When Your Child Has a Cardiac Arrhythmia

The heartbeat is the strong, rhythmic heart action that pumps blood to the body and lungs. It’s controlled by electrical signals in the heart. An abnormal change in the rate or pattern of the heartbeat is called a cardiac arrhythmia. It can cause the heart to move blood less efficiently. There are many types of cardiac arrhythmias. They can be described as “fast” (tachycardias or tachyarrhythmias) or “slow” (bradycardias or bradyarrhythmias). Many arrhythmias are harmless and don’t need treatment. If an arrhythmia causes symptoms, it can often be treated.

The Heart’s Electrical System 

Diagram showing the heart’s electrical system

The heart has an electrical system that sends signals to trigger the heartbeat. The sinoatrial (SA) node is located in the right atrium. The SA node functions as the heart’s natural pacemaker. It generates the signal that starts a heartbeat. The signal then travels through the atria, causing them to squeeze and move blood into the ventricles. The signal next passes into the atrioventricular (AV) node. The AV node directs the signal into pathways called bundle branches. These pass the signals to the ventricles so they squeeze and pump blood to the lungs and body. This completes a heartbeat. After each heartbeat, the heart recharges. Then the cycle begins again.

What Causes a Cardiac Arrhythmia?

An arrhythmia occurs when the normal electrical activity of the heart is disrupted. This may be due to problems with the electrical system in the heart. An arrhythmia can be present in children with:

• Congenital heart defects (structural heart problems that are present at birth).

• Cardiomyopathy (damaged heart muscle).

• An isolated heart problem (such as an abnormal additional electrical pathway in the heart).

• Postoperative changes following heart surgery.

What Are the Symptoms of a Cardiac Arrhythmia?

Symptoms of an arrhythmia vary depending on whether it’s a fast or slow rhythm. These can include:

• Lightheadedness or syncope (fainting spells)

• Tiredness

• Chest pain

• Sweating

• Trouble breathing

• Nausea or vomiting

• Palpitations (an extra or skipped heartbeat)

• Tiring easily during exercise (in older children)

How Is a Cardiac Arrhythmia Diagnosed?

Heart problems in children are usually diagnosed and treated by a doctor called a pediatric cardiologist. If needed, your child may be referred to an electrophysiologist. This is a doctor who is trained to treat electrical problems of the heart. The following tests may be done to check for an arrhythmia:

• Electrocardiography (ECG or EKG): During this test, the electrical activity of the heart is recorded to check for abnormal heart rhythms or problems with heart structure. Small pads (electrodes) are placed on the chest, arms, and legs. Wires connect the pads to an ECG machine, which records the heart’s electrical signals.

• Holter or event monitor: During these tests, the electrical activity of the heart is recorded over time with a special device to track the heartbeat. A log is kept of your child’s activities and symptoms during the day. This log is then compared with ECG results. With a Holter monitor, the heartbeat is tracked continuously over 24 hours. With an event monitor, a button is pressed to record the heartbeat each time your child has symptoms. It is usually worn for periods longer than 24 hours.

• Exercise stress test: During this test, the electrical activity of the heart is recorded while your child exercises on a treadmill or a stationary bike. This is done to check your child’s response to different levels of activity (stress). Electrodes are placed on the chest, arms, and legs.

  Medications may help control your child’s cardiac arrhythmia.

How Is a Cardiac Arrhythmia Treated? 

An arrhythmia that causes few symptoms may cause little disruption to a child’s routine and normal growth and development. Your child may not need treatment. An arrhythmia that causes significant symptoms can lead to serious health problems if untreated. Treatment is determined by the type of arrhythmia and may include:

• Medications: Certain medications may be prescribed to regulate your child’s heart rate.

• Catheter ablation: This is a procedure during which thin, flexible tubes (catheters) containing special wires are guided into the heart. The problem area(s) causing the arrhythmia are destroyed (ablated).

• Electrical cardioversion: This is a procedure during which an electric shock is used to briefly stop the abnormal electrical activity in the heart. The heart can then restart in a normal rhythm.

• Pacemaker: This is a device that is placed in the chest (or abdomen if it’s for a newborn or infant) with leads (wires) attached to the heart. This device is used to start the electrical signal needed to make the heart beat at a regular rate. A pacemaker may be placed in the heart if the SA or AV node isn’t working properly.

• Implantable cardioverter defibrillator (ICD): This is a device that is placed in the chest and tracks the heart rate. It delivers an electric shock to the heart to stop a dangerous fast heart rhythm when needed.

What Are the Long-term Concerns?

• After treatment, most children with an arrhythmia can be active. The level and extent of physical activity will vary with each child. Check with the cardiologist about what activities are appropriate for your child.

• Regular visits with the cardiologist may be needed for the rest of your child’s life to check that the heart is working properly. The cardiologist will need to check a pacemaker or ICD regularly if your child has one.