Long QT syndrome usually lasts a lifetime. The risk of an irregular heartbeat leading to fainting or sudden cardiac arrest may decrease with age but never completely disappear. There are several important things you need to do for the rest of your life to prevent an abnormal heart rhythm.

Some people with drug-induced LQTS may also have another genetic disorder. They may not have symptoms unless they are taking drugs that prolong the QT interval or reduce potassium levels in the blood. When LQTS does not cause symptoms, it is called silent LQTS.