Holter Monitor

A Holter monitor is a small device connected to electrodes on your chest that record the electrical activity of your heart for 14 to 16 hours while you perform conscious and unconscious tasks, like eating and sleeping. The Holter monitor detects abnormal heart rate, palpitations, and arrhythmia, and can help explain symptoms such as dizziness for patients with pacemakers. Your doctor may refer you for this exam to see if your heart medication is working optimally.

Due to the COVID-19 pandemic, all holter monitoring exams are temporarily unavailable. We apologize for any inconvenience this may cause. 

Holter Monitor vs. Electrocardiogram

Electrocardiograms, or ECGs, measure the electrical activity of your heart at one point in time, for a short duration. Holter monitors are attached for a significant time - in our case 14 to 16 hours. Since abnormal heart rhythms and cardiac symptoms are unpredictable and sporadic, a Holter monitor is more likely to detect an event since it has a longer window of observation.

Essentially, ECGs are snap shots of your heart’s activity, whereas a Holter monitor records a full episode. Holter monitors give your doctor more information for an accurate diagnosis. Insight Medical Imaging provides Holter monitoring at our Meadowlark Cardiac Lab.

What Happens During my Holter Monitor Exam?

  • You will need to wear loose-fitting clothing so we can easily attach the device and electrodes (no one-piece outfits or dresses, please). You will also spend some time learning about your monitor.
    • We may need to shave parts of your chest if we are unable to attach electrodes due to excessive hair.
    • Your monitor will be stored inside a small pouch that hangs around your neck and under your shirt.
    • A technologist will show you how to reattach the electrodes in case they fall off during the exam period.
  • After all your paperwork is completed and the device is properly attached, you are free to leave.
  • You will be asked to record activities while you are wearing the Holter monitor so we can cross-reference any symptoms you may be feeling with the test results.
  • The next day you must return in the morning between 7:30 a.m. and 11 a.m. to have the electrodes and monitor removed by a technologist.
  • The information will be reviewed by our on-site cardiologist and the results will be sent to your doctor as soon as possible.


If you have an Alberta Health Care card or valid healthcare card from out of province, there is no cost for a Holter monitor exam (except Quebec).


Holter recording exams typically take 30 minutes to complete on day one – approximately 10 to 20 minutes to attach the electrodes and learn about the device, and 10 minutes for paperwork.

The patient must return the device the next morning between 7:30 a.m. and 11 a.m. Removing the electrodes takes only five minutes.

Exam Preparation

Being prepared for your Holter Monitor helps us take the best possible diagnosis. Please visit our exam prep page for more instructions specific to Holter Monitor preparation.