Tachycardia (with pulse) Algorithm

Question 1

If a patient is found to be tachycardic, and ABCDE approach has been applied, what needs to be considered next?

Answer 1

Presence of adverse features:

• shock
• syncope
• myocardial ischaemia
• heart failure

Question 2

If the patient has adverse features, what does this mean?

What is the Mx of these patients?

Answer 2

They are unstable -
give synchronised DC shock up to 3 times

seek expert help

Amiodarone 300mg IV over 10-20 min
Repeat shock
Amiodarone 900mg over 24h

Question 3

If the patient does not have adverse features, what does this mean?
What is the next step to be considered?

Answer 3

They are stable

Look at the QRS complex - is it narrow? (<0.12s)

Question 4

If the QRS complex is broad, what is the next step to be considered?

Answer 4

Whether the broad QRS complexes are regular or irregular

Question 5

What are the possible causes of an irregular broad QRS and how are they treated?

Answer 5

AF with bundle branch block
- treat as for a narrow complex tachycardia.

Pre-excited AF
- consider amiodarone

Question 6

What are the possible causes of an regular broad QRS and how are they treated?

Answer 6

VT (or uncertain rhythm)
- amiodarone 300mg IV over 20-60 min then 900mg over 24h

SVT with bundle branch block
- treat as for regular narrow complex tachycardia

Question 7

If the QRS complex is narrow, what is the next step to be considered?

Answer 7

Whether the narrow ARS complexes are regular or irregular

Question 8

How is a regular narrow QRS complex tachycardia treated?

Answer 8

Vagal manoeuvres
Adenosine 6mg rapid IV bolus - if no effect give further 12mg, then another if no effect
Continous ECG monitoring

Question 9

If a regular narrow QRS complex tachycardia is not restored to sinus rhythm with vagal manoeuvres or adenosine, what is the probable cause and how is it treated?

Answer 9

Probable atrial flutter
Seek expert help!
Control rate with B-blocker

Question 10

If a regular narrow QRS complex tachycardia is restored to sinus rhythm with vagal manoeuvres or adenosine, what was the probable cause?

Answer 10

Re-entry paroxysmal SVT

Question 11

What is the probable cause of an irregular narrow QRS complex tachycardia and how is it treated?

Answer 11

Atrial Fibrillation

control rate - B-blocker or diltiazem
If in HF consider digoxin or amiodarone
Assess thromboembolic risk and consider anticoagulation