What should you know about a Holter ECG machine?

Small adhesive electrodes sit on the chest and connect to a recorder worn on the body. Unlike a brief ECG taken in a clinic, Holter monitoring can capture rhythm changes that come and go. The recording may be compared with a diary of palpitations, dizziness, chest discomfort, breathlessness, exercise, sleep, and medicines.

The device does not send treatment into your body and does not diagnose every cause of symptoms. A clinician reviews the tracing alongside your history; an unusual result may lead to another test or a discussion about treatment.

Follow the fitting instructions and keep the electrodes and recorder dry unless your clinic says otherwise. Wear comfortable clothing that does not pull on the wires. Continue ordinary activities if advised, and write down symptoms with the time they begin and end so they can be matched with the recording.

Do not remove the electrodes or change prescribed medicines unless your healthcare professional tells you to. Ask what to do if an electrode loosens, the skin becomes irritated, or the recorder stops working.

Holter monitoring should not delay urgent help. Seek emergency care for chest pressure that does not settle, severe breathlessness, fainting, or sudden weakness with difficulty speaking. If you have ongoing racing or irregular heartbeats with dizziness, contact a healthcare service promptly and follow the plan given when the monitor was fitted.

Ask how long to wear the monitor, whether you may shower or exercise, which symptoms to record, and when your results will be discussed.