The normal QT interval is controversial, and multiple normal durations have been reported. In general, the normal QT interval is below 400 to 440 milliseconds (ms), or 0.4 to 0.44 seconds.

Because QT-interval prolongation may predispose to torsades de pointes, health care practitioners must be able to assess and balance the risk and benefit of QT prolonging medications.

QT prolongation is the medical term for an extended interval between the heart contracting and relaxing. This condition can increase a person’s risk of experiencing abnormal heart rhythms and ...

Long QT interval is a condition that affects the heart’s electrical rhythm, which can lead to potentially life threatening arrhythmia. Behind the pumping action of the heart is an electrical ...

At hospital admission, the 44-day-old infant had ventricular fibrillation (Panel A). After the restoration of sinus rhythm, the corrected QT interval was found to be prolonged (648 msec) (Panel B).

Congenital long QT syndrome (LQTS) affects an estimated 1 in 2500 people and typically presents with syncope, seizures or sudden death. Whereas someone exhibiting marked prolongation of the QT ...

Aim To determine factors affecting the QT interval in athletes and find an improved means of QT correction (QTc) Method Data was gathered from the CAYA (Cardiovascular Assessment in Young Athletes) ...

Objective: To assess health care practitioners' ability to correctly measure the QT interval, and to identify factors and medications that may increase the risk of QT-interval prolongation and ...