Find out about COVID-19, COVID-19 vaccines, and Mayo Clinic patient and visitor updates.
Featured conditions Brain tumor, breast cancer, colon cancer, congenital heart disease, heart arrhythmia. See more conditions.
Featured conditions
A prolonged QT interval is an irregular heart rhythm that can be seen on an electrocardiogram. It reflects a disturbance in how the heart's bottom chambers (ventricles) send signals. In a prolonged QT interval, it takes longer than usual for the heart to recharge between beats.
Mayo Clinic does not endorse companies or products. Advertising revenue supports our not-for-profit mission.
Check out these best-sellers and special offers on books and newsletters from Mayo Clinic Press.