WHAT IS LONG QT SYNDROME?
Long QT Syndrome (LQTS) is a disorder of the heart's electrical system. The condition leaves you vulnerable to fast, chaotic heartbeats that may lead to fainting — and in some cases, cardiac arrest and possibly sudden death.
Complications 1 Prolonged QT intervals may never cause any problems. However, physical or emotional stress may "trip up" a heart susceptible to prolonged QT intervals and cause the heart's rhythm to spin out of control.
A prolonged QT interval may trigger a particular irregular heart rhythm (arrhythmia) called torsades de pointes, in which your heart's ventricles beat fast. When this arrhythmia occurs, less blood is pumped out from your heart. Less blood then reaches your brain, causing you to faint.
If torsades de pointes is short lasting — lasting less than one minute — your heart can correct itself and beat normally again seconds later, and you regain consciousness on your own. However, if torsades de pointes persists, it can lead to a life-threatening arrhythmia called ventricular fibrillation.
In ventricular fibrillation, the ventricles beat so fast that your heart quivers and ceases pumping blood. Unless your heart is shocked back into a normal rhythm by a device called a defibrillator, ventricular fibrillation can lead to brain damage and death.
Sudden Death Syndrome SADS
is a malfunction of electrical activity in the heart
Sudden Arrhythmia Death Syndrome is a disorder of the electrical system of the heart that can lead to the death of apparently healthy people without any warning.
What is SADS? Sudden Arrhythmia Death Syndrome (SADS), otherwise known as Long QT Syndrome, is a disorder of the electrical system of the heart. The problem centres on the length of time it takes the electrical system to recharge following a heart beat. This is known as the QT interval. People who have a long QT interval are more vulnerable to a very fast, abnormal heart rhythm, or arrhythmia. When this rhythm occurs, no blood is pumped out from the heart, and the brain quickly becomes deprived of blood causing sudden loss of consciousness and sudden death.
What causes SADS? The condition is caused by dysfunction of protein structures in the heart cells called ion channels. These channels control the flow of ions like calcium, sodium and potassium molecules. The flow of these ions in and out of the cells produces the electrical activity of the heart. Abnormalities of these channels can be acquired or inherited. The acquired form is caused by certain medications. The inherited form occurs when a mutation develops in one of the genes which makes a channel. The mutations cause the electrical recovery of the heart to be slow.
When do symptoms occur? Abnormal heart rhythms can be fatal Sudden loss of consciousness, or syncope, usually occurs during physical exertion or emotional excitement like anger or fear. Sudden death can often occur when the victim is asleep, or when they are waking up. In patients with syncope the heart rhythm reverts spontaneously to normal. When this occurs, the patient regains consciousness within a minute or two When the abnormal rhythm persists, however, the outcome is death. It is not common for the syncope or sudden death to occur when the person is awake and at rest. Not all patients who have this condition have symptoms - about one-third never develop any. In the other two-thirds, some have just one or two syncopal spells as children. Others have many episodes over a number of years.
The symptoms may begin as early as the first days or weeks of life, or as late as middle age. Most commonly, however, the symptoms first occur during pre-teen and teenage years. The symptoms start earlier in males than females, beginning on average at approximately eight years in males and 14 years in females.
How common is SADS? Scientists do not know how common the condition is. It was thought to be rare, but it is now thought that on many occasions the condition was not properly diagnosed and that it is in fact a relatively common cause of sudden and unexpected death in children and younger adults.
Is there any treatment? The condition can be diagnosed by measuring the QT interval using an electrocardiogram (ECG). Patients identified as being at risk can be given drugs known as beta-blockers to slow heart beat. Other drugs can be used for patients who have a specific form of the disorder. Once treated, it is very important that the medication be taken every day and not missed or omitted. The medications are not curative - they only provide protection while being taken and the protecting effect is gone within a day or two of stopping the medication.
What about exercise? Patients with a
long QT interval are advised not to compete in competitive sports. However, once treated they should be able to take part in recreational sports.
Inform other people.
Make family, friends, teachers, neighbors and anyone else who has regular contact with you aware of your heart condition.
Wear some sort of
medical alert identification
to notify health care professionals of your condition IMMEDIATELY.
In addition, have plans in place in the case of an emergency cardiac event.
Urge family members to learn cardiopulmonary resuscitation (CPR) so that they can provide immediate resuscitation efforts if it ever becomes necessary.
In some situations, possession of or rapid access to an automatic external defibrillator may be appropriate.
Some doctors advise patients to make sure that their friends know about their condition so that they can call for IMMEDIATE help in the event of an attack .
AED's SAVE LIVE'S
This page contains basic information. If you are concerned about your health, you should consult a doctor.
1 © 1998-2006 Mayo Foundation for Medical Education and Research (MFMER).