Long QT Syndrome

Treating Cardiovascular Diseases in Wisconsin and Northern Illinois

With every heartbeat, an electrical signal travels from the top of your heart to the bottom, causing your heart to contract and pump blood. Electrocardiogram testing (ekg) measures this electrical activity as it travels through your heart.  The timing of the heart's electrical activity is very complex, and the body carefully controls it.

Long QT syndrome, or LQTS, is a disorder that affects the heart’s electrical system, and can cause dangerous arrhythmias, or irregular heartbeats.  The term “long QT” refers to an abnormal delay in the QT portion of your hearts electrical system.   Normally the QT interval is about a third of each heartbeat cycle. However, in people who have LQTS, the QT interval lasts longer than normal.  This is usually detected on an electrocardiogram (EKG).   

Long QT syndrome is a condition that mayoften goes undiagnosed.  It is thought to affect about one in 7,000 people.

Long QT Syndrome Symptoms

If you have long QT syndrome, your QT interval lasts longer than normal, which can upset the careful timing of your heartbeat. Long QT syndrome may cause a very dangerous type of irregular heartbeat known as ventricular tachycardia.

Usually Long QT syndrome symptoms first appear in childhood and include:

  • Abnormal heart rhythm during sleep.Unexplained fainting, which can occur when the heart isn’t pumping enough blood to the brain
  • Palpitations, which feel as fluttering in the chest
  • Sudden cardiac arrest, which can occur when the heart suddenly stops beating for no obvious reason

People who have sudden cardiac arrest can die within minutes unless they receive immediate treatment. In about 10 percent of people who have LQTS, sudden cardiac arrest  is the first sign of this disorder. In the United States, LQTS causes about 3,000 to 4,000 sudden deaths in children and young adults each year. 

Long QT Interval Causes 

Long QT syndrome can be inherited or acquired. Most people with this condition inherit it and have it their entire lives. There are several  types of inherited LQTS, which are assigned a number based on what triggers the heart arrhythmias. The most common types of inherited LQTS are triggered by the following conditions:

  • LQTS 1 - Emotional stress or strenuous exercise, especially swimming 
  • LQTS 2 - Extreme emotions, especially surprise 
  • LQTS 3 - A slow heart rate while sleeping 

Half of all people who have LQTS have their first abnormal heart rhythm by the time they’re 12 years old. About 90 percent have an abnormal heart rhythm by age 40. Some people with inherited LQTS never have symptoms. For this reason, doctors advise family members of people who have LQTS to be tested for this disorder.

Occasionally, people acquire LQTS, meaning they develop it during their lifetime. Some medications and other health conditions can cause acquired LQTS. These medications include antihistamines and decongestants, diuretics, certain antibiotics, antiarrhythmics, antidepressants, cholesterol-lowering medications and diabetes medications.

Health conditions that can cause acquired LQTS include severe diarrhea or vomiting, eating disorders, such as anorexia nervosa and bulimia, and some thyroid disorders. These conditions lower the sodium or potassium levels in your blood, which can trigger long QT symptoms.

Diagnosing Long QT Syndrome

If your doctor suspects any type of arrhythmia, he or she may refer you to a heart specialist (cardiologist) or an electrophysiologist, which is a heart specialist who specializes in diagnosing and treating arrhythmias.

To diagnose LQTS, your doctor will ask about your medical and family histories and perform a physical exam. Be sure to tell your doctor if you experience an abnormal heart rhythm, fainting, heart palpitations or loud gasping during sleep.

If Long QT syndrome is suspected, your doctor is likely to perform:

Treating Long QT Syndrome

Treatment is based on your symptoms. If you have LQTS without symptoms, you may be advised to:

  • Avoid certain sports and strenuous exercise that can trigger abnormal heart rhythms, such as swimming
  • Avoid medications that may trigger abnormal heart rhythms
  • Take beta-blockers to reduce the risk of symptoms by slowing your heart rate

If you have LQTS with arrhythmias and fainting spells, the goal will be to prevent these conditions from recurring. Along with the recommendations listed above, your doctor may prescribe more aggressive treatments, such as:

  • A pacemaker
  • Implantable cardioverter defibrillator (ICD)
  • Surgery on the nerves that regulate your heartbeat

Many people with this condition can be successfully treated and live healthy lives. However, it’s important to see your doctor regularly. It’s also helpful to inform friends, roommates and co-workers that you have a condition that can cause you to go into cardiac arrest. Tell them to call 911 immediately if you faint. You may also want to keep an automated external defibrillator with you. This device uses electric shocks to restore a normal heart rhythm.

For some people, living with LQTS may cause fear and anxiety. Let your doctor and loved ones know how you feel. You may benefit from counseling or participating in support groups with others who face this condition.

A Leader in Diagnosing and Treating Arrhythmias

Aurora Health Care is a nationally recognized leader in diagnosing, managing and treating long QT syndrome. Starting in 1977, Aurora Health Care’s Cardiac Electrophysiology Department in Milwaukee, Wisconsin, was one of the first programs in the nation to diagnose and treat patients with heart rhythm disorders. Our program treats patients from all over the country.

Our physicians and nurses provide state-of-the art, comprehensive care for patients suffering from all types of heart rhythm disorders. We use the most advanced technologies available, some of which we developed. We also partner with other health care professionals to help manage and treat patients with arrhythmia.

Aurora doctors are conveniently located throughout eastern Wisconsin and northeastern Illinois. Find a doctor or heart specialist near you. To get a second opinion or if you need assistance finding a provider, please call 888-649-6892.