Triggered activity, related to __________________ problems, is the cause of torsades de pointes.

Triggered activity, particularly in the context of torsades de pointes, is primarily associated with repolarization problems. Torsades de pointes is a specific type of polymorphic ventricular tachycardia that is characterized by a prolonged QT interval, which leads to abnormal repolarization of the cardiac ventricles. The repolarization phase of the cardiac cycle is critical because it allows the heart muscle to return to its resting state following depolarization (the contraction phase).

When repolarization is impaired, it can lead to early afterdepolarizations (EADs) or delayed afterdepolarizations (DADs). These abnormal waveforms can trigger rapid and chaotic contractions of the heart muscle, manifesting as torsades de pointes on an electrocardiogram. Conditions that prolong the QT interval, such as electrolyte imbalances (like hypomagnesemia or hypokalemia), certain medications, or congenital syndromes, are frequent underlying causes of these repolarization issues.

This highlights the vital role of repolarization in maintaining stable cardiac rhythms and the significance of monitoring QT intervals in patients at risk for torsades de pointes.