What is an Event recorder?
Event recorder is a tape recorder like device which records the patient’s ECG whenever it is activated. There are many circumstances wherein a rhythm disturbance, or symptoms presumed to be due to a rhythm disturbance, occur infrequently and cannot be documented during a single 24 hour record, such as that obtained with a Holter monitor. These infrequent events require that electrocardiographic documentation be recorded at the time of the symptoms. An event monitor is loaned to such patients for periods of a week up to a month with instructions regarding its simple application to the chest wall and activation of the marker at the time of symptoms. The electrocardiogram at the time of such events can thus be recorded and a diagnosis can be reached. Event monitors are excellent at correlating patient’s heart rhythm with symptoms. If the symptoms are caused by a transient cardiac arrhythmia, event monitors are often the best way to make the diagnosis.
Event recorders do not record every heart beat on a tape. Instead, event recorders use a loop recorded system which stores approximately 2 minutes (i.e. 30 second before and the 90 seconds after activation) of the ECG rhythm. When the patient experiences the symptom of interest, he/she presses a button that freezes the recording and stores it. It can then be viewed on the computer and the rhythm at the time of symptoms can thus be seen. A major advantage of event recorders is that they can be used for up to 30 - 60 days, until the transient symptom being looked for occurs.
What is done for the test?
The tape recorder like device is given to the patient and kept on person for a period of at least 7 days and three electrodes are attached to the skins which are connected to the device with wires.
The patient is explained the simple technique of removal and attaching the recorder at times of activities like taking bath. Otherwise, the device should remain on person all the time.
Whenever the patient experiences any symptoms like palpitations, fainting, etc he presses the marker button on the device which automatically results in a permanent record of the rhythm.