1 channel vs multi-channel holter monitoring

By Prof Harry Mon

I was recently asked about the differences between one and multi-channel ambulatory ECG monitor recordings and whether, one was superior to the other.

At Cardiac Monitoring Service, we always use and recommend multi-channel 24-hour Holter monitors to be sure about our diagnosis of arrhythmias. Anyone with experience with early model one channel event recorders will remember how useless those recordings were mainly because of artefact.   

A major advancement has been the development of the patch holter in which the electrodes are embedded. These also have a metal snap to which a V lead can be attached (for the third channel) using a standard electrode and cable. If this electrode/cable becomes detached, then the recorder automatically reverts to two channels of ECG data.   

The question being asked; is one channel as good as three?

Since I was asked the question, I have reviewed the way I report three channel holter monitors and I strongly believe that three channels are much easier to report than just looking at one.

Firstly, each channel confirms the findings of the other making the report not only easier, but faster and probably more accurate. This is most certainly with atrial fibrillation. Secondly, when there is artefact on one or more channels, there is hopefully enough information on one channel to prevent misdiagnosis.

Here’s a few examples:

Image 1: The artefact here is predominantly in one channel. If this was the only channel, it would  make interpretation very difficult.

Image 1: The artefact here is predominantly in one channel. If this was the only channel, it would
make interpretation very difficult.


Image 2: In this example, you require three channels to diagnose artefact and exclude ventricular tachycardia.

Image 2: In this example, you require three channels to diagnose artefact and exclude ventricular tachycardia.


Image 3: The trace above demonstrates that you need all three channels to confirm sinus rhythm.

Image 3: The trace above demonstrates that you need all three channels to confirm sinus rhythm.


Image 4: This example reveals you need all three channels to confirm sinus rhythm.

Image 4: This example reveals you need all three channels to confirm sinus rhythm.


Image 5: To exclude an atrial tachyarrhythmia diagnosis you require all three channels.

Image 5: To exclude an atrial tachyarrhythmia diagnosis you require all three channels.


Image 6: The timed spikes are the sinus QRS waves. Three channels are required to exclude a  ventricular tachyarrhythmia.

Image 6: The timed spikes are the sinus QRS waves. Three channels are required to exclude a
ventricular tachyarrhythmia.


Image 7: This shows a run of an atrial tachyarrhythmia with aberration. Difficult diagnosis with only  one channel.

Image 7: This shows a run of an atrial tachyarrhythmia with aberration. Difficult diagnosis with only
one channel.


Image 9: The artefact on the top channel makes the diagnosis difficult. The bottom two channels  confirm the artefact and ventricular ectopic.

Image 9: The artefact on the top channel makes the diagnosis difficult. The bottom two channels
confirm the artefact and ventricular ectopic.


The arrhythmias in the next three Holter recordings are more difficult to diagnose and dependent on
the three leads complimenting each other. There is at least one channel which is almost iso-electric
and by itself gives very limited information.

Image 11.jpg
Image 12.jpg
Image13.jpg

These examples are seen every day with Holter recordings and are not unusual studies. I have no doubt that even with improved technologies such as patches, three channel recordings are far superior to one channel.

The patch electrode and monitor that Cardiac Monitoring Service uses is myPatch and allows two or three channels. Although relatively expensive, such patches are hopefully able to provide better quality recordings and can be used with activities such as showering and sports. Single channel recorders with patches have also become available, and hopefully will provide better recordings than in the past.

myPatch in Adult, Pediatric and Neonate sizes

myPatch in Adult, Pediatric and Neonate sizes

Harry Mond

Chelsea Cunningham