What is a lethal cardiac arrhythmia associated with long QT syndrome?

Long QT syndrome is a condition that affects the heart's electrical system, leading to prolonged repolarization of the heart after a heartbeat. This elongation can precipitate serious arrhythmias. Among these arrhythmias, Torsade de Pointes is particularly significant because it involves a distinctive type of polymorphic ventricular tachycardia characterized by a rapid, twisting pattern on the electrocardiogram.

Torsade de Pointes occurs due to the prolonged QT interval that can lead to susceptibility to early afterdepolarizations and can result in the heart being unable to maintain an effective rhythm. This situation can deteriorate quickly and may lead to syncope or even sudden cardiac death, making it a lethal arrhythmia.

In the context of long QT syndrome, identifying Torsade de Pointes is crucial for patient management, as it requires immediate medical intervention, such as electrolyte correction or the use of antiarrhythmic medications. The other arrhythmias listed do not share the same direct association with long QT syndrome in terms of being a lethal outcome linked to the condition.