Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Sp: Methods 1 > 6. Preexcitation and SVT > Flashcards

6. Preexcitation and SVT Flashcards

(76 cards)

Start Studying
1
Q

what are the two possible electrical pathways to the ventricles?

A
  • normal AV node pathway
  • abnormal accessory pathways (in the AV node or myocardium)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

most common electrical pathway to ventricles

A

normal AV node pathway

alpha pathway

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

beta pathway

A

abnormal conduction pathways

av node or myocardium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

other names for beta pathways

A

accessory pathways
bypass tracts
preexcitation pathway
aberrant pathway

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

do pts just have alpha or beta pathways?

A

they have both but beta pathways are normally dormant

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

when the beta pathways are activated what is the pt at risk for?

A

developing arrhythmias

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

triggers to activate beta pathways

A

stress, catecholamine surge
caffeine, tobacco, street drugs
electrolyte abnormalities
acid base imbalance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

electrical properties of alpha pathway

A
  • slow conduction
  • short refractory period (fast reset)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

electrical properties of beta pathway

A
  • rapid conduction
  • long refractory period (slow reset)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

when a current travels the beta pathway would we expect that the ventricles would depolarize earlier or later than normal

A

earlier because of the rapid conduction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

when a beta pathway is activated, does the current continue to flow to the alpha pathway?

A

yes - the current goes to both alpha and beta

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

preexcitation

A

anytime the ventricles depolarize earlier than they were supposed to

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

preexcitation + tachycardia =?

A

form reentrant loops that lead to SVT (supraventricular tachycardia)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What will the PR interval look like if a beta pathway in the AV node is activated? (normal, short, or prolonged?)

A

short

due to rapid conduction in beta pathway

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What will the QRS complex look like if a beta pathway in the AV node is activated? (normal or wide?)

A

normal

signal travels through normal conduction pathways in ventricles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What will the PR interval look like if an accessory pathway in the myocardium is activated? (normal, short, or prolonged?)

A

short

rapid conduction through beta pathway

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What will the QRS complex look like if an accessory pathway in the myocardium is activated? (normal or wide?)

A

wide (delta wave)

upper vent depolarized by myocardium and rest of vent by purkinje (Fast)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

2 types of preexcitation

A

wolff parkinson white
lgl syndrome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

what is the accessory pathway for WPW called?

A

kent bundle

direct connection between atria and ventricle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

what are the two things that will be on an ECG for WPW

A 
short pr interval
delta wave (upward slurring of Q wave)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

why does the delta wave occur?

A

upper ventricle is depolarized by myocardium and the rest of ventricle is depolarized by purkinje system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

symptoms of WPW without tachycardia

A

preexcitation

asymtomatic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

why is WPW with tachycardia a problem?

A

turns symptomatic

need to avoid ketamine, pain, hypovolemia, anxiety

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What can WPW tachycardia be confused with on ECG?

