Long QT Syndrome (LQTS) Symptoms and Diagnosis
Not everyone with LQTS has symptoms.
When they do have symptoms, the most common are:
- Fainting spells.
- Heart palpitations.
If your doctor suspects you have LQTS, they'll ask you about your symptoms, medical history, and family history.
They'll also do a physical exam and may order tests, such as:
- EKG. This test records your heart's electrical activity.
- Holter monitor. This test also records your heart's electrical activity, but for longer than an EKG. You wear this device for 24 or 48 hours.
- Exercise stress test. This test will catch a long QT interval that occurs only during exercise.
Genetic testing for LQTS
Because LQTS is an inherited disorder, 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.