A Holter monitor is a small, battery-operated electronic device. It is portable enough to be carried in a small purse or jacket pocket, though they can also be carried by the strap that is attached to the monitor. There are many different brands, which will look different from one to the next, but they will usually contain a small screen and should have an “Event" button on them. If you are to experience a cardiac event, be it chest pain or abnormal rhythms, you would press the button and the monitor would record this.
Out of the monitor, there will be at least five wires which will connect to sticky pads. These small pads will be stuck to your torso. Men with hairy chests may be required to shave on the spots where these pads, called electrodes, will be placed. It will also be necessary to wear a loose fitting button-up shirt or blouse, so that the leads will not be interrupted for the duration of the testing.
The monitors are not waterproof, so patients wearing them are not permitted to shower during the test period. However, patients should eat, drink and perform normal daily activities while wearing the monitor. A careful sponge bath is allowed.