A

ventricular tachycardia bc QRS are wide

look for delta wave

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
what are the 3 treatments for stable SVT/AVRT
transvenous catheter ablation beta blockers antiarrhythmic drugs
26
what is the treatment for unstable SVT/AVRT
synchronized cardiaoversion
27
what is the most effective and permanent solution for WPW?
transvenous catheter ablation
28
what antiarrhythmic drugs should be avoided in SVT/AVRT?
drugs that block conduction through AV node | adenosine, calcium channel blockers, digoxin
29
what antiarrhythmic drugs can be given to pts with SVT/AVRT?
beta blockers | amiodarone
30
why do we not want to fully block the AV node?
then the entire conduction is going through the beta pathway and that can lead to serious arrhythmias
31
Lown Ganong Levine (LGL) syndrome accessory pathway
james bundle | direct connection between atria and bundle of His (bypass AV node)
32
activation of LGL pathway on ECG
- short PR interval - NO delta wave
33
LGL syndrome symptoms
usually asymptomatic and no treatment required
34
technically what does SVT refer to?
tachycardia originating above ventricles (sinus tach, afib, aflutter)
35
clincally what does SVT refer to?
tachycardia greater than 150bpm caused by reentry loops/beta pathways
36
ECG of SVT
HR >150 QRS normal difficult to differentiate between sinus and junctional tachycardia (p wave may not be present)
37
symptoms of SVT
ventricular filling decreased | CO decreased
38
paroxysmal SVT
SVT when it begins and ends abruptly "occuring in spasms" | irregularly irregular with p waves
39
what can paroxymal SVT look like on ECG?
afib
40
Suppose a patient has an active accessory pathway in the myocardium. When the SA node depolarizes, which pathway will the current travel to get to the ventricles?
travels antegrade down both alpha and beta pathways | preexcitation occurs
41
Suppose that in this same patient with an active accessory pathway in the myocardium, a premature atrial contraction (PAC) occurs. From this PAC, which path will the current travel through to get to the ventricles? 4
1- impulse goes through slow alpha pathway (bc beta pathway from previous beat is still in refractory) 2- beta pathway repolarizes when impulse is traveling down av node 3- travels retrograde through accessory pathway 4- travels antegrade through the alpha pathway again REENTRANT LOOP
42
what does the reentrant loop in the myocardium look like on ECG?
delta wave | wide QRS
43
what does the reentrant loop in the av node look like on ECG?
normal QRS complex
44
the majority of SVT originates in
SVT in AV node | AV Nodal Reentrant Tachycardia (AVNRT)
45
incidence of AVNRT vs AVRT
AVNRT is 2x AVRT
46
ECG for AVNRT
narrow QRS | may or may not have p wave
47
treatments for SVT in AV node (AVNRT) that slow conduction of AV node
vagal maneuvers adenosine calcium channel blockers sotalol digoxin amiodarone
48
vagal maneuver
- valsalva- ask pt to blow through a straw - carotid massage - cold stimulus
49
when should you avoid a carotid massage? why?
could dislodge plaque | avoid in geriatric, high cholesterol, previous stroke
50
pharmacology of adenosine
5-10 sec acting | uncomfortable for pt (can stop heart)
51
dose of adenosine
inital 6mg bolus | up to 2 more doses of 12mg
52
what does sotalol do?
beta blocker antiarrythmic | slow conduction in AV node suppress ventricular ectopy
53
dose for sotalol to treat SVT?
100mg or 1.5mg/kg
54
when should sotalol be avoided?
pts with prolonged QT syndrome
55
full list of treatment for SVT within the AV node
``` slow conduction through AV node antiarrhythmics beta blocker synchronized cardioversion transvenous catheter ablation ```
56
what is SVT in the myocardium referred to as?
atrioventricular reentrant tachycardia (AVRT)
57
ECG for AVRT
p waves | possible delta waves
58
Is AVRT the same thing as Wolff Parkinson White?
WPW can become AVRT if has tachycardia
59
treatment for SVT within myocardium
antiarrhythmics beta blockers synchonized cardioversion transvenous catheter ablation
60
should you avoid av node blockers in AVRT?
yes
61
what is the treatment option for people who have arrhythmias (usually afib) that are unrespinsive to medications
doctors map area that is causing the disturbance and ablate the abnormal conduction pathways
62
cardiac ablation goes into the heart via _______ access
femoral vein
63
if you need to ablate the Left side of heart, what does the surgeon do?
creates a hole in the interartrial septum
64
monitoring for cardiac ablation cases?
central line arterial line
65
what side of the heart is more risky for cardiac ablation?
left side
66
what additional items do we place during cardiac ablation cases?
OG tube w/special stylet LET esophageal temp probe
67
what does the LET probe measure
esophageal temperature during posterior left atrium ablation
68
what drug do you avoid in cardiac ablation?
lidocaine (suppresses ectopy)
69
when should you avoid paralytics in cardiac ablation?
if surgeon is using cryoablation, to avoid phrenic nerve injury
70
when will the cardiologist ask for apnea during cardiac ablation?
when ablating near the carina
71
what MAP should you keep during cardiac ablation?
>60mmHg
72
when should you alert surgeon of temperature changes during cardiac ablation?
>0.5C changes in temp during posterior wall ablation
73
what infusion is started at end of cardiac ablation?
isoproterenol infusion
74
SE of isoproterenol infusion?
dramatic BP decrease treat w/phenylephrine
75
kent bundle pathway
RA to RV
76
james bundle pathway
RA to BoH

Sp: Methods 1 (15 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions