Torsade de Pointes
Description:
Torsades de pointes is a polymorphic ventricular tachycardia that differs from general ventricular tachycardia in both appearance and cause. The phrase “torsades de pointes” means “twisting on a point” which explains the action of the QRS complex and how it varies from beat to beat. Each QRS complex is wide and changes in size with each beat. The QT interval is increased to 600 milliseconds or more. Torsades can occur as both a perfusing or non-perfusing rhythm. It is a shockable rhythm.
If possible, check in between bursts of this rhythm to assess for a prolonged QT interval. For perfusing rhythms, the heart rate is generally between 165 – 300 beats per minute. The R to R interval varies in an irregularly irregular pattern.
Etiologies:
Medication (mainly antidysrhthmics)
Electrolyte imbalance
Family history
Treatment:
1-2 grams of magnesium sulfate placed in 100mL of D5W and administered over 1-2 minutes. This can be repeated every 4 hours. Amiodarone has sometimes proven effective in the treatment of torsades but overall, antidysrhythmics usually produce disastrous consequences with this rhythm.