Abnormal Heart Rhythm

Arrhythmia

Signs and Symptoms
Diagnosis
Treatment

Diagnosis

You child's pediatrician may hear an abnormal heart beat while using a stethoscope during an exam. Bradycardias — or slow heartbeats due to heart block or sinus node dysfunction — can be continuous and may be detected during such an exam. But tachycardias — or fast heartbeats — often occur spontaneously with unpredictable timing and require more specialized tests.

If your doctor suspects that your child has an arrhythmia or irregular heart rhythm, he or she will order one or more of the following tests to determine the source of the symptoms.

• Electrocardiogram (ECG or EKG) — The electrocardiogram records the heart's electrical activity. Small patches called electrodes are placed on your child's chest, arms and legs and are connected by wires to the ECG machine. The electrical impulses of your child's heart are translated into a graph or chart, enabling doctors to determine the pattern of electrical current flow in the heart and to diagnose arrhythmias.

• Holter Monitor — A Holter monitor is a small, portable machine that your child wears for 24 hours. It is about the size of a portable tape deck. This provides a continuous 24-hour record of your child's heartbeat. You will be asked to keep a diary of your child's activities and symptoms. This monitor may detect arrhythmias that might not show up on a resting ECG that only records for a few seconds.

• Event Monitor — This is a small monitor about the size of a pager that your child can have for up to a month. Since the arrhythmia may occur at unpredictable times, this will help to record the abnormal rhythm when your child is experiencing symptoms. He or she can just push a button on the pager and record the heartbeat. The recording can than be transmitted by phone to the doctor.

• Exercise Stress Test — The exercise stress or treadmill test records the electrical activity of your child's heart during exercise, which differs from the heart's electrical activity at rest.

• Electrophysiology Study — In an electrophysiology (EP) study, doctors insert special electrode catheters — long, flexible wires — into veins and guide them into the heart. These catheters sense electrical impulses and also may be used to stimulate different areas of the heart. Doctors then can locate the sites that are causing serious arrhythmias. The EP study allows doctors to examine an arrhythmia under controlled conditions; and acquire more accurate, detailed information than with any other diagnostic test. In many cases, doctors can provide treatment, such as catheter ablation, during the same session as the EP study.

• Tilt Table Test — Tilt table testing is used to diagnose fainting or black-out spells by trying to reproduce these episodes. Your child will be placed on a special table and then tilted to an angle of about 70 degrees while recording your child's heart rhythm and blood pressure.