Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

2nd year > Ventricular tachycardia - Torsades de pointes > Flashcards

Ventricular tachycardia - Torsades de pointes Flashcards

1
Q

what is ventricular tachycardia?

A

potentially life-threatening arrhythmia

originates in cardiac ventricles

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

what causes ventricular tachycardia?

A 
cardiac scars 
conduction disorders
drugs 
long-QT syndrome - congenital or acquired 
electrolyte imbalances 
ischaemic stroke 
intracranial haemorrhage 
endocrine disorders 
nutritional disorders 
can rarely occur in healthy individuals
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what cardiac scars can cause ventricular tachycardia?

A

cardiomyopathy
myocardial infarction
iatrogenic
post-op

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

conduction disorders

A

e.g. cardiomyopathy

disruption of conduction pathways

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

what drugs cause ventricular tachycardia?

A 
antiarrhythmics 
antibiotics 
antidepressants 
antipsychotics 
anticonvulsants
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

which antiarrhythmics cause VT?

A 
class Ia - quinidine and disopyramide 
class III - sotalol, amiodarone
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

which antibiotics cause VT?

A

macrolides

fluoroquinolones

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

which antidepressants cause VT?

A

most tricyclic and tetracyclic antidepressants

lithium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

which antipsychotics cause VT?

A

haloperidol

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

which anticonvulsants cause VT?

A

felbamate

fosphenytoin

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

what electrolyte imbalances cause VT?

A

hypokalemia
hypomagnesemia
hypocalcemia

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

what is the most ECG abnormality after ischaemic stroke or intracranial haemorrhage?

A

QT prolongation

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

what endocrine disorders cause VT?

A

hypothyroidism

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

what nutritional disorders cause VT?

A

anorexia nervosa

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

pathophysiology of VT

A

monomorphic VT
polymorphic VT
decreased cardiac output

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

monomorphic VT

A

all QRS complexes look similar
increased automaticity
re-entry circuit

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

what is a re-entry circuit?

A

myocardial scarring creates an area of poor electrical conduction so the impulse travels around the scar

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

polymorphic VT

A

dissimilar QRS complexes
caused by abnormal ventricular repolarisation
e.g. long QT syndrome, drug toxicity and electrolyte abnormalities

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

decreased cardiac output

A

asynchronous atrial and ventricular beats
rapid ventricular rhythm
decreased blood flow into the ventricle during diastole
decreased CO
haemodynamic compromise

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

what are the clinical features of VT

A

often asymptomatic - especially if non-sustained

symptoms if sustained

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

clinical features of sustained VT

A 
palpitations
hypotension 
syncope
severe cases:
chest pain/pressure - in conjunction with MI 
cardiogenic shock
loss of consciousness 
progression to ventricular fibrillation 
sudden cardiac death
22
Q

what are the subtypes/variants of VF

A

torsades de pointes

23
Q

what is torsades de pointes?

A

polymorphic ventricular tachycardia with QRS complexes that appear to twist around the isoelectric line
can progress to life-threatening ventricular arrhythmia

24
Q

what causes torsades de pointes?

A

prolonged QT interval caused by congenital disease, electrolyte abnormalities and drugs

25
Q

treatment for torsades de pointes

A

defibrillation if haemodynamically unstable

IV magnesium sulfate if haemodynamically stable

26
Q

diagnosis of ventricular tachycardia

A

ECG - main
holter monitor
patient-activated event recorder
echocardiography

27
Q

ECG VT findings

A

3 or more consecutive premature ventricular beats - widened QRS
>120bpm = HR

28
Q

ECG findings sustained vs nonsustained

A 
nonsustained = <30seconds
sustained = >30 seconds
29
Q

ECG findings - morphology

A 
monomorphic = all QRS complexes look similar 
polymorphic = QRS complexes are different
30
Q

other possible ECG findings

A

AV dissociation
Fusion complex
capture beats

31
Q

AV dissociation

A

no relationship between P waves and QRS complexes

ventricular rhythm is often faster than atrial rhythm

32
Q

Fusion complex

A

atrial and ventricular impulses occur simultaneously

33
Q

Capture beats

A

supraventricular impulse may reach AV node and produce a subsequent ventricular beat

34
Q

holter monitor

A

24-48 hour ambulatory monitor

useful for diagnosing intermittent VT which may not be present on a single ECG

35
Q

patient-activated event recorder

A

device to evaluate patient’s heart rhythm during symptomatic episodes - can be manually initiated or automatic

36
Q

echocardiography

A

provides information about possible causes of VT

37
Q

common differential diagnosis

A

supraventricular tachycardia with aberrancy - RBBB, LBBB or wolff-parkinson-white

38
Q

signs and symptoms that suggest VT rather than SVT

A

over 35 year olds
history of structural heart defects or past MI
AV dissociation, fusion beats and capture beats

39
Q

signs and symptoms that suggest SVT with aberrancy rather than VT

A

BBB on prior ECG
history of SVT
evidence of wolff-parkinson-white

40
Q

what is SVT with aberrancy?

A

group of tachyarrhythmias that originate in the atria or AVN
wide QRS complex
due to conduction defects
can be irregular or regular

41
Q

what is wolff-parkinson-white?

A

congenital condition
intermittent tachycardia and ventricular pre-excitation pattern on ECG
due to bundle of kent which connects the atria and ventricles, bypassing the AVN - delta wave and shortened PR interval

42
Q

treatment of VT

A

initial therapy and long-term therapy

43
Q

initial therapy for VT

A

different depending on whether patient is haemodynamically unstable or stable

44
Q

initial therapy is patient is hemodynamically unstable

A

VT with pulse = cardioversion
VT without pulse = defibrillation
advanced cardiac life support
look for and address possible causes = electrolyte abnormalities and correct, medication induced QT prolongation

45
Q

initial therapy is patient is hemodynamically stable

A

antiarrhythmics
cardioversion if medical therapy fails
look for and address possible causes = electrolyte abnormalities, metabolic-induced QT prolongation

46
Q

which antiarrhythmics can be used to treat VT?

A

lidocaine
procainamide
amiodarone

47
Q

what electrolyte abnormalities cause VT?

A

hypokalaemia

correct as part of treatment

48
Q

medication-induced QT prolongation

A

remove any causative medication

use digoxin immune fragment antigen binding for digoxin toxicity

49
Q

long-term therapy for VT

A

intracardiac devices
catheter ablation
antiarrhythmics

50
Q

intracardiac devices

A

most effective treatment for reducing mortality from VT - used when VT doesn’t respond to therapy

51
Q

catheter ablation

A

used when intracardiac devices cannot be tolerated or often receive intracardiac device shocks because of repeated VT

2nd year (48 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions