Types of Arrhythmia in Children

Updated:Mar 20,2014

Doctor Listening To young Boy's HeartThere are many different kinds of abnormal heart rhythms that may occur in children and adults. Learn about the types of arrhythmias that may occur and how they might manifest in children. If an abnormal rhythm occurs, it's important to find out what kind it is. Treatment recommendations depend on its type. Arrhythmias can cause the heart rate to be irregular, fast or slow (View an animation of arrhythmia). Fast rhythms are called tachycardia. Slow ones are called bradycardia.

Abnormal Heart Rhythms

(LQTS) is an infrequent, hereditary disorder of the heart's electrical rhythm that can occur in otherwise healthy people. It usually affects children or young adults. Studies of otherwise healthy people with LQTS indicate that they had at least one episode of fainting by the age of 10. The majority also had a family member with a long Q-T interval.

When the heart contracts, it emits an electrical signal. This signal can be recorded on an electrocardiogram (ECG) and produces a characteristic waveform. The different parts of this waveform are designated by letters — P, Q, R, S and T. The Q-T interval represents the time for electrical activation and inactivation of the ventricles, the lower chambers of the heart. A doctor can measure the time it takes for the Q-T interval to occur (in fractions of a second), and can tell if it occurs in a normal amount of time. If it takes longer than normal, it's called a prolonged Q-T interval.

What are the symptoms of LQTS?
People with LQTS may not have any symptoms. People who do have symptoms often exhibit fainting (syncope) and abnormal rate and/or rhythm of the heartbeat (arrhythmia). People with this syndrome may show prolongation of the Q-T interval during physical exercise, intense emotion (such as fright, anger or pain) or when startled by a noise. Some arrhythmias are potentially fatal, causing sudden death. In one type of inherited LQTS, the person may also become deaf.

People with LQTS don't necessarily have a prolonged Q-T interval all the time. At the time that they have an electrocardiogram (such as during a routine physical examination), the Q-T interval may actually be normal. Alternatively, some healthy young people may not have a routine ECG, and LQTS may be suspected because of their family history or because of unexplained fainting episodes. In any family where repeated episodes of fainting or a history of sudden death exists, an investigation of the cause, including LQTS, should be undertaken.

How is LQTS treated?
There are treatments for LQTS, including medications such as beta blockers. Sometimes a surgical procedure is performed, and some people may benefit from an implantable defibrillator.


 

Checklist for Parents of Children with Arrhythmias

Parents of all children should learn CPR and how to reduce the risk of injuries and sudden infant death syndrome (SIDS).  This information is available with all American Heart Association child and infant CPR courses. 

Learn the new 2010 CPR Guidelines
Get an American Heart Association CPR Anytime Personal Learning Program
Find an Emergency Cardiovascular Care class near you
 

CPR skills, including recognition of signs of breathing difficulties and cardiac arrest, are particularly important if a child has heart disease and is at risk for sudden arrhythmias including sudden death. 
 

Parents should know what to do if their child suddenly collapses and becomes unresponsive. If a child under 8 years old is found unresponsive, the typical sequence of actions for a lone rescuer includes performing about one minute of CPR, then phoning 9-1-1 or other emergency medical services (EMS) number (CPR first, phone fast).  The reason for this sequence is that most children who suffer cardiopulmonary arrest have breathing problems and need prompt rescue breathing with other steps of CPR. 


However, when a parent is alone with the child with heart disease and that child collapses suddenly, the likely cause of the collapse is sudden cardiac arrest.  In this case, the parent should phone 9-1-1 first, then begin CPR (phone first, then CPR).

Learn about Cardiac Arrest in Children: Special Consideration.





This content was last reviewed on 5/30/2012.

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