i was a little confused by the two at first (especially since we implant and explant loop recorders in our cath lab).
i came across this informative site when i did a search for your question:
quote below is from the site:
event (transtelephonic) recorders
when symptoms presumed to be due to a rhythm disturbance occur less frequently than once during a single 24- or 48-hour period, an event recorder may be used. event recorders are small devices capable of recording short episodes of ecg which are not worn at all times. when you have symptoms, you attach the device to your body temporarily, usually by putting on bracelets that attach to the recorder or by pressing the device itself against your chest. you then press a button on the device to start a recording of your heart rhythm. the recording lasts for up to a minute. the electrocardiogram that is recorded is transmitted over the telephone to the electrophysiologist's office for interpretation. the event monitor is lent to patients for one month at a time with instructions regarding its use. event monitors are ideal for recording sustained rhythms that allow the patient the time and the capacity to capture the event.
continuous loop recorder
this is an ecg recorder which records only a few minutes worth of the electrocardiogram at a time on a computer chip. it continuously records new information and discards the oldest information, so that at any time it has in memory only the last few minutes of your electrocardiogram. when you have symptoms, you can "freeze" the recording in the device's memory. the frozen recording can then be transmitted over the telephone to the physician's office for him or her to review. since the loop recorder is continuously refreshing its memory, the loop recorder can be carried for long periods. loop recorders are ideal for capturing brief episodes when it takes too long to apply an event recorder or for capturing ecg recordings of episodes that are associated with incapacitating symptoms such as syncope.
implantable loop recorder (ilr)
the ilr is a continuous loop recorder that is implanted in the body under the skin. like a continuous loop recorder applied to the body surface, the ilr is useful for diagnosing infrequent rhythm problems associated with incapacitating symptoms, such as syncope. no external electrodes or power source is required. the patient or a bystander uses a small hand-held activator which communicates through the skin with the ilr to "freeze" the ecg surrounding the event. the stored data is then retrieved by the physician using a second computer to communicate with the ilr through the skin. the device can be reset to record subsequent events. minimally invasive subcutaneous placement of the ilr in the chest area can be performed with local anesthesia, sometimes even in the doctor's office.