Prolonged QT interval can lead to which serious condition?

A prolonged QT interval can lead to arrhythmias, which are abnormalities in the heart's rhythm. The QT interval is a measure of the time it takes for the electrical system of the heart to reset after each heartbeat. When this interval is prolonged, it can result in the heart taking longer than normal to repolarize, potentially leading to dangerous arrhythmias such as Torsades de Pointes.

These arrhythmias can cause the heart to beat irregularly, which might lead to fainting, palpitations, or even sudden cardiac arrest if not treated promptly. While prolonged QT can be associated with other conditions, such as heart attack, stroke, or seizures, the most direct and immediate risk stems from the development of life-threatening arrhythmias resulting from this prolonged electrical activity. Thus, understanding the implications of the QT interval is crucial in assessing a patient's risk for cardiac complications.