Which description correctly distinguishes Torsades de Pointes from other ventricular tachyarrhythmias?

• A. Corkscrew QRS morphology is unique to Torsades.
• B. It always has a narrow QRS.
• C. It is never associated with QT prolongation.
• D. It is not a type of VT.

Answer: (A)

The key feature being tested is the distinctive QRS pattern of torsades de pointes. Torsades is a polymorphic ventricular tachycardia where the QRS complexes continually change shape and axis beat to beat, so they appear to twist around the baseline—this corkscrew or twisting pattern is the hallmark that helps distinguish it from other ventricular tachyarrhythmias, which typically have a uniform, single shape (monomorphic VT).

This pattern sets torsades apart from other choices because it reflects the dynamic, rotating electrical vectors of a heart with prolonged repolarization, often seen when the QT interval is extended. In contrast, the other statements are not true: torsades usually presents with wide QRS complexes, is commonly associated with QT prolongation, and is indeed a type of ventricular tachyarrhythmia.

So, the corkscrew QRS morphology uniquely points to torsades de pointes.