Long QT syndrome is diagnosed by electrocardiograph (ECG). It appears to be a common cause of sudden death in children and young adults. Fainting can be a symptom of Long QT syndrome and is sometimes mistaken for a seizure. About one-third of people who have Long QT syndrome do not have any symptoms.
Warning signs of long QT syndrome
You should be investigated for Long QT syndrome if:
- You faint for no apparent reason
- You faint during or shortly after exercise or emotional excitement
- There is a family history of unexplained fainting or sudden death in your family.
If you have Long QT syndrome, the ECG test can come back normal. Further tests may be required to confirm the diagnosis if you have the above symptoms.
An inherited condition
There are two types of inherited Long QT syndrome:
- Romano-Ward type - this is being recognised with increasing frequency. Researchers have found six genes that cause Long QT syndrome. When all the genes have been found, genetic testing for the syndrome will be possible.
- Jervell, Lange-Nielson type - this form is rare and also causes deafness.
Acquired Long QT syndrome
Long QT syndrome can also be acquired by taking certain over the counter medications and some prescribed medications. If you have Long QT syndrome, always tell your doctor before they give you a prescription. There is an updated list of medications to avoid: Center for Education and Research on Therapeutics.
Exercise, noise or stress can trigger an event
An event can be triggered by:
- Exercise
- Being startled by a loud noise, such as a horn, ringing telephone or alarm clock
- Exams, test or other stressful situations
- Anger or crying.
Treatment for Long QT syndrome
Treatment includes:
- Medications - beta blockers are effective for 90 per cent of people with Long QT syndrome.
- Pacemaker - you may require the implantation of a pacemaker or defibrillator as well as beta blocker medication.
Things to remember
- If you are diagnosed with Long QT syndrome your entire family should be tested including extended relatives.
- Long QT syndrome is usually inherited although it can be acquired after taking certain medications.
Where to get help
- Your doctor should refer you to a knowledgeable cardiologist.
- Royal Children’s Hospital Melbourne, Cardiology Department
- Australian Sudden Arrhythmia Death Syndromes (SADS) Foundation.
You might also be interested in:
Circulatory system.
ECG test.
Fainting.
Genetic services in Victoria.
Heart arrhythmia and palpitations.
Heart disease - risk factors explained.
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