Cardiac Medicine Certification (CMC) Practice Exam

Which condition is commonly associated with Torsades de Pointes?

1. Hyperkalemia

2. Hypermagnesemia

3. Hypomagnesaemia

4. Hypokalemia

The correct answer is: Hypomagnesaemia

Torsades de Pointes is a specific type of polymorphic ventricular tachycardia that often occurs in the setting of a prolonged QT interval. Hypomagnesemia, characterized by low levels of magnesium in the blood, is one of the electrolyte disorders that can lead to a prolongation of the QT interval. Magnesium plays a critical role in cardiac repolarization, and insufficient magnesium levels can disrupt this process, making arrhythmias like Torsades de Pointes more likely. Additionally, magnesium is important for maintaining normal cardiac electrical activity, and its deficiency can also lead to increased automaticity and reentrant circuits, both of which contribute to the development of Torsades de Pointes. Therefore, hypomagnesemia is closely associated with this specific arrhythmia as it creates a favorable milieu for the occurrence of this potentially life-threatening condition.