A 67-year-old woman taking sotalol is prescribed azithromycin and develops syncope. ECG shows polymorphic ventricular tachycardia with twisting QRS

Question

A 67-year-old woman taking sotalol is prescribed azithromycin and develops syncope. ECG shows polymorphic ventricular tachycardia with twisting QRS complexes around the baseline. Potassium is 3.2 mEq/L. Which of the following is the most likely explanation for this patient's findings?

Accepted Answer

Torsades de pointes from QT prolongation

Answer

Ventricular fibrillation from hypercalcemia

Answer

Complete heart block from digoxin toxicity

Answer

Atrial flutter with fixed block

Answer

Sinus arrest from hypothyroidism

Long QT medication safety — USMLE Step 3 MCQ

A 67-year-old woman taking sotalol is prescribed azithromycin and develops syncope. ECG shows polymorphic ventricular tachycardia with twisting QRS complexes around the baseline. Potassium is 3.2 mEq/L. Which of the following is the most likely explanation for this patient's findings?