What is long QT syndrome (LQTS)?
Long QT syndrome (LQTS) is a rare problem that affects the heart's electrical system. It may cause the heart to beat in a fast and abnormal way. This can cause fainting, seizures, or abnormal heartbeats that can become life-threatening. If the heart stops pumping blood, sudden death can happen.
What are the symptoms of long QT syndrome (LQTS)?
Some people don't have symptoms. But in those who do, symptoms include fainting, seizures, and feeling dizzy or lightheaded. Heart palpitations also can occur. LQTS can also cause sudden cardiac arrest. This means that the heart suddenly stops beating. In some people, symptoms may be triggered by exercise, stress, or being startled.
How is long QT syndrome (LQTS) diagnosed?
Your doctor will do a physical exam and ask questions about your symptoms. The doctor will also ask about your past health and your family history.
Most people are diagnosed using an electrocardiogram (EKG). It shows your heart's electrical activity as line tracings on paper. People with the syndrome have a certain pattern to their heartbeat. Your doctor can see the pattern on the tracing.
Your doctor may want to do other tests too. You might get a test to measure your heartbeat during exercise. Or the doctor may ask you to wear a small device at home. It measures your heartbeat during regular activity outside of the doctor's office.
A test may also be done to see if you carry the changed gene that causes LQTS. Your close relatives may also get tests. Not everyone who has the gene will have symptoms.
How is long QT syndrome (LQTS) treated?
The goals of treatment are to prevent life-threatening heart rhythms and to control symptoms. Treatment depends on your symptoms and on what type of LQTS you have.
For instance, if you got LQTS later in life, treatments include stopping any medicines that can cause the problem and fixing any mineral imbalances you have. If that doesn't work, or if you were born with LQTS, you may have other treatments. They include:
- Medicines to control your heartbeat. These are called beta-blockers.
- A device called a pacemaker. It's implanted under the skin of your chest. It helps control your heartbeat.
- A device called an implantable cardioverter-defibrillator. It's implanted in your chest. It uses a shock to stop a dangerous heart rhythm.
- Surgery to remove nerves that make abnormal heartbeats more likely.
Caring for yourself when you have long QT syndrome (LQTS)
There are things you can do to help prevent a dangerous heart rhythm from LQTS.
- Tell all of your doctors and your pharmacist about your condition.
They can help you avoid medicines that can start a fast or abnormal heartbeat.
- Ask your doctor for a list of over-the-counter medicines that you shouldn't take.
These include some common medicines, such as certain antacids and antihistamines. They can trigger abnormal heartbeats in people with LQTS.
- Talk to your doctor about whether lifestyle changes are a good idea for you.
Some people with LQTS may need to avoid loud noises, such as alarm clocks and loud ringtones.
- Ask your doctor about safe levels of activity.
Most people with LQTS should avoid intense physical activity. Talk to your doctor about what type of activity and exercise is safe for you.
©2011-2025 Healthwise, Incorporated