What Causes Torsades de pointes?

     Torsades de Pointes (TdP) is a type of arrhythmia that can be life-threatening. Persons with long QT syndrome (LQTS) are at an increased risk of developing TdP. The QT interval is measured on an electrocardiogram (ECG). Torsades de pointes means “twisting of the points”, which refers to the appearance on the ECG during the condition. Long QT syndrome can be caused by genetics, certain types of medications, or low magnesium or low potassium levels. Antiarrhythmic medications (such as quinidine), macrolide antibiotics (such as azithromycin [Zithromax] and clarithromycin [Biaxin]), and certain antipsychotic medications (such as haloperidol [Haldol]) can lead to an increased risk of developing LQTS. Taking multiple medications that prolong the QT interval  should be avoided.  Signs and symptoms of LQTS may include fainting or seizures.

     If TdP occurs, any medication that may be causing the condition should be stopped. If low magnesium or potassium is the cause, treatment should be aimed at restoring normal levels. For persons who are diagnosed with LQTS because of a genetic cause, a beta blocker such as propranolol (Inderal) may be prescribed. A pacemaker may be needed to prevent abnormal heart rhythms.