Tachycardiac Algorithm (with pulse)

Assess using the ABCDE approach
Give oxygen if appropriate and obtain IV access
Monitor ECG, BP, SpO₂, record 12 lead ECG
Identify and treat reversible causes (e.g. electrolyte abnormalities)

End

Synchronized DC shock^*
Up to 3 attempts

Amiodarone 300 mg IV over 10–20 min and repeat shock followed by:
Amiodarone 900 mg over 24 h

Is QRS narrow ( < 0.12 sec)?

Broad

Narrow

If Ventricular Trachycardia (or uncertain rhythm):

Amiodarone 300 mg IV over 20–60 min; then 900 mg over 24 h

If previously confirmed SVT with bundle branch block:

Give adenosine as for regular narrow complex tachycardia

Seek expert help

!

Broad QRS is QRS regular?

Regular

Irregular

Possibilities include:

AF with bundle branch block treat as for narrow complex
Polymorphic VT
(e.g. torsades de pointes-give magnesium 2 g over 10 min)

Irregular Narrow Complex Tachycardia
Probable atrial fibrillation
Control rate with:

-blocker or diltiazem
Consider digoxin or amiodarone if evidence of heart failure

Anticoagulate if duration >48 h

Use vagal manoeuvres
Adenosine 6 mg rapid IV bolus; if unsuccessful give 12 mg; if unsuccessful give further 12 mg.
Monitor ECG continuously

Narrow QRS is rhythm regular?

Regular

Irregular

Probable re-entry PSVT:

Record 12-lead ECG in sinus rhythm
If recurs, give adenosine again & consider choice of anti-arrhythmic prophylaxis

Seek expert help

!

Normal sinus rhythm restored?

Yes

No

Possible atrial flutter

Control rate (e.g. -blocker)

Assess for evidence of adverse signs

shock
syncope
Myocardial ischaemia
Heart failure

Stable

Unstable

^* Attempted electrical cardioversion on conscious patients is always under sedation or general anaesthesia