| Subject | Contents |
| Definition | A continuous recording of heart rhythm during normal activity, usually for 24-hours (see also ECG ). |
| Alternative Names | Ambulatory electrocardiography; Electrocardiography - ambulatory |
| How the test is performed | Electrodes (small conducting patches) are placed on your chest and attached to a small recording monitor that can be carried in a pocket or small pouch worn around your neck. The monitor is battery operated. Your heart electrical activity is recorded (similarly to the recording of an electrocardiogram), usually for a 24-hour period while you keep a diary of your activity during this period. The recording is then analyzed, a report of the heart's activity is tabulated, and irregular heart activity is correlated with activity. In some Holter monitoring, a person may be asked to manually activate a recording if symptoms such as palpitations , chest pain , or irregular rhythms are noticed. |
| How to prepare for the test | Adults: There is no special preparation for the test. The recording monitor will be initiated (started) by the health care provider, and instructions will be given on how to replace electrodes should they become loosened. Instructions will also be given on how to record activity for the diary. Infants and children: The physical and psychological preparation you can provide for this or any test or procedure depends on your child's age, interests, previous experience, and level of trust. For specific information regarding how you can prepare your child, see the following topics as they correspond to your child's age:infant test or procedure preparation (birth to 1 year) toddler test or procedure preparation (1 to 3 years) preschooler test or procedure preparation (3 to 6 years) schoolage test or procedure preparation (6 to 12 years) adolescent test or procedure preparation (12 to 18 years) |
| How the test will feel | There is no discomfort associated with the test. Hair may be shaved from the chest for electrode placement. The recording monitor is kept close to the body in a pouch worn around the shoulder or neck. Continue activities while wearing the monitor. |
| Why the test is performed | To determine how the heart responds to normal activity, or in some cases, to cardiac medication. It may be done on some people after a heart attack . |
| Normal Values | Normal variations in heart rate occur with activities. No significant alterations in the rhythm or ST elevations occur. |
| What abnormal results mean | Abnormal results may include various arrhythmias . ST segment changes are alterations in the wave form of the electrical conduction pattern of the heart that may indicate the heart is not receiving enough oxygen and may also correlate with chest pain . Additional conditions under which the test may be performed: atrial fibrillation/fluttermultifocal atrial tachycardiaparoxysmal supraventricular tachycardia palpitations fainting (syncope) |
| What the risks are | There are no risks associated with the test. However, the monitor should not get wet. |
| Special considerations | Electrodes must be firmly attached to the chest to permit accurate recording of the heart's activity. Avoid magnets, metal detectors, electric blankets, and high-voltage areas while wearing the device. |
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