A Holter monitor is a 24-hour recording of the electrical activity of the heart. The monitor is a diagnostic tool used to record the rate and rhythm of the heart.

A Zio monitor records the electrical activity of the heart from three to 30 days. The Zio monitor is another diagnostic tool to record the rate and rhythm of the heart. Irregularities such as fast heart rate (tachycardia), slow heart rate (bradycardia), and abnormal rhythms of the heart can be recorded. Because many irregularities in heart rate or rhythm may not be present all the time, a standard electrocardiogram (EKG) may miss them.

By recording the heart rate and rhythm continuously for 24 hours (Holter monitor) or a prescribed amount of time (Zio monitor) in the various activity levels your child goes through, there is a greater chance of finding abnormalities.

Holter Monitoring

No preparation is needed before the monitor is applied. This should be done as the last test of the day (if other tests are needed), as it needs to be worn for a full 24 hours. The recorder is applied to your child in the Cardiology department by a technician. The technician attaches five electrode patches with wires to your child's chest.

The electrodes are like EKG patches and record the heart's electrical activity. The wires are attached to a digital recorder that is worn for 24 hours on a belt around the waist or on a shoulder strap. The tape and electrodes may irritate the skin. Your child should not bathe or shower while the electrodes are on. All equipment should stay dry.

You or your child can remove the monitor after 24 hours, or bring the child back to Cincinnati Children's Heart Institute for removal of the monitor.

If you remove the monitor, it should be brought to the Heart Institute or shipped back via overnight delivery within 24 hours so the tracing can be analyzed. After the monitor is returned, a technician analyzes the recording within one business day. The cardiologist interprets the results within one business day and the interpretation is sent to the ordering provider.

You or your child will need to keep a log of activities during the day that the monitor is attached. The log will help record any symptoms that may be related to a cardiac rhythm problem. When the symptoms occur, you or your child will press the event button located on the recorder. You will get instructions on how and when to push the event button.

Zio Monitoring

The monitor is put on your child in the Cardiology department by a technician or can be applied at home. The Zio monitor is like a big sticker that is applied to bare skin over the heart. If your child feels a symptom, they will press the button on the Zio monitor to log the event. The sticker may cause some skin irritation. If the monitor falls off before the time it should be removed, call Zio Customer Service at (888) 693-2401. If your child needs to travel during the time the monitor is in place, have the Security Screening Statement found in the symptom log or in the MyZio app available. Your child should avoid heavy activities that make them sweat. They should avoid getting the monitor wet.

Once the Zio monitor is worn for the time as directed by your provider, return the monitor in the mail with the provided postage and packing. If you choose not to return the monitor through the post office, it may be sent back by expedited shipping (FedEx, UPS) at your expense. This allows the clinical team to review the data on the monitor to help make the best treatment plan for your child.