What is the normal QT interval range?

The normal QT interval range is generally recognized to be up to 440 milliseconds in adult males and can extend to 460 milliseconds in adult females. This span takes into account various factors that can influence the QT interval, such as heart rate, age, and gender. Therefore, a QT interval of up to 440 milliseconds is considered normal for males, making this the appropriate choice for the question.

Understanding this threshold is important as prolongation of the QT interval can increase the risk of serious arrhythmias, underscoring the significance of monitoring it in clinical practice. Additionally, the factors mentioned above are critical for accurately interpreting an individual's QT interval, as deviations from the norm may prompt further investigation or management.