# Multi-channel visualization¶

In this tutorial you will learn how to visualize several ECG channels within the PhysioZoo Peak detection module.

## Introduction¶

PhysioZoo allows you to visualize several ECG channels in parallel. This can be use to facilitate the review of Holter recordings for example. This tutorial will show how to display several channels in parallel.

## Displaying several channels¶

To display several channels of an ECG, follow these steps:

2. On the right panel, select the desired leads to be displayed. By default, only channel 1 is selected.

### What is the format of the files to be loaded to PhysioZoo to display several channels ?¶

If recordings are provided in .mat format then each column will represent a different channel.

An other option is to use a .txt file which will contain the following header:

Mammal: Mammal type (human, rabbit…)
Fs: Sampling frequency
Integration_level: electrocardiogram

Channels:

- type: electrography
name: Channel name
unit: Units (usually mV)
enable: yes

- type: electrography
name: Channel name
unit: Units (usually mV)
enable: yes

- type: electrography