Tachyarrhythmias

Question 1

what does SVT stand for

Answer 1

supraventricular tachycardia

Question 2

what does SVT involve

Answer 2

SAN, AVN, atria

Question 3

5 types of SVT

Answer 3

1. PSVT (paroxysmal supraventricular tachycardia)
2. AVNRT (atrioventricular nodal re-entrant tachycardia)
3. AVRT (atrioventricular reciprocating tachycardia)
4. AF (atrial fibrillation)
5. Atrial flutter

Question 4

4 drugs that can treat PSVT

Answer 4

adrenaline, verapamil (4), diltiazem (4), amiodarone (3)

Question 5

can get ventricular tachycardias which involve

Answer 5

Bundle of His, Purkinje Fibres and ventricles

Question 6

what is more dangerous SVTs or VTs?

Answer 6

VTs

Question 7

4 drugs mainly used to treat VT

Answer 7

amiodarone (3), flecainide (1c), disopyramide (1a) and lidocaine (1b)

Question 8

what does VF stand for

Answer 8

ventricular fibrillation

Question 9

5 different factors that can cause tachyarrhythmias

Answer 9

pre-existing CV diseases, electrolyte imbalance, drugs, emotions and lifestyle choices AND genetic disorders

Question 10

6 types of drugs that can cause tachyarrhytmias

Answer 10

1. asthma inhalers
2. anti arrhythmias
3. anti-hypertensive (this is a reflex reaction)
4. antifungals
5. antibiotics
6. antihistamines

Question 11

3 main mechanisms for tachyarrhythmias

Answer 11

1. re-entry (AVNRT, micro re-entry and macro re-entry)
2. EADs
3. DADs

Question 12

tachyarrhythmias are caused by…

Answer 12

sympathetic overactivity and an abnormal pacemaker

Question 13

what does the re-entry mechanism cause?

Answer 13

paroxysmal supraventricular tachycardia

Question 14

how to treat PSVT

Answer 14

Class 4: verapamil
Class 2: beta blockers
Class 3: sotalol
Class 1c: flecainide 
Adenosine

Question 15

what is micro-re-entry?

Answer 15

similar to AVNRT but occurs in the ventricular myocardium and purkinje fibres

Question 16

what causes micro-re-entry

Answer 16

focal ischaemia or infarction

Question 17

if a pulse is present, then use:

Answer 17

amiodarone (3), flecainide (1c) or lidocaine (1b)

Question 18

which class of anti-arrhythmic drugs are not effective for ventricular tachycardia

Answer 18

class 4

Question 19

what is macro re-entry ?

Answer 19

re-entry via congenital accessory pathway between the atria and ventricles

Question 20

example of a macro re-entry disease

Answer 20

Wolff-Parkinson-White syndrome - caused by an abnormal pathway completely missing the SA node

Question 21

how to treat macro re-entry

Answer 21

CATHETER ABLATION or flecainide (1c) or amiodarone (3)

Question 22

what drugs are not effective in AVRT

Answer 22

AVN blockers

Question 23

what is another way of saying macro re-entry

Answer 23

AVRT

Question 24

what does EAD stand for?

Answer 24

early after depolarisation

Question 25

what does DAD stand for

Answer 25

delayed after repolarisation

Question 26

what causes EADs

Answer 26

the prolonging of the cardiac AP

Question 27

what class of anti-arrhythmics can cause EADs

Answer 27

Class 3, 1a OR medicine that is know to inhibit repolarising K channels in phase 3 of the cardiac AP

Question 28

during prolonged AP, are the Na channels activated?

Answer 28

no

Question 29

what channel triggers the EAD

Answer 29

the L-type Ca channels in the heart can still recover and trigger EAD

Question 30

what happens to the heart rate during an EAD

Answer 30

slows down

Question 31

EADs can trigger

Answer 31

TdP, a type of ventricular tachycardia

Question 32

what are DADs due to

Answer 32

calcium build up in the cardiac myocyte that doesn't have enough time to recover to basal level in between APs

Question 33

what promotes a Ca build up in the cell?

Answer 33

fast HR

Question 34

drugs that increase Ca release

Answer 34

caffeine

Question 35

another cause of DAD

Answer 35

digoxin overdose

Question 36

what causes atrial fibrillation

Answer 36

micro re-entry or EADs

Question 37

drug used to control the rate of atrial fibrillation

Answer 37

digoxin

Question 38

what can be used to treat EADs and DADs

Answer 38

``` class 2 - beta blockers class 1c - flecainide class 3 - amiodarone class 4 - diltiazem ```