What to expect, what to wear, and what you can and cannot do while wearing a Holter monitor (24-hour heart/ECG) or a 24-hour blood pressure monitor — plus a printable diary to take with you.
📋 Sources
Guidance compiled from the Cardiac Society of Australia and New Zealand (CSANZ); Heart Foundation Australia; and Healthdirect Australia. Your cardiology clinic’s own instructions always take precedence — devices and protocols vary between providers.
This is general information to help you prepare — it is not medical advice, and it does not interpret your results. These monitors record your heart for your doctor to review later; they do not alert anyone in real time. If you have severe symptoms such as severe or lasting chest pain, trouble breathing, or you collapse, treat it as an emergency and call 000 — do not wait for the test. Always follow the specific instructions your clinic gives you, as devices differ.
Which monitor are you having?
Holter monitor (24-hour heart/ECG)
Records every heartbeat, usually over about 24 hours (sometimes up to 7 days). A small recorder clips to your belt with leads to sensors on your chest.
Before your appointment
Arrive showered — you cannot get the device wet once it is on.
Wear a loose two-piece outfit (a top you can lift).
Some chest hair may be shaved so the electrodes stick.
While you are wearing it, & what to expect
Keep it on at all times, including sleep — do not take it off (unless you have a 7-day monitor with showering instructions).
Do your usual activities — the test needs a normal day.
Keep the diary below: note what you were doing and the time, and any symptoms (dizziness, light-headedness, chest pain, shortness of breath) with the time.
Keep it dry — no shower, bath or swimming — unless told it is a waterproof/7-day type. Ask for spare electrodes before you leave if you will need to shower.
It is safe and painless with no significant risks; electrodes are hypoallergenic and it will not interfere with electronics. A report usually goes to your doctor within about 48 hours.
Source: Heart of Australia — Holter Monitor patient guide.
24-hour blood pressure monitor (ambulatory BP)
An arm cuff connected to a small monitor on a shoulder strap takes a reading every 20–30 minutes, day and night, for 24 hours (about 30–40 seconds each).
Before your appointment
Nothing special to do beforehand — fitting takes about 15 minutes.
Wear a loose-fitting shirt — the cuff sits under your sleeve.
You return about 24 hours later to have it removed.
While you are wearing it, & what to expect
When the cuff tightens, stop and keep your arm still until the reading finishes.
Take your medicines as normal.
Press the button (and note the time in your diary) if you feel dizziness, headache, chest pain or sudden shortness of breath.
Keep it connected and dry — no shower or bath while it is on.
Keep the diary below of your activities, sleep/wake times and any symptoms.
Source: Heart Foundation — 24-hour blood pressure monitoring (reviewed January 2024).
For both monitors — the basics
Keep the device connected and dry, and return it on time — the test needs the full recording.
Go about your normal day unless told otherwise. Results go to your doctor to review — the monitor does not give you a reading or alert.
Follow your clinic’s own instructions — devices and rules vary (some newer monitors are waterproof).
📓 Activity & symptom diary
Both tests work best if you keep a simple diary. Print this, fill it in through the day, and hand it back with the monitor. Note the time you go to sleep and wake up, and the time of anything you feel.
Time
What I was doing
Any symptoms (and how I felt)
Sources. Heart Foundation — 24-hour blood pressure monitoring (reviewed January 2024). Heart of Australia — Holter Monitor patient guide. This page is general preparation information current as of June 2026 and does not replace the specific instructions from the clinic fitting your monitor, or advice from your doctor.