Which of the following statements about torsades de pointes is true?

The statement that torsades de pointes typically presents with a heart rate between 150 and 250 beats per minute accurately reflects the nature of this condition. Torsades de pointes is a specific form of polymorphic ventricular tachycardia that can occur in the setting of prolonged QT interval. During an episode of torsades, the heart rate can vary widely within this range, often resulting in a rapid and chaotic electrical activity seen on the electrocardiogram (ECG). The high heart rates contribute to an increased risk of syncope and other severe outcomes if not addressed promptly.

The other statements do not accurately describe torsades de pointes. It is not characterized by a uniform pattern of QRS complexes; in fact, one of its defining features is the characteristic "twisting of the points" of the QRS complexes, which is indicative of its polymorphic nature. It is also not considered benign or rarely life-threatening; rather, torsades de pointes can be life-threatening and may lead to ventricular fibrillation if not treated. Lastly, it is characterized by a wide QRS complex rather than a narrow one, as the QRS duration typically exceeds 120 milliseconds during episodes of torsades de pointes.