Which antiarrhythmic drug is associated with a prolonged QT interval?

Amiodarone is known to be associated with a prolonged QT interval, which is significant in the context of managing arrhythmias. This drug works by blocking potassium channels, which can delay repolarization in the cardiac cycle, leading to an increased risk of torsades de pointes, a potentially life-threatening arrhythmia caused by a significant prolongation of the QT interval.

Additionally, the association of amiodarone with the QT prolongation reflects its mechanism of action and highlights the importance of monitoring patients who are prescribed this medication for any signs of electrical disturbances in the heart.

The other options, while they have their own effects and implications in treatment, do not have a direct and significant association with prolonged QT interval. For example, digoxin primarily affects cardiac contractility and might not have the same implications for QT prolongation. Furosemide is a diuretic that does not typically affect the QT interval, and a coronary artery bypass graft is a surgical procedure rather than a pharmacological agent, thus being unrelated to QT interval considerations.