A cardiac event monitor is a battery-powered, portable device that you control to record your heart's electrical activity. The monitor records and stores your heart rhythm for your cardiac team to review. This test allows on-demand heart monitoring outside of a clinical setting, so that you can record symptoms as you go about your normal routine.

The monitor will detect abnormal heart rhythms and records your heart's electrical activity (rhythm) at the push of a button. You trigger the device when you first begin to feel signs (an "event") such as dizziness, weakness, lightheadedness, or heart racing and/or fluttering.

The test results help guide your cardiac team to choose treatment options to meet your specific needs. The monitor, about the size of a deck of cards, is clipped to your waistband and is connected to a set of wires that attaches to two electrodes worn on your chest (like an EKG). The monitor can be worn for up to 30 days. It is removed during bathing.

You'll receive guidelines for transmitting recordings, which can be done daily, weekly or whenever you feel your symptoms need immediate attention. In most cases, it is important to transmit after three or four "events" (due to the monitor's limited storage capacity). Recordings cannot be transmitted by cell phone or any other portable phone. Should the findings indicate that you need medical care, your physician will be notified right away.

When you're done using your cardiac event monitor, remove it as instructed. Return the monitor, wires, unused electrodes and batteries along with your diary to Northwestern Medicine. Your final test report will be sent to your physician after the monitor is returned and all the recordings have been reviewed by a cardiologist. A full report will be sent to your physician.