A 60-year-old man arrives at the emergency department complaining of dizziness and palpitations. This morning, he awoke with a pounding sensation in his chest. The patient had previously experienced a similar sensation but did not consider it serious. He later became lightheaded while mowing the lawn and had to sit down to avoid passing out. Following a thorough examination, the patient is diagnosed with a cardiac arrhythmia and begins treatment with a medication known to prolong the QT interval. However, compared to other QT-prolonging agents, the drug is associated with a lower incidence of torsade de pointes. Which of the following medications was most likely used in this patient?

Question

Quizplus · Accepted Answer

Eductional Objective: Amiodarone (and other class III and class IA antiarrhythmic drugs) causes the cardiac action potential to lengthen, resulting in QT interval prolongation on the ECG. In contrast to other drugs, QT prolongation caused by amiodarone is associated with a very low risk of torsades de pointes.

A 60-Year-Old Man Arrives at the Emergency Department Complaining of Dizziness