FN: Narrow Complex Tachycardias = SVT

Question 1

Definition

Answer 1

rate >100 bpm

QRS width

Question 2

differentials

Answer 2

Sinud tachycardia
Atrial:
1. AF
Atrial flutter
Atrial tachycardia

AV nodal re-entry tachycardia
AV re-entry Tachycardia

Question 3

Rx patient compromised

Answer 3

Sedate + DC cardioversion

Question 4

Rx if patient not compromised

Answer 4

Vagal manoeuvers (carotid sinus massage, valsalva) transiently increase AV block and may unmask underyling atrial rhythm

Question 5

If manoeuvres unsuccessful

Answer 5

Give adenosine while recording rhythm strip

1. transient AV blook, unmasking atrial rhythm
2. Cardioverts AVNRT, AVRT to sinus rhythm

Question 6

If adenosine fails

Answer 6

digoxin
Atenolol
Verapamil (not if on beta blocker)
Amiodarone

Question 7

If unsuccessful

Answer 7

DC cardioversion

Question 8

Management pathway

Answer 8

1. Oxygen + IV access
2. Irregular rhythm? treat as AF
3. Regular rhythm?
   - -> ECG trace continues
4. Vagal manoeuvres
5. Adenosine 6mg IV bolus, then 12mg, then 12mg
6. Adverse signs - cardioversion
7. No adverse signs - medical management

Question 9

Adverse signs?

Answer 9

BP 200

Question 10

No adverse signs Rx

Answer 10

Digoxin (500ug over 30min)
Amiodarone
Verapamil
Atenolol

Question 11

Adenosine MOA

Answer 11

Temporary AVN block

Question 12

Adenosine SE

Answer 12

Transient chest tightness
Dyspnoea
Flushing
Headache

Question 13

Adenosine Relative CI

Answer 13

Asthma

2nd/3rd degree block

Question 14

Adenosine interactinos

Answer 14

Fx increased by dipyridimole

Fx increased by theophyline

Question 15

Prophylaxis of tachycardia

Answer 15

Beta-blockers
AVRT: flecainide
AVNRT: verapamil