Prolonged QT interval

What it means

Increased time between the start of the Q wave and the end of the T wave as measured by the electrocardiogram (EKG).

The QT interval represents electrical depolarization and repolarization of the left and right ventricles.

Rare diseases that can present with this27

The range is how often this sign appears among people diagnosed with each disease — it is not a probability of having any of them. Many of these signs also occur in common, non-rare conditions. A sign on this page is a conversation to have with a clinician, not a conclusion.

Part of the broader category

Also called: Long Q-T syndrome · Long QT syndrome · Prolong qt interval on ekg