What does 'long QT' mean?

Every time your heart beats, it produces tiny electrical signals. An electrocardiogram (ECG) machine traces these signals on paper a typical pattern is shown below.

As the graphshows, each heartbeat is mapped as five distinct electrical waves P, Q, R, S and T. The part of the pattern from Q to T represents the electrical activity of the heart's lower chambers, or ventricles.

In people with long QT syndrome, this QT interval lasts abnormally long. In other words, it takes longer for the heart cells in the ventricles to recharge after each heartbeat. This can upset the timing of the heartbeat and may trigger an abnormally fast heart rhythm.

Content supplied by the NHS Website

Medically Reviewed by a doctor on 21 Dec 2018