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Flashcards in exam 2 Deck (56):
1

arrhythmia

- any electrical disturbance that changes rate, regulatity, site of origin or conduction pathway in pathologic way
- single beat or sustained
- benign to life threatening

2

causes of arrhythmias

-hypoxia
- ischemia and irritability
- sympathetic stimulation
- drugs
- electrolyte disturbances
- enlargement and hypertrophy

3

types of arrhythmias

- form SA node
- ectopic rhythm
- recurrent arrhythmia

4

ectopic rhythms

- originate form focus other than SA node

5

recurrent arrhythmias

electrical activity trapped in a continuous circuit

6

sinus tachycardia

- rhythm > 100 bpm
- normal or pathologic
- pathologic due to hyperthyroidism or PE**

7

sinus bradycardia

- rhythm < 60 bpm
- normal or pathologic
- normal happens in well conditioned athletes
- pathologic- vasovagal syncope

8

sinus arrest

- sinus node stops firing
- causes flat line
- length of line depends on if and when rescue beat occurs

9

asystole

prolonged sinus arrest

10

rescue beat

- aka escape beat
- originate from atria, AV node, or ventricles

11

sick sinus syndrome

- dysfunction of SA node
- inability to generate heart rate that meets physiological needs

12

possible results of sick sinus syndrome

- bradycardia
- sinus pauses
- sinus arrest
- paroxysmal supraventricular tachycardia

13

supraventricular arrhythmias

- originate in atria or AV node
- single beat or sustained rhythm

14

ectopic rhythms

- arises elsewhere not sinus node
- sustained rhythms
- enhanced automaticity of non-sinus site
- abnormal acceleration of depolarization

15

what is a common cause of ectopic rhythms

medication

16

what does AVNRT stand for

- AV node reciprocating tachycardia
- type of reentry loop

17

characteristics of AVNRT

- sudden onset and offset*
- can vary in size
- if no P wave then it originated below atria

18

what reentry loop involves entire heart

AV reentry tachycardia- AVRT

19

characteristics of AVRT

- accessory pathway between atrium and ventricle bypasses AV node
- connects directly to his bundle, ventricular myocardium or one of fascicles

20

4 questions to ask about rhyhm

- is it regular or irregular
- P waves present?
- do P waves precede each QRS?
- are QRS narrow or wide?

21

premature atrial contractinon

- usually due to ectopic focus
- isolated beat that comes early
- P wave morphology sometimes looks different

22

types of supraventricular arrhythmias

- paroxysmal supraventriclar tachy
- a flutter
- a fib
- multifocal atrial tachycardia
- paroxysmal atrial tachycardia

23

supraventricular tachycardia (SVT)

- usually initiated by premature supraventricular beat
- driven by recurrent loop in AV node
- regular rhythm, very rapid

24

causes of SVT

- very common
- can occur in normal heart
- alcohol
- coffee
- excitement

25

mechanisms to break SVT

-valsalva maneuver first
- if valsalva doesnt work give adenosine
- carotid massage

26

atrial flutter

- common
- regular but very rapid rate
- rapid fire atrium
- have "flutter" p waves
- saw tooth appearance

27

common conditions associated with a flutter

- HTN
- electrolyte abnormalities
- alcohol
- drug abuse (Stimulants)
- thryotoxicosis
- cardiac conditions

28

atrial fibrillation

- atria activity is completely chaotic
- AV node can be bombarded with > 500 impluses/ min
- multiple reentrant circuits
- no true P waves
- irregularly irregular ventricular rate

29

conditions associated with a fib

- HTN
- mitral valve disease
- PE
- thyrotoxicosis
- pericarditis

30

multifocal atrial tachycardia

- irregular rhythm at 100-200 bpm
- random firing of several different ectopic atrial foci
- common in lung disease
- p waves vary in morphology

31

what is multifocal atrial tachycardia called if its less than 100 bpm

wandering atrial pacemakers

32

premature ventricular contraction

- most common ventricular arrhythmia
- QRS wide and bizarre
- happens before next beat should occur
- isolated PVC is normal

33

ventricular bigeminy

- for every sinus beat you get a ventricular ectopic beat/ PVC

34

ventricular trigeminy

two normal beats to one PVC

35

when are PVCs dangrous?

- when frequent
- when runs of more than 3 in a row (called v tach)
- when variable in morphology
- when pt is having MI

36

ventricular tachycardia classifications

- non-sustained v tach (NSVT)
- sustained v tach (SVT)

37

non-sustained v tach

- common
- usually asymptomatic
- potential marker for sustained v tach but usually benign if no heart disease
- usually < 30 sec

38

sustained v tach

- pulse present vs. pulseless
- conscious vs unconcious
- leads to v fib -> death
- lasts greater than 30 sec

39

ventricular fibrilation

- v tach degenerates into v fib
- no discernible QRS complexes
- no cardiac output
- immediate CPR and defibrillation required

40

causes of v fib

- MI (most common)
- myocardial ischemia
- HF
- hypoxemia or hypercapnia
- hypotension/ shock
- electrolyte imbalances
- stimulants
- often preceded by v tach

41

torsades de pointe

- unique form of v tach
- usually seen with prolonged QT intervals
- QRS complexes spiral around baseline, change amplitude and axis

42

conduction block

- obstruction or delay of flow of electricity along normal electrical pathway

43

types of conduction blocks

- sinus node block
- AV block
- BBB

44

sinus node block

- sinus node fires but wave of depol is immediately blocked
- atria doesnt contract
- causes sinus pause/arrest

45

AV block

- any conduction block between sinuse node and purkinje fibers

46

types of AV block

- first degree AVB
- second degree- mobitz I or II
- third degree ABV

47

bundle branch block

- conduction block in one or both ventricular BB
- can occur in main BB or within one of fascicles
- wide QRS

48

what is LBB associated with

- coronary artery disease
- very concerning in setting of MI

49

first degree AV block

- prolonged delay in AV node conduction
- normal depol of atria
- prolonged PR
- every atrial impulse makes it through

50

second degree AV block

- not every atrial impulse makes it through
- P to QRS >1:1
- either mobitz I or mobitz II

51

mobitz type I

- aka wenchebach
- each atrial impulse gets has longer delay
- usually 3rd of 4th impulse fails to make it through
- not indication for pacemaker

52

mobitz type II

- block below AV node in his
- some but not at atrial impulses transmitted
- two or more beats with normal PR then dropped beat
- cycle is repeated
- indication for pacemaker

53

third degree heart block

- aka complete heart block
- no atrial impulses make it to ventricles
- site can be at AV node or lower
- escape rhythm generated below block
- atria and ventricles become dissociated
- pacemaker indicated

54

RBBB

- R ventricular depolarization is delayed
- wide QRS
- r-R' bunny ear pattern
- wide S in V6
- can be in normal or sick hearts

55

LBBB

- delayed ventricular depolarization
- prolongation in rise of R waves in leads over left ventricle
- broad and notched QRS
- leads over R ventricle will show broad S wave

56

what does LBBB usually suggest

coronary artery disease