WPF: How to freeze a ListView header row so that it won't scroll off the screen

I am new to WPF development, I have a ListView and I want to freeze the header row so that it won't scroll off the screen when the user scrolls the list. The xaml code, I have inherited, looks something like this:

<ScrollViewer HorizontalScrollBarVisibility="Auto" VerticalScrollBarVisibility="Auto">
  <DockPanel>
    <forms:BindableGrid DockPanel.Dock="Top" [code snipped] >
    <ListView.View>
      <GridView>
        <GridViewColumn Header="ColA" DisplayMemberBinding="{Binding ColA}" />
        <GridViewColumn Header="ColB" DisplayMemberBinding="{Binding ColB}" />
           [etc]