A 24-hour Holter monitor is a device that records the electrical activity of the heart including rate and rhythm over a 24-hour period. It consists of a battery-operated, portable device about the size of your palm which is connected by wires to electrodes placed on your chest.
The test records heart rhythms over a 24-hour period, to detect irregular heart activity that may not have shown up during a regular electrocardiogram at your doctor’s clinic. Based on the test results, your doctor determines if there is any delay in the electrical impulses of the heart or if the oxygen supply to the heart is adequate.
The Holter monitor is placed in a pouch that you can hang around your neck and remains connected to the electrodes fixed on your chest, recording data of your heart’s activity as you go about your daily activities. You are instructed to keep a log of your activities, or changes in mood and behavior so that your doctor can correlate this information with the data obtained from the monitor.
The monitor should be kept dry and you need to avoid magnetic or electrical fields that may alter the readings on the monitor. You will be taught to replace the electrodes should they come off.
After the 24-hour period, your doctor will study the data obtained along with your activity log and decide on your diagnosis, treatment or need for further testing.