Long QT Syndrome

Long QT

Signs and Symptoms
Diagnosis
Treatment

Signs and Symptoms

The most common symptom of long QT syndrome (LQTS) is a sudden loss of consciousness, also known as syncope. The condition may also cause seizures and in some instances, cardiac arrest and sudden death.

The severity of the condition varies greatly. Some people never experience syncope and others may have frequent episodes that could possibly lead to cardiac arrest and sudden death.

It is important to note that symptoms usually occur without warning and are caused by a very fast heart rhythm called torsade de pointes. Syncope may occur during or just after physical exertion, emotional excitement or sudden auditory arousal, such as from an alarm clock.

Reviewed by health care specialists at UCSF Medical Center.
Last updated January 31, 2008