What effect may sinus bradycardia have on the QT interval?

Sinus bradycardia is characterized by a heart rate of less than 60 beats per minute, which can have several physiological implications for the heart, including an influence on the QT interval. The QT interval represents the time it takes for the heart's electrical system to depolarize and then repolarize, which is crucial for the coordinated contraction of the heart.

In the context of sinus bradycardia, the prolonged QT interval occurs due to the increased duration between heartbeats. When heart rates are slower, there is more time for the heart's electrical system to reset. This can lead to an increase in the time to repolarization, resulting in a prolonged QT interval.

As heart rate decreases, the action potential duration can lengthen, contributing to this prolongation. Moreover, drugs or other medical conditions may exacerbate this effect, but in a straightforward case of bradycardia alone, the QT interval is typically prolonged. Therefore, the assertion that the QT interval becomes prolonged in the context of sinus bradycardia is accurate and based on the understanding of cardiac electrophysiology.