Long QT syndrome (LQTS) is a type of arrhythmia that can lead to an abnormally fast or chaotic heartbeat. This fast heartbeat can cause heart palpitations, fainting, seizures, and rarely, sudden cardiac arrest. Getting treatment for LQTS from the experts at UPMC can prevent serious complications.
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LQTS is a problem with the heart’s electrical system that causes the heart to beat in a fast, chaotic way. The condition gets its name from electrocardiogram (ECG) graphs that show a prolonged QT interval — meaning that your heart is taking longer than normal to “recharge” after each beat.
LQTS is a rare disorder that can occur at any age.
There are two types of LQTS:
Sometimes, a combination of genetics and other factors can lead to LQTS.
Inherited LQTS is caused by a genetic mutation that affects the levels of minerals that generate electricity inside the heart. Acquired LQTS can be caused by health conditions, medication, and mineral imbalances in the body.
Acquired LQTS can be triggered by several conditions, including:
Some people are more likely to get LQTS than others. This includes people who:
LQTS can lead to fainting spells, seizures, or, rarely, sudden cardiac arrest.
The heart rhythm changes from LQTS often correct on their own — but can be deadly when they don't. Young people with LQTS are at higher risk of sudden cardiac arrest.
Treatment for LQTS helps prevent complications.
Because LQTS is an inherited disorder or is triggered by other medical conditions, there is nothing you can do to prevent LQTS.
If you have a family member with LQTS, your doctor may also suggest genetic testing.
Before the test, a genetic counselor will talk to you about the risks and benefits of DNA testing. They'll also tell you about any limits in translating the results.
If you carry a gene change for LQTS, there's a risk that you may pass it along to your children. Doctors may suggest that your parents, siblings, and children also have the test.
Your care team can talk with family members about their LQTS risks and DNA testing.
Not everyone with LQTS has symptoms. Sometimes LQTS is found on an ECG or genetic testing that is done for other reasons.
When people have symptoms, the most common are:
Fainting spells often come on suddenly, but sometimes people have warning symptoms such as blurred vision, lightheadedness, or weakness. People with LQTS may experience fainting in response to emotions such as excitement, anger, or fear.
If you experience unexplained fainting or a seizure, you should go to the Emergency Department or dial 911. Make an appointment with your doctor if you have heart palpitations.
If your doctor suspects you have LQTS, they'll ask you about your symptoms, medical history, and family history.
Your doctor will do a physical exam and may order tests to confirm a LQTS diagnosis. Your doctor or nurse will tell you when to expect your test results and will call you when they're available.
We offer a full range of tests for LQTS, including:
Your doctor will review your test results to see if your heart’s electrical system is taking longer than average to “recharge” after each beat. This recharging time is known as the QT interval. If you are diagnosed with LQTS, your ECG results will show a prolonged QT interval.
Getting early treatment can help you manage your LQTS and may prevent dangerous complications. Your doctor will discuss your condition and prognosis with you.
People who get proper treatment for LQTS have a low death rate and can live a full life. However, if LQTS is untreated, there is a higher risk of death — especially within the first two years after the first cardiac event.
The goal of treatment for LQTS is to avoid sudden cardiac arrest, fainting spells, and fatal heart rhythms.
Your doctor will plan your treatment based on how severe your LQTS symptoms are and your risk for life-threatening problems.
Your doctor may ask you to make changes to your habits and routines to reduce the risk of LQTS episodes.
Your doctor may prescribe beta-blockers to slow your heart rate, or a combination of a beta blocker and heart rhythm medication to shorten your QT interval.
Surgery may help you manage LQTS, especially if symptoms are severe and other treatments have not worked. Surgical procedures include:
The goal of LQTS treatment is to reduce your risk of sudden cardiac death. Some causes of LQTS can be treated by addressing the underlying problem. Medications and ICDs are effective LQTS treatments. However, even with treatment, you may not have a normal QT result on an ECG.
UPMC doctors have special expertise in treating LQTS. Our team:
Last reviewed by a UPMC medical professional on 2024-10-01.
