Has a twisting pattern to the QRS complexes and a prolonged QT interval in sinus rhythm It is usually due to a QT–prolonging drug, ± hypokalaemia

Pharmacological

Stop all QT-prolonging drugs. Correct serum potassium.

• Magnesium sulphate 2 g I.V over 5–10 minutes If recurrent episodes after initial dose of magnesium sulphate:

• Magnesium sulphate 2 g I.V over 24 hours Torsade’s complicating bradycardia: temporary pacing.

• Adrenaline infusion to raise heart rate to > 100 per minute (if temporary pacing unavailable).

Referral: All cases of wide QRS tachycardia, after resuscitation and stabilization

Non-pharmacological

• Cardioversion/defibrillation, as necessary.

• Torsade’s complicating bradycardia: temporary pacing.