Narrow Complex Tachycardia (Supraventricular Tachycardia)

Question 1

Initial Mx of narrow complex tachycardia (supraventricular tachycardia):

Answer 1

1. O2 if hypoxic
2. IV access
3. ECG
4. Regular rhythm - continuous ECG tracing
5. Perform **vagal manoeuvres **
6. **Adenosine 6mg ** bolus IVI Followed by 12mg, then 12mg if necessary
7. Check for adverse signs - BP ≤90, HF, Impaired consciousness, HR ≥200 bpm

Question 2

Mx of narrow complex tachycardia (supraventricular tachycardia) if NO adverse signs:

Answer 2

1. B-blockers - IV metoprolol 1–10mg
2. Digoxin - max IV dose 500μg over 30min repeated after 90min if needed
3. Amiodarone - 300mg over IV 1h; may be repeated once if necessary via a central line if possible
4. Overdrive pacing - not AF
5. Alternative drugs - seek cardiology advice

Question 3

Mx of narrow complex tachycardia (supraventricular tachycardia) if adverse signs PRESENT:

Answer 3

1. Sedation
2. Synchronized cardioversion -150J - 360J - 360J
3. Amiodarone 300mg over 20–60min followed by 900mg over 24h

Question 4

Mx of Irregular narrow complex tachycardia:

Answer 4

1. Treat as AF—by far the most likely Dx
2. Control rate with either B-blocker or digoxin
3. If onset <48h consider cardioversion with either amiodarone 300mg IVI over 20–60min, then 900mg over 24h; or DC shock
4. Consider anticoagulation with heparin and/or warfarin to reduce the risk of stroke

Question 5

Full Mx algorithm:

Answer 5