It can cause sudden, uncontrollable, dangerous arrhythmias ah-RITH-me-ahs in response to exercise or stress. Arrhythmias are problems with the rate or rhythm of the heartbeat. People who have LQTS also can have arrhythmias for no known reason. However, not everyone who has LQTS has dangerous heart rhythms. When they do occur, though, they can be fatal. An EKG is a test that detects and records the heart's electrical activity.

Long QT Syndrome: Diagnosis, Causes and Treatment



Long QT Syndrome (LQTS) - Brigham and Women's Hospital
Learn more. It can be present at birth, but may not be detected until later in life. LQTS is rare and affects children and young adults. The heart uses a complex electrical system to make the muscle walls of the atria and ventricles work together to pump blood.


Long QT syndrome
The electrical system controls the rate speed and rhythm of your heart. When it is working properly , your heart beats in a regular rhythm, at a normal rate. LQTS is a type of arrhythmia. An EKG electrocardiogram measures and records the electrical activity that passes through the heart as it beats.



When people talk about the heartbeat, the forceful contractions of the heart's four chambers get most of the attention. But the pause between beats is just as important. This pause that refreshes the heart is normally much quicker than the blink of an eye. In some people, though, it lasts longer than it should. The delay signals that heart muscle cells are having trouble getting ready for the next contraction.