<telerikChart:RadCartesianChart x:Name="chart">
    <telerikChart:RadCartesianChart.BindingContext>
        <local:ViewModel />
    </telerikChart:RadCartesianChart.BindingContext>
    <telerikChart:RadCartesianChart.HorizontalAxis>
        <telerikChart:DateTimeContinuousAxis LabelFitMode="Rotate" 
                                                x:Name="horizontal"/>
    </telerikChart:RadCartesianChart.HorizontalAxis>
    <telerikChart:RadCartesianChart.VerticalAxis>
        <telerikChart:NumericalAxis />
    </telerikChart:RadCartesianChart.VerticalAxis>
    <telerikChart:RadCartesianChart.Series>            
        <telerikChart:SplineSeries ValueBinding="Value"
                                    CategoryBinding="Date"
                                    ItemsSource="{Binding Data}"
                                    ShowLabels="True"
                                    />
    </telerikChart:RadCartesianChart.Series>
    <telerikChart:RadCartesianChart.Annotations>
        <telerikChart:CartesianGridLineAnnotation Stroke="#0E72F6" 
                                                StrokeThickness="2"
                                                Value="{Binding Threshold}"
                                                Axis="{x:Reference horizontal}">
            <telerikChart:CartesianGridLineAnnotation.DashArray>
                <x:Array Type="{x:Type x:Double}">
                    <x:Double>4.0</x:Double>
                    <x:Double>2.0</x:Double>
                </x:Array>
            </telerikChart:CartesianGridLineAnnotation.DashArray>
        </telerikChart:CartesianGridLineAnnotation>
    </telerikChart:RadCartesianChart.Annotations>
</telerikChart:RadCartesianChart>  

<telerikChart:RadCartesianChart x:Name="MyChart"  Zoom="2, 1"  PanOffset="-400,0" >

<telerikChart:RadCartesianChart x:Name="MyChart"  Zoom="2, 1" 
                                                     NativeControlLoaded="MyChart_OnNativeControlLoaded">

private async void MyChart_OnNativeControlLoaded(object sender, EventArgs e)
{
    await Task.Delay(100);
    
    MyChart.PanOffset = new Point(-400, 0);
}