What are the symptoms of long QT syndrome?
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Dr. William D. Knopf of Piedmont Heart Institute answered:Major Signs and Symptoms
If you have long QT syndrome (LQTS), you're prone to developing a sudden and dangerous arrhythmia (abnormal heartbeat). Signs and symptoms of LQTS-related arrhythmias often first appear during childhood and include:
- Unexplained fainting. This happens because your heart isn't pumping enough blood to your brain. Fainting may occur when you're under physical or emotional stress. Some people will have fluttering feelings in their chests before they faint.
- Unexplained seizures. Those around you may mistake your fainting from LQTS as a seizure due to epilepsy. In children, fainting may be seen as a hysterical reaction to a stressful situation.
- Unexplained drowning or near drowning. This may be due to fainting while swimming.
- Unexplained sudden cardiac arrest (SCA) or death. This means that your heart suddenly stops beating for no obvious reason. People who have SCA will die within minutes unless they receive treatment. Most people who have SCA die. In about 1 out of 10 patients, SCA or sudden death is the first sign of LQTS.
Other Signs and Symptoms
Often, people who have LQTS 3 will develop an abnormal heartbeat during sleep. This may cause them to have noisy gasping while sleeping.
This answer from the National Heart, Lung and Blood Institute has been reviewed and/or edited by Dr. William D. Knopf.
Major Signs and Symptoms If you have long QT syndrome (LQTS), you're prone to developing a sudden and dangerous arrhythmia (abnormal heartbeat). Signs and symptoms of LQTS-related arrhythmias often first appear during childhood and include:... More -
Fainting (syncope) and an abnormal heartbeat (arrhythmia) are common. Symptoms occur especially during physical exercise, intense emotion (such as fright, anger, or pain), or when awakened or startled by a noise such as an alarm clock, telephone, or thunder. Syncope is commonly misdiagnosed as a common faint, but it can be fatal. Usually, there is no warning before syncope.Fainting (syncope) and an abnormal heartbeat (arrhythmia) are common. Symptoms occur especially during physical exercise, intense emotion (such as fright, anger, or pain), or when awakened or startled by a noise such as an alarm clock, telephone, or... More -
General: Long QT syndrome (LQTS) often goes undiagnosed or is misdiagnosed as a seizure disorder. Children, teenagers, and young adults with unexplained fainting, near-drowning or other accidents, unexplained seizures, or a history of cardiac arrest may have a genetic defect that causes LQTS. About half of the people with LQTS do not have any signs or symptoms. They may be aware of their condition only from results of an electrocardiogram (ECG) or because they have a family history of LQTS.
Symptoms of inherited LQTS may start during the first months of life or as late as middle age. Most LQTS-related deaths occur in people aged 11-30. Rarely, symptoms of LQTS occur during sleep or arousal from sleep. Usually, an affected person suddenly faints or passes out during exercise or when experiencing intense emotions, such as fear. There is usually no warning or sensation of feeling faint or dizzy. In 30% of cases where death results, the person appears quite fit and healthy and appears to have no symptoms at all before cardiac arrest.
Fainting (syncope): Fainting, or syncope, is a sudden loss of consciousness. It most often occurs when the blood pressure is too low (called hypotension) and the heart does not pump a normal supply of oxygen to the brain. Typically, a faint lasts only a few seconds or minutes and then the individual regains consciousness. A single fainting spell usually is not serious. It may be explained by factors such as stress, grief, overheating, dehydration, exhaustion, illness, or arrhythmias.
Seizures: If the heart continues to beat erratically, the brain becomes increasingly deprived of oxygen, which may lead to seizures. Some people with LQTS have been misdiagnosed as having a seizure disorder and have been incorrectly treated with antiepileptic medications.
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General: Long QT syndrome (LQTS) often goes undiagnosed or is misdiagnosed as a seizure disorder. Children, teenagers, and young adults with unexplained fainting, near-drowning or other accidents, unexplained seizures, or a history of cardiac... More
