Arrhythmias in Children

An arrhythmia is an abnormal rhythm of the heart, which can cause the heart to pump less effectively. It most often occurs in adults, but can also occur in children.

Some arrhythmias are not dangerous, while others can be life threatening.

Arrhythmias are classified by the area of the heart where they start: the upper chambers (atria) or lower chambers (ventricles). They can be related to the heart beating too fast (tachycardia), too slow (bradycardia), or in an irregular pattern (fibrillation).

There are many types of arrhythmias, including:

• Long QT syndrome (LQTS). LQTS occurs when the ventricles take too long to contract and release. This can cause fast, erratic heartbeats.
• Sinus tachycardia. A sinus tachycardia is a normal increase in the heart rate that’s common in children. It most often occurs with exercise, fever, or excitement and usually doesn’t need treatment.
• Supraventricular tachycardia (SVT), also called paroxysmal atrial tachycardia (PAT). This is the most common type of tachycardia in children. It occurs when the electrical signals from the heart’s atria fire abnormally, causing a fast heartbeat.
• Sick sinus syndrome. Occurs when the sinus node in the heart doesn’t fire properly and the heartbeat slows down. It can sometimes occur in children who have had open-heart surgery.
• Catecholaminergic polymorphic ventricular tachycardia (CPVT). This is a rare inherited cardiac condition. These abnormal rhythms most often occur at times of high adrenaline levels, such as during exercise or strong emotion. Left untreated, CPVT can cause the heart to stop beating.
• Premature ventricular contractions (PVC) or premature atrial contractions (PAC). These are caused when an extra or premature heartbeat occurs, either in the atria or ventricles. They are common in children and teens and usually need no treatment.
• Atrial flutter. This is a very fast heartbeat caused when the muscles in the atria contract quickly.
• Atrial fibrillation (AFib). AFib is rare in children. It occurs when the electrical signals that firing in or around the heart cause the atria to quiver, or fibrillate. This causes the ventricles to then contract at an abnormal rate and work less effectively.
• Ventricular tachycardia (VT). This is an uncommon, but serious and potentially life-threatening condition. It is caused by a very fast electrical signal that starts in the ventricles. In some cases, it is caused by serious heart disease.
• Wolff-Parkinson-White (WPW) syndrome. WPW is a malfunction of the electrical pathways between the atria and ventricles, causing the signals to signal that gets to the ventricle over an extra electrical pathway. It's present since birth. A fast heart rate is a common symptom. Or a child may not have symptoms. Sudden cardiac death may rarely occur.
• Complete heart block. Heart block occurs when the electrical signal from the atria to the ventricles is blocked. This causes the heart to beat more slowly. Complete heart block may be caused by heart disease or happen after heart surgery.

Some children with an arrhythmia have no symptoms. When they do, symptoms can include:

• Fatigue
• Rapid breathing
• Palpitations
• Dizziness
• Fainting

Arrhythmias occur when there is a problem with the electrical signals that control the heartbeat. Sometimes the nerve cells that create the electrical signals don't work the way they should or don’t move normally through the heart. In some cases, other areas of the heart begin to produce electrical signals that disrupt the normal heartbeat.

In addition to a complete medical history and physical examination, there are several different tests that may be used to diagnose arrhythmias, including:

• Electrocardiogram (EKG or ECG)
• Stress/rest myocardial perfusion imaging
• Exercise stress test
• Holter or event monitor
• Continuous recording
• Electrophysiologic study (EPS)

Not all arrhythmias need treatment, especially those that don’t cause any symptoms. When the arrhythmia does cause symptoms, there are several options for treatment, including:

• Lifestyle changes. These may include reduce stress and avoiding caffeine.
• Medications. Medications may help lower fast heartbeats or correct irregular heart patterns.
• Cardioversion. This is a small electrical shock, that can help stop certain fast arrhythmias.
• Ablation. This procedure uses a small, thin tube, called a catheter, placed into the heart through a blood vessel in the groin or arm to heat or freeze the tissue around the area of the arrhythmia.
• Pacemaker. This is a small device placed under the skin that sends electrical signals to start or regulate a slow heartbeat.
• Implantable cardioverter defibrillator (ICD). This is a small device similar to a pacemaker that is implanted under the skin. It senses the rate of the heartbeat and delivers a small electrical shock to the heart if the heartbeat is too fast.

If none of these treatments work, your doctor may suggest a surgical procedure, such as ablation or a Maze procedure.

The Electrophysiology Service at Boston Children’s Hospital specializes in diagnosing and treating heart arrhythmias in children and young adults. Our program is one of the largest and most experienced in the country, and we treat more patients with congenital heart problems than any other hospital in the world. We perform hundreds of electrophysiology procedures annually.