)

Answer 15

at least 3 diff. P wave morphologies

100-200 bpm

WAT if <100 bpm

Question 16

Paroxysmal Atrial Tachycardia (PAT)

Answer 16

100-200 bpm
warm-up period

Carotid massage - no effect or mild slowing

Question 17

VT vs. PSVT

Answer 17

v - diseased heart, no effect from carotid massage, cannon A waves may be present, AV dissociation may be seen, slightly irregular, fusion beats may be seen, abnormal QRS

Everything is opposite in PSVT

Question 18

1st degree AV block

Answer 18

PR interval >0.2 s

beats conducted through to ventricles

Question 19

Wenckebach Type I 2nd degree AV block

Answer 19

Progressive prolongation of the PR interval until a QRS is dropped

Usually from block w/in AV node

Question 20

Mobitz Type II 2nd degree AV block

Answer 20

QRS complexes dropped w/o PR interval prolongation

Usually from block below AV node in His bundle

Question 21

3rd degree AV block

Answer 21

no beats are conducted through to the ventricles

complete heart block w/ AV dissociation

atria & vent. driven by independent pacemakers

Question 22

RBBB

Answer 22

wide QRS

RSR’ in V1&V2 w/ ST depression & T wave inversion
Bunny ears!!!

Reciprocal changes in V5, V6, I & aVL
(L lateral leads)

Question 23

LBBB

Answer 23

Wide QRS

broad or notched R wave, ST depression & T wave inversion
-bunny ears in L lateral leads

Reciprocal changes in V1&V2

L axis deviation may be present

Question 24

L anterior hemiblock

Answer 24

L axis dev >-30
w/ no other cause of dev.

more coomon

Question 25

L posterior hemiblock

Answer 25

R axis dev. w/ no other cause of dev. only seen in diseased hearts

Question 26

Bifascicular block

Answer 26

RBBB w/ L anterior or posterior hemiblock

Question 27

Describe the effects from carotid massage

Answer 27

PSVT - slows/terminates A flutter - inc. block A fib - slow vent. rate

Question 28

What is the most common cause of enlargment?

Answer 28

V overload

Question 29

What is a normal P wave?

Answer 29

btwn 0 & 70 | 0.12s

Question 30

Why do arrhythmias happen?

Answer 30

``` H - hypoxia I - ischemia & irritability S - sympathetic stimulation D - drugs E - electrolyte disturbances B - bradycardia S - stretch ```

Question 31

Nonsinus pacemakers

Answer 31

Atrial 60-75 bpm Junctional 40-60 bpm Ventricular 30-45 bpm

Question 32

What is the most common cause of paroxysmal supraventricular tachycardia?

Answer 32

PSVT | reentrant circuit w/in AV node

Question 33

What is the most common cause for atrial flutter?

Answer 33

a reentrant circuit that runs around the annulus of the tricuspid valve sawtooth in II & III

Question 34

What arrhythmia is irregularly irregular?

Answer 34

A fib

Question 35

accelerated idioventricular rhythm

Answer 35

looks like Vtach but slower 50-100 bpm

Question 36

Ashman phenomenon

Answer 36

wide aberrantly conducted supravent. beat after a QRS then long pause usually seen in Afib

Question 37

Reciprocal changes w/ vent. hypertrophy

Answer 37

1. ST segment depression 2. T wave inversion Seen best in leads w/ tall R waves R - V1 & V2 L - I, aVL, V5 & V6

Question 38

What is the most common nonsinus pacemaker?

Answer 38

junctional | 40-60 bpm

Question 39

What is the common cause of PSVT?

Answer 39

reentrant circuit in AV node

Question 40

What is Aflutter usually caused by?

Answer 40

reentrant circuit that runs around the annulus of the tricuspid

Question 41

PVC

Answer 41

wide & abnormal QRS compensatory pause Bigeminy - 1 beat then 1 PVC Trigeminy - 2 beats then 1 PVC

Question 42

What are the rules of malignancy w/ PVCs?

Answer 42

1. Frequent 2. Runs w/ 3 or + in a row 3. Multiform 4. PVC falling on T wave of previous beat = R on T phenomenon 5. PVC w/ acute MI

Question 43

Uniform vs. polymorphic Vtach

Answer 43

U - often seen w/ healed infarcts P - common w/ ischemia, infarcts, electrolyte disturbances & conditions w/ prolonged QT intervals

Question 44

Accelerated idioventricular rhythm

Answer 44

looks like PSVT but slower rate 50-100 bpm idioventricular rhythm - <50 bpm rarely req. Tx seen during acute MI or during reperfusion

Question 45

Incomplete BBB

Answer 45

RBBB or LBBB w/ narrow QRS (0.10-0.12)

Question 46

Who should get pacemakers?

Answer 46

1. 3rd degree AV block 2. AV block or bradycardia if symptomatic 3. Blocks w/ MI 4. Recurrent tachycardias

Question 47

What is cardiac resynchonization therapy?

Answer 47

vent. pacemaker to correct timing only helps in Pts w/ wide QRS & LV dysfunction