Long QT Syndrome
Inherited Heart Disease Clinic
What is LQTS?
LQTS is a rare heart rhythm disorder. It causes a disruption of the electrical
signal that stimulates your heart to beat. It occurs in about 1:10,000 people.
In a normal heartbeat, an electrical signal travels through the heart cells until it
reaches the heart muscle and causes it to beat (or contract). In order for the
electrical signal to flow properly, it must ‘jump’ from cell to cell. For this to
happen, each cell has special ‘doors’ (or channels) that open and close quickly
to allow the signal to enter. The ‘door’ that is affected in LQTS is called a
‘potassium channel’. This door does not work properly. So, the electrical signal
that was sent to trigger a heartbeat may not pass through the ‘door’ properly.
This may lead to a deadly heart rhythm.
What causes LQTS?
LQTS is mainly an inherited disorder (genes passed from one generation to the
next). Members of families who are affected with this disease have a 50:50
chance of inheriting the genetic defect. It is caused by an abnormality in one the
genes that produce the ‘potassium channel’ (or door). If your LQTS is hereditary,
your doctor may recommend genetic counselling for you and your family. Certain
medications may also cause the disorder.
Families and individuals identified with LQTS present in different ways. Some
report the sudden death of a family member at a young age, have a history of
fainting spells, ‘seizures’, palpitations, chest pain and/or blackout spells. If you or
any of your family members have any of these symptoms, they should be
reported to your doctor for further testing.
The 2 main tests that help to determine if you have LQTS are:
An electrical tracing of your heartbeat is used to measure different parts of
the electrical tracing picture.
Exercise Stress Test (EST):
You will be asked to walk on a treadmill while your blood pressure, heart rate
and heartbeat are recorded.
Other tests may also be needed or suggested by your cardiologist. They will
be discussed with you at that time, if needed.
This may be offered/available to some people with this kind of heart rhythm
problem. Your doctor or nurse will discuss this with you.
Family inherited causes of LQTS are not curable, but some treatments may
make you feel better. Your treatment will depend on your medical and family
history and how you are feeling. Your doctor will review all of your test reports.
You and your doctor will decide on the best treatment for you.
Some of these may be: a medication called a beta-blocker, a pacemaker (to
help control heart rate) and sometimes an internal defibrillator (ICD – to detect
and treat dangerous heart rhythms). It is also important to be aware of
medications that may make the condition worse and should be avoided.
Activity and LQTS: How much can I do?
If you are diagnosed with LQTS, your doctor will discuss what activities are safe
for you and what activities you should avoid. These GENERAL GUIDELINES
may vary from person to person:
AVOID strenuous exercise as this can often trigger blackouts.
DO NOT compete in competitive sports. Competitors tend to ‘push’
themselves past their physical limitation.
NEVER swim alone. Swimming can bring on a blackout event and therefore,
may lead to drowning.
BE AWARE that sudden events may trigger a potentially deadly rhythm (a
sudden arousal or a startling noise when sleeping from a ringing of an alarm
clock or telephone). It is recommended that these items not be used or
volumes turned off/down when sleeping or napping.
KNOW the medications that can make the problem worse. Some of these are
over the counter medications. An updated list can be found at:
Make sure your family and friends are aware of your condition and
symptoms and that they know what to do if you have any of your symptoms.
For More Information Visit
• Dr. Martin Gardner FRCP(C), FACC
• Dr. Magdy Basta MB.Bch. FRACP
• Dr. John Sapp Jr. MD, FRCP(C)
• Marina Romeo RN, BScN
• Dr. Sarah Dyack, MD, FRCPC, FCCMG
Looking for more information on this topic?
Contact your local public library for books, videos, magazine articles and online health information.
For a list of public libraries in Nova Scotia go to http://publiclibraries.ns.ca
Capital Health promotes a smoke-free and scent-free environment. Please do not wear perfumed products.
Capital Health, Nova Scotia
Funding for the Inherited Heart Disease Clinic provided by Medtronic of Canada
Prepared by: Marina Romeo, RN, BScN; Inherited Heart Disease Clinic, QEII, Halifax
Designed and Printed by: QEII Audio Visual and Printing Departments
WG85-1021 Revised March 2007
The information in this pamphlet is to be updated every 3 years.