Long QT Syndrome: Exercise Recommendations

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Congenital long QT syndrome (LQTS) is an inherited disorder affecting the heart’s electrical system. It is one of the conditions associated with sudden death in young athletes. The life-threatening arrhythmias seen with LQTS are more likely to occur during exercise, so in many people with this condition exertion must be limited. 

However, there are several types of LQTS, and the risk of participating in exercise varies among the types, and among different individuals. So exercise recommendations with LQTS have to be individualized.

If you have congenital LQTS, it is important for you and your doctor to determine which kinds of exercise are permissible for you, and which kinds need to be avoided. 

What Is Long QT Syndrome?

Congenital LQTS is a genetic abnormality that delays the “recharging” of cardiac cells after they have been “fired off” by the heart's electrical system. This delay is manifested by a prolonged QT interval on the ECG. The electrical abnormality associated with LQTS can produce cardiac arrhythmias (a form of ventricular tachycardia called torsades de pointes) which can lead to syncope (loss of consciousness) or sudden death.

In many people born with LQTS, the risk of developing these dangerous arrhythmias increases during exercise.

Generally, a person with LQTS has no symptoms whatsoever until they have sudden episodes of ventricular tachycardia (again, usually during exertion). When this arrhythmia occurs, symptoms may vary from a few seconds of intense dizziness all the way to sudden unconsciousness, and even death from cardiac arrest. The diagnosis is made by examining the ECG, which shows a prolonged QT interval.

While LQTS is an inherited disorder, there are many variants of it (corresponding to several different genes that may be involved). While some variants have a high risk of sudden death, others are far less dangerous.

Often, those who are at the highest risk will have a strong family history of individuals who have experienced syncope or sudden death, most often during exercise. Anyone who has such a family history should be evaluated for possible LQTS.

LQTS is often treated with beta blockers, and by avoiding drugs that cause further prolongation of the QT interval. If the risk of sudden death is judged to be high, an implantable defibrillator may be required.

In addition, anyone with LQTS should be given specific recommendations regarding exercise: what types to avoid, and what types they may enjoy without exposing themselves to unreasonable risk.

What Are the General Exercise Recommendations For Young Athletes With LQTS?

People with LQTS should avoid high-intensity activities, and limit themselves to low-intensity sports, if either one of the following applies to them:

  1. They have a history of loss of consciousness (syncope) or being resuscitated from cardiac arrest.
  2. Their QT intervals are very prolonged (that is, a measure called the “corrected QT interval - QTc - is prolonged to at least 470 msec in men, or 480 msec in women). This is a measurement their doctor makes by examining their ECG.

Even without either of these important risk markers, any person with LQTS should talk with their doctor about specific recommendations about their activity. 

In general, a person with LQTS who is not in a high-risk category can participate safely in low-intensity exercises such as bowling or golf, and moderate-intensity exercise such as doubles tennis, biking and skating. 

In some cases, people with LQTS can be classified into specific variants, or subgroups, and different activity recommendations may be optimal for some of these variants. For instance, people with LQTS type 3 appear to have a somewhat lower risk during exercise than those with other types; people with LQTS type 1 may be at particular risk during swimming or diving. 

So, serious athletes may want to consider having genetic subtyping, in order to allow their exercise recommendations to be tailored to their particular genetic variant.

In November 2015, exercise recommendations for competitive athletes with LQTS were formally updated by the American Heart Association and the American College of Cardiology. These recommendations were intended to liberalize exercise recommendations as much as possible, while maintaining a reasonable level of safety, for athletes with LQTS who wish to participate in competitive sports.

Experts now recommend that, if young athletes with LQTS have no symptoms (specifically, they have had no episodes of lightheadedness or syncope associated with exercise), they may participate in competitive sports IF:

  • They, their physicians, and their parents or guardians (if they are minors) understand the potential risks involved with competitive athletics, and are willing and able to take appropriate precautions.
  • They avoid taking any drugs that prolong the QT interval.
  • They obtain a personal automatic external defibrillator (AED) as part of their routine personal sports equipment.
  • Team officials are trained and prepared to take appropriate action if an emergency should arise, including the capability and the willingness to use the AED.

These recommendations have allowed many athletes with LQTS to enjoy competitive sports, as long as they and their coaches are willing to accept a certain amount of personal responsibility for their safe participation.

A Word From Verywell

Congenital LQTS is a genetic disorder of the heart's electrical system that can increase a person's risk of developing dangerous cardiac arrhythmias, especially during exercise. It is important for anyone with this condition to work with their doctor to determine what types of exercise they can engage in safely, and what precautions they should take while doing so.

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