A Holter monitor is a device that enables 24-hour, continuous recording of a patient’s EKG. Since the monitor can be worn during regular daily activities, it helps the physician correlate symptoms of dizziness, palpitations (a sensation of fast or irregular heart rhythm) or black outs. Because it monitors continuously, the Holter Monitoring method is much more likely to detect an abnormal heart rhythm when compared to the EKG, which lasts less than a minute.
An event recorder is similar to a Holter Monitor, except that the electrical activity of the heart is monitored for up to 30 days instead of 24 hours. This enables assessment of heart rhythm abnormalities that are infrequent and may not occur in a 24 hour period.