Mean QT Duration

**Semantic type:** Quantitative Concept

**Definition:** The average (mean) duration (time) of the QT interval, obtained from a set of measurements of the QT interval. The QT interval is defined as the time from the beginning of the QRS complex to the end of the T wave, representing the time it takes for the ventricles to depolarize and subsequently repolarize. In some cases, the Q wave will be absent, in which case the QT interval is measured from the beginning of the R wave to the end of the T wave.

**Synonyms:** - Summary (Mean) QT Duration