EKG

Question 1

normal axis

Answer 1

I: up
aVF: up

Question 2

left axis deviation

Answer 2

I: up
aVF: down

Question 3

right axis deviation

Answer 3

I: down
aVF: up

Question 4

extreme right axis deviation

Answer 4

I: down
aVF: down

Question 5

Heart rate from EKG

Answer 5

300/ big boxes

Question 6

duration of small box

Answer 6

40 msec

Question 7

duration of big box

Answer 7

200 msec

Question 8

inferior leads

Answer 8

II, III, aVF
right coronary artery
appearance: normal
(II: no S wave)

Question 9

septal leads

Answer 9

V1, V2
left anterior descending artery
appearance: small P wave; upside down
(V2: upright T wave)

Question 10

anterior leads

Answer 10

V3, V4
left anterior descending artery
appearance: small P wave, tall QRS and T
(V3: upside down QRS)

Question 11

lateral leads

Answer 11

I, aVL, V5, V6
circumflex artery
appearance: small P waves

Question 12

What is unique about lead aVR?

Answer 12

no Q wave

Question 13

P wave

Answer 13

atrial depolarization/ contraction

Question 14

QRS complex

Answer 14

ventricular depolarization/ contraction
atrial repolarization
less than 120ms

Question 15

T wave

Answer 15

ventricular repolarization

Question 16

QT interval

Answer 16

less than 1/2 R-R interval
beginning of Q to end of T wave
less than 440ms
ventricular depol and repol

Question 17

ST segment

Answer 17

end of S wave to beginning of T wave

Question 18

PR interval

Answer 18

beginning of P wave to R wave

less than 200ms

Question 19

PR segment

Answer 19

end of P wave to beginning of Q wave

AV node conduction to Bundle of His

Question 20

intraventricular conduction delay (IVCD)

Answer 20

widened QRS with no other abnormalities

Question 21

RBBB

Answer 21

widened QRS with rabbit ears on V1 or V2 (big split)

Question 22

LBBB

Answer 22

widened QRS with rabbit ears on lead V5 or V6

considered a STEMI if new

Question 23

ventricular origin of beat

Answer 23

no P wave before widened QRS

Question 24

ischemia

Answer 24

ST segment depression (2mm or 2 small boxes)

T wave inversion

Question 25

injury

Answer 25

``` ST elevation (2mm or 2 small boxes) T wave hypertrophy (tombstone) ```

Question 26

infarction

Answer 26

significant Q waves (at least 1/3 size of QRS)

Question 27

STEMI

Answer 27

ST segment elevation | severe if there is a giant Q wave

Question 28

Wolf-Parkinson-White syndrome

Answer 28

short PR interval direct pathway from SA node to ventricles: high HR due to re-entry

Question 29

What does a prolonged QT interval put a patient at risk for?

Answer 29

ventricular tachyarrhythmias | ex: torsades de pointe and v. fib

Question 30

type 1 AV block

Answer 30

prolonged PR interval

Question 31

type 3 AV block (complete heart block)

Answer 31

P waves and QRS complexes are not related to each other | Tx: pacemaker

Question 32

type 2 AV block: Mobitz type I

Answer 32

increasing length of PR intervals leading to a dropped QRS | going going gone

Question 33

type 2 AV block: Mobitz type II

Answer 33

normal PR interval leading to a dropped beat | risk for type 3 AV block

Question 34

type 3 AV block (complete heart block)

Answer 34

P waves and QRS complexes are not related to each other

Question 35

ventricular hypertrophy

Answer 35

increase voltage, can have inverted T wave (increases CAD risk) delayed depolarization/repolarization

Question 36

pericarditis

Answer 36

diffuse ST elevation in all leads

Question 37

altered automaticity

Answer 37

myocyte fires that is not stimulated by SA node | can alter slope of depolarization: phase 4 pushed to threshold

Question 38

triggered automaticity

Answer 38

AP "triggers" a 2nd AP immediately after it | delayed after-depolarization

Question 39

Re-entry

Answer 39

unidirectional block in normally contiguous pathway(ex: from fibrosis or MI = now noncontiguous) impulse takes a slower alternative pathway: moves anterograde and retrograde (normal pathway has had time to repolarize enough to trigger) retrograde pathway sets up loop leading to ventricular tachycardia HR: >140 and sustained

Question 40

junctional rhythm

Answer 40

no P waves, constant firing of atria seen in digitalis intoxication due to enhanced automaticity

Question 41

multifocal atrial tachycardia

Answer 41

constant firing from multiple sites in the atria: lots of EKG morphologies see in emphysema due to high CO levels due to enhanced automaticity

Question 42

V-tach

Answer 42

due to organized re-entry Tx: DC cardioconversion then maintain with Class I (slow conduction and increse refractory period) or III (prolong repol. and increase effective refractory period)

Question 43

SVT

Answer 43

due to re-entry

Question 44

arrhythmias due to enhanced automaticity

Answer 44

sinus tachycardia atrial premature beat ventricular premature beat

Question 45

What might make a latent pacemaker prone to acceleration?

Answer 45

``` beta stimulation hypokalemia fiber stretch hypoxemia acidosis injury ```

Question 46

arrhythmias due to abnormal "triggered" automaticity

Answer 46

early after depolarization: interrupts phase 3 (can trigger long QT (torsades)) delayed after depolarization: interrupts phase 4 (occur as a result of Ca overload (digitalis))

Question 47

ventricular bigeminy

Answer 47

due to digitalis (Ca overload) | exacerbated by: catecholamines, hypokalemia

Question 48

torsades de pointes

Answer 48

polymorphic ventricular tachycardia triggered by EAD occurs in QT prolongation (phase 2 and 3) see in K channel blockers exacerbated by: low HR, hypokalemia re-entry

Question 49

arrhythmias due to re-entry

Answer 49

atrium: a. fib/flutter AV node: PSVT ventricle: ventricular tachycardia/fibrillation Drugs treat by interrupting re-entry: change conduction velocity, refractory period, convert unidirectional block to complete block