How you prepare

If your doctor recommends a Holter monitor, you'll have the device placed during a scheduled appointment. Unless your doctor tells you otherwise, plan to bathe before this appointment. Most monitors can't be removed and must be kept dry once monitoring begins.

A technician will place sensors (electrodes) on your chest. These electrodes detect your heartbeat and are about the size of a silver dollar. For men, a small amount of hair may be shaved to make sure the electrodes stick.

The technician will then connect the electrodes to a recording device with several wires and will instruct you on how to properly wear the recording device so it works properly. The Holter monitor recording device is about the size of a deck of cards.

Once your monitor is fitted and you've received instructions on how to wear it, you can leave your doctor's office and resume your normal activities.