What is one potential result of a significant prolonged QT interval?

A prolonged QT interval can lead to the phenomenon known as Torsades de Pointes (TdP), which is a specific type of polymorphic ventricular tachycardia. The QT interval represents the time the heart takes to electrically reset after each heartbeat, and when it is prolonged, it increases the risk for abnormal heart rhythms.

When the heart's electrical conduction system experiences these delays, it can create an environment where early afterdepolarizations occur, ultimately leading to rapid, disorganized electrical activity in the ventricles. This potentially life-threatening dysrhythmia can result in ineffective pumping of the heart and presents as a rapid heart rate originating in the ventricles.

The association of a prolonged QT interval with ventricular tachycardia underlines the importance of monitoring this interval in patients who are on medications that can prolong the QT segment or who have conditions known to contribute to this prolongation.