EMmedonline

• Torsades de pointes is a variant of polymorphic VT.

• The ECG shows rapid irregular complexes that oscillate from an upright to an inverted position and seem to twist around the baseline as the mean QRS axis change.

• They are usually non sustained and repetitive but may degrade into ventricular fibrillation.

• Torsades de pointes is usually initiated by a VPB starting at the peak of a prolonged T-U wave.

Etiology

• Acquired Long QT Syndrome

  • Drugs: Quinidine, ibutilide, sotalol, procainamide,amiodarone, tricyclic antidepressants, other drugs like pentamadine, erythromycin.

  • Electrolyte imbalance: Hypokalemia,hypomagnesemia and less commonly hypocalcemia.

  • High grade AV Heart Block

  • Subarachnoid hemorrhage

• Hereditary Long QT Syndrome

• Jervell and Lange Nielsen Syndrome

• Romano-Ward Syndrome

Note the twisting around the baseline where  QRS axis changes

Management

• Magnesium

  • ACLS guidelines recommends to use 1 – 2gm of magnesium sulphate in 10 ml 5% D.

  • Studies have shown that administration of magnesium sulfate can facilitate termination of torsades de pointes. It is not likely to be effective in terminating irregular/polymorphic VT in patients with a normal QT interval.

  • It is administrated over 15 minutes.

Updated on 2/2/2015

Reference

• Tintinalli

• Davidson

• Goldberger's Clinical Electrocardiography

• 2010 AHA Guideliones for CPR and emergency cardiovascular care. Part 8. ACLS