When symptoms such as dizziness, fainting, low blood pressure, prolonged fatigue, or palpitations continue to occur without a definitive diagnosis obtained with a resting electrocardiogram (ECG), your child's physician may request an ECG tracing to be run over a long period of time. Certain arrhythmias (a fast, slow, or irregular heartbeat) which can cause the symptoms noted above may occur only sporadically, or may occur only under certain conditions, such as stress. Arrhythmias of this type are difficult to obtain on an ECG tracing that only runs for a few minutes.
A prolonged type of ECG tracing, called a Holter monitor, provides the physician a better opportunity to capture any abnormal heartbeats or rhythms that may be causing your child's symptoms, especially if they occur frequently.
The Holter monitor test is used to record your child's ECG tracing continuously for a period of 24 hours or longer. You will receive instructions on how long your child will wear the recorder (usually 24 hours, but sometimes longer), how to keep a diary of your child's activities and symptoms during the test, and personal care/activity instructions.
Event monitoring is very similar to Holter monitoring, and is often performed for the same reasons. With an event monitor, your child wears ECG electrode patches on his/her chest, and the electrodes are connected by wire leads to a recording device. However, unlike the Holter monitor, which records continuously throughout the testing period of 24 to 48 hours, the event monitor does not record until your child feels symptoms and you or your child trigger the monitor to record the ECG tracing at that time. An auto-trigger event monitor may be used to record rhythms when symptoms are rare or suspected to occur during sleep. The auto-trigger event monitor automatically records rhythm events and can be manually activated if your child experiences symptoms.
When your child feels one or more symptoms, such as chest pain, dizziness, or palpitations, one of you will push a button on the event monitor recorder. Some monitors have a feature called "memory loop recording," in which the monitor can include a recording of a short period of time prior to the moment you triggered the recording and afterwards. This feature can help your child's physician determine more details about the possible change in your child's EKG at the time the symptoms started, and what was happening with your child's EKG just before you or your child triggered the recorder. Other monitors, called "post-event recorders," simply start recording the EKG from the moment you trigger it.
After symptoms are experienced and recorded, you will send the recording to your child's physician or to a central monitoring center. You will also keep a diary of your child's symptoms and corresponding activities, just as with the Holter monitoring procedure.
Some reasons for your child's physician to request a Holter monitor procedure include, but are not limited to, the following:
The following steps provide information regarding how a Holter monitor procedure is performed:
Depending on the results of the Holter monitor, additional tests or procedures may be scheduled to gather further diagnostic information